免费的黄色小说,黑人巨大国产9丨视频,欧美香蕉网 http://www.ahjfzs.com/en/category/blogs/ Thu, 21 Aug 2025 09:51:42 +0000 en-US hourly 1 https://wordpress.org/?v=6.8.3 http://www.ahjfzs.com/wp-content/uploads/2024/04/cropped-logo-32x32.png Blog Archive - SANDI TECHNOLOGY CO. http://www.ahjfzs.com/en/category/blogs/ 32 32 How 3D printing can solve the problem of high casting scrap rate: revolutionize casting process, improve quality and efficiency http://www.ahjfzs.com/en/blogs/how-3d-printing-solves-the-problem-of-high-scrap-rates-in-casting/ Thu, 21 Aug 2025 09:48:39 +0000 http://www.ahjfzs.com/?p=2377 Castings scrap rate remains high? In this paper, an in-depth analysis of industrial 3D printing through the moldless, one-piece molding and digital simulation, from the source to eliminate porosity, shrinkage and other defects, and comprehensively improve the casting quality and production efficiency.

3D打印如何解決鑄造高報廢率問題:革新鑄造工藝,提升品質(zhì)與效率最先出現(xiàn)在三帝科技股份有限公司。

]]>
As the cornerstone of industrial manufacturing, the foundry industry has long faced a number of deep-rooted challenges. Among them, high scrap rates are a "hidden cost" that not only means direct waste of raw materials, but also leads to long product development cycles, high rework costs, and the loss of valuable market opportunities. For some complex structure, high technical requirements of the castings, the yield of the traditional process will drop dramatically. This predicament has prompted the industry to urgently seek a technological change that addresses the root causes of the problem. In this context, additive manufacturing (commonly known as 3D printing) with its unique advantages for the traditional casting industry to provide a subversive whole chain digital solutions for the transformation and upgrading of the industry provides a new path.

Chapter 1: Deep Dive: The Root Challenge of Traditional Casting Defects

1.1 Common casting defects and their deep causes

Casting defects are the direct cause of high scrap rates. These defects are not accidental, but are dictated by the physical and process limitations inherent in conventional casting processes.

firstlystomatogether withshrinkage. Porosity mainly originates from the involvement or inability to effectively discharge gases (e.g. hydrogen, mold outgassing) in the liquid metal during the pouring and solidification process. When the dissolved gases in the liquid metal are released due to reduced solubility during cooling and solidification, bubbles will form inside or on the surface of the casting if they are not discharged in time. Related to this is shrinkage, which is a natural phenomenon of volume contraction of the metal during solidification. If the cooling system is not properly designed, resulting in local mold temperature is too high, or insufficient complementary shrinkage, it will form internal voids or depressions, the so-called shrinkage holes.

Next.sandwichedtogether witherror type (math.). In conventional sand casting, sand molds and sand cores usually need to be assembled and bonded after being made from multiple pieces separately. In this process, any tiny rupture of the sand core or improper bonding may lead to sand particles being caught in the metal liquid, forming sand entrapment defects. In addition, if the mold parting surface or the sand core is not positioned accurately, it may also lead to the casting of the upper and lower parts of the misalignment of the mis-shape defects.

endcold storagetogether withcrackles. When the fluidity of the metal liquid is poor, the pouring temperature is too low, or the runner design is narrow, the two metal streams are solidified without being fully integrated at the leading edge, leaving a weakly connected cold segregation. And during cooling and solidification, if there are uneven stresses within the casting, thermal cracks may occur during shrinkage.

1.2 The traditional mold manufacturing "high cost" and "low efficiency" dilemma

Another core pain point of the traditional casting process is its mold manufacturing process. Traditional wood or metal core box manufacturing is a labor-intensive, highly skilled worker-dependent process with long lead times and significant costs. Any minor design change means that the mold needs to be rebuilt, resulting in high additional costs and weeks or even months of waiting time.

This over-reliance on physical molds also fundamentally limits the design freedom of castings. Traditional mold-making processes are unable to mold complex internal runners and hollow structures in one piece, which must be disassembled into multiple independent sand cores and then assembled by complex tooling and labor. 2. This process limitation forces designers to compromise and sacrifice part performance for manufacturability, such as simplifying cooling channels to accommodate drilling processes that do not allow for optimal cooling.

To summarize, the high scrap rate of traditional casting is not an isolated technical problem, but a product of its core processes. The traditional "physical trial and error" mode makes the foundry in the discovery of defects, need to go through a long process of mold modification and retesting, which is a high-risk, inefficient cycle. 3D printing's revolutionary value is that it provides a "moldless" solution, fundamentally reshaping the entire production process, will be the traditional "physical trial and error" mode, will be the traditional "physical trial and error" mode, will be the traditional "physical trial and error" mode, will be the traditional "casting" high scrap rate is not an isolated technical problem, but its core process products. The revolutionary value of 3D printing is that it provides a "moldless" solution that fundamentally reshapes the entire production process, transforming the traditional "physical trial-and-error" model into a "digital simulation validation" that puts the risk in front of the process, thus eliminating most of the causes of scrap at the source.

Chapter 2: 3D Printing: A Revolutionary Breakthrough from Technology to Solution

2.1 Moldless production: eliminating the root causes of obsolescence

The core advantage of 3D printing is its "moldless" production method, which allows it to bypass all of the mold-related challenges inherent in traditional casting, thus radically reducing scrap rates.

Directly from CAD to sand mold. Binder Jetting in Additive Manufacturing is the key to making this happen. It works by precisely spraying liquid binder onto thin layers of powder (e.g. silica sand, ceramic sand) from an industrial-grade printhead based on a 3D CAD digital model. By bonding layer by layer, the 3D model in the digital file is constructed in the form of a solid sand mold or sand core. This process completely eliminates the need to rely on physical molds. Because there is no need for lengthy mold design and manufacturing, the mold-making cycle can be shortened from weeks or even months to hours or days, enabling "print-on-demand" and rapid response to design changes, dramatically reducing up-front investment and trial-and-error costs.

One-piece molding and complex structures. 3D printing's layered manufacturing approach gives unprecedented design freedom. It is able to mold complex sand cores that would traditionally have to be split into multiple parts, such as the meandering runners inside an engine, into a single monolithic piece. Not only does this simplify the casting process, but more importantly, it completely eliminates the need for core assembly, bonding and misalignment, thus eradicating common defects such as sand entrapment, dimensional deviations, and misshaping caused by such issues.

2.2 Optimization process: data to guarantee casting quality

The value of 3D printing goes beyond "moldlessness" itself. It elevates the manufacturing process to a whole new digital dimension, allowing data to be verified and optimized before physical manufacturing, turning "after the fact" into "before the fact".

Digital Simulation and Design. During the digital design phase prior to 3D printing, engineers can use advanced Finite Element Analysis (FEM) software to perform accurate virtual simulations of the pouring, make-up shrinkage and cooling processes. This makes it possible to anticipate and correct potential defects that could lead to porosity, shrinkage or cracks before actual production. For example, by simulating the flow of the liquid metal in the runners, the design of the pouring system can be optimized to ensure smooth filling and effective venting. This digital foresight greatly improves the success rate of the first trial run and guarantees casting yields at the source.

Excellent sand properties. 3D printed sand molds, due to their layer-by-layer construction, can achieve uniform densities and air permeability that are difficult to achieve with traditional processes. This is crucial for the casting process. Uniform gas permeability ensures that gases generated inside the sand mold can escape smoothly during the pouring process, significantly reducing porosity defects caused by poor venting.

Cooling with shape. Conformal cooling technology is another revolutionary application of 3D printing in the field of casting molds. Mold inserts manufactured through metal 3D printing have cooling runners that can be designed to exactly mimic the surface contours of the casting. This achieves fast, uniform cooling, significantly reducing deformation and shrinkage due to uneven shrinkage, thus dramatically reducing the scrap rate. According to data, molds with follow-through cooling can reduce injection cycle times by as much as 70%, while significantly improving product quality.

From "physical trial and error" to "digital foresight". The core contribution of 3D printing is to transform the traditional foundry model of "trial and error" into "anticipatory manufacturing". It enables foundries to perform numerous iterations in a digital environment in a cost-effective manner, which is a fundamental shift in mindset and business process. This "hybrid manufacturing" model makes 3D printing easier to adopt by traditional foundries and enables the most efficient production. For example, 3D printing can be used to create the most complex and error-prone sand cores, and then combined with sand molds made using traditional methods to "build on the strengths".

Chapter 3: SANTI TECHNOLOGY: A Digital Engine to Empower the Foundry Industry

3.1 Core equipment: "hard power" for casting innovation

As a pioneer and leader in the field of additive manufacturing in China, 3DPTEK provides strong "hard power" support for the foundry industry with its self-developed core equipment.

The company's core product lines are3DP Sand Printerthat highlights its leadership in technology. Flagship devices3DPTEK-J4000With an extra-large molding size of 4,000 x 2,000 x 1,000 mm, it is highly competitive on a global scale. This extra-large size allows large, complex castings to be molded in one piece without the need for splicing, further eliminating potential defects caused by splicing. At the same time, for example

3DPTEK-J1600PlusDevices such as these offer high accuracy of ±0.3 mm and efficient printing speeds, ensuring that superior quality is achieved while producing quickly.

In addition, SANTI Technology'sSLS (Selective Laser Sintering) Equipmentseries, such asLaserCore-6000The machines are also excellent in the field of precision casting. This series of equipment is particularly suitable for the manufacture of wax molds for investment casting, providing a more accurate solution for high-end, fine parts in aerospace, medical and other fields.

It is worth mentioning that SANDI Technology is not only an equipment supplier, but also an expert in material and process solutions. The company has developed more than 20 binders and 30 material formulations, compatible with cast iron, cast steel, aluminum, copper, magnesium and other casting alloys. This ensures that its equipment can be seamlessly integrated into a wide range of casting applications, providing customers with comprehensive technical support.

3.2 All-link services: integrated casting solutions

The competitive advantage of SANDI Technology lies not only in its hardware, but also in the integrated solutions it provides along the whole chain. The company has a strong "Trinity" innovation system - "research institute + post-doctoral workstation + R&D team". This model ensures continuous technology iteration and innovation momentum, and its accumulation of more than 320 patents is a strong proof of its technological leadership.

The company offers a "one-stop" turnkey service from design and 3D printing to casting, machining and inspection. This vertically integrated model greatly simplifies the customer's supply chain management, reduces communication costs and risks, and allows the foundry to focus on its core business.

3.3 Classic Case: Data-Driven Proof of Value

Successful cases are the most persuasive tool to convince potential customers. Through a series of real-world projects, SANDY Technology has quantified the significant business value that 3D printing technology brings.

in order toAutomotive water-cooled motor housingAs an example, this case perfectly demonstrates how the 3DP sand casting process solves the one-piece molding problem of "large size, thin wall, complex spiral cooling channels". 21. The successful application of this technology in the field of new energy vehicles has proved its significant advantages in the production of high-performance, complex structure castings.

On the otherIndustrial pump bodyIn the case of SANDI, SANDI adopted the hybrid manufacturing model of "3DP outer mold + SLS inner core". This complementary strategy shortened the production cycle by 80%, and at the same time improved the dimensional accuracy of the castings to CT7 level, which perfectly proved the powerful effect of the hybrid manufacturing mode.

The joint venture project with Xinxin Foundry provides the strongest business argument. By introducing 3D printing technology, the foundry achieved a turnover increase of 1,35%, doubled its profitability, halved its lead time and reduced its costs by 30%. This series of quantitative data provides irrefutable proof of the return on investment of 3D printing technology in the foundry industry.

The following table visualizes how 3D printing can address the pain points of the foundry industry on both a technical and business value level:

Casting defects or pain pointsCauses and limitations of traditional crafts3D Printing Solutions and Value
stomaPoor mold venting; liquid metal entrapped in gasUniform, controlled sand permeability; digital simulation optimizes pouring system
shrinkageUneven cooling; inadequate retractionPredictive optimization by numerical simulation; uniform cooling by shaped cooling channels
Sandwich, Mis-shapeMulti-core assembly, bonding and misalignment; parting face fit errorsOne-piece molding of complex sand cores eliminates assembly; no physical parting surfaces required
High molding costsRequires physical molds, highly skilled labor, long lead timesMold-less production; print directly from CAD files, manufacture on demand
Inefficiency and long lead timesLong mold making; repeated trial and errorReduced cycle time of 80%; rapid iterative design possible; print on demand
Increased business valueLow margins and erratic deliveryTurnover up 1,35%, margins doubled; costs down 30%

Chapter 4: Looking to the future: digitalization and sustainability in the foundry industry

3D printing technology is leading the foundry industry from the traditional "manufacturing" to "smart manufacturing" fundamental transformation. According to the relevant report, the scale of China's additive manufacturing industry continues to grow at a high rate, and in 2022 it will exceed RMB 32 billion. This data clearly shows that digital transformation has become an irreversible industry trend.

In the future, 3D printing will be deeply integrated with artificial intelligence (AI), IoT and other technologies to achieve full automation and intelligent management of production lines. Foundries can use AI algorithms to optimize casting parameters and IoT sensors to monitor the production process in real time, thus further improving yield rates and production efficiency.

In addition, the unique advantages of 3D printing in realizing complex lightweight design will help automotive, aerospace and other downstream industries to improve product performance and reduce energy consumption, which is a perfect fit for the requirements of global sustainable development. 3D printing's on-demand production mode and extremely high material utilization (can be recycled more than 90% unbonded powder), also significantly reduces the generation of waste, for the casting industry to bring the environmentally friendly development path for the foundry industry.

concluding remarks 3D printing is not the end of casting, but its innovator. It gives the traditional foundry industry unprecedented flexibility, efficiency and quality assurance through its two core advantages of "moldless" and "digital". It enables foundries to free themselves from the plight of high scrap rates and enter a new era of greater efficiency, competitiveness and embrace of innovation. For any foundry seeking to stand out in a competitive market, embracing 3D printing technology, represented by SanDi Technology, is no longer an optional choice, but a necessary path to the future.

3D打印如何解決鑄造高報廢率問題:革新鑄造工藝,提升品質(zhì)與效率最先出現(xiàn)在三帝科技股份有限公司。

]]>
How 3D printing can eliminate casting shrinkage by optimizing internal structure http://www.ahjfzs.com/en/blogs/casting-shrinkage-cavity-issues/ Thu, 21 Aug 2025 08:44:33 +0000 http://www.ahjfzs.com/?p=2374 Is casting shrinkage your problem? This article provides an in-depth analysis of how industrial 3D printing can solve the casting shrinkage problem from the root by optimizing the internal structure and shape-following cooling by virtue of the freedom of mold-free design, and achieve a comprehensive improvement in cost, time and quality.

3D打印如何通過優(yōu)化內(nèi)部結(jié)構(gòu)來消除鑄件縮孔最先出現(xiàn)在三帝科技股份有限公司

]]>
Shrinkage, as hidden in the casting of the internal "dark wound", is the traditional casting process in a common, difficult to eradicate defects. It not only affects the beauty of the casting, but also directly threatens its strength and mechanical properties. When the molten metal in the solidification process volume contraction, and do not get enough liquid metal supplement, it will be in the casting or the surface of the formation of voids, that is, we often say shrinkage or shrinkage! The  

Eliminating shrinkage holes has always been a complex challenge for foundries and engineers, with traditional methods often relying on experience and adjusting mold design, pouring systems and cooling processes through trial and error . However, with the advent of additive manufacturing technologies, especially industrial-grade sand 3D printing, casting design and production have been revolutionized, providing unprecedented new ways to completely solve shrinkage problems.  

1. Root causes of casting shrinkage: geometrical limitations of conventional molds

To understand how 3D printing solves problems, it is first necessary to deeply analyze the pain points of traditional casting. The main reasons for shrinkage formation can be attributed to two things:

  1. Compensate for shrinkage deficiencies: As a casting solidifies and shrinks, it needs to be constantly replenished with liquid metal through the pouring system and riser. If the replenishment channels are not properly designed or are insufficient, the liquid metal cannot be transported to the areas most in need of replenishment, resulting in the creation of voids. ?
  2. Uneven solidification: If the cooling rate of different areas of the casting is not consistent, the heat is difficult to effectively disseminate, the formation of hot joints (hot spot). These hot spots are the last solidified areas, when the surrounding metal has solidified, they lack the liquid metal supplement, very easy to form shrinkage holes. ?

In conventional casting, molds and cores are manufactured with physical tools whose geometry is limited by machinability and releaseability. For example, the holes drilled for cooling water paths can only be straight lines. . This makes it difficult for engineers to design complex, curved make-up shrinkage channels or follow-through cooling channels inside the mold to precisely control the solidification process, thus increasing the risk of shrinkage defects The  

2. 3D printing solutions: freedom of design to give "life" to molds and dies

The core strengths of industrial sand 3D printers areDesign Freedomcap (a poem)No mold productionIt prints sand molds and cores layer by layer directly from 3D CAD files. . This characteristic radically breaks through the geometric limitations of conventional processes and provides several powerful means of eliminating shrinkage as follows:  

Option 1: Optimize the fill and contraction channel, precise infusion

Using 3D printing technology, engineers can design the optimal make-up shrinkage system inside the mold without having to consider machinability.

  • Integrated pouring system: Traditionally, the sprue system (including the sprue and riser) has to be fabricated and assembled separately. 3D printing allows the entire sprue system, the filler riser and the mold itself to be printed in one piece. This integrated design ensures a seamless connection and precise alignment of the channels, greatly reducing the risk of shrinkage failure due to assembly errors. ?
  • Design of precise filler risers: 3D printing allows the precise design and printing of shrinkage risers above the hot joint areas of the casting, ensuring a constant flow of molten metal to fill the void created by solidification shrinkage. It has been shown that overflow risers above the casting can effectively vent gases, thus reducing porosity defects in the casting. ?
  • Eliminate undercutting and complex structural barriers: In traditional processes, complex undercuts and internal passages require multiple cores to be assembled, which not only increases assembly errors, but can also easily lead to dislodged or misaligned cores. 3D printing allows multiple individual cores to be combined into a single, complex, integrated core, eliminating the need for assembly altogether, and improving the accuracy and quality of the casting. ?

Option 2: Conformal cooling for uniform solidification

For the molds themselves, 3D printing can be equally revolutionary. ByConformal cooling(conformal cooling) technology, which allows the design of cooling channels inside the mold that match the surface contour of the casting. The  

  • Principle: Conventional cooling channels are drilled in straight lines and do not cover all the areas that need to be cooled, resulting in uneven temperatures in the mold . Conformal cooling, on the other hand, uses 3D printing to integrate curved, serpentine cooling waterways into the mold so that they fit snugly on the surface of the casting . ?
  • Advantage: This design results in more uniform cooling and significantly reduces the risk of localized overheating of the mold. A more balanced temperature gradient means that the solidification process is more controlled, radically reducing the formation of hot joints and thus preventing shrinkage. It has been demonstrated that the use of a form-following cooling mold reduces the temperature variation during mold cooling to as low as 18°C, thus significantly reducing the risk of casting warpage. ?

Scenario 3: Digital Simulation and Rapid Iteration to Prevent Problems Before They Happen

The digital workflow of 3D printing provides engineers with valuable opportunities for "trial and error" before going into production. The  

  • Casting simulation software: Engineers can use casting simulation software (e.g. Cimatron) to simulate the flow and solidification of molten metal. If the simulation results show a risk of shrinkage, the mold design can be quickly adjusted, e.g. by changing the location of the sprue or riser, and then tested virtually again. ?
  • Rapid prototyping and iteration: If a physical prototype is required, 3D printing can print a mold or core in hours or days. This allows engineers to iterate and validate designs multiple times at a fraction of the cost and speed. This agile development model is unimaginable in traditional casting, which requires expensive mold making and long waiting times. ?

3. Not just eliminating defects, but a leap in efficiency

The use of 3D printing technology to solve the problem of casting shrinkage, bringing not only the improvement of product quality, but also a series of chain of business value:

  • Reduce costs: 3D printing significantly reduces production costs by eliminating the expensive physical mold and tooling manufacturing aspects . According to research, 3D printing can save up to 50%-90% compared to traditional methods . ?
  • Shorten the delivery time: Mold making time has been reduced from weeks or even months to hours, allowing companies to respond more quickly to market demands . In one case, a company was able to reduce lead times by 9 weeks by using a sand 3D printer. ?
  • Reduce scrap rates: The accuracy and consistency of the molds have been greatly improved, reducing casting defects due to human error or mold wear, thus significantly reducing scrap rates. ?
  • Simplify the process: Consolidating multiple parts into a single integrated component simplifies complex assembly processes and reduces reliance on highly skilled labor. ?

Conclusion: 3D printing - a "cure" for the foundry industry

Casting shrinkage is not an isolated technical problem, but the traditional casting process in the face of complex design and high-precision requirements of the systematic challenges exposed. Industrial sand 3D printers, with their unique technological advantages, offer a "cure" for the problem at its source. It eliminates the risk of shrinkage by giving engineers unprecedented design freedom, enabling them to build optimized internal structures and cooling systems. The  

For the pursuit of excellent quality, efficient production and cost optimization of modern foundry enterprises, 3D printing is no longer dispensable "additional options", but to promote industrial upgrading, in the fierce competition in the market to win the first chance of the key technology. It is not just a piece of equipment, but also to the "digital casting" bridge to the future, so that the former "casting problems" to be solved! The

3D打印如何通過優(yōu)化內(nèi)部結(jié)構(gòu)來消除鑄件縮孔最先出現(xiàn)在三帝科技股份有限公司

]]>
2025 Sand 3D Printer Selection Guide: Choosing the Right Machine Parameters Based on Casting Size and Material http://www.ahjfzs.com/en/blogs/2025-sand-mold-3d-printer-selection-guide/ Thu, 21 Aug 2025 08:05:26 +0000 http://www.ahjfzs.com/?p=2371 2025 How to choose a sand 3D printer? 3DPTEK full-size models (J1600/J2500/J4000) + open-source material process, help foundry enterprises to accurately select the model, reduce costs 30%+, improve the casting accuracy to ±0.3mm.

2025 砂型 3D 打印機(jī)選型指南:根據(jù)鑄件尺寸、材質(zhì)選對設(shè)備參數(shù)最先出現(xiàn)在三帝科技股份有限公司。

]]>
In the casting industry towards intelligent process, sand 3D printer with "mold-free, high-precision, complex structure molding" advantage, become the key equipment to enhance the competitiveness of enterprises. However, there are many models of sand 3D printers on the market (molding size from 500×500×500mm to 4000×2000×1500mm, suitable for materials covering silica sand, zirconia sand, ceramic sand, etc.), if the selection is not appropriate, it will not only lead to idle equipment, waste of costs, but also affect the delivery of production due to the substandard quality of printing. This article takes 3DPTEK sand 3D printer as an example to analyze how to accurately match the parameters of the equipment based on the size and material of the casting and maximize the benefits of equipment investment.

I. Equipment selection strategy based on casting size

The size of the casting is a central factor in determining the specification of a sand 3D printer, which needs to be selected with a balance between current needs and future developments:

  1. Statistical analysis of existing casting dimensions
    1. Enterprises need to comprehensively sort out the past 1-2 years of casting orders, categorized by product type (such as automotive parts, aviation structural components, pumps and valves shells), statistics on the length, width and height of each type of casting size range, drawing size distribution histogram. For example, an automobile foundry statistics found that 60% engine block castings in 300-500mm in length, width 200-350mm, height 150-250mm;
    1. Identify the "core size range" with the highest percentage and use it as a basis for filtering printers. As in the case above, 3DPTEK's 3DPTEK-J1800(molding size 1800×1200×1000mm) can easily cover most of the engine block sand printing needs, to avoid "small horse-drawn cart" (equipment molding size is too large, waste of equipment space and printing costs) or "too big to use" (equipment) (equipment molding size is not enough to print large castings).
  2. Considering future business expansion
    1. Combined with the enterprise's market planning for the next 3-5 years, new product development plan, prejudge the casting size changes that may be involved. If you plan to develop the wind power equipment castings business, you need to investigate in advance the size of wind power hubs, blades and other large castings (wind power hub diameter of up to 3-5 meters), to reserve enough space for equipment upgrades;
    1. If large castings are only occasionally undertaken, consider 3DPTEK's 3DPTEK-J4000 Ultra-large size printer (maximum molding size 4000×2000×1500mm), or "sand cut block + combined assembly" printing strategy (3DPTEK equipment supports localized printing, which facilitates the operation of the cut block), to reduce the cost of equipment procurement.
  3. Handling of special size requirements
    1. For castings with special dimensions such as extra-long, extra-wide, extra-thin, etc. (e.g., elongated shaft castings with an aspect ratio of more than 5:1, thin-walled parts with a thickness of less than 5mm), it is necessary to examine the printing accuracy and stability of the equipment in addition to the molding dimensions. 3DPTEK's bonded injection technology ensures that the molding of special-sized castings is performed with a high degree of precision of ±0.3mm, thus avoiding the scrapping of castings due to deviations in dimensions. avoid scrapping the castings due to dimensional deviation.

Second, suitable for the casting material equipment parameters selection

Different casting materials (e.g. cast iron, cast aluminum, cast steel) have different requirements for sand strength, air permeability and gas generation, which need to be matched with the corresponding equipment parameters and material technology:

  1. Material properties and sand demand analysis
    1. Cast iron parts: due to the good fluidity of iron and moderate solidification shrinkage, the strength of the sand mold is required to be high (tensile strength ≥ 0.8MPa) to prevent the sand mold from erosion and breakage during pouring. The high-strength furan resin binder matched with 3DPTEK equipment, together with silica sand, can meet the needs of sand mold printing for cast iron parts;
    1. Aluminum casting: Aluminum liquid solidification speed is fast, easy to absorb air, the sand type is required to have good air permeability (air permeability value ≥ 150) and low outgassing (outgassing ≤ 15ml/g), to avoid casting porosity defects. 3DPTEK's open-source material process can be adjusted according to the needs of the binder formula, suitable for ceramic sand, zirconia sand and other low outgassing, high air permeability sand, to meet the casting of aluminum casting sand print.
  2. Material compatibility and parameter adjustment
    1. The 3DPTEK sand 3D printer supports a wide range of casting sands (including quartz sand, pearl sand, chromite sand, etc.), allowing companies to choose sand materials flexibly according to casting materials and cost considerations. For example, when producing high-end stainless steel castings, zirconium sand (high temperature resistant and chemically stable) is used with 3DPTEK's special binder to improve the sand mold's anti-washout and anti-sticking properties;
    1. The nozzle parameters (e.g., orifice diameter, spraying frequency) and heating and curing parameters (curing temperature and time) of the equipment need to be precisely adjusted according to the characteristics of the sand material and the type of binder. For example, when using fine-grained quartz sand, it is necessary to reduce the diameter of the spray hole (e.g., from 0.3mm to 0.2mm) and increase the spraying frequency to ensure that the binder evenly covers the sand particles; for thermosetting binder, it is necessary to optimize the heating curing curve (e.g., increase the curing temperature from 150℃ to 180℃, and extend the curing time from 30 seconds to 45 seconds), so as to ensure that the strength of the sand pattern curing.
  3. New material application and technical support
    1. As the casting industry's demand for high-performance, lightweight castings increases, new types of sand materials (such as composite sand mixed with metal powders and nano-modified sand) are gradually being applied. 3DPTEK continues to research and develop new material processes that can be customized to meet the needs of enterprises and customize material solutions to help them quickly realize the application of new materials in sand printing.

Comprehensive Advantages of 3DPTEK Sand 3D Printers

  1. Full-size product matrix: 3DPTEK has a full line of sand 3D printers ranging from 1.6 meters to 4 meters in size, including 3DPTEK-J1600Pro,3DPTEK-J1600Plus,3DPTEK-J1800,3DPTEK-J1800S,3DPTEK-J2500,3DPTEK-J4000 A variety of models, such as to meet the different sizes of enterprises, different sizes of castings printing needs, to avoid enterprises due to the limitations of equipment specifications missed orders.
  2. open source material processIt supports users to adjust the binder and sand material formula as needed to reduce the material cost 20%-30%. At the same time, it is equipped with high-performance resin binder, curing agent and cleaning agent to ensure the stable quality of sand molding and solve the problems of material selection and process optimization of the enterprise.
  3. High-precision molding technologyThe company adopts piezoelectric inkjet technology, high-resolution inkjet system, and special binder formula to realize ±0.3mm high-precision printing, which effectively reduces the machining allowance of the castings, improves the quality of the castings and the production efficiency, and is especially suitable for aerospace, automotive and other industries with stringent requirements for precision.
  4. Flexible area molding without sand boxAs 3DPTEK-J4000 Innovative use of sandbox-free flexible area molding technology, support for local printing, can economically and efficiently realize the manufacture of oversized sand molds, compared with the traditional box printing, the equipment footprint is reduced by more than 30%, and the printing cost is reduced by 15%-20%.

Through the above selection strategy based on casting size and material, combined with the comprehensive advantages of 3DPTEK sand 3D printers, enterprises can accurately match the parameters of the equipment to achieve a high degree of compatibility between equipment performance and production needs, and at the same time improve the quality of castings, reduce production costs and enhance market competitiveness.

2025 砂型 3D 打印機(jī)選型指南:根據(jù)鑄件尺寸、材質(zhì)選對設(shè)備參數(shù)最先出現(xiàn)在三帝科技股份有限公司

]]>
Industrial Wax Mold 3D Printer: A Complete Guide to Large-Scale Casting in 2025, 80% Cycle Time Reduction + Accuracy Enhancement Solutions http://www.ahjfzs.com/en/blogs/industrial-grade-wax-mold-3d-printer-2025-large-casting-guide/ Wed, 20 Aug 2025 09:21:38 +0000 http://www.ahjfzs.com/?p=2365 In the field of large-scale casting (aerospace turbine blades, automotive engine components, heavy machinery shells), traditional wax mold making has long been subject to "long cycle time, low precision, complex junction [...]

工業(yè)級蠟?zāi)?3D 打印機(jī):2025 年大型鑄造全指南,縮短 80% 周期 + 提升精度方案最先出現(xiàn)在三帝科技股份有限公司

]]>
In the field of large-scale casting (aerospace turbine blades, automotive engine components, heavy machinery housings).Traditional Wax Mold MakingConstrained by the three major pain points of "long cycle time, low precision, and difficulty in realizing complex structures", it takes 2-3 weeks to manually make a set of wax molds for turbine blades, with an error of more than 0.5mm, and it is impossible to complete the design of internal cooling channels. And the design of internal cooling channels cannot be completed.Industrial Wax Molds 3D printer(The emergence of SLS (SLS technology as the core) has completely changed the status quo: large wax molds can be printed in 3 days, with an accuracy of ±0.1mm, and complex structures that are not possible with traditional processes can also be realized. In this article, we will analyze the definition, advantages, workflow, selection guide and 2025 hot models of industrial wax 3D printers, which will provide foundries with hands-on solutions for technological transformation and cost reduction.

I. What is an industrial-grade wax 3D printer? Core Definition + Comparison to Traditional Processes

Industrial-grade wax mold 3D printers are based onSelective laser sintering (SLS) TechnologyIt is an industrial machine for the production of high-precision wax molds made of casting wax powder / wax-like powder, which are fused layer by layer and can be used directly for lost wax investment casting. It has significant advantages over the traditional wax molding process and is especially suitable for large casting scenarios (part sizes above 500 mm):

comparison dimensionIndustrial Wax Mold 3D PrinterTraditional wax molding process (handmade / CNC)
production cycle3-7 days (large wax models)2-4 weeks
Dimensional accuracy±0.1mm±0.5-1mm
Complex structure realizationEasy printing of internal cooling channels, thin-walled honeycomb structuresMultiple sets of wax molds need to be disassembled and are prone to assembly errors.
labor costAutomated printing, one person can operate multiple machinesDependence on skilled tradesmen, high labor costs 300%
Material utilization90% above (unsintered wax powder recyclable)60%-70% (cutting / manual waste)
Design IterationCAD files can be reprinted within a few hours after modification.Need to remake the mold, long cycle time

The 4 core benefits of industrial-grade wax mold 3D printers for foundries (solving industry pain points)

1. Reduced cycle time 80% for fast response to order requirements

It takes 3 weeks to make a wax mold of a large automotive engine block using traditional processes, but an industrial-grade 3D printer can do it in just 3 days. An aerospace foundry used LaserCore-5300 to print a wax model of a turbine blade, from design to finished product in 48 hours, shortening 80% compared with the traditional process, and compressing the trial production cycle of a new product from 3 months to 1 month, thus seizing the first opportunity in the market.

2. 5 times higher accuracy and lower casting scrap rate

Industrial-grade wax mold 3D printer has an accuracy of ±0.1mm and surface finish Ra≤1.6μm, which can reduce the casting post-treatment process. Due to the large error of wax mold made by traditional process, the casting scrap rate is more than 15%; while the 3D printed wax mold reduces the scrap rate to below 5%, and a foundry produces large valve castings and reduces the loss of scrap by 800,000 RMB annually.

3. Breaking through structural limitations and realizing difficult casting

No need to consider "mold release" issues, allowing for designs not possible with conventional processes, especially for high-end manufacturing:

  1. Aerospace:Multi-layer cooling channels inside the turbine blades(The traditional process requires 5 sets of wax molds to be disassembled, while 3D printing molds the mold in one go, with no assembly errors);
  2. Cars:Engine block integrated runners(Reduced post-drilling process and increased fluid efficiency by 10%);
  3. Heavy machinery:Thin-walled honeycomb structure for large shells(Wall thickness as low as 2mm, weight reduction 20%, strength increase 15%).

4. Long-term cost reductions 40%, offsetting equipment investment

Despite the high initial investment ($50,000+) for an industrial-grade wax-molded 3D printer, the cost advantage is significant when calculated over the full lifecycle:

  • Eliminate mold costs: Traditional large CNC wax mold mold costs over 200,000 yuan, 3D printing can be completely eliminated;
  • Reduced labor costs: 1 person can operate 3 machines, reducing 80% labor compared to the traditional process;
  • Reduction of scrap loss: precision improvement has reduced the casting scrap rate from 15% to 5%, saving more than 500,000 yuan in material cost per year.

Industrial Wax Mold 3D Printing Workflow: 6 Steps from Design to Wax Mold (for Large Casting)

The industrial wax 3D printing process is highly automated and does not require complex human intervention. The core steps are as follows (for example, wax molding of a large turbine blade):

  1. Digital Design and OptimizationThe 3D model of the wax mold is constructed in SolidWorks/AutoCAD, the shrinkage is reserved according to the casting metal properties (e.g. steel needs to be enlarged from 1%-2%), and the structure of the sprue and the vent is designed and exported as an STL format file;
  2. Device parameter settingLoad casting wax powder into a printer (e.g. LaserCore-6000) and set the parameters: layer thickness 0.08-0.35mm, laser power 55-300W, molding rate 80-300cm3/h to ensure that it is suitable for large wax models;
  3. automated printingAfter the equipment is started, the laser sinter the wax powder layer by layer according to the slicing trajectory. It takes 10-20 hours for a large wax model (e.g. 1050×1050×650mm) to be printed unattended at night without human intervention;
  4. Cleaning up after printingAfter the wax mold is completed, remove it from the molding chamber, blow off the excess wax powder on the surface with compressed air (this wax powder can be recycled directly), and inspect the wax mold for holes and cracks (the defect rate of 3D printed wax molds is less than 1%);
  5. Wax mold assembly (mass production)If batch casting is required, individual wax molds are attached to a "wax tree" to improve pouring efficiency;
  6. Suitable for lost wax castingThe wax mold is immersed in ceramic slurry to form a high-temperature-resistant ceramic shell, which is then burned in a 700-1000°C kiln to remove the wax mold (the ash content of the 3D printing wax mold is <0.1%, and the combustion is complete with no residue), and then the metal can be poured in.

How to choose industrial-grade wax 3D printers for foundries? 4 core selection criteria

1. Prioritizing molding space: adapting to the needs of large-scale casting

Large casting parts (such as automotive engine blocks, aerospace frames) with dimensions of 500-1000mm, need to choose the molding space ≥ 500 × 500 × 500mm model:

  • For small and medium-sized foundries (part sizes 500-700mm): A model with a molding space of 700×700×500mm (e.g. LaserCore-5300) is available;
  • Large foundries (part size 700-1000mm): We recommend a model with a molding space of 1050 x 1050 x 650mm (e.g. LaserCore-6000).

2. Technology Type Lock SLS: Ensuring strength and precision of wax molds

SLS technology sintered wax powder by laser, the wax molds have high density (≥0.98g/cm3) and high strength (flexural strength ≥15MPa), which can withstand the external force during ceramic paste coating and handling to avoid deformation. Wax molds made by other technologies (e.g. FDM) have low strength, are easily damaged and are not suitable for large-scale casting.

3. Focus on core parameters: accuracy, speed and material compatibility

  • accurate: Choose a ±0.1mm model to ensure casting dimensions are met and to minimize post-processing;
  • Molding rateThe priority is given to models with more than 200 cm3/h (e.g. AFS LaserCore-6000 up to 300 cm3/h) to increase the efficiency of the production of large wax molds;
  • Material compatibility: A wide range of casting waxes (e.g. low ash casting waxes, high temperature waxes) are required to support the casting of different alloys (aluminum alloys, steel, titanium alloys).

4. Software and services: making the transition less difficult

  1. The software must be compatible with the main CAD formats (STL/OBJ) and come with casting simulation (optimization of the structure of the wax model and reduction of defects);
  2. Service providers need to provide full-process support: free operator training (to ensure that the operation is mastered within 3 days), equipment installation and commissioning, 24-hour after-sales response (domestic door-to-door service ≤ 24 hours).

V. 2025 industrial-grade wax mold 3D printer popular models recommended (suitable for different casting needs)

Based on industry feedback and actual application cases, the following 3 models in 2025 are outstanding in the large casting field, covering entry to high-end scenarios:

modelsMolding space (mm)Type of technologyaccurateMolding rateApplicable ScenariosCore Advantages
AFS-500 (entry level)500 x 500 x 500SLS±0.1mm80-150cm3/hIndustrial tools, small and medium-sized castings (up to 500mm)Cost-effective, low power consumption (15KW), suitable for small and medium-sized foundry trial production
LaserCore-5300 (mid- to high-end)700 x 700 x 500SLS±0.1mm150-250cm3/hAerospace turbine blades, automotive parts (500-700mm)Rapid iteration, stable accuracy, suitable for multi-material printing
LaserCore-6000 (high-end)1050 x 1050 x 650SLS±0.1mm250-300cm3/hLarge automotive engine blocks, aerospace frames (700-1000mm)Extra large molding space, high efficiency of mass production, suitable for high production foundries

Model highlights analysis

  1. AFS-500Low entry cost, easy to operate, 1 person can manage multiple machines, suitable for small and medium foundries trying 3D printing for the first time, for small and medium-sized wax molds such as industrial tools, valves, and so on;
  2. LaserCore-5300The wax molds of turbine blades are widely used in the aerospace industry. The wax molds have a high surface finish and do not need to be polished, increasing the yield of the castings to more than 95%;
  3. LaserCore-6000The machine is one of the few in China that can print 1050mm wax models, and can nest 20 small and medium-sized wax models (e.g., automotive parts) in a single run, which increases the utilization rate of the machine by 60%.

Industrial Wax Mold 3D Printing Common Problems + Expert Solutions

1. High initial investment in equipment? -- Phased investment reduces risk

Small and medium-sized foundries can purchase entry-level models (e.g., AFS-500) for wax molding of high value-added parts (e.g., precision valves), quickly recoup their costs through high-margin orders, and then upgrade to higher-end models after 1-2 years.

2. Incomplete burning of wax molds leading to defective castings? -- Optimization of sintering and firing parameters

  1. When printing: Adjust the laser power (55-80W) to ensure that the sintered density of the wax mold is ≥0.98g/cm3 and to reduce the internal porosity;
  2. Firing: gradually increase the kiln temperature from 700°C to 1000°C and hold for 2-3 hours to ensure complete vaporization of the wax model (can be verified by the change in weight of the ceramic shell).

3. Wax powder recycling is difficult, material waste? -- Configure automated recycling system

By choosing the wax powder recycling equipment with automatic screening and drying function, the unsintered wax powder can be reused directly after treatment, and the material utilization rate is increased from 90% to more than 95%, which saves 200,000 yuan of material cost per year.

4. Unskilled team operation, affecting productivity? -- Give preference to "equipment + training" as an all-in-one service.

Choose a service provider that provides free training (such as AFS brand), 1 to 1 teaching operators to master the daily operation of the equipment, troubleshooting, to ensure the normal operation of the equipment.

VII. Conclusion: Industrial-grade Wax Mold 3D Printer, "Must-have Equipment" for Foundry Transformation

In the increasingly competitive large-scale foundry industry, "high precision, fast cycle time, low cost" has become the core competitiveness -- industrial-grade wax mold 3D printers help foundries break through the limitations of traditional processes by shortening the cycle time by 80%, increasing the accuracy by 5 times, and reducing the cost by 40% in the long run. to help foundries break through the limitations of traditional processes.

In 2025, the commercialization of models such as the LaserCore series will provide a fast track from design to wax mold for industries such as aerospace, automotive and heavy machinery. For foundries, choosing the right industrial-grade wax 3D printer will not only reduce costs and increase efficiency, but also unlock difficult casting orders and secure a place in high-end manufacturing - the core value of industrial-grade wax 3D printing in the future of the foundry industry.

工業(yè)級蠟?zāi)?3D 打印機(jī):2025 年大型鑄造全指南,縮短 80% 周期 + 提升精度方案最先出現(xiàn)在三帝科技股份有限公司。

]]>
4-Meter Large-Scale Sand Casting 3D Printer: Unlocking Large-Scale Casting Manufacturing by 2025, Reducing Cycle Time by 80% + Cost Reduction Solutions http://www.ahjfzs.com/en/blogs/4-meter-class-large-sand-mold-casting-3d-printer/ Wed, 20 Aug 2025 07:58:59 +0000 http://www.ahjfzs.com/?p=2360 In the field of large casting manufacturing (e.g., engine blocks, industrial machinery shells, aerospace components), the traditional sand molding process has long been subject to "size limitation, long cycle time, high cost [...]

4 米級大型砂型鑄造 3D 打印機(jī):2025 年解鎖大型鑄件制造,縮短 80% 周期 + 降本方案最先出現(xiàn)在三帝科技股份有限公司。

]]>
In the field of manufacturing large castings (e.g. engine blocks, industrial machinery housings, aerospace components).Traditional sand molding processConstrained by the three major pain points of "size limitation, long lead time and high cost" for a long time - it takes several months to make a 4-meter sand mold, and it needs to be assembled manually by disassembling several groups of sand cores, with a scrap rate of more than 15%.4-meter large-scale sand casting 3D printer(in the form of) 3DPTEK-J4000 On behalf of the emergence of), completely break this dilemma: 1 time printing to complete the 4-meter overall sand, shorten the cycle of 80%, reduce the cost of 40%, but also to achieve the complex internal structure of the traditional process can not be completed. In this paper, we will analyze the core parameters, advantages, application scenarios and industry value of this equipment, and provide technical transformation guidelines for heavy manufacturing enterprises.

First, the 4 major pain points of the traditional large-scale sand molding process, 4-meter 3D printing how to crack?

Traditional large-scale sand mold manufacturing (size over 2 meters) needs to go through "mold making - sand core disassembly - manual assembly", there are difficult to solve the pain points, but 4-meter sand 3D printing through the "integrated molding + digital process" to achieve a comprehensive breakthrough. process" to realize a comprehensive breakthrough:

Type of pain pointStatus of traditional crafts4-Meter Sand 3D Printing Solution
long lead time4-8 weeks to produce a 4-meter sand mold (2-4 weeks for molding alone)2-5 days to complete the entire sand mold printing, full cycle time reduction 80%
Structural limitationsComplex internal channels, topology optimization structure requires more than 10 groups of sand cores to be disassembled, which is prone to assembly errors.Print complex structures in one piece, no need to disassemble, error ≤ 0.3mm
high costLarge metal molds cost over $500,000 and require 10 people/day for manual assembly.No mold costs, automated printing reduces 80% labor
High scrap rateSand core splicing gaps lead to casting defects, scrap rate 15%-20%Seamless sand molding + simulation optimization to reduce scrap rate to below 5%
4 meters, large sand 3D printer

Second, 4-meter-class large sand 3D printer core analysis: 3DPTEK-J4000 parameters and technical advantages

1. Key parameters: meeting the full scenario requirements for large castings

3DPTEK-J4000 As a benchmark equipment in the industry, it is not a simple enlargement of a small printer, but an exclusive design for large-scale sand manufacturing with the following core parameters:

  1. Maximum molding size: 4000mm x 2000mm x 1000mm (can print the whole sand pattern of 4 meters long and 2 meters wide without splicing);
  2. Process Type: Inkjet binder injection (3DP), suitable for special casting sands such as quartz sand, ceramic sand and ceramic sand;
  3. Accuracy and Resolution: Dimensional accuracy ±0.3mm, nozzle resolution 400dpi, surface finish up to Ra6.3μm;
  4. Layer thickness and efficiencyLayer thickness can be adjusted to 0.2-0.5mm, and 2-3 sets of medium-sized sand patterns (e.g. 2-meter-long pump body sand patterns) can be printed in a single day;
  5. Material utilization: 100% of uncured sand recycled with less than 5% of material waste.

2. Core technology: "sand-free flexible area molding" cost reduction

Traditional 4-meter sand molding equipment needs to be fixed large sand box, a single print needs to be filled with tens of tons of sand, the cost is extremely high. And 3DPTEK-J4000 A breakthrough was achieved with the "Sandless Flexible Area Molding Technology":

  • Eliminates the need for a fixed sand box, dynamically adjusts the sand bed area to the size of the sand pattern, and reduces the amount of 70% sand used;
  • Elimination of large sanding box infrastructure investment (traditional sanding box cost more than 200,000 yuan);
  • Equipment purchase cost is the same as 2.5-meter class equipment, with a 50% return on investment.

The 5 core advantages of 4-meter sand 3D printing: directly enhancing enterprise competitiveness

1. Shorter cycle time 80% to seize the market opportunity

It takes 6 weeks to make a 4-meter engine block sand mold by traditional process, but 3DPTEK-J4000 takes only 3 days to finish printing, and the whole cycle from design to casting delivery is compressed from 3 months to 1 month. A heavy machinery company used it to make large gearbox shell sand mold, new products on the market 2 months ahead of schedule, to seize a share of 30% market segment.

2. Achievement of "oversized + complex" integrated molding

No need to consider the constraints of "stripping" and "splicing" of conventional processes, making it possible to accomplish difficult designs:

  • Aerospace: 4-meter-long turbine casing for theInternal multi-layer cooling channels(The traditional process requires 12 sets of sand cores to be disassembled, while 3D printing molds them in a single pass);
  • Energy sector: 3-meter diameter wind turbine flangesTopology-optimized weight-reducing structures(Weight reduction 20%, strength increase 15%);
  • In the field of industrial machinery: 4-meter-long pump bodies for theSpiral Worm Structure(No splicing seams, 8% increase in fluid efficiency).

3. Long-term cost reduction 40% with short payback period

Despite the high initial investment in the equipment, the cost advantage is significant when calculated over the full life cycle:

  1. Save mold cost: large castings need to replace 2-3 sets of molds per year, 3D printing can be completely eliminated, saving more than 1 million yuan per year;
  2. Reduce scrap loss: a foundry with its production of large valve sand mold, scrap rate from 18% to 4%, reducing annual losses of 500,000 yuan;
  3. Digital inventory: sand patterns are stored as CAD files, eliminating the need to stack physical patterns in the warehouse and saving 100 square meters of storage space.

4. Support "batch + customized" dual-mode production

The 4-meter molding space not only prints large sand molds, but also allows for the nested mass production of small parts:

  1. 200 small pump body cores can be nested in a single print run (traditional processes require batch production);
  2. Supports "1 set of large sand molds + batch of small sand cores" mixed printing, increasing equipment utilization by 60%;
  3. Fast response to customization needs, modifications to the design only require updating the CAD file, no need to recreate the mold.

5. Comply with environmental requirements and help green production

Global environmental regulations are tightening (e.g., China's "dual carbon" policy, EU carbon tariffs), and 4-meter sand 3D printing meets environmental needs through two major technologies:

  1. Use of low VOC binders (emissions below national standard 60%) to reduce air pollution;
  2. Sand 100% is recycled and reused, reducing solid waste emissions by more than 100 tons per year, which meets the requirements for green factory certification.

Fourth, 4-meter sand 3D printing 4 major industry application scenarios (with actual cases)

1. Automotive and commercial vehicle sector: core components for new energy trucks

  • Application: 4-meter long new energy heavy truckIntegral motor housingThe sand molding of large engine block;
  • Case in point: a car company uses 3DPTEK-J4000 Printing the sand mold of the motor shell, the cycle time is shortened from 4 weeks to 3 days, and the casting has no defects at the thin wall (2.5mm), realizing a weight reduction of 30% for the motor and a range increase of 100km.

2. Aerospace and defence: large lightweight structural components

  • Application: 4 meters longAero-engine turbine casing, Missile Launcher Tank Sand Type;
  • Advantage: integrated printing to avoid sand core splicing errors, casting dimensional accuracy up to CT7 level, to meet the aerospace "zero defect" requirements.

3. Industrial machinery and energy sector: core components for heavy equipment

  • Application: 4 meters longLarge Pump Body Worm CasingThe sand molding of wind turbine gearbox shells with a diameter of 3 meters;
  • Case: A heavy industry enterprise uses it to print the sand pattern of the pump body, the surface finish of the fluid channel is improved by 50%, the efficiency of the pump body is improved from 75% to 82%, and the annual energy consumption is saved by 1.2 million yuan.

4. In the field of art and architecture: oversized bronze sculptures

  • Application: 60 meters long bronze sculptureSegmented sand molding(e.g. the "Nine Horses" sculpture in Nanjing);
  • Benefits: Eliminates the need for large wood moldings, allows for complex artistic textures, and reduces the sculpture production cycle from 1 year to 3 months.

Fifth, choose the right solution: 3DPTEK "equipment + ecological" integrated services

The success of 4-meter sand 3D printing requires not only high-quality equipment, but also a complete ecological support. 3DPTEK provides "end-to-end" solutions to reduce the difficulty of enterprise transformation:

  • Proprietary materialsMore than 30 sand-binder formulations (e.g., low viscosity binder for aluminum alloy casting, high temperature resistant binder for steel casting) ensure casting quality;
  • intelligent software: It comes with casting simulation system, which can simulate the flow of metal liquid, cooling contraction, optimize the sand design in advance, and reduce the cost of trial and error;
  • Full Process Service: Full process support from CAD modeling, sand printing to post-processing of castings, free operator training (3 days to master the operation of the equipment);
  • after-sales service24-hour door-to-door service at home, 5 service centers abroad (Germany, the United States, India, etc.), spare parts arrival cycle ≤ 72 hours, to ensure that the equipment is on throughout the year ≥ 95%.

Future Trends in Large-Scale Sand 3D Printing in 2025: Toward "Bigger and Smarter"

1. Continuing size breakthroughs: 6-10 meter class devices in development

3DPTEK has started the research and development of 6-meter-class sand printer, which can realize the whole printing of "8-meter-long ship propellers" and "10-meter-diameter nuclear power equipment shells" in the future, and completely eliminate the defects of large casting splicing.

2. AI+3D Printing: Realizing Intelligent Control of the Whole Process

Integrated AI system for automated completion:

  • Optimization of sand mold design (automatically generate the optimal structure according to the casting material and size);
  • Printing process monitoring (real-time adjustment of binder injection volume to avoid sand cracks);
  • Quality prediction (AI algorithms predict possible defects in castings and adjust the process in advance).

3. Multi-material composite printing: expanding application boundaries

The future equipment can realize "sand + metal powder" composite printing, printing high-temperature-resistant metal coatings on key parts of the sand mold (e.g., the sprue), adapting toTitanium alloy, ultra-high strength steelRefractory alloy casting, expanding the application in the field of high-end equipment.

Conclusion: 4-meter sand 3D printing opens a new era of large casting manufacturing

For heavy manufacturing enterprises, 4-meter-class large sand casting 3D printer is no longer a "technological novelty", but a "necessity to enhance competitiveness" - it breaks the traditional process of It breaks the size and cycle time limitations of traditional processes, and realizes the triple breakthrough of "large-scale + complexity + low cost".

The commercialization of 3DPTEK-J4000 and other equipment has provided a fast track from design to casting for automotive, aerospace, industrial machinery and other industries. In the future, with the research and development of 6-10 meter-class equipment and the integration of AI technology, large casting manufacturing will enter a new stage of "full digitalization, zero defects and greening", and the enterprises that take the lead in laying out this technology will have an absolute advantage in the market competition.

4 米級大型砂型鑄造 3D 打印機(jī):2025 年解鎖大型鑄件制造,縮短 80% 周期 + 降本方案最先出現(xiàn)在三帝科技股份有限公司。

]]>
Sand 3D Printing: Reshaping the Metal Casting Industry by 2025 with 80% Cycle Time Reduction + Cost Reduction Solution Explained http://www.ahjfzs.com/en/blogs/sand-mold-3d-printing-technology-transforming-the-metal-casting-industry-by-2025/ Wed, 20 Aug 2025 06:17:48 +0000 http://www.ahjfzs.com/?p=2358 How Sand 3D Printing Technology Reinvented Metal Casting? 2025 Analyzing its core advantages of shortening 80% sand cycle time and reducing cost by 40%, breaking through the limitations of complex structures, with 3DPTEK equipment parameters and case studies from automotive/aerospace industry to help foundries transform.

砂型 3D 打印技術(shù):2025 年重塑金屬鑄造行業(yè),縮短 80% 周期 + 降本方案解析最先出現(xiàn)在三帝科技股份有限公司。

]]>
In the metal casting industry, theConventional sand mold makingLong limited by "long cycle time, low complexity, high cost" three major pain points - the production of a set of complex sand mold takes weeks, and it is difficult to realize the internal cooling channels, thin-walled structure and other complex designs. Andsand mold 3D printing technology(The emergence of (binder jetting technology as the core) has completely changed the status quo: it takes only 24-48 hours from the CAD model to the finished sand model, complex structures are molded in one go, and the material utilization rate is increased by more than 90%. This article will comprehensively analyze the principle of sand 3D printing, core advantages, industry applications and 3DPTEK equipment selection, to provide foundries with technical transformation and cost reduction and efficiency of the practical guide.

I. What is Sand 3D Printing? Core Definition + Process Characteristics (different from traditional mold making)

Sand 3D printing is based onPrinciples of Additive ManufacturingThis is an industrial technology that directly transforms digital CAD models into solid sand molds / cores. Instead of the traditional "mold-making - sand-turning" process, the sand mold is formed by laying sand layer by layer on the printer and curing it by spraying a binder. The core process isBinder jetting technologyThe J1600Pro, J2500, and J4000 models from 3DPTEK, for example, offer significant advantages over conventional molding:

comparison dimensionSand 3D PrintingTraditional mold making process
production cycle24-48 hours2-4 weeks
Complex structure realizationEasy printing of internal channels, thin-walled partsDifficult to realize, need to split multiple sand cores
Tooling CostsNo need for physical molds, cost is 0Customized wood / metal molding required, high cost
Material utilization90% or more (uncured sand can be recycled)60%-70% (much cutting waste)
Design FlexibilitySupports real-time modification of CAD models for fast iterationModification of the design requires re-modeling and long lead time

Second, the foundry must use sand 3D printing 4 core reasons (to solve the industry pain points)

1. Reduced cycle time 80% for fast response to order requirements

While traditional processes take 2-4 weeks to produce complex sand molds (e.g. pump bodies, turbine casings), sand 3D printing takes only 1-2 days. Especially suitable forPrototype molding, small batch customization, emergency spare parts productionScenario -- A foundry uses the 3DPTEK J1600Pro to print sand molds of pump bodies from design to delivery in just 36 hours, a reduction of 80% compared to the traditional process, helping to bring products to market 2 weeks earlier.

2. Breaking through structural limitations and realizing difficult casting

Sand 3D printing eliminates the need for "mold release" issues, making it easy to create designs that would be impossible with traditional processes:

  1. in the field of aerospaceTurbine blade internal cooling channels(The traditional process requires more than 5 sets of sand cores to be disassembled, which is prone to assembly errors);
  2. AutomotiveLightweight thin-walled motor housing(Wall thickness can be as low as 2mm, conventional sand type is prone to fracture);
  3. industrial machineryIntegrated oil passages transmission housing(Reduces post-drilling process and reduces scrap rate).

3. Long-term cost reductions 40%, offsetting equipment input costs

Despite the high initial investment in sand 3D printers, the cost advantage is significant when calculated over the full life cycle:

  • Elimination of mold production costs (a set of large metal mold cost more than 100,000 yuan, 3D printing can be completely eliminated);
  • Reduced scrap rate (digital design + simulation optimization, casting scrap rate reduced from 15% to less than 5%);
  • Reduced labor costs (automated printing eliminates the need for manual assembly of multiple sand cores, reducing labor by 50%).

4. Comply with environmental requirements and realize green production

As global environmental regulations tighten (e.g., the EU REACH standard), sand 3D printing meets the need for environmental protection through two main technologies:

  • adoptionLow Emission Binder(3DPTEK proprietary formulation with VOC emissions below industry standard 50%);
  • Uncured sand can be 100% recycled, reducing solid waste generation and environmental treatment costs.

Three, sand 3D printing principle: 4 steps from design to sand (full process automation)

Sand 3D printing (binder jetting technology) is a simple, highly automated process that requires no complex human intervention, with the following core steps:

  1. Digital Design and Simulation: Engineers use CAD software to build sand models, and simulate the flow of liquid metal, cooling and shrinkage processes through the 3DPTEK casting simulation system to optimize the pouring system and riser position of the sand model, so as to avoid defects such as shrinkage holes and porosity in the castings;
  2. Layer-by-layer molding: The printer automatically lays down 0.26-0.30mm thick sand (quartz sand/chromite sand optional) and then, based on the slicing data, sprays the binder on the area to be cured and builds up the sand pattern layer by layer;
  3. Curing and sand cleaning: After printing, the sand model is left to cure (strengthen) in a closed environment for 2-4 hours, after which the uncured loose sand (which can be recycled directly) is blown out with compressed air;
  4. Casting and post-processingThe molten metal (aluminum alloy, steel, copper alloy, etc.) is poured into the sand mold, which is then cooled, cracked and removed for finishing - the entire process requires no human intervention in the sand mold making process.

Parameters of 3DPTEK Sand 3D Printer (Applicable to Different Industries)

3DPTEK, as an industry leader, has introduced several models of sand printers covering small to very large casting needs with the following core parameters:

modelsPrint size (L × W × H)layer thicknessApplicable ScenariosSuitable for casting alloys
3DPTEK-J1600Pro1600×1000×600mm0.26-0.30mmSmall and medium-sized sand molds (e.g., motor housings, small pump bodies)Aluminum, cast iron
3DPTEK-J25002500×1500×800mm0.26-0.30mmMedium to large sand molds (e.g. gearbox housings, turbine housings)Steel, copper alloys
3DPTEK-J40004000×2000×1000mm0.28-0.32mmOversized sand molds (e.g. ship propellers, large valves)Stainless steel, specialty alloys

Core AdvantagesAll models support "sand + binder" custom formulations, and 3DPTEK has over 30 proprietary formulations to match the needs of different alloys (e.g., aluminum alloy casting for low-viscosity binder, steel casting for high-temperature-resistant sand).

V. Sand 3D printing 4 major industry application scenarios (with actual cases)

1. The automotive sector: core support for the electrification transition

  • Application Scenarios:Electric vehicle water-cooled motor housing, lightweight battery tray sand molding.;
  • Example: A commercial electric truck manufacturer used the 3DPTEK J2500 to print a sand mold of the motor case, realizing an "integrated cooling channel" design, which improved the motor cooling efficiency by 30%, while reducing the weight of the case by 25% and increasing the range by 50km.

2. Aerospace industry: high-precision casting of complex parts

  • Application Scenarios:Turbine blades, aero-engine combustion chamber sand molding.;
  • Advantage: The dimensional accuracy of the sand mold reaches CT7 level, which meets the requirement of "zero error" for aerospace parts, and at the same time, avoids the scrapping of blades caused by the assembly error of traditional sand cores.

3. Industrial machinery industry: core components for large equipment

  • Application Scenarios:Sand molding of large pumps and compressor housings.;
  • Case: A heavy industry enterprise used 3DPTEK J4000 to print a 4-meter-long pump body sand mold, the traditional process requires the production of three sets of metal molds (costing more than 300,000 yuan), 3D printing directly eliminates the cost of molds, and shortens the production cycle from 4 weeks to 3 days.

4. Energy and marine industry: manufacture of very large castings

  1. Application Scenarios:Ship propeller, wind turbine shell sand molding.;
  2. Advantage: The J4000 model's 4-meter wide print size allows for the printing of very large sand molds in one pass, eliminating the need for splicing and reducing mold-fitting defects in castings.

Why choose 3DPTEK sand 3D printing solution? (4 core competencies)

1. Full-scene equipment coverage, adapting to different capacity needs

From 1.6-meter compact machines (J1600Pro) to 4-meter ultra-large machines (J4000) forSmall batch trial production to large scale mass productionThe J1600Pro is available for small and medium-sized foundries with a capacity of 5-8 sand molds per day, and the J4000 is available for large foundries with a capacity of 2-3 oversized sand molds per day.

2. Proprietary material formulas to ensure casting quality

3DPTEK has more than 30granuleExclusive formulation for bonding agents, optimized for different alloys:

  1. Aluminum alloy casting: low viscosity binder, good sand permeability, reduce casting porosity;
  2. Steel casting: high-strength binder, sand mold high temperature resistance (more than 1500 ℃), to avoid the defect of sand washing;
  3. Copper alloy casting: low ash binder to prevent inclusions on the casting surface.

3. Integrated technical support to reduce the difficulty of transition

Provide "equipment + software + service" full-process support:

  1. free of chargeCasting Simulation Software(Optimize sand design and reduce trial and error costs);
  2. Inside the casting technology center, can assist customers in sand testing, casting process debugging;
  3. Provide operator training (1 to 1 instruction to ensure equipment operation within 3 days).

4. Global after-sales network to ensure production stability

The equipment has been landed in more than 20 countries in Europe, Asia, the Middle East, etc., and the after-sales response speed is fast:

  1. Domestic 24-hour door-to-door service (48 hours for remote areas);
  2. 5 service centers abroad (Germany, India, USA, etc.) for quick replacement of spare parts;
  3. Free equipment maintenance 2 times a year to extend the life of the equipment (average life of more than 8 years).

VII. Future Trends of Sand 3D Printing in 2025 (3 Directions to Watch)

1. AI+3D Printing for Zero Defect Casting

The future of sand 3D printing will be integratedAI Design Optimization System-- Input casting parameters (material, size, performance requirements), AI can automatically generate the optimal sand structure, while real-time monitoring of the printing process, by adjusting the amount of binder injection, sand laying thickness, to avoid cracks, uneven density and other problems in the sand, to achieve "zero defects " production.

2. Closed-loop sand recycling, material utilization rate of 98%

exploit (a resource)Automatic Sand Recovery SystemIn addition, the uncured sand and old sand will be screened, decontaminated and recycled, and the material utilization rate will be increased from the current 90% to more than 98%, which further reduces the material cost and meets the requirements of the "Double Carbon" policy.

3. Multi-material composite printing to expand application boundaries

The future of sand 3D printers will enable "sand + metal powder" composite printing - printing metal coatings on critical parts of the sand model (e.g., gates) to improve the sand model's high-temperature resistance, and to accommodateUltra-high strength steel, titanium alloyRefractory alloys such as casting, expanding the application in the field of aerospace, high-end equipment.

VIII. Conclusion: Sand 3D printing is not an "optional technology" but a "must-have transformational tool"

In the increasingly competitive metal casting industry, "fast response, complex structure, green cost reduction" has become the core competitiveness - sand 3D printing by shortening the cycle time of 80%, realizing difficult designs, long-term cost reduction 40% and help foundries break through traditional process constraints.

3DPTEK, as a leading company in the field of sand 3D printing, provides customized solutions for foundries of different sizes through multiple models of equipment, exclusive material formulations, and integrated technical support. Whether in the automotive, aerospace, industrial machinery or energy sectors, choosing sand 3D printing means choosing the double advantage of "cost reduction and efficiency + technological leadership", which is also the core way for foundries to survive in 2025 and beyond.

砂型 3D 打印技術(shù):2025 年重塑金屬鑄造行業(yè),縮短 80% 周期 + 降本方案解析最先出現(xiàn)在三帝科技股份有限公司

]]>
Industrial SLS 3D Printers: A Revolutionary Solution for Precision Manufacturing of Complex Parts, Technology Analysis and Industry Applications 2025 http://www.ahjfzs.com/en/blogs/industrial-sls-3d-printer-precision-manufacturing-for-complex-parts/ Wed, 20 Aug 2025 03:41:18 +0000 http://www.ahjfzs.com/?p=2355 Learn about the principles, advantages, materials and applications of industrial-grade SLS 3D printers! In 2025, we will analyze how it breaks through the traditional process, realizes the precision manufacturing of complex parts, shortens the cycle time of 70%, and reduces the cost of 40%, and adapts the 3DPTEK equipment to aerospace/automotive/medical/casting scenarios.

工業(yè)級 SLS 3D 打印機(jī):復(fù)雜零件精密制造的革新方案,2025 年技術(shù)解析與行業(yè)應(yīng)用最先出現(xiàn)在三帝科技股份有限公司。

]]>
In the wave of transformation and upgrading of the modern manufacturing industry, theHigh precision, high durability, complex structural partsDemand continues to rise. Traditional manufacturing methods are repeatedly limited in small lot production, rapid prototyping and machining of complex geometries, and theIndustrial Grade SLS 3D PrinterWith Selective Laser Sintering (Selective Laser Sintering) technology, become the core equipment to break through these bottlenecks. This article will comprehensively analyze the principle, advantages, applicable materials, industry applications and future trends of industrial-grade SLS 3D printing, to provide manufacturing enterprises with technology selection and production optimization reference.

I. What is an Industrial Grade SLS 3D Printer? Core Definition and Technical Characteristics

Industrial-grade SLS 3D printers use a high-powered laser toNylon, composite polymers, specialty casting sands/waxesThe industrial-grade equipment for selective fusion of powder materials and other materials to build up solid 3D parts layer by layer. Its core technical characteristics are significantly different from desktop-level SLS equipment:

comparison dimensionIndustrial Grade SLS 3D PrinterDesktop SLS Devices
Molding spaceLarge (some models up to 1000mm)few
production efficiencyHigh, supports mass productionLow, mostly single-piece printing
Quality of partsStable and meets mass production standardsLower precision, suitable for prototyping
Material compatibilityHiro (engineering plastics, casting sand, wax)Narrow (mostly basic nylon powder)

In addition, industrial-grade SLS printing requires no support structure (unsintered powder naturally supports the part), making it easy to accomplish things that are impossible with traditional processes.Complex internal channels, lightweight lattice structures, active componentsAll-in-one molding.

4 Core Benefits for Manufacturers Choosing Industrial SLS 3D Printing

In the aerospace, automotive, medical, foundry and other fields, industrial-grade SLS technology has become the key to improve productivity and innovation, the core advantages are reflected in the following four points:

1. No upper limit of design freedom, breaking through the traditional process limitations

No support structure is required, allowing engineers to designComplex internal cavities, integrated moving parts, topology-optimized lightweight structure-- such as hollow structural parts in aerospace and complex runner components in automotive engines -- are difficult to achieve with traditional processes such as CNC machining and injection molding.

2. Strength of parts up to standard, directly used in mass production scenarios

SLS printed parts are not "prototypes" but finished parts with useful functionality. Commonly usedPA12 (nylon 12), PA11 (nylon 11), glass fiber reinforced nylonThese materials have mechanical properties close to those of injection-molded parts, as well as excellent chemical resistance and impact resistance, and can be used directly in mass-production scenarios such as automotive interior parts and medical and surgical tools.

3. Reduced production lead time 70%, rapid response to market demand

From CAD model to finished part, industrial-grade SLS prints in3-7 daysThis is much faster than traditional mold making, which typically takes weeks. For R&D teams in prototype validation, small batch customized production, and emergency spare parts replenishment, this advantage can dramatically shorten the time-to-market cycle and seize the market opportunity.

4. Supporting scale-up and transition production to reduce costs

Industrial-grade SLS equipment can nest dozens or even hundreds of parts in a single print run, making it ideal forSmall batch mass productionSLS can also be used as a "bridge manufacturing" tool - using SLS to quickly produce transitional parts before committing to expensive injection molds, avoiding risky tooling investments and reducing upfront production costs.

Third, the core material of industrial-grade SLS 3D printing: more than nylon, casting application materials into a new hot spot

Nylon is the first material that comes to mind when you think of SLS materials, but industrial-grade equipment has achieved multi-material compatibility and specialized materials, especially in the foundry sector, are driving the digital transformation of traditional casting processes:

1. Foundry sand: direct production of metal casting sand molds / cores

by combiningQuartz Sand / Ceramic SandMixed with a special binder for laser sintering, industrial-grade SLS printers can directly print sand molds and cores for metal casting, with core benefits including:

  • Suitable for pump bodies, turbine housings, automobile engine blocks, etc.Complex internal cavity castings.;
  • Eliminates the need for traditional wood/metal molds, reducing mold costs and lead times;
  • High precision of sand size (error ≤0.1mm), smooth surface, improve the yield of castings.

  • Low surface roughness (Ra≤1.6μm) to meet the needs of precision parts casting;
  • Ash content <0.1%, no residue when casting dewaxing, avoid casting defects;
  • Shortened production cycle time 50% for rapid production of small quantities of precision wax molds.
  • 3DPTEK Industrial SLS Casting Equipment Recommendation

    As a leading brand in the industry, 3DPTEK offers specialized models for foundry scenarios, adapted to the needs of industrial-grade production:

    • SLS Sand 3D PrinterThe molding length is up to 1000mm, which supports the mass production of large-size casting sand molds and is suitable for casting of large mechanical parts;
    • SLS Wax Mold 3D Printer: High-resolution printing (layer thickness 0.08mm), compatible with standard casting wax formulations for seamless integration into traditional investment casting processes.

    Industrial-grade SLS 3D printing works: from design to finished product in 5 steps

    The industrial-grade SLS print process is highly automated, with a 5-step core process that eliminates the need for complex manual intervention:

    1. 3D design and pre-processing: Completion of the part design in CAD software, optimization of the structure (e.g., increase of wall thickness, nesting arrangement) by means of special software, and generation of STL files that are recognized by the SLS equipment;
    2. Powder laying: The equipment automatically spreads the powder material evenly on the molding platform, and the layer thickness is controlled at0.08-0.35mm(precision adjustable);
    3. Selective Laser Sintering: High-power laser scanning based on the cross-section trajectory of the part fuses and solidifies the powder particles to form a single-layer part structure;
    4. pile up layer by layer: The molding platform is lowered one level, the machine is re-laid with new powder, and the laser sintering step is repeated until the part is fully formed;
    5. Cooling & Powdering: The parts are cooled slowly in a closed environment (to avoid deformation), and the unsintered powder is removed after cooling (recyclable, with a material utilization rate of more than 90%).

    V. Industrial SLS 3D Printer Industry Applications: Typical Scenarios in 4 Major Fields

    With the advantages of high precision, high compatibility and fast production, industrial-grade SLS technology has landed in many key industries, and the typical application scenarios are as follows:

    1. Aerospace: combining light weight with high reliability

    • give birth to a childLightweight ducting, air handling componentsThe weight of the part is reduced 30%-50% through lattice structure optimization, while strength is guaranteed;
    • Manufacturing of complex structural satellite components, aircraft interior mounts without assembly, reducing the risk of failure.

    2. Automotive: rapid prototyping combined with low-volume mass production

    • R&D phase: rapid printingHousing, bracket, dashboard prototypeThe design is validated in 3 days, shortening the development cycle;
    • Mass production stage: small batch production of customized automotive interior parts and maintenance spare parts, avoiding investment in molds and reducing costs.

    3. Medical field: personalization and safety at the same time

    • customizablePatient-Only Anatomical Models(e.g., orthopedic surgical planning models) to help physicians accurately develop surgical plans;
    • Produces personalized orthopedic instruments and surgical tools with materials that meet medical grade standards and biocompatibility.

    4. Foundry sector: promoting the digital transformation of traditional processes

    • Large metal castings: Direct printing of sand molds/cores for complex parts such as pump bodies and turbine housings;
    • Precision parts casting: Printing of low ash wax molds for investment casting of precision parts such as aerospace turbine blades and jewelry.

    Case Study: European Automotive Supplier Uses SLS 3D Printing to Reduce Cost by 40% and Increase Efficiency by 70%

    A European automotive supplier needed to customize tooling for a short-term production task. The traditional solution used CNC machining, which required a 10-day lead time and high equipment costs; it switched to CNC machining.3DPTEK Industrial Grade SLS 3D PrinterAfter:

    • Material Selection: High strength PA12 powder is used, the strength of the part meets the requirements of the tooling;
    • Production cycle time: only 3 days from design to finished product, 70% shorter than CNC machining;
    • Cost Control: No need for molds and complex machining, reducing overall costs by 40%;
    • Result: Successful completion of a short production run and verification of the feasibility of SLS technology in tooling manufacturing.

    3DPTEK Industrial Grade SLS 3D Printer: Why is it the Industry's Preferred Choice?

    Among the many brands of industrial SLS equipment, 3DPTEK has become a popular choice for manufacturing companies due to its "mass-production oriented" design philosophy, which is reflected in its core competence in four ways:

    1. Large size and high speed at the same timeSome models have a molding length of up to 1000mm, which supports the production of oversized parts. Meanwhile, the printing speed is 20% higher than the industry average, which improves the efficiency of mass production;
    2. Strong multi-material compatibilityThe machine can be adapted to a wide range of materials such as engineering plastics, casting sand, casting wax, etc., so that one machine can meet the needs of multiple scenarios;
    3. Full Process Solutions: Provides a wide range of services from printing devices toCasting simulation software, post-processing equipmentThe all-in-one solution eliminates the need for additional third-party tools;
    4. Global Technical Support: Full-cycle service covering equipment installation, operation training and after-sales maintenance to ensure stable operation of the production line.

    VIII. Future Trends of Industrial SLS 3D Printing in 2025: 3 Directions of Concern

    With the advancement of material science and automation technology, industrial SLS printing will develop to higher efficiency, wider application and higher quality, and the 3 major trends in the future are obvious:

    1. Increased print speed without sacrificing accuracy: Through laser power optimization and multi-laser simultaneous sintering technology, the printing speed will be increased by more than 50%, while maintaining a high accuracy of 0.08mm;
    2. Expansion of material categoriesHigh-temperature composite materials (such as PEEK-based powders) and metal-based composite powders will be gradually landed, expanding the application of SLS in high-temperature and high-strength scenarios;
    3. Closed Loop Intelligent ProductionThe integrated real-time monitoring system monitors the printing process through AI algorithms and automatically adjusts the laser parameters to realize "zero-defect" mass production and reduce the scrap rate.

    IX. Conclusion: Industrial Grade SLS 3D Printing, More Than a "Printer", It's a Tool for Manufacturing Innovation

    Industrial-grade SLS 3D printers are no longer just "prototyping machines", they are "design-production-application" machines that are capable of linking the entire design-production-application process.Production-grade solutionsIndustrial SLS technology provides efficient, cost-effective solutions to the lightweight needs of the aerospace and automotive industries. Whether it's the lightweight needs of aerospace, the rapid response needs of the automotive industry, the personalization needs of the medical field, or the digitalization needs of the foundry industry, industrial-grade SLS technology provides an efficient, cost-effective solution.

    For manufacturing companies, choosing the right industrial-grade SLS equipment (such as 3DPTEK's sand/wax mold models) not only improves productivity, but also breaks through the limitations of traditional processes and seizes the high ground for innovation - which is the core value of industrial-grade SLS 3D printing in the future of manufacturing.

    工業(yè)級 SLS 3D 打印機(jī):復(fù)雜零件精密制造的革新方案,2025 年技術(shù)解析與行業(yè)應(yīng)用最先出現(xiàn)在三帝科技股份有限公司。

    ]]>
    3D printing sand casting, a must for traditional foundry owners http://www.ahjfzs.com/en/blogs/3d-da-yin-sha-xing-zhu-zao-chuan-tong-zhu-zao-chang-lao-ban/ Thu, 20 Mar 2025 08:31:14 +0000 http://www.ahjfzs.com/?p=2146 This article analyzes the depth of the technology, from the principle, to solve the core problem, to procurement assessment, talent needs, for the foundry bosses comprehensive interpretation. Help you accurately determine whether to introduce this technology, enhance enterprise competitiveness, realize the transformation and upgrading, seize the market opportunities!

    3D打印砂型鑄造,傳統(tǒng)鑄造廠老板必看最先出現(xiàn)在三帝科技股份有限公司。

    ]]>
    In the traditional foundry industry, sand mold making has always been a key link affecting productivity, cost and molding capability of complex structure castings. With the increasing market demand for high-precision, short-delivery and complex structure castings, the traditional manual molding and mold manufacturing methods have been difficult to meet modern manufacturing requirements. Sand 3D printers, as an advanced additive manufacturing technology, can directly print complex sand molds and cores without the need for molds, dramatically shortening the production cycle, reducing costs, and enhancing design freedom. In this article, we will discuss why traditional foundries should consider introducing sand 3D printing technology to enhance competitiveness, optimize production processes, and meet market demand for efficient and accurate casting. The following is written exclusively for foundry owners, and we hope it will inspire you.

    As a foundry owner, do you encounter this situation often?

    --Customers want to do small quantities of trial parts, do a metal mold to 200,000, the result of the order is only 50 pieces, a calculation found that the mold cost more than the money earned, can only give up the order!
    --The customer had an order for an aerospace part with honeycomb structure, and the traditional sand core assembly error was bigger than the part size, so it was a big headache to stare at the scrapped casting!
    --Competitors with 3D printing took a well-known automotive battery pack orders, their own offer is lower than others 30% or did not win the bid, and finally inquired about the delivery of people faster than us 2 months, very helpless!

    --Customers do not move to change the design of the warehouse piled up more than 300 sets of scrap molds, checking the accounts found that the mold inventory occupied half a year of profit, which is too painful to taste!

    --Customers sent a complex structure of the pieces over, and said that the price is not a problem, an assessment found that the traditional casting process can not be done, looking at such a high value-added orders can only be given up!

    Below we help all bosses one by one to sort out clearly, an article to let you fully understand the 3D printing sand casting technology!

    What is sand 3D printing?

    Sand 3D printing is a relatively new technology, simply put, is like building blocks, with special materials layer by layer "pile" out of the casting sand.

    In the past, the traditional method of making sand molds may need to make molds first, and then use the molds to shape, the process is more complicated, and if you want to make some sand molds with very strange and complex shapes, it will be particularly difficult and costly. But sand 3D printing is different, it works with a 3D model in your computer. You input the data of the 3D model of the designed casting into the 3D printer, and the printer will, according to the shape and structure of the model, put special sand or sand-like materials, according to the layer by layer in a precise way and bonded up, just like using countless thin "sand pieces" gradually built into a complete sand mold. In this way, no matter how complex the shape, as long as it can be designed in the computer, it can be printed out, and the speed is quite fast, and do not need to make complex molds like the traditional method, can save a lot of time and cost it.

    Principle of Sand 3D Printer

    Sand 3D printing is usually done usingBinder Jetting (BJ)The basic principle is as follows:

    1. spread sand: The printer spreads a specific casting sand (e.g. silica sand, ceramic sand or coated sand) evenly over the printing platform.
    2. spray binder: The spray nozzles precisely spray the binder according to a computer model (CAD data) to bond the sand grains in a specific area.
    3. pile up repeatedly: The platform is lowered, sand is spread again and the binder is sprayed, curing and molding layer by layer until the entire sand print is completed.
    4. reprocess: Remove unbonded loose sand, harden and clean the printed sand model, which can then be used for metal casting.

    What are the core problems addressed by 3D printed sand casting?

    The existence or birth of each technology must have its "mission". Commonly known as a solution to a particular problem, to meet market demand, this is the value of its existence. Below we take a look at the sand 3D printing technology to solve the thorny problems encountered in the traditional casting, as follows:

    • Manufacture of complex shaped partsTraditional sand casting to manufacture complex shapes is difficult and costly, such as aviation engine blades inside the fine cooling channels, traditional processes are difficult to accurately mold. 3D printing sand based on digital models, can easily turn complex shapes into reality, from the dense concave, raised automotive engine block sand, to have a subtle biomimetic structure of the shell of the medical device sand, can be perfectly rendered.
    • long production lead timeTraditional sand casting need to go through a long process of designing molds, manufacturing molds, debugging molds, large-scale mold manufacturing cycle often exceeds a few months. 3D printing sand without mold production, directly according to the digital model printing, design modification is only required to operate the model on the computer, reprinting can be, can significantly shorten the production cycle. Such as research and development of new automotive engine block, the traditional casting mold scrap remake at least two weeks, 3D printing sand can be completed on the day of the new model printing, the next day can be put into casting.
    • Difficulty in cost controlTraditional casting mold manufacturing material waste is serious, the utilization rate of complex mold materials is less than 30%, and high labor costs. 3D printing sand on-demand printing, accurate sand, material utilization rate of more than 90%, reduce waste. High degree of automation of the printing process can reduce labor costs. Take a small foundry as an example, with an annual production capacity of 5,000 pieces of small pipe fittings castings, after the introduction of 3D printed sand, the material cost will be reduced by 150,000 yuan per year, and the labor cost will be cut by 200,000 yuan.
    • Low precision of castingsThe traditional sand mold due to mold wear, parting surface fitting error, casting size deviation often exceeds ±1mm, subsequent machining allowance, material waste, and prone to local loosening, sand entrapment and other defects, resulting in uneven mechanical properties of the casting. 3D printing of the sand model by the digital model of the precise drive, sand size accuracy of up to ±0.5mm, can achieve uniform compactness, to avoid uneven sand loose, and at the same time optimize the solidification process to significantly reduce shrinkage holes, shrinkage, to ensure reliable internal quality of the casting. At the same time, the solidification process is optimized, greatly reducing shrinkage holes and shrinkage loosening, and ensuring stable and reliable internal quality of castings.
    • High environmental pressureTraditional casting mold manufacturing produces a large amount of waste metal, waste plastic, sand processing waste sand piles up. 3D printing sand production, unused sand can be recycled and reuse, very little waste, and the printing process does not require a large number of chemical binders, reducing the emission of hazardous gases, and improve the workshop environment. According to statistics, after the adoption of 3D printing sand mold, the casting workshop waste emissions reduced by more than 80%, dust, harmful gas concentration of environmental standards.

    How does a foundry evaluate if they need to buy a sand 3d printer?

    The price of a sand 3D printer is not cheap (usually the larger the size the more expensive), to buy is relatively cautious, especially small and medium-sized foundries. In order to help bosses to assess whether there is a need to buy, we have specially organized the following some evaluation points, to give the boss of the traditional foundry a reference, and then according to their own situation to decide whether to buy:

    production requirement

    • Product complexity: If the foundry often produces complex shapes, castings with fine structure or internal channels, such as aero-engine blades, automobile cylinder blocks, etc., the traditional process is difficult to meet the requirements, sand 3D printer can play an advantage.
    • Production size and lot size: For small-volume, multi-variety casting production, sand 3D printers offer the flexibility to quickly switch products without the need to make molds, reducing costs and cycle time. However, for large-scale, single-species castings, traditional processes may be more cost-effective.
    • Delivery period requirementsThe sand 3D printers allow for shorter lead times and quicker order response if the customer has stringent lead times.

    cost-effectiveness

    • Investment in equipmentThe cost of purchasing a sand 3D printer, installation and commissioning costs, and maintenance costs need to be taken into account.
    • running cost: Includes printing materials, energy consumption, and labor costs. Compare with the traditional casting process and analyze the high and low long-term running costs.
    • potential gainConsider the potential benefits of using sand 3D printers in terms of improved product quality, shorter cycle times, and lower scrap rates.

    technical capability

    • Employee Skills: Evaluate how well your current employees know 3D printing technology and whether you need to train or recruit specialized talent.
    • Technical Support: To understand the technical support capability of the equipment supplier, including whether the services such as installation and commissioning, training and fault repair are timely and effective.

    market competition

    • Industry Trends: Keep an eye on your peers to see if they are already adopting sand 3D printing, and if competitors are already using it and gaining an advantage, foundries may need to consider purchasing it in order to remain competitive.
    • client needThe purchase of sand 3D printers can help to meet the needs of customers who want to see foundries adopting advanced technologies to improve product quality and productivity, as well as to increase their competitiveness in the marketplace.

    environmental requirement

    • If the local environmental protection requirements are strict, the traditional casting process is under great pressure in terms of waste sand treatment and exhaust gas emission, etc., sand 3D printers can help enterprises meet the environmental protection requirements due to the advantages of high material utilization rate and low waste.

    What kind of talent is needed for sand 3D printing?

    Considering that many traditional foundry enterprises may not be equipped with 3D printing sand casting related professionals, we have specially organized the position of workers need to have what aspects of the skills and usual job duties, so that factories in the recruitment of reference.

    Professional Requirements:

    1. Mechanical Engineering, Materials Science, Foundry Engineering, Additive Manufacturingand other related majors;
    2. Familiarity with sand 3D printing (Binder Jetting) technology and experience in operating related equipment is preferred;
    3. skillful useCAD, 3D modeling software (e.g. SolidWorks, AutoCAD, Magics, etc.), with basic data processing skills;
    4. Understand the casting process, familiar with sand material properties, post-treatment process and common casting defects analysis;
    5. Ability to maintain and troubleshoot equipment and independently solve common problems in equipment operation;
    6. Good teamwork skills, able to work closely with casting engineers and production team to optimize the production process;
    7. Strong learning ability to quickly grasp new technologies and a keen interest in the application of additive manufacturing in the foundry industry.

    Job Description:

    1. be in charge ofSand 3D Printerday-to-day operations, including equipment commissioning, print job execution and quality control;
    2. Process 3D printing data, including CAD model optimization, slicing and printing parameter settings;
    3. Supervise the printing process to ensure that the quality of the sand mold meets the casting requirements and that the necessary post-processing (e.g., cleaning, hardening, etc.) is performed;
    4. Responsible for the maintenance of equipment, troubleshooting and solving problems in the printing process to ensure stable equipment operation;
    5. Collaborate with the casting technology team to optimize the process of 3D printing sand molds to improve casting quality and production efficiency;
    6. Research and introduce new materials and processes to continuously improve the application of sand 3D printing in casting production;
    7. Responsible for in-house training of personnel on 3D printing technology to improve the overall technical level of the team.

    summarize

    In summary, sand 3D printing technology has brought many opportunities and changes for traditional foundries, which can effectively solve a series of thorny problems faced by the traditional casting process, such as the manufacturing of complex shaped parts, long production cycle, difficult to control the cost, poor casting accuracy and environmental protection pressure. Through a comprehensive assessment of production demand, cost-effectiveness, technical capabilities, market competition and environmental requirements, foundry owners can be more scientific and rational judgment whether to introduce sand 3D printer. Equipped with professional technical personnel, is to ensure that this technology in the foundry in the smooth landing, play the key to maximize performance.

    In the increasingly competitive foundry market, take the initiative to embrace new technologies, and actively make changes, may be able to seize the first opportunity to realize the transformation and upgrading of enterprises and sustainable development. For traditional foundries, sand 3D printing technology is not only a technology change, but also a breakthrough in the development of bottlenecks, enhance core competitiveness of the perfect opportunity. I hope that all foundry bosses can combine the actual situation of their own enterprises, fully weigh the pros and cons, to make the most suitable for the long-term development of the enterprise's decision-making, so that the enterprise in the tide of the times to ride the waves, sailing to a broader market blue sea.

    3D打印砂型鑄造,傳統(tǒng)鑄造廠老板必看最先出現(xiàn)在三帝科技股份有限公司。

    ]]>
    What core problem do sand 3D printers solve? This article tells you the truth http://www.ahjfzs.com/en/blogs/sand-3d-printers-solve-core-problems/ Sun, 12 Jan 2025 08:24:49 +0000 http://www.ahjfzs.com/?p=2083 Many foundries want to buy sand 3D printer but it is not very understanding of what it can solve the core problem, read this article you will be able to understand everything, you can make a preliminary guidance on whether to purchase equipment.

    砂型3D打印機(jī)解決了什么核心問題?這篇文章告訴你真相最先出現(xiàn)在三帝科技股份有限公司

    ]]>
    In modern manufacturing, casting process has been an important method to produce complex metal parts. However, the traditional casting process faces many challenges, such as the difficulty of molding complex structures, limited customized production, long production cycle, difficult cost control, unstable product quality and environmental issues. With the rapid development of 3D printing technology, sand 3D printers have emerged as a revolutionary tool to solve these problems. In this article, we will delve into how sand 3D printers have changed the foundry industry and analyze the multiple advantages they bring (what core problems they solve).

    1. Addressing the limitations of traditional casting processes

    Difficulty in molding complex structures 

    Conventional casting processes often face enormous technical difficulties and high costs when manufacturing sand molds of complex shapes. For example, aircraft engine blades usually have fine and complex cooling channels inside, the traditional process of manufacturing such molds is extremely difficult. The sand 3D printer through digital modeling and layer-by-layer printing technology, can easily achieve the manufacture of complex shapes of sand molds, greatly reducing the technical threshold and cost.

    Customized production is limited 

    With the rise of personalized consumption and niche markets, the demand for small-lot, customized castings is growing explosively. However, the traditional casting process, with its high mold opening costs and long customization cycle, is difficult to meet the market's rapid response needs. Sand 3D printers do not require molds and are able to quickly design and print sand molds according to customers' special specifications, shapes and performance requirements, greatly improving the flexibility and efficiency of customized production.

    2. Enhancing production efficiency and cost control

    long production lead time

    Traditional sand casting requires a lengthy process of designing the mold, manufacturing the mold, commissioning the mold, etc. The manufacturing cycle for large molds often exceeds several months. During the period may also be due to design changes or mold defects lead to rework, further extending the production cycle. Sand 3D printers do not need to make molds, directly according to the digital model printing, can significantly shorten the product development cycle, improve production efficiency.

    Difficulty in cost control

    In the traditional casting mold manufacturing process, the material waste is serious, and the material utilization rate of complex molds is less than 30%. In addition, from the molders to the molding workers, mold repair workers, the manpower investment is large, which further pushes up the cost. Sand 3D printer on-demand printing, accurate sand, material utilization rate of more than 90%. high degree of automation in the printing process, reducing the cost of manpower, significantly reducing production costs.

    3. Improving product quality

    Low dimensional accuracy

    Traditional sand mold due to mold wear, parting surface fitting errors and other issues, casting size deviation often exceeds ± 1mm, subsequent machining allowance, material waste. Sand 3D printer by the digital model precision drive, sand size accuracy up to ± 0.5mm or less, reducing the machining process, reducing costs.

    Uneven internal quality

    Traditional sand molds are prone to localized looseness, sand entrapment and other problems, resulting in uneven mechanical properties of castings, prone to cracks and other defects. Sand 3D printer can achieve uniform compactness, to avoid uneven sand loose, and at the same time, optimize the solidification process, significantly reduce shrinkage holes, shrinkage, to ensure stable and reliable internal quality of the casting, to enhance the performance and service life of the product.

    4. Environmental advantages

    Traditional casting mold manufacturing produces a large amount of waste metal, waste plastic, sand processing waste sand piles up. The annual capacity of 10,000 tons of castings of the factory, the annual emissions of waste sand more than 5,000 tons, high treatment costs and pollution of the environment. Sand 3D printer in the production, unused sand can be recycled and reuse, very little waste. In addition, the printing process does not require a large number of chemical binders, reducing the volatilization of harmful gases and improving the workshop environment.

    5. Reasons why foundries deserve sand 3D printers

    Improvement of production efficiency

    Sand 3D printer can quickly respond to market demand, especially suitable for frequent re-modeling of small batch products. It allows foundries to quickly meet customers' individual customization needs and improve customer satisfaction and market competitiveness. At the same time, the sand 3D printer supports mass production, which can print a large number of high-quality sand molds in a short period of time to meet the needs of large-scale production and improve production efficiency and yield.

    Reduced production costs

    Sand 3D printing technology directly prints sand molds without opening molds, thus greatly reducing the cost of opening molds, especially suitable for small batch and complex structure production needs. In addition, sand 3D printing equipment can be operated with only simple training, and does not require a lot of manpower synergy, which can effectively reduce the dependence on skilled workers, so that foundries can easily cope with the recruitment difficulties and expensive labor problems.

    Enhancing Product Quality

    Sand 3D printers are more accurate, such as the3DPTEKof 3D printing equipment, which means that the dimensional accuracy of castings is dramatically improved, the one-time pass rate of products is significantly increased, the scrap rate is reduced, and the foundry is allowed to utilize its resources more efficiently. At the same time, the 3D printed sand mold has better precision and surface quality, reduces the amount of grinding and finishing work, makes the production process cleaner, and improves product quality and process consistency.

    Optimization of production management

    With a compact body design, the sand 3D printer occupies a small area and is flexible to install, which is suitable for the different site layout requirements of small and medium-sized foundries. Modular production solutions can also support easy expansion of enterprises to achieve multi-machine linkage. Part of the sand 3D printer support digital monitoring system, business managers can monitor the production progress and equipment status in real time, to achieve a fully controllable production process, equipment operation data can be automatically stored to facilitate the optimization of production strategies.

    6. Concluding remarks

    The emergence of sand 3D printers not only solves many problems in the traditional casting process, but also brings unprecedented opportunities for the foundry industry. It provides foundries with strong competitiveness by improving production efficiency, reducing production costs, improving product quality and optimizing production management. With the continuous progress of technology, sand 3D printers will play an increasingly important role in the future of the manufacturing industry, promoting the foundry industry to a more efficient, more environmentally friendly and smarter direction.

    砂型3D打印機(jī)解決了什么核心問題?這篇文章告訴你真相最先出現(xiàn)在三帝科技股份有限公司

    ]]>
    Explore sandbox-free 3D printers http://www.ahjfzs.com/en/blogs/tan-suo-wu-sha-xiang-3d-da-yin-ji/ Tue, 24 Dec 2024 09:25:00 +0000 http://www.ahjfzs.com/?p=1940 This article explores sandbox-less 3D printers and how they can provide dimensional flexibility, high accuracy, cost-effectiveness, and design freedom from the limitations of traditional sandboxes to improve manufacturing efficiency. At the same time, it provides readers with an understanding of the innovative value and growth potential of sandbox-less 3D printers in the foundry sector.

    探索無砂箱3D打印機(jī)最先出現(xiàn)在三帝科技股份有限公司。

    ]]>
    This article explores sandbox-less 3D printers and how they can provide dimensional flexibility, high accuracy, cost-effectiveness, and design freedom from the limitations of traditional sandboxes to improve manufacturing efficiency. At the same time, it provides readers with an understanding of the innovative value and growth potential of sandbox-less 3D printers in the foundry sector.

    Why is it called a sandbox-less 3D printer?

    The boxless 3D printer is so named because it eliminates the use of a traditional box in the sand 3D printing process, significantly differentiating it from conventional sand 3D printers. Here's more about it from a variety of perspectives:

    The role and limitations of traditional sandboxesSandboxes are an indispensable part of the traditional sand casting process and some traditional sand 3D printing techniques. It is used to hold the sand, provide molding space for the sand model, ensure that the sand maintains a specific shape during the molding process, and ensure the integrity of the sand model during transportation and box closing. However, the fixed size of the sand box limits the size of the sand mold that can be produced, and the production and maintenance costs are high. For the complex structure of the sand mold, the sand box is difficult to design and manufacture, and it may also affect the heat dissipation and air permeability of the sand mold, which may affect the quality of the castings.

    How sandless box 3D printers work: The sandbox-less 3D printer adopts sandbox-less flexible area molding technology, in which abrasive and binder are stacked and molded layer by layer by the nozzle directly on the worktable. The equipment has a precise sand spreading system, which can evenly spread the sand material in the printing area, and the nozzle accurately sprays the binder according to the model cross-section information, so that the sand particles are bonded to form the sand shape layer by layer. In this process, there is no need for a sand box to provide molding space and constraints, which greatly improves printing flexibility and freedom.

    Basis of namingThe naming of the 3D printer directly reflects its core technical feature, which is that it is free from the constraints of the traditional sand box, creating a new mode of sand 3D printing. This naming scheme is simple and clear, highlighting the essential difference with the traditional sand 3D printing equipment, and emphasizing its unique advantage of realizing high-precision and high-efficiency manufacturing of sand patterns without the assistance of a sand box during the printing process.

    Sandless Box 3D Printer vs. Traditional Sand 3D Printer

    There is a clear difference between the working principle of a boxless 3D printer and that of a traditional sand 3D printer. Traditional sand 3D printers rely on a fixed sand box to define the molding space, and rely on the sand box to provide partial support, and the print path is limited by the sand box; while sand box 3D printers use flexible area molding technology, expanding the printing platform on demand, breaking through the size limitations, and supplying the sand and binder with greater precision, and adjusting the internal sand buildup and binder injection to provide support, so the print path is more freely and flexibly planned, and it can effectively improve the printing efficiency and sand quality. It can effectively improve the printing efficiency and the quality of the sand mold.

    3dptek-J4000 Sand Mold 3D Printer
    Large-size sandbox-less 3D printer: 3DTEPK-J4000

    Prospects for sandbox-less 3D printers in the foundry sector

    The development of sandbox-free 3D printers in the foundry field is very promising, mainly in the following aspects:

    Technological innovation and breakthroughs

    Sandbox-free 3D printers continue to realize technological innovations, such as SANDI's 3DPTEK-J4000 Adoption of sandbox-less flexible area molding technology, can be customized to expand the printing platform, the maximum molding 4 meters of sand, to meet the production needs of 10 meters + level, breaking through the traditional casting equipment size limitations, for the manufacture of large and complex castings to provide the possibility of.

    Significant cost advantages

    On the one hand, the cost of ownership is reduced, as the price of 4-meter and larger boxless 3D printers is comparable to that of 2.5-meter machines, allowing companies to obtain larger sizes of abrasive molds at a lower cost per unit. On the other hand, material waste is reduced, as boxless 3D printers allow precise use of materials such as sand and binder, reducing production costs.

    Strong growth in market demand

    Aerospace, automotive, energy power and other fields of large, complex, high-precision castings demand continues to rise. For example, the manufacture of aircraft engine components, automotive engine block, etc., sandless 3D printers can meet the high-performance requirements for castings in these fields, the market potential is huge.

    Significant increase in design freedom

    The sandless box 3D printer can manufacture complex geometric shapes and cavities that are difficult to achieve by traditional methods, realizing parts integration and lightweight design, providing more space for product innovation and helping to improve product performance, reduce costs and enhance the market competitiveness of enterprises.

    Significant increase in productivity

    Compared to traditional mold making methods, sandbox-less 3D printing of sand molds or cores takes only a few hours to a few days, dramatically shortening the development and production cycle of new products, helping manufacturers respond faster to changes in market demand, and improving productivity and economic efficiency.

    Superior environmental performance

    Sandless 3D printers use materials on demand, reducing waste and disposal costs of leftover materials, and some of the equipment can use environmentally friendly materials and binders, which reduces environmental pollution, meets the requirements of sustainable development, and helps foundry companies to meet the increasingly stringent restrictions of environmental regulations.

    Deepening Industrial Integration

    The integration of sand box 3D printer and foundry is deepening, enterprises through mergers and acquisitions of foundries and other ways to open up the "3D printing + casting" process, to provide the whole industry chain overall solution, and promote the foundry industry to the green, intelligent, high-end direction of development.

    探索無砂箱3D打印機(jī)最先出現(xiàn)在三帝科技股份有限公司。

    ]]>
    国产人妻精品一区二区三区不卡 | 日本在线不卡一区 | 成人午夜视频在线观看 | 爱情岛论坛亚洲入口 | 欧美 亚洲 另类 激情 另类 | 先锋成人av | 日韩av一区二区三区在线观看 | 日韩色图在线观看 | 欧美黄色免费视频 | 免费超碰在线 | 欧美日韩三 | 青草综合| 国产成人一区二区三区免费看 | 亚洲欧美日韩图片 | 成人高潮片免费视频 | 国产高清毛片 | 九九热精品视频在线播放 | 中文字幕在线观看一区二区 | 胸大被男同桌强解开胸罩床吻 | 欧美性猛交富婆 | 欧美视频亚洲 | 第一次处破女h圆房~h嗯啊 | 欧美国产激情 | 公妇乱淫100集 | 搡8o老女人老妇人老熟 | 打美女白嫩光屁屁视频 | 亚洲精品精品 | 久久精品免费观看 | 一边摸一边抽搐一进一出视频 | 伊人天天干 | 开心激情播播网 | 伦理《禁忌6》 | 国精产品一区一区三区有限在线 | 亚洲av无码久久精品色欲 | 九九99久久 | mm131视频| 久久久久久黄 | 午夜精品久久久久久久 | 91美女精品网站 | free女性xx性老大太 | 爱情岛论坛亚洲入口 | 色一区二区 | 日韩免费看 | 少妇精品一区二区 | 一线毛片 | 高h乱l高辣h文短篇h | 手机看片1024你懂得 | 午夜欧美视频 | 高清一区二区 | 日韩黄色免费 | 久久不卡视频 | 六月婷婷激情 | 日本免费在线观看 | 日本学生初尝黑人巨免费视频 | 91精品久久久久久综合五月天 | 日韩综合在线观看 | 日韩精品人妻中文字幕 | 丝袜在线视频 | 无码人妻精品一区二区50 | 偷偷在线观看免费播放电视剧大全 | 91久| 黄色三级小说 | 欧美色亚洲 | 边做边爱视频 | 绿帽社区 | 一级黄色片一级黄色片 | 97国产精品 | 中文字幕一区二区三区四区 | 亚州男人天堂 | 久久丫精品忘忧草西安产品 | 无码人妻久久一区二区三区蜜桃 | 精品国产91 | 1769国产精品视频 | 久操资源网 | 青青视频网 | 鬼六终极篇之镣铐女犯人第二部 | 色婷婷丁香 | 黄色91在线观看 | 精品国模 | 女生抠逼视频 | 久久久久久黄色 | 日韩精品成人免费观看视频 | 亚洲电影一区二区三区 | 最好看的2019年中文在线观看 | 哺乳期给上司喂奶hd | 精品久久久久久中文字幕人妻最新 | 国产91网| 亚洲精品视频一区二区 | 日韩综合在线观看 | 香蕉视频免费在线观看 | 激情五月综合 | 国产超帅gaychina男同 | 无码人妻丰满熟妇精品区 | 日本最黄视频 | 99自拍 | 亚洲国产成人91精品 | 亚洲精品视频观看 | 久操这里只有精品 | 久久久国产精华液 | 黄瓜污视频 | 一边吃奶一边摸做爽视频 | 沈芯语老师家访麻花视频 | 日本三级日本三级日本三级极 | av在线亚洲天堂 | 校园激情av | 国产草草| 一本一道波多野结衣一区二区 | 一本色道久久综合熟妇 | 免费99精品国产自在在线 | 国产成人精品无码免费看夜聊软件 | 影音先锋男| 美女主播福利视频 | 精品人妻一区二区三区换脸明星 | 久久爱99 | 男女那个视频 | 第一次处破女h圆房~h嗯啊 | 国产美女免费视频 | 日韩精品色哟哟 | 操操操免费视频 | 亚洲人精品 | 成人网视频 | 国产清纯在线 | 538在线精品视频 | 欧美日韩激情视频 | 姐姐8免费完整高清电视剧在线看 | 女人的天堂av在线 | 青草综合 | 国产在线视频自拍 | 国产精品毛片久久久久久 | 一本大道久久东京热无码av | 午夜激情影视 | 操欧美女人| 亚洲伦乱 | jk半裸无内裤露全屁股 | 蜜臀av网| 国产一区二区三区四区在线观看 | 欧美激情视频一区二区 | 国产精品久久久久久网站 | av不卡在线看 | 国产一级黄色大片 | 免费看黄色网 | av网站推荐| 日韩在线观看成人 | 3d动漫精品h区xxxxx区 | 泡妞18视频 | 国产精品扒开腿做爽爽爽视频 | 水果派解说av | 精品人妻少妇嫩草av无码 | 成人免费视频国产免费麻豆 | 九九热这里都是精品 | 97精品人妻一区二区三区 | 国产成人亚洲精品自产在线 | 精品人妻少妇嫩草av无码 | 成人午夜精品 | 亚洲欧美国产毛片在线 | 毛片一区二区 | 国产美女免费看 | 日本黄色大片在线观看 | mm131丰满少妇人体欣赏图 | 黄色一级视频免费观看 | 中文字幕乱码人妻无码久久 | 考逼视频| 精品久久久久久中文字幕人妻最新 | 麻豆视频免费观看 | 粉嫩在线 | 人妻少妇被猛烈进入中文字幕 | 轻点呻吟耸动炕上被窝 | 国产成人综合网 | 操p视频| 成年人av| 91丨九色丨蝌蚪丨少妇在线观看 | 无码人妻一区二区三区在线 | 午夜在线精品 | gogo亚洲国模私拍人体 | 久久免费成人 | 超碰色人阁 | 国产精品久久精品 | 激情五月综合 | 夜夜爽爽 | 一边摸一边抽搐一进一出视频 | 美女脱衣服的网站 | 高h乱l高辣h文短篇h | 天天干夜夜干 | 性淫bbwbbwbbw| 久久午夜影院 | 在线国产区 | 91小视频| 香蕉视频免费在线观看 | 日本久久精品视频 | 国产成人亚洲综合 | 亚洲色图欧美色 | 看动漫的软件 | 高h乱l高辣h文短篇h | 亚洲视频久久 | 欧美日韩www | 成人av免费观看 | 五月天激情婷婷 | 黄站在线观看 | 久久国产精品波多野结衣av | 成人高潮片免费视频 | 日韩激情影院 | 精品人妻少妇嫩草av无码 | 陪读庥麻张开腿让我爽了一晚播放 | 两个男人躁一个女人免费视频 | 小泽玛利亚一区二区三区视频 | 无码人妻丰满熟妇区96 | 国产在线观看 | 在线视频日本 | 操操操免费视频 | 在线播放亚洲 | www日本视频| 精品国产aⅴ一区二区三区东京热 | 91久久精品一区二区三区 | 日本护士毛茸茸体内精 | 亚洲激情视频在线 | 亚洲欧美国产一区二区 | 欧美日韩免费在线 | 动漫3d精品一区二区三区乱码 | 99久久婷婷国产综合精品电影 | 青青草免费在线视频 | 午夜视频在线观看免费视频 | 亚洲国产小视频 | 天堂网av在线 | 国产精品成人自拍 | 已满18岁免费观看电视连续剧 | 中文字幕首页 | 成人黄色网 | 日一日操一操 | 国产91在线免费观看 | 国产高清免费在线观看 | 黄色三级网站 | 亚洲精品乱码久久久久久蜜桃 | 美女扒开粉嫩的尿口 | 激情五月综合 | 欧美激情在线观看视频 | 日韩成人精品一区二区 | 妇女主任大腚耸动着 | 色婷婷精品国产一区二区三区 | 精品国产制服丝袜高跟 | 全黄裸片武则天一级 | 日本在线三级 | 女人自述被囗交过程 | 男人手机天堂 | 日本在线免费播放 | 免费看色 | 神马午夜888 | www.天堂av | 亚洲精品国产精品乱码不卡√香蕉 | 骚虎免费视频 | 国产一区二区三区四区在线观看 | 韩国做爰三级在线观看 | 欧美va亚洲va | 北条麻妃一区二区三区免费 | 911美女片黄在线观看游戏 | 色婷婷欧美 | 欧美一区二区三区四区五区 | 欧美午夜精品一区二区三区 | 禁漫天堂导航 | 欧美色老太 | 天堂成人在线 | 一边亲嘴一边做好爽视频 | 高h乱l高辣h文短篇h | 91精品久久久久久综合五月天 | 胸啊嗯~下面出水了 | 91呦呦| 午夜视频福利 | 在线99| 国产极品视频 | 夜夜狠狠 | 六月色婷婷 | 欧美日韩影院 | 操操操操操操操操 | 中文字幕福利视频 | 成人午夜视频在线观看 | 日本少妇videos高潮 | 99国产精品 | 乳色吐息免费观看 | 九九一级片 | 天天干在线播放 | 欧美a级片在线观看 | 婷婷在线看 | 亚洲日本免费 | 不穿衣服的网站 | 校园激情av| 日日夜夜综合网 | 一区二区三区黄色片 | 另类小说第一页 | 男女做爰猛烈叫床爽爽免费网站 | 亚洲精品第二页 | 丁香五婷 | 婷婷综合网站 | av女人的天堂 | 日本亚洲一区二区 | 欧美日韩五区 | 国产网友自拍视频 | www.激情五月 | 成年人网站免费观看 | 激情内射亚洲一区二区三区爱妻 | 色福利网 | 我要看一级黄色片 | 第四色视频 | 天天干,天天操 | 色婷婷婷婷 | 性久久久| 一区二区三区在线 | 午夜电影免费看 | 碧蓝之海动漫在线观看免费高清 | 亚洲天天看 | 日本性网站 | jizzjizz视频| 看动漫的软件 | 无码一区二区三区在线观看 | 黄色三级电影网站 | 法国空姐在线观看免费 | 欧美a级片在线观看 | 国产精品2020 | 曰曰av日日av| 91小仙女jk白丝袜呻吟 | 亚洲爱色| 性少妇mdms丰满hdfilm | 国产男男gay体育生网站 | 久久丫精品忘忧草西安产品 | 国产主播在线观看 | 麻豆短视频 | 少妇裸体挤奶汁奶水视频 | 成人动漫一区二区三区 | 妇女主任大腚耸动着 | 免费观看一区二区 | 一本大道久久东京热无码av | 91视频在线观看 | 中文字幕日本在线观看 | 国产成人亚洲精品自产在线 | 美女露100%胸无遮挡免费观看 | 国产免费一区二区 | 娇妻被恩人征服h版 | 天天躁日日躁aaaaxxxx | 丰满人妻av一区二区三区 | 天天夜夜人人 | 看动漫的软件 | 欧美人狂配大交3d | 韩国做爰三级在线观看 | 黄色一级生活片 | 国产日本欧美在线 | 日韩精品在线观看免费 | 色呦呦国产精品 | www.伊人网| 91国产一区 | 国产在线观看一区二区三区 | 四虎在线免费 | 天堂岛av | 99riav在线 | 日韩黄色免费 | 欧美成人午夜 | 国产欧美日韩综合精品一区二区三区 | 福利视频一区二区三区 | 视频二区中文字幕 | av网址观看 | 夜夜爽夜夜爽 | 欧美成人精品一区二区 | 日韩色综合 | 夜夜爽夜夜爽 | 国产三级大片 | 亚洲电影中文字幕 | 婷婷丁香久久 | 久久久久91 | 国产a级网站 | 精品国产aⅴ一区二区三区东京热 | 亚洲网站免费看 | 两个男人躁一个女人免费视频 | 奇米影视亚洲 | 美女露乳网站 | 强伦人妻一区二区三区 | 精品人妻一区二区免费视频 | fvreexⅹ性欧美hd护士 | 日本xxxxxⅹxxxx69 | 91浏览器在线观看 | 久久影视中文字幕 | 色婷婷精品国产一区二区三区 | 久久91| 日韩av一级 | 丁香花电影版免费观看第二季 | 幸福宝在线观看 | 日韩精品电影在线 | 99re热这里只有精品视频 | 亚州av在线 | 日韩激情在线观看 | 日韩裸体视频 | 国产日韩欧美视频在线观看 | 扒开腿| 91刺激| 18国产免费视频 | 午夜电影免费看 | 天海翼香汗女教师在线播放 | 国产又爽又黄免费视频 | 91在线一区二区 | 精品午夜福利视频 | 波多野42部无码喷潮在线 | 法国空姐在线观看免费 | 黄色激情视频在线观看 | 一线毛片 | 国产99精品视频 | 亚洲一区在线观看视频 | 国产91清纯白嫩初高中漫画 | 国产成人精品无码免费看夜聊软件 | 校草憋尿揉捏裆部呻吟小说川 | 国产猛男猛女超爽免费视频 | 88国产精品欧美一区二区三区 | 中文字幕日本人妻久久久免费 | 日本免费在线观看 | 91久 | 免费靠逼视频 | 欧美一级爱爱 | 99国产精品| 妖精视频一区二区 | www.羞羞漫画 | 精品国产一 | 成年人激情网 | 国产精品污www在线观看 | 亚洲免费三区 | 女人高潮叫床骚话污话 | 国产无套丰满白嫩对白 | 91久久超碰 | 九九精品视频在线 | av在线试看 | 不卡的av在线免费观看 | 一级性视频 | 国产一区二区毛片 | 免费黄网址 | 国产chinese中国hdxxxx | 韩国一级电影 | 91精品一区二区 | 成人一区二区在线观看 | 孕妇疯狂做爰xxxⅹ 免费成人美女女 | 欧美伦交| av色婷婷 | 欧美aa视频| 香蕉福利视频 | 后进极品美女圆润翘臀 | 精品久久久久久中文字幕人妻最新 | 国产经典一区二区三区 | 午夜国产片 | 香蕉久久网 | 中文av电影 | 精品国产人妻一区二区三区 | 91精品婷婷国产综合久久 | 69免费视频 | www.天天干.com | 最新高清无码专区 | 成年人免费小视频 | 秋霞理论电影网 | 日本久久精品视频 | 99re热这里只有精品视频 | 久操视频在线观看 | 水果派解说av | 九七超碰在线 | 蜜桃精品一区二区 | 欧美少妇视频 | 中文字幕黄色 | 大香焦久久 | 国产一区二区三区四区在线观看 | 亚洲网站免费看 | 中文字幕一区二区三区四区视频 | 国产精品99精品无码视 | 荫蒂被男人添免费视频 | 天天干天天色天天射 | 姐姐在线观看动漫第二集免费 | 日本高清不卡视频 | 欧美大片在线看免费观看 | 黄色亚洲视频 | 日韩av在线观看免费 | 资源av | 黄骗免费网站 | 91浏览器在线观看 | 无码一区二区三区在线观看 | 靠逼网站在线观看 | 色偷偷亚洲 | 欧美亚洲影院 | 国产精品国产三级国产aⅴ浪潮 | 国产1区在线 | 久久久精品网站 | 五月天激情啪啪 | 16一17女人毛片 | 在线99 | 亚洲最新偷拍 | 日本r级电影在线观看 | 亚洲黄色片 | 玖玖在线播放 | 成人伊人网 | free女性xx性老大太 | 日韩精品电影在线 | 国产最新在线 | 嫩草嫩草嫩草嫩草嫩草嫩草 | 污污免费网站 | www网站在线免费观看 | 国产一区二区精品丝袜 | 91av在线播放 | igao在线视频| 欧美性做爰猛烈叫床潮 | 丰满少妇一区二区三区专区 | 亚洲欧美国产毛片在线 | av激情网站 | 欧美激情一区二区三区 | 日韩欧美视频 | 亚洲精品大全 | 欧美日韩网 | 日产精品久久久一区二区 | 丰满的寡妇hd高清在线观看 | 女人18片毛片60分钟翻译 | 国产夫妻性爱视频 | 五月天一区二区三区 | 韩国一级电影 | 3d动漫精品啪啪一区二区 | 四色在线观看 | 国产一级高清 | 射黄视频 | 亚洲黄色小视频 | 日本免费一区二区视频 | 国产又爽又黄免费视频 | 韩日一区二区 | 国产猛男猛女超爽免费视频 | 天天射天天爽 | 无码人妻丰满熟妇精品区 | 九七超碰在线 | 日韩伦理视频 | 欧美a大片 | 成年女人免费视频 | 碧蓝之海动漫在线观看免费高清 | 成人av免费观看 | 一区二区三区在线 | 奇米四色网 | 蜜桃视频无码区在线观看 | 中国hd高清xxxxvideo | www.天堂av | 日本亚洲一区二区 | 欧美xxxxx自由摘花 | av一区二区三区四区 | 榨精tickle丨vk全部脱 | 午夜18视频在线观看 | 男人av的天堂| 国产黄色小视频在线观看 | 欧美成人一级视频 | av综合一区| 欧美浮力影院 | 16一17女人毛片| 亚洲女人的天堂 | 快播一级片 | 女教师被调教到性隶 | 青青草视频污 | 国产青青青 | 精品久久久无码中文字幕 | 天天看夜夜看 | 一级国产视频 | 日韩欧美大片 | 激情偷乱人成视频在线观看 | 久久久午夜精品 | 成年人视频免费在线观看 | 男人舔女人逼动态图 | 国产伦精品一区二区三毛 | 国产伦精品一区二区三区四区免费 | 日本学生初尝黑人巨免费视频 | 中文永久免费观看 | 制服av网 | 将军含着她粉红的乳尖 | 惩罚揉捏小豆豆不让高潮 | 国产精品久久久久国产a级 欧美黑人粗大 | 国产精品久久免费视频 | 豆花在线观看 | 森泽佳奈在线播放 | 日本打屁股网站 | 无码人妻精品一区二区50 | 女m被s玩胸虐乳哭着求饶 | 国产成人免费电影 | 国产精品4 | 水果派解说av | 亚洲自拍偷拍图 | 综合在线观看 | 第一次破处视频 | 欧美国产日韩一区 | 婷婷在线综合 | 伊人宗合| 成人午夜精品 | 快猫成人短视频 | 激情av网站| 韩国三级电影在线观看 | 欧美视频久久久 | 亚洲精品欧美日韩 | 精品国产a | 亚洲一区二区在线 | 亚洲三级黄色片 | 秋霞国产午夜精品免费视频 | 在线观看国产网站 | 香蕉福利视频 | 欧美精品久久96人妻无码 | 午夜人体 | 日本亚洲视频 | 日本人做爰全过程 | 中文字幕第一区 | 九色tv| 国产精视频 | 亚洲欧美日韩高清 | 欧美啪视频| 五月天综合激情网 | 中文字幕日本人妻久久久免费 | 欧美日韩精品一区二区三区视频播放 | 国产一区二区三区免费观看 | 色猫咪av | 欧美性一级 | 欧美裸体女人 | 亚洲av成人精品日韩在线播放 | 成人黄色网 | 国产午夜精品一区二区理论影院 | 国产在线一区二区三区四区 | 日韩成人免费在线视频 | 侵犯小太正gay初精视频 | 亚洲精品免费在线观看 | 无码人妻久久一区二区三区蜜桃 | 用力挺进新婚白嫩少妇 | 日韩精品在线免费 | 午夜爽爽视频 | 91操碰| 国产裸体永久免费视频网站 | 中国女人内射6xxxxx | 天天操天天插 | 精品免费一区二区三区 | 久久福利影视 | 无码人妻丰满熟妇区毛片18 | 深夜福利一区二区三区 | 久久精品国产亚洲a | 国产一区二区三区免费观看 | 黄色成人免费网站 | 娇bbb搡bbbb揉bbbb | 中文字幕在线播出 | 米奇影院7777免费观看高清完整喜剧电影 | 亚洲午夜一区 | 亚洲人xxxx | 国精产品一区一区三区有限在线 | 老妇女毛片 | 精品伦精品一区二区三区视频密桃 | 色七七桃花影院 | 修仙淫交(高h)h文 | 久久av影视 | 欧美香蕉网 | 男女做爰猛烈叫床爽爽免费网站 | 欧美一区二区三区四区五区 | aaa在线 | 日本少妇性高潮 | 手机黄色网址在线观看 | 成人av软件| 国产伦子伦对白视频 | 亚洲自拍偷拍图 | 五月天社区 | 黄色成人av | 182tv午夜福利在线观看 | 午夜电影一区二区三区 | 婷久久 | 欧洲一区二区在线观看 | 久久久成人免费视频 | 精品视频免费看 | h视频在线免费观看 | 欧美三级视频 | 国产精品178页 | 精品人妻在线视频 | 91久| 青青精品 | 高清乱码毛片 | 免费国产在线视频 | 无码人妻一区二区三区在线 | 久久99国产精品 | 宝贝乖高潮给我看h | 日韩激情在线观看 | 成人一区二区在线观看 | 动漫3d精品一区二区三区乱码 | 免费视频亚洲 | xxx泡妞视频 | 国产一区二区波多野结衣 | 欧美日韩激情在线 | 黄频在线免费观看 | 又粗又猛又爽又黄的视频 | 91色国产 | 成人在线观看网站 | 我要看一级黄色片 | 久久人体视频 | 国产青青视频 | 久久视频一区 | 国产欧美日韩综合精品一区二区三区 | 91精品免费 | 中文字幕日本在线观看 | 美女福利在线观看 | 日韩视频在线观看视频 | 毛片一区二区 | 午夜一区二区三区免费观看 | 公妇乱淫100集 | 国产一线在线观看 | 美女扒开腿让男人操 | 少妇裸体挤奶汁奶水视频 | 亚洲国产精品二区 | 狠狠操av | 久久女同 | 久久大陆| 欧美裸体视频 | 草草影院ccyycom | 国产在线一区二区三区四区 | 夜夜爽夜夜爽 | 老司机午夜影院 | 亚洲综合影视 | 高跟鞋和丝袜猛烈xxxxxx | 日韩另类在线 | 日韩无码精品一区二区三区 | 欧美浮力影院 | 国产在线一区二区三区四区 | 在线99| 国产一区二区三区日韩 | 亚洲女人网| 日本人做受免费视频 | 天天射天天爽 | 国产成人一区二区三区免费看 | 中文字幕一区二区av | 在线播放91灌醉迷j高跟美女 | 玖玖在线播放 | 日本特级淫片 | 国产高清免费在线观看 | 免费杨幂裸体视频 | 粉嫩在线 | 爱情岛论坛成人av | 国产在线一区二区三区四区 | 五月丁香啪啪 | 免费在线一级片 | 我的奴性朱竹清便器精厕贱奴视频 | 亚洲精品视频免费 | 饱满乳沟h揉捏 | 久久桃花网| 成人网视频 | av性天堂网| 视频网站在线观看18 | 国产精品4| 亚洲熟妇一区 | 亚洲爱色 | 天海翼香汗女教师在线播放 | 亚洲国产成人在线观看 | 亚洲精品欧美日韩 | 又粗又猛又爽又黄的视频 | 97干干干| 国产情侣av在线 | 青青精品| 日本黄色xxxx| spy3wc撒spy3wc撒 | 京香视频| 一区二区伦理片 | 少妇熟女高潮流白浆 | 日韩精品在线电影 | 好吊妞这里只有精品 | 丁香九月激情 | 性欧美精品男男 | 一级片黄色片 | 美女极度色诱图片www视频 | 日韩美女视频网站 | 一本一道久久a久久精品蜜桃 | 韩国大尺度边吃胸边摸田禹治 | 理论片高清免费理伦片 | 国产你懂的 | 久久免费激情视频 | 精品国产乱码久久久久久蜜臀网站 | 乱淫视频 | 污在线观看| 日本一区二区中文字幕 | 欧美色图亚洲激情 | 五月天激情影院 | 香港a毛片| 亚洲欧美国产一区二区 | 亚洲xx视频 | 国产免费观看视频 | 久久精品影视 | 午夜久久福利 | aa级片| 毛片大全 | 国精产品一区一区三区有限在线 | 免费看日产一区二区三区 | 女人做爰全过程免费观看美女 | 国产午夜福利一区 | 亚洲在线影院 | 手机看片欧美日韩 | 国产精品白虎 | 男女交性视频播放 | 182tv午夜福利在线观看 | 免费福利av| 日产精品久久久一区二区 | 美女极度色诱图片www视频 | 婷婷俺来也 | 制服丝袜中文字幕在线 | 久久免费高清视频 | 久久久久91| 亚洲精品大全 | 先锋成人av | 国产91极品 | 国产一区二区不卡在线 | 八戒,八戒电影在线观看 | 成年人网站在线免费观看 | 波多野吉衣毛片 | 欧美精品综合 | 瑟瑟视频网站 | 91亚色| 91亚洲一区 | 91美女精品网站 | 色福利网| 日本在线不卡一区 | 国产日韩欧美自拍 | 北条麻妃一区二区三区 | 日韩和的一区二区 | 3d动漫精品h区xxxxx区 | 伊人一区 | 欧美成人影片 | 精品国产91| 91美女片黄在线观看91美女 | 国内精品久久久久久久久 | 97国产精品 | 亚洲天堂2013| 日韩伦理在线播放 | 主人调教巨奴性奶牛警察 | 波多野42部无码喷潮在线 | 欧美日韩一卡二卡三卡 | 饥渴的少妇和男按摩师 | 六月婷婷网 | 免费99精品国产自在在线 | 中文字幕在线观看视频网站 | 亚洲精品乱码久久久久久蜜桃91 | 资源av | 午夜两性视频 | 亚洲综合干| 我的奴性朱竹清便器精厕贱奴视频 | 高h乱l高辣h文短篇h | 91国产一区 | 国产夫妻性爱视频 | 国产精品www色诱视频 | 欧美日韩一区二区三区在线视频 | www.日日日| 91在线免费视频观看 | 少妇邻居伦理2 | 97干干| 一级黄色片一级黄色片 | 一边吃奶一边摸做爽视频 | 日本r级电影在线观看 | 亚洲精品乱码久久久久久蜜桃 | 亚洲精品人人 | 午夜电影一区二区三区 | 天天干天天色天天射 | 惩罚揉捏小豆豆不让高潮 | 久久久黄色片 | 极品白嫩的小少妇 | 啪啪的视频 | 亚洲自拍偷拍图 | av免费观看入口 | 国产乱真实合集 | 国产精品福利小视频 | 又黄又爽的免费视频 | 精品人妻一区二区三区换脸明星 | 太粗太长岳受不了 | 亚洲视频免费观看 | 欧美老少交 | 日韩毛片在线免费观看 | 国内免费精品视频 | 亚洲午夜激情视频 | 欧洲色综合 | 牛牛影视免费观看 | 天天干夜夜干 | 免费的黄色网 | 男女车文 | 张起灵调教喷水沦为肉奴视频 | 精品一区在线视频 | 在线观看中文字幕网站 | 制服丝袜av在线 | 成人在线观看网站 | 99自拍偷拍 | 成人免费网站 | 淫男乱女视频 | 在线观看视频一区二区 | 激情成人综合网 | 老师胸乳裸露网站 | av激情网站 | 日韩一区二区精品视频 | 免费午夜视频 | 男人天堂综合 | 四虎在线网址 | 天堂成人在线 | 秋霞影院午夜丰满少妇在线视频 | 国产精品九九九九九 | 妇女主任大腚耸动着 | 草莓污视频 | 国产又黄又粗又猛又爽 | 尤物一区| 伊人av网 | 欧美高清大白屁股ass18 | 一级激情片 | 视频一区在线播放 | 一本久久久 | 欧美另类xxxx | 女攻总攻大胸奶汁(高h) | 亚洲欧美日本国产 | 一级黄色网址 | 四虎网站 | 久久精品视频网站 | 国产91热爆ts人妖系列 | 国产福利在线免费观看 | 亚洲一区在线观看视频 | 亚洲精品国产精品乱码不卡√香蕉 | 男女www视频| 搡8o老女人老妇人老熟 | 姐姐8免费完整高清电视剧在线看 | 波多野吉衣在线视频 | 欧美人性生活 | 好姑娘5免费观看全集 | 女人做爰全过程免费观看美女 | 女人床技48动态图 | 欧美日韩一区在线 | 97碰碰碰| 国产午夜精品一区二区理论影院 | 韩国午夜影院 | 国产伦子伦对白视频 | 91夫妻论坛 | 色婷婷丁香 | 天天干夜夜干 | 3d动漫精品啪啪一区二区 | 影音先锋国产在线 | 亚洲精品伦理 | 欧美黑人又粗又大的性格特点 | 亚洲一区二区三区在线免费观看 | 国产99页 | 免费av成人 | 欧洲亚洲一区二区 | 欧美毛片网站 | 天天精品视频 | 青娱乐国产在线 | 亚洲一区二区在线 | 欧洲精品一区 | 狠狠操狠狠操狠狠操 | 欧美丰满熟妇xxxx | 娇妻被邀上台玩多p | 亚洲女人网 | 中文字幕无码毛片免费看 | 18网站视频 | 丰满人妻一区二区三区免费 | 日韩免费在线观看网站 | 91麻豆成人精品国产免费网站 | 在线不卡免费av | 欧美激情xxx| 干干日日| 亚洲一区人妻 | 欧美日韩一二三四 | 搡8o老女人老妇人老熟 | 在线视频免费播放 | 日韩av手机在线看 | 国产一线在线观看 | 天天干夜夜艹 | 在线观看国产网站 | 米奇影院7777免费观看高清完整喜剧电影 | 欧美年轻男男videosbes | 宅男噜噜噜 | 影音先锋第一页 | 天天cao在线 | 污网址在线观看 | 亚洲av无码国产精品久久不卡 | 特级黄色一级片 | 亚洲视频久久 | 在线观看a级片 | 国产在线9| 中国熟老太另类 | 亚洲成人自拍 | 欧美午夜精品一区二区三区 | 国产久草视频 | 日本 奴役 捆绑 受虐狂 | 日日躁夜夜躁 | 亚洲狠狠操 | 中文字幕一区二区三区四区视频 | 亚洲精品一区二区三区蜜桃久 | 国产婷婷久久 | 四虎影视亚洲精品 | 香蕉成人网 | 用力插好舒服 | 亚洲久草视频 | 轻点呻吟耸动炕上被窝 | 男人插女人逼视频 | 无码人妻一区二区三区在线 | 成人爱爱| 日韩精品在线电影 | 免费杨幂裸体视频 | 欧美性猛交xxxx乱大交蜜桃 | 黄色片视频免费 | 姐姐在线观看动漫第二集免费 | 乱淫视频 | 久久亚洲国产成人精品性色 | 国产午夜精品一区二区 | av色婷婷| 最新视频在线观看 | 欧美日韩激情在线 | 日韩精品色哟哟 | 俄罗斯美女av | 已满18岁免费观看电视连续剧 | 国产盗摄一区 | 日本人妻丰满熟妇久久久久久 | 国产片淫乱18一级毛片动态图 | 男人舔女人逼动态图 | 色香蕉网 | 92看片| 男人av的天堂 | av电影在线免费观看 | 亚洲成人tv| 久久久黄色片 | 精品黑人一区二区三区国语馆 | 1级黄色大片 | 亚洲一区欧美一区 | 精品少妇 | 老司机精品导航 | 91视频a | 超级碰在线视频 | 精品无码一区二区三区 | 韩国少妇厨房做爰 | 91精品国产电影 | 榨精tickle丨vk全部脱 | 91资源在线| 两个男人躁一个女人免费视频 | 中文天堂在线资源 | 她享受粗啪滋嗯大爷轻点视频 | 娇bbb搡bbbb揉bbbb | 天堂成人在线视频 | 日本久久久久久久 | 碧蓝之海动漫在线观看免费高清 | 天天干夜夜干 | 色婷婷yy| 正在播放91 | 91日本在线 | 久久人人爱 | 欧美在线视频一区二区三区 | 亚洲精品精品 | 日韩精品成人免费观看视频 | 在线观看中文字幕网站 | 黄片毛片在线观看 | 草草视频在线 | 高跟鞋和丝袜猛烈xxxxxx | 福利第一页 | 黄色小说av | 欧美激情一区二区三区 | 亚洲蜜臀av乱码久久精品蜜桃 | 久久久亚洲一区二区三区 | 饭冈加奈子奶水哺乳2019年 | 91网站在线免费看 | av天堂一区二区三区 | 亚色网站| 国产成人精品无码免费看夜聊软件 | 蜜桃精品在线 | 97人妻人人澡人人爽人人精品 | 欧美老少交 | 免费av入口| 日韩天堂av | 香蕉网站在线观看 | 欧洲视频在线观看 | 丰满的寡妇hd高清在线观看 | 国产精品福利小视频 | 乳色吐息免费观看 | 97人妻人人澡人人爽人人精品 | 久久99久久久久久久久久久 | 永久免费av无码网站性色av | 精彩视频一区二区三区 | 九九热精品在线视频 | 女人做爰全过程免费观看美女 | 污污免费网站 | 精品国产一区二区三 | av一二三四| 午夜欧美激情 | 香蕉久久国产av一区二区 | 精东影视文化传媒 | 久久精品视频一区二区三区 | 免费黄色a级片 | 久久图库| ass高耸美乳裸体pics | 自拍偷拍在线播放 | 亚洲最大福利网 | 极品在线| 欧美在线色图 | 男人舔女人逼视频 | 精彩视频一区二区三区 | 国产偷人妻精品一区二区在线 | 午夜天堂精品 | 狠狠操av | 精品一区在线视频 | 成人av黄色 | 红桃视频国产精品 | 在线综合网 | 男男受被啪到高潮自述 | 水浒传三级艳史 | 国产三级大片 | 爽爽网| 久久久久一区二区 | 免费网站污 | 免费在线观看视频 | 极品美女开粉嫩精品 | 久久综合导航 | 少妇高潮一区二区三区99欧美 | 日日干天天射 | 女优一区| 全国男人的天堂网 | 手机在线看片一区二区 | 色哟哟日韩精品 | 亚洲av成人精品日韩在线播放 | 成人伊人网 | 成人午夜精品 | 极品在线 | 天码人妻一区二区三区在线看 | 久久精品99 | 亚洲欧美国产毛片在线 | 久久99久久久久久久久久久 | 免费看黄色的视频 | 亚洲黄色片 | 乱淫视频 | 婷婷深爱网 | 少妇高潮露脸国语对白 | www.涩 | 日韩精品福利 | 午夜美女福利视频 | 欧美a级片在线观看 | 国产欧美另类 | 精品少妇| 日本裸体视频 | 亚洲三级av| 一本大道香蕉在线视频 | 国产综合久| 扒开腿| 国产三级a | 美艳尤物h双性受1v1 | av网址观看 | 国产精品自拍偷拍视频 | 亚洲精品伦理 | 波多野结衣久久精品 | 精品午夜福利视频 | 麻豆久久久 | 国产色呦呦 | 久久久电影 | 亚洲国产精品麻豆 | 免费色播 | 性少妇mdms丰满hdfilm | 波多野结衣网址 | 久久国产精品影视 | 日韩视频在线观看免费 | 日韩诱惑 | 在线视频免费播放 | 欧美日韩一级二级 | 大香伊人久久 | 日韩国产一区二区 | 吊侵犯の奶水授乳羞羞漫画 | 欧美草比| 丰满人妻av一区二区三区 | 法国空姐在线观看免费 | 日韩中文在线观看 | 黄色大片网站 | 日韩精品一区二区亚洲av | 全国最大色 | 黄色免费入口 | 精品国产一区二区三 | 欧美裸体女人 | 天堂8中文在线 | 黄频在线免费观看 | 美国免费毛片 | 国产精品久久久久久网站 | 桃色av| 国产一级精品毛片 | 青娱乐国产盛宴 | 欧洲一区二区在线观看 | 在线看片你懂得 | 96视频在线观看 | 青草久久久 | 一本大道久久东京热无码av | 第一次处破女h圆房~h嗯啊 | 国产特级片 | 麻豆电影网站 | 婷婷深爱网 | 91在线看视频 | 中文字幕在线免费视频 | 日本福利在线 | 色99999 | 国产成人综合网 | 高清视频一区二区三区 | 嫩操影院 | 波多野结衣中文字幕在线播放 | 国产精品一区二三区 | 久草这里只有精品 | 日本美女啪啪 | 在线不卡的av | 好吊妞这里只有精品 | 日韩av在线观看免费 | 91色国产| 欧美a级片在线观看 | 日本天天操 | 丝袜脚精子18 | 尻穴视频| 国产三级电影网站 | 日本美女啪啪 | 爱爱15p| 爱草视频| 外国视频网站 | 精品国产aⅴ一区二区三区东京热 | 免费看黄色片网站 | 中文久久乱码一区二区 | 一区二区影院 | 九九一级片 | 六月婷婷在线 | 亚洲最大福利网 | 全彩本子h强制侵犯公交车痴汉 | 美国特级片 | 欧美日本三级 | 四虎成人网 | 精品国产制服丝袜高跟 | 久久女同 | 在线观看欧美日韩 | 欧美激情一区二区三区 | 欧美色电影 | 男生操女生的 | 色女生影院 | 欧美伊人久久 | 男男h黄动漫啪啪无遮挡软件 | 国产网友自拍 | 日产精品久久久一区二区 | 日韩美女视频网站 | 欧美一区二区三区成人片在线 | 少妇高潮一区二区三区99欧美 | 日本黄色小说 | 亚洲欧美综合另类 | 女人自述被囗交过程 | 蜜臀av粉嫩av懂色av | 伦理《禁忌6》 | www.天堂av | 久久aaa | 亚洲天堂美女 | 国产超碰人人 | 舔花蒂| 污污动态图 | mm131丰满少妇人体欣赏图 | 女女h百合无遮涩涩漫画软件 | 国产在线三区 | 99热这里只有精品9 黄色一级视频免费观看 | 人妻精品一区 | 亚洲欧美日本一区 | 中文字幕综合 | 女同在线视频 | 98国产视频 | 日日夜夜噜噜噜 | 高跟鞋和丝袜猛烈xxxxxx | 午夜爽爽视频 | 《女心理师》免费观看完整版 | 伊人一区| 欧美aa在线 | 日本最黄视频 | 午夜影院福利 | 国产毛片毛片 | 91麻豆免费视频 | 色婷婷av一区 | 性色综合 | 欧美精品久久96人妻无码 | 一区二区三区美女 | 夜夜导航 | japanese久久| 小舞被调教成奶奴魅魔视频 | 久久久三级 | 超碰超碰97 | 亚洲成人91 | 99性视频 | 亚洲人成色777777老人头 | 国色天香一区二区 | 欧美午夜精品一区二区三区 | 免费性情网站 | 91精品91久久久中77777 | 一级国产视频 | 欧美瑟瑟 | 一本久久久| 亚洲国产精品麻豆 | 日本视频色 | 成人精品福利 | 亚洲高清视频在线 | 国产又粗又猛又爽 | 天堂资源在线播放 | 国产欧美精品一区二区 | 久久久国产精品黄毛片 | 欧美拍拍视频 | 日本a在线播放 | 偷偷在线观看免费播放电视剧大全 | 免费观看一区二区 | 男人肌肌桶女人肌肌 | 国产91国语对白在线 | 欧美精品久久久久久久久 | 亚洲av无码国产精品久久不卡 | 日本色综合 | 精品黑人一区二区三区国语馆 | 免费午夜视频 | 久久精品国产亚洲a | 国产又猛又黄又爽 | 精品国产一| 成人高潮片免费视频 | 国产91亚洲 | 少妇精品久久久久久久久久 | 少妇裸体视频 | 本田岬在线观看 | 亚洲高清视频在线 | 日本欧美一区二区三区 | 亚洲图片一区二区三区 | 99re6这里只有精品 | 亚洲美女视频 | 黄色片视频免费 | 亚洲人xxxx| 国产成人在线看 | 成年人网站在线 | 男叉女视频 | 二级片网站| 国产精品扒开腿做爽爽爽视频 | 一级黄色免费观看 | 色免费在线观看 | 韩国少妇厨房做爰 | 91www在线观看| 人人艹超碰| 操欧美女人 | 午夜久久 | 美女打屁股网站 | 久久久精品网站 | 午夜精品久久久久久久久久 | 亚洲国产精品二区 | 欧美成人午夜 | 亚洲精品欧美日韩 | 国产欧美a | www.伊人网 | 91黄瓜视频 | 精选视频 | 激情麻豆 | 福利视频一区二区三区 | 91超级碰 | 兄弟的妈妈免费观看电视剧完整版中 | 国产毛片视频 | 911美女片黄在线观看游戏 | 久草这里只有精品 | spy3wc撒spy3wc撒 | 性巴克成人免费网站 | 天天摸天天射 | 高h乱l高辣h文短篇h | 校园激情av | 兄弟的妈妈免费观看电视剧完整版中 | 中文字幕avav | 成人精品福利 | 国产又爽又黄免费视频 | 一区二区三区四区视频 | 欧美亚洲日本国产 | 一级片黄色片 | 欧美日韩五区 | 亚洲伦理在线观看 | 自拍在线 | 日韩伦理在线播放 | 久久亚洲国产成人精品性色 | 美女扒开粉嫩的尿口 | 欧美精品久久久久久久久 | 欧美人与牛zoz0性行为 | 欧美亚韩一区二区三区 | 国产欧美a| 超碰色人阁 | 国产三级三级三级 | 美女扒开腿让男人操 | 你懂的福利视频 | 免费成人深夜夜视频 | 国产做受视频 | 四虎永久免费地址 | 国产精品污www在线观看 | 免费超碰在线 | 欧美日韩一级大片 | 永久免费av网站 | 亚色在线 | av综合一区 | 成人黄色网 | 国产最新在线 | 99视频网| 尤物视频网址 | 国产黄a | 已满18岁免费观看电视连续剧 | a视频在线免费观看 | 亚洲精品自拍偷拍 | 四虎在线网址 | 天天躁日日躁aaaaxxxx | 黄瓜视频污在线观看 | 制服丝袜一区 | 短裙公车被强好爽h吃奶视频 | 久久精品免费观看 | 娇bbb搡bbbb揉bbbb | 肉肉视频在线观看 | 中文字幕在线免费视频 | 日韩精品片 | 精品国产a | 娇妻被邀上台玩多p | 色香蕉网| 欧美黄色三级 | 国产黄色三级电影 | aaaa毛片 | 女仆扒胸让人桶爽 | 99中文字幕在线观看 | 成人免费av网站 | www.羞羞漫画 | 日韩一二三四区 | 中文字幕一区二区三区av | 国产超碰人人 | 亚洲精品欧美日韩 | 综合另类 | 高h乱l高辣h文短篇h | 欧洲一区二区在线观看 | 欧美日韩三 | 日韩美女视频网站 | 日韩成人免费在线视频 | 久久精品久久久久 | 久久久久久黄色 | 日韩少妇高潮抽搐 | 免费看黄色网 | 欲色视频 | 国产精品1234 | 日韩一区二区精品视频 | 日本一区二区中文字幕 | 爱爱15p| 亚洲精品乱码久久久久久蜜桃91 | 日本久久久久久久 | 麻豆一区二区三区 | 麻豆少妇水电工003 亚洲精选一区 | 黄色爱爱视频 | 成人综合社区 | 五月激情综合 | 蜜桃av在线免费观看 | 久久免费成人 | 五月激情视频 | 久久精品av | 91在线不卡| 日本 奴役 捆绑 受虐狂 | 久久国产精品波多野结衣av | 91视频a| 成年人网站免费观看 | 欧美一级爱爱 | 国产精品www色诱视频 | 亚洲综合干| 深夜福利一区二区三区 | 张起灵调教喷水沦为肉奴视频 | 黄色三级网站 | 蜜桃视频无码区在线观看 | 老司机精品导航 | 99精品欧美一区二区三区 | 在线播放第一页 | 美女破处视频 | 人妻换人妻仑乱 | 国产va在线观看免费 | 成人免费网站 | 欧美日韩一级大片 | 95视频在线观看 | 免费在线观看亚洲 | 午夜欧美激情 | 曰曰av日日av | 制服丝袜中文字幕在线 | 我的奴性朱竹清便器精厕贱奴视频 | 黑人精品xxx一区一二区 | 91久久国产| 高h言情| 第一页在线 | 免费在线观看视频 | 国产精品福利小视频 | 寡妇毛片一区二区三区 | 91久久精品一区二区三区 | 女女h百合无遮涩涩漫画软件 | 韩国一级视频 | 蜜臀99| 国产在线一区二区三区四区 | 在线看一区二区 | 91麻豆免费视频 | 被无耻变态上司侵犯 | 五月天综合激情网 | 又粗又猛又爽又黄的视频 | 中文字幕日本人妻久久久免费 | www.涩 | 亚洲视频在线一区 | 她享受粗啪滋嗯大爷轻点视频 | 五月深爱婷婷 | 麻豆少妇水电工003 亚洲精选一区 | 无码人妻久久一区二区三区蜜桃 | 快色视频在线观看 | 她享受粗啪滋嗯大爷轻点视频 | 熟女人妻aⅴ一区二区三区60路 | 一级免费av | 天天干在线播放 | 久久久午夜精品 | 精品一区二区电影 | 美女主播福利视频 | 欧美亚韩一区二区三区 | 99精品欧美一区二区三区 | 国产乱人对白 | 成人一级视频 | 欧美年轻男男videosbes | 女人日批视频 | 空乘伦理hd | 亚洲福利视频导航 | 精品无码人妻一区二区三区品 | 91porny在线| 精品人妻一区二区免费视频 | 亚洲香蕉在线 | 一区二区三区美女 | 老师胸乳裸露网站 | hitomi一区二区在线播放 | 娇妻被邀上台玩多p | 无码人妻一区二区三区在线 | 欧美精品1区2区3区 国产三级91 | 国产成人免费电影 | 日韩亚洲一区二区三区 | 黄色高潮视频 | 精品人妻一区二区三 | 精品国产乱码久久久久久蜜臀网站 | 米奇影院7777免费观看高清完整喜剧电影 | 精品人妻少妇嫩草av无码 | 五月天色网站 | 农民工hdxxxx性中国 | 中文天堂在线资源 | 精品国产一区二区三 | 日韩网站在线 | 甘婷婷全部三级裸体电影 | 伊人av电影| 麻豆久久久 | 国产精品2020 | 欧美特黄aaaaaa | www.色网| 天天草天天 | 亚洲人网站 | 日韩久久在线 | 亚洲天天看 | 直男被扒开双腿狂小说 | 女人裸体添荫蒂视频 | 亚洲成人一级片 | 日日夜夜综合网 | 成人免费久久 | 人妻少妇被猛烈进入中文字幕 | 亚洲精品乱码久久久久久蜜桃欧美 | 成人午夜网址 | 黄色激情视频在线观看 | 黑人黄色一级片 | 久热伊人 | 亚洲第二页 | 蜜臀久久精品 | 亚洲视频免费观看 | 天天操狠狠干 | 我要看一级黄色片 | 90岁肥老奶奶毛毛外套 | 天天看夜夜看 | 亚洲欧美国产毛片在线 | 成人夜视频 | 亚洲久久成人 | 中文字幕一区电影 | 久久视频一区 | 在线日韩av| 乱淫视频 | 成人午夜网址 | 国产欧美a | 性久久久| 欧美成人影片 | 已满18岁免费观看电视连续剧 | 欧美三级不卡在线观看 | 国产精品视频不卡 | 五十路六十路 | 爱爱15p | 一级片久久久 | 黄网在线免费观看 | 国产视频一区在线 | 水浒传三级艳史 | 欧美日韩www | 女m被s玩胸虐乳哭着求饶 | 欧美一级射 | 国产毛片一区二区三区 | 中文字幕一区二区三区四区视频 | 中文字幕第十一页 | 国产99精品视频 | 男男上床视频 | www.成人av.com| 少妇流白浆 | 成人av在线看| 久久久一区二区 | 瑟瑟视频网站 | 麻豆视频网页 | 亚洲乱码视频 | 大黑人交交护士xxxxhd | 国产伦精品一区二区三毛 | 国产精品视频第一页 | 麻豆福利视频 | 伊人国产在线观看 | 中国女人一级一次看片 | 精品久久无码中文字幕 | 少妇高潮久久久久久潘金莲 | 国产绿帽一区二区三区 | 波多野结衣在线观看 | 伊人动漫| 久久九九99| 国产欧美精品一区二区三区 | 狠狠av| 秋霞午夜伦理 | 成人夜视频 | 青青草国产精品 | 欧美激情一区二区三区 | av免费大全| 欧美中文字幕一区 | 免费99精品国产自在在线 | 久久99国产精品 | 天天干在线播放 | 亚洲成人日韩 | 亚洲高清网站 | 日本三级日本三级日本三级极 | 后进极品美女圆润翘臀 | 日本r级电影在线观看 | 久久免费成人 | 国产绿帽一区二区三区 | 精品黑人一区二区三区国语馆 | 欧美日韩激情在线 | 人人射人人爽 | 一区二区三视频 | 欲奴3大尺度无删减 | 精品人妻一区二区免费视频 | 亚洲天堂美女 | 办公室大战高跟丝袜秘书经理ol | 国产人妻精品一区二区三区不卡 | 麻豆网页 | 黄色国产在线 | 波多野结衣一区 | 国产色一区 | 美女扒开粉嫩的尿口 | 狠狠狠狠狠干 | 精品一区二区三区不卡 | 色午夜影院 | 无码人妻久久一区二区三区蜜桃 | 韩国少妇厨房做爰 | 99热这里只有精品9 黄色一级视频免费观看 | 精品国产一区二区三区四区精华 | 你懂的网址在线观看 | 长河落日 | 全彩本子h强制侵犯公交车痴汉 | 全彩本子h强制侵犯公交车痴汉 | 成人性做爰aaa片免费 | 午夜两性视频 | 欧美黄色性视频 | 成人免费毛片入口 | 99久久久国产精品 | 菠萝蜜av | 人人干人人干人人干 | 日韩精品免费一区二区在线观看 | 小泽玛利亚一区二区三区视频 | 昭和の肉体の一冢本 | 在线看的av| aaaa毛片| 国内精品久久久 | 欧美日韩精品一区二区三区视频播放 | 丰满的寡妇hd高清在线观看 | 911美女片黄在线观看游戏 | 国产人妖网站 | 任你操精品 | 亚洲精品二区 | av电影免费观看 | 中文字幕福利视频 | 99riav在线 | 91看片成人| 正在播放久久 | 欧美一二三区视频 | 黄文在线观看 | 亚洲精品乱码久久久久久久 | 国产高清毛片 | 轻点呻吟耸动炕上被窝 | 欧美激情视频一区二区 | 成人午夜视频在线观看 | 丁香五婷 | 少妇打晨炮口述 | 免费黄色a级片 | www网站在线免费观看 | 亚洲一区在线观看视频 | 日韩视频免费观看 | 中文字幕一区二区av | 足交在线观看 | 二级毛片视频 | 风间由美av在线 | av免费观看入口 | 午夜精品视频在线观看 | 亚洲av无码久久精品色欲 | 热热热热色| 女m被s玩胸虐乳哭着求饶 | 国产精品第八页 | 一级二级毛片 | 亚洲精品女人 | 中文字幕一区二区三区四区 | 激情小说视频 | 色猫咪av| 毛片网站免费观看 | 少妇裸体挤奶汁奶水视频 | 夜夜草视频 | 女同vk| 亚洲一区二区三区在线免费观看 | 天天cao在线 | 久久久久无码精品国产 | 成人录像| 天美视频在线观看 | 老师胸乳裸露网站 | 黄免费看 | 中文字幕乱码人妻无码久久 | 国产精品久久久久国产a级 欧美黑人粗大 | 亚洲欧美日韩精品久久亚洲区 | 亚洲蜜桃视频 | 亚洲精品区 | 在线播放日本 | 亚洲图片一区二区三区 | 狠狠久久 | 少妇邻居伦理2 | 男女叉叉视频 | 欲奴3大尺度无删减 | 欧美亚洲日本国产 | 91亚洲免费| 领导揉我胸亲奶揉下面 | 调教边c边哭拍屁股女女 | 永久免费av无码网站性色av | 999国产精品视频免费 | 国产在线一区二区三区四区 | 国模私拍xvideos私拍 | 色眯眯av| 91在线视频免费 | 嫩草嫩草嫩草嫩草嫩草嫩草 | 91精品国产自产在线观看 | 成年人激情网 | 玖玖在线播放 | 国产一区二区三区四区在线观看 | 豆花在线观看 | 国产1区在线观看 | 最新国产精品视频 | 轻点呻吟耸动炕上被窝 | 久久久久无码精品国产 | 亚洲最大福利网 | 91成人免费电影 | 欧美日韩三 | 亚洲精品免费在线观看 | 生活一级片 | 亚洲av午夜精品一区二区三区 | 日韩av在线播放观看 | 成人欧美一区二区三区白人 | 五月天激情婷婷 | 尤物视频网址 | 88av在线| 欧美亚洲日本国产 | 骚虎在线观看 | 国产伦精品一区二区三区四区免费 | 九九热精品在线视频 | 韩国做爰三级在线观看 | 91精品婷婷国产综合久久 | 国产精品厕所 | 你懂的亚洲 | 成人中文字幕在线 | 日韩电影免费在线观看中文字幕 | 久久精品视频网站 | 六月色婷婷 | www日本视频 | 无人高清电视剧在线观看直播动漫 | 日本国产精品视频 | 在线综合网 | 欧美午夜精品一区二区三区 | 美女黄视频网站 | 国产精品污www在线观看 | 欧美aa视频 | 无码人妻av免费一区二区三区 | 日本熟妇一区二区 | 日韩一区二区精品视频 | 裸体女网站 | 嗯啊男男 | 丰满人妻一区二区三区免费 | 国产日韩欧美视频在线观看 | 亚洲福利视频导航 | 福利第一页| 黄色一级视频在线观看 | 91国视频| 91刺激| 在线播放a | 99久热在线精品996热是什么 | 粉嫩在线| 麻豆射区 | 88av在线| 后宫秀女调教(高h,np) | 无人高清电视剧在线观看直播动漫 | 婷婷综合网站 | 亚洲天堂视频在线观看 | 久久色网站 | 国产精品污www在线观看 | 动漫裸体女同2d | 国产一区成人 | av综合一区 | 男男受被啪到高潮自述 | 亚洲一区二区在线 | 操女人视频网站 | 亚洲欧美日韩系列 | 豆花在线观看 | 99热这里只有精品9 黄色一级视频免费观看 | 国产精品厕所 | 88国产精品欧美一区二区三区 | 秋霞影院午夜丰满少妇在线视频 | 黄色三级网站 | 成人免费毛片入口 | 日韩伦理在线播放 | av片网站 | 韩国一区二区视频 | 久久国产网站 | 青青插 | 天天摸天天射 | 久草这里只有精品 | 性少妇videosexfr老师 | 亚洲一区二区三 | 熟女人妻aⅴ一区二区三区60路 | 修仙淫交(高h)h文 | 在线欧美一区 | 97人妻人人澡人人爽人人精品 | 日本妻子迷妹网 | 91亚洲国产成人久久精品麻豆 | 亚洲欧美日韩一区二区 | 国产毛片一区二区三区 | 国产精品污www在线观看 | 国产一区二区三区免费观看 | 久久免费看视频 | 又粗又猛又爽又黄的视频 | 90岁肥老奶奶毛毛外套 | 欧美日韩一卡二卡三卡 | 精品视频在线看 | 免费午夜视频 | 欧美在线精品一区二区三区 | 中文久久乱码一区二区 | 日本视频色 | 国产一区二区三区日韩 | 影音先锋国产在线 | 国产午夜一区二区 | 欧美黄色一级网站 | 波多野吉衣在线视频 | 99久久婷婷国产综合精品电影 | 日本爱爱视频 | 成人动漫一区二区三区 | 国产高清久久久 | 欧美日韩毛片 | 张起灵调教喷水沦为肉奴视频 | 小泽玛利亚一区二区 | 好吊视频一区二区三区 | 巨乳女教师的诱惑 | 在线视频日本 | 日韩伦理视频 | 精东影视文化传媒 | 婷婷综合激情网 | 精品九九九九九 | 天天人人精品 | 只有精品| 日韩视频精品 | av不卡在线看| 成人动漫av在线 | 国产在线伊人 | 天天天天天操 | 免费久草视频 | 秋霞影院午夜丰满少妇在线视频 | 香港a毛片 | 久久福利影视 | 欧美特黄aaaaaa| 国产一区二区波多野结衣 | 我要看一级黄色片 | av色婷婷| 亚洲视频一二区 | 90岁肥老奶奶毛毛外套 | 三级色网| 国产三级黄色片 | 欧美黑人xxxⅹ高潮交 | 好吊妞这里只有精品 | 亚洲精品乱码久久久久久蜜桃欧美 | 久久yy| 日韩国产免费 | 色综合人人 | 插插插亚洲| www.天堂av | 国产伦精品一区二区三区高清版禁 | 波多野结衣一区 | 欧美视频h | 午夜激情影院 | 国模精品视频一区二区 | 啪啪的网站 | 久色网| 91精品国产电影 | 东北一级片| 欧美激情一区二区三区 | 手机黄色网址在线观看 | 蜜桃久久精品成人无码av | 人妻熟女一区二区aⅴ水 | 日韩精品一区在线观看 | 午夜视频福利 | 天天操天天干天天爱 | 少妇精品久久久久久久久久 | 男人舔女人逼动态图 | 少妇裸体视频 | 亚洲天堂2013 | 中文字幕无线码一区 | 国产丰满麻豆 | 轻点呻吟耸动炕上被窝 | 乱日视频 | 娇妻被恩人征服h版 | aaa黄色片 | 亚洲成年网站 | av久在线| 91午夜理伦私人影院 | 韩国r级《瑜伽教练》在线 国产乡下妇女三片 | 亚洲天堂女人 | 四虎在线免费 | 超碰免费91 | 久久久亚洲一区二区三区 | 中文字幕日本人妻久久久免费 | 五月激情综合 | 日精品 | 狠狠av | 欧美夫妻性生活视频 | 国产人妖网站 | 欧美少妇视频 | 免费杨幂裸体视频 | 国产成人精品无码免费看夜聊软件 | 日韩中文字幕免费观看 | 91精品一区二区 | 999国产精品视频免费 | 精品人妻一区二区三 | 高清视频一区二区三区 | 好吊妞这里只有精品 | 9人人澡人人爽人人精品 | 成人动漫av在线 | 麻豆电影网站 | 欧美色图亚洲激情 | 精品久久久久久中文字幕人妻最新 | 人妻精品一区 | 日本精品一区 | 国产av无码专区亚洲av毛片搜 | 可以在线观看的av | 色免费在线观看 | 亚洲一区二区三 | 一级做a在线观看 | 被各种男人cao到呻吟跪趴h | 日韩精品中文在线 | 国产黄拍 | 国产精品亚洲lv粉色 | 日韩一级中文字幕 | 在线观看h片 | 中国女人内射6xxxxx | 午夜看黄神器 | 极品白嫩的小少妇 | 国产视频成人 | 蜜臀av粉嫩av懂色av | 337p粉嫩色噜噜噜大肥臀 | 久久aaa| 黄色片网站在线观看 | 国产美女精品视频 | 99亚洲视频 | 美艳尤物h双性受1v1 | 美女高潮爽到尿喷出来 | 可以在线观看的av | 中文久久乱码一区二区 | 黄色小说视频在线观看 | 肉肉h | 空乘伦理hd | 远古野人粗壮h灌满3p | 日韩一区二区三区不卡 | hd极品free性xxx护士 | 日韩一级片免费 | 乱淫视频| 亚洲a级片 | 国产最新精品 | 夜夜看| 午夜影音 | 成人午夜视频在线观看 | 手机成人在线 | 成人蜜桃av| 黄大片18满岁 | av免费大全| 黄色福利| 日韩电影中文字幕在线观看 | 91久久久久久久久久久久 | 在线综合网 | 亚洲图片一区二区三区 | 51成人做爰www免费看网站 | 久操视频在线观看 | 韩国一级视频 | 麻豆网页| 91国产一区 | 毛片大全 | 一级黄色短视频 | 午夜国产片 | 蜜桃做爰免费网站 | 国产成人一区二区三区免费看 | 欧美区日韩区 | 激情五月av | 胸大被男同桌强解开胸罩床吻 | 大香伊人久久 | 色多多在线视频 | 日本免费网站 | 国产黄色三级电影 | 久久国产精品波多野结衣av | 亚洲一区二区三区在线免费观看 | 免费的黄网站 | 国产伦精品一区二区三区88av | 日本色中色 | 噜噜噜久久 | 91污污| 欧美浮力影院 | 国产高清毛片 | 你懂的网址在线观看 | 久久丫精品忘忧草西安产品 | 亚洲福利视频导航 | 天天天天天操 | 日本高清不卡视频 | 国产乱码在线 | 国产成人二区 | free性丰满白嫩白嫩的hd | 日本一区二区三区中文字幕 | 少妇熟女高潮流白浆 | 久久色网站 | 中文字幕亚洲乱码熟女1区2区 | 第一福利丝瓜av导航 | 香港日本三级 | 一级色网站 | 免费成人深夜夜视频 | 久久视频一区 | 免费成人深夜夜视频 | 欧美另类xxxx| 国产不雅视频 | 亚洲天堂美女 | 一区二区三区四区视频 | 亚洲视频免费看 | 91在线看视频 | 91丨九色丨国产在线 | 91精品免费| 影音先锋男| 亚洲色偷偷色噜噜狠狠99网 | 欧美三级一区二区三区 | 久久在现 | 五月天中文字幕 | 娇妻被恩人征服h版 | 亚洲精品视频一区二区 | 亚洲美女av在线 | 一级片黄色片 | 粉嫩在线 | www.天天干.com| 国产精品免费网站 | 久操这里只有精品 | 亚洲高清网站 | 东方欧美色图 | 手机看片国产 | 欧美黑人粗大 | 精品人妻无码一区二区三区 | 第一页在线| 天天干夜夜爱 | 天美视频在线观看 | 亚洲高清视频在线 | 在线观看h| 91精品一区二区 | 在线观看欧美日韩 | 91呦呦| 轻点呻吟耸动炕上被窝 | 黄片毛片在线观看 | 成人欧美一区二区三区在线观看 | 欧美aa视频 | 无码一区二区三区在线观看 | 一本久久久| 男男h黄动漫啪啪无遮挡软件 | 草草视频在线 | 国产精品5 | 激情内射亚洲一区二区三区爱妻 | 日本三级在线 | 大奶子少妇 | 国产又爽又黄免费视频 | 亚洲精品一区二区三区蜜桃久 | 亚州欧美日韩 | 香港三级做爰在线播放 | 用力插好舒服 | 无码人妻av免费一区二区三区 | 免费播放男人添女人下边app | 欧美无遮挡 | 日韩av第一页 | 三级做爰在线观看视频 | 日韩美女性生活 | 午夜91 | 日韩一二三四区 | 日本69视频| 免费日韩欧美 | 波多野结衣乳巨码无在线观看 | 日日操av | 在线欧美一区 | 成人免费在线观看 | 日本最黄视频 | 久久yy| 午夜电影一区二区三区 | 中国国产bdsm紧缚捆绑 | 草莓污视频 | 国产三级自拍视频 | 免费在线观看视频 | 欧美精品久久久久久久久 | 黄色片免费下载 | 欧美精品综合 | 亚洲天堂女人 | 跪下被主人玩乳sm惩罚 | 秋霞理论电影网 | 修仙淫交(高h)h文 | 中文字幕第6页 | 免费播放男人添女人下边app | free性丰满白嫩白嫩的hd | 亚洲欧美日韩精品久久亚洲区 | 丰满人妻老熟妇伦人精品 | 136fldh精品导航福利 | 色福利网| 痞子gay大猛—xnxx2 | 99久热在线精品996热是什么 | 日韩一区二区精品视频 | 免费网站18| 中文字幕一区二区三区av | 伊人久操 | 蜜桃成熟时3d | 国产精品亚洲lv粉色 | 天天人人精品 | 国产成人亚洲精品自产在线 | 久久在现 | 91免费播放 | 久久精品av | 一区二区在线视频观看 | 少妇与公做了夜伦理 | 久久精品视频在线 | 日韩免费精品视频 | 日本一区二区中文字幕 | 大咪咪dvd | 黄av网站 | a视频在线免费观看 | 亚洲大片免费看 | 午夜两性 | 女人做爰全过程免费观看美女 | 欧美视频| 中文av电影 | 深夜av | 国产三级电影 | 欧美在线综合视频 | 午夜免费福利电影 | 欧美最猛黑人xxxx黑人猛交 | 国产精品久久久精品 | 中文不卡av | 黄色性视频 | 90岁肥老奶奶毛毛外套 | 国产精品3区 | 色婷婷婷婷 | 姐姐在线观看动漫第二集免费 | 久久国产网站 | 中文字幕乱码人妻无码久久 | 日韩美女性生活 | 国产免费黄色片 | www.天天干.com| 青青草视频污 | 国产精品扒开腿做爽爽爽视频 | 粉嫩小女生 | 日本妻子迷妹网 | 欧美香蕉网| 成人免费午夜视频 | 国产视频三区 | 黄网在线免费观看 | 丰满少妇一区二区三区专区 | 被乞丐下药挺进双腿疯狂侵犯 | 欧洲一区二区在线观看 | 少女忠诚电影高清免费 | 在线观看黄av | 精品国产一区二区三 | 麻豆福利视频 | 久久久久黄色 | 成人午夜视频在线观看 | 久久国产精品影视 | 日本电视剧二人世界第十六集 | 三级av网站 | 日本国产一区 | 京香视频| 人妻少妇被猛烈进入中文字幕 | 在线亚洲综合 | 国产精品久久午夜夜伦鲁鲁 | 狠狠久久 | 无码人妻一区二区三区在线 | 人妻换人妻仑乱 | 小泽玛利亚一区二区三区视频 | 成人毛片在线 | 青娱乐国产视频 | 好妈妈6 | 美女搞黄网站 | 亚洲一二三 | 亚洲国产小视频 | 伊人av网 | 日韩精品免费一区二区在线观看 | 狠狠操av | 岛国av动作片 | 爱情岛论坛亚洲入口 | 精品人妻一区二区免费视频 | 伊人伊人鲁 | 一级黄色短视频 | 欧洲一区二区视频 | 国产精品久久久久久网站 | 美女脱衣服的网站 | 伊人宗合 | 黄色网战大全 | 久久丫精品忘忧草西安产品 | 一级片国产 | 精品国产人妻一区二区三区 | 国产成人一区二区三区免费看 | 国产一区二区三区四区在线观看 | 97在线视频人妻无码 | 色猫咪av| 日日夜夜综合网 | 欧美日韩一区二区三区在线视频 | 成人免费网站 | 久久婷婷五月综合 | 亚洲免费在线视频 | 飘雪影视在线观看西瓜高清免费 | 久久久久无码精品国产 | 日日夜夜噜噜噜 | 国产理伦 | 日本黄a三级三级三级 | 一区二区三区在线 | av香港经典三级级 在线 | 日本黄色片免费 | 少妇熟女高潮流白浆 | 国产清纯在线 | 视频二区中文字幕 | av香港经典三级级 在线 | 免费看爱爱视频 | 国产高清在线观看视频 | 主人调教巨奴性奶牛警察 | 色婷婷777777仙踪林 | 欧美日韩五区 | 无码人妻丰满熟妇区96 | 自拍偷拍在线播放 | 中文天堂在线资源 | 添女人荫蒂全部过程视频 | 免费在线观看视频 | 老司机久久| 女人与公拘交酡zozo | 日本在线观看网站 | 国产伦精品一区二区三区88av | 亚洲一区二区视频在线观看 | 国产精品扒开腿做爽爽爽视频 | 91亚洲一区 | 校园春色亚洲色图 | 国产片淫乱18一级毛片动态图 | 免费一级黄色大片 | 亚洲精品国产精品乱码桃花 | 在线观看污视频网站 | 69激情网| 蜜桃久久精品成人无码av | 欧美性猛交xxxx乱大交蜜桃 | 青草久久久 | 激情综合激情 | 日本香蕉网 | 成人免费av网站 | 国产欧美另类 | 午夜久久 | 99精品欧美一区二区三区 | 免费色播 | 一级黄色短视频 | 日韩操操| 黄色裸体网站 | 人与动物黄色片 | 国产成人精品亚洲男人的天堂 | 91国内精品久久久久 | 丰满人妻一区二区三区免费 | 偷偷在线观看免费播放电视剧大全 | 91污污| 91在线免费视频观看 | 亚洲特级毛片 | 无码无套少妇毛多18pxxxx | 欧美日韩免费 | 欧美瑟瑟| 狠狠爱av | 日日日干干干 | 中文字幕一区二区三区人妻在线视频 | 99热这里只有精品9 黄色一级视频免费观看 | 中文字幕一区二区三区视频 | 日韩精品在线观看免费 | 91麻豆免费视频 | 日韩av第一页 | 污污动态图 | 国产伦精品一区二区三区高清版禁 | 少妇视频在线观看 | 男生和女生搞鸡视频 | 奇米影视网 | 91亚洲国产成人久久精品麻豆 | 美女扒开粉嫩的尿口 | av在线试看 | 国产午夜福利一区 | 92看片| 国产夫妻性爱视频 | 人妻精品一区 | 欧美a级片视频 | 久久99国产精品 | 大奶一区二区 | 秋霞国产 | 黄色一级视频免费观看 | 色婷婷777777仙踪林 | 97碰碰碰| 蜜桃视频在线播放 | 裸身不知火舞被羞羞漫画 | 二级片网站 | 二级片网站 | 蜜桃久久久久久久 | 被各种男人cao到呻吟跪趴h | 精品国产aⅴ一区二区三区东京热 | 夜夜操夜夜骑 | 欧美另类z0zxhd电影 | 二次元女裸体羞羞黄漫 | 亚洲欧美日本一区 | 成人精品福利 | 国产日韩欧美自拍 | 欧美色拍 | 永久免费av网站 | 色99999| 久久精品无码专区 | 91tv在线观看 | 息与子五十路翔田千里 | 欧美视频| 国产毛片视频 | 国产精品美女一区 | 中文字幕一区电影 | 在线观看二区 | 欧美激情视频一区二区 | 欧美日韩网 | 黑人精品xxx一区一二区 | 久久福利视频导航 | 在线国产区 | 高跟鞋和丝袜猛烈xxxxxx | 熟女人妻aⅴ一区二区三区60路 | 久久99国产精品 | 福利第一页 | 国产精品久久久国产盗摄 | 亚洲精品自拍 | 欧美人与牛zoz0性行为 | 久久丫丫| 91免费播放| 污污免费网站 | 91久久久久久久久久久久 | 五月激情综合 | 黄色香蕉网站 | 一区二区三区在线 | 欧美在线综合视频 | 国产最新精品 | 国产在线视频自拍 | 中文不卡av | 国产精品亚洲lv粉色 | 99re久久 | 日韩色图在线观看 | 狠狠久久| 欧美丰满熟妇xxxx | 高h言情 | 亚洲国产精品久久 | 美女视频毛片 | 在线观看h片| 领导揉我胸亲奶揉下面 | 欧美 亚洲 一区 | 日本精品国产 | 亚洲欧洲另类 | 久久久久黄色 | gogogo高清免费播放 | 国产精品亚洲lv粉色 | 欧美草比 | 中文字幕一区二区三区四区 | 胸大被男同桌强解开胸罩床吻 | 麻豆视频网页 | 一区二区三区人妻 | 亚洲操操操 | 无码一区二区三区在线观看 | 我的奴性朱竹清便器精厕贱奴视频 | 国产伦精品一区二区三区四区免费 | 欧美aa在线 | 久久精品无码一区 | 女教师被调教到性隶 | 91在线视频免费 | 丰满人妻一区二区三区免费 | 毛片一区二区 | 亚洲黄色小说网站 | 国产久草视频 | 电影女教师日记 | 亚洲精品乱码久久久久久蜜桃 | 黄网站免费观看 | 午夜两性 | a v视频在线观看 | 米奇影院7777免费观看高清完整喜剧电影 | 久久久精品网站 | 成人av免费观看 | 精品人妻一区二区免费视频 | 婷婷激情网站 | 国产午夜精品一区二区理论影院 | 麻豆精品国产传媒av | 裸身不知火舞被羞羞漫画 | free性丰满白嫩白嫩的hd | 亚洲色综合 | 91成人精品一区在线播放 | 一边吃奶一边摸做爽视频 | 青青草福利 | 一区二区黄色 | 亚洲午夜激情视频 | 免费的黄网站 | 91亚色 | 波多野结衣家庭教师6 | 日韩精品成人免费观看视频 | 色猫咪av| 一级黄色片一级黄色片 | 一级黄色片一级黄色片 | 日本黄色免费视频 | 国产伦精品一区二区三毛 | 亚州av在线 | 欧美日韩一区二区三区在线视频 | 亚洲xx视频 | 调教h视频| 欧美日韩激情在线 | 成人动漫一区二区三区 | 91成人免费电影 | 男女小黄文 | 91久久超碰 | 嗯啊男男 | 91久久精品一区二区三区 | 美女视频毛片 | 九七超碰在线 | 国产大学生av | 国产精品99精品无码视 | 丰满少妇视频 | 欧美精品综合 | 成人av在线看 | av激情网站 | 久久综合导航 | 国产主播在线观看 | 91免费在线看 | 全国最大色 | 后进极品白嫩翘臀在线视频 | 婷婷综合网站 | 又黄又爽的免费视频 | 人人干人人干人人干 | 亚洲一区欧美一区 | 琪琪久久 | 在线播放日本 | 亚洲经典一区二区 | 懂色av粉嫩av | 吊侵犯の奶水授乳羞羞漫画 | 国产欧美精品一区二区 | 免费看爱爱视频 | 日本在线免费播放 | 久久久久一区二区 | 婷婷天堂网 | 国产精品免费久久 | 日本福利在线 | 日韩一区二区精品视频 | 玖草在线| 女人做爰全过程免费观看美女 | 午夜免费福利电影 | 后进极品白嫩翘臀在线视频 | 免费观看一区二区 | 女尊高h男高潮呻吟 | 欧美激情视频一区二区 | 精品人妻在线视频 | 飘雪影视在线观看西瓜高清免费 | 成人一区二区在线观看 | 精品国产乱码久久久久久蜜臀网站 | 男人午夜av | 亚州男人天堂 | 91刺激 | 奇米影视77777 | 精品一区二区三区不卡 | 国产精品久久在线观看 | 五月天激情啪啪 | 女教师被调教到性隶 | 日日躁夜夜躁 | 一区二区伦理片 | 91婷婷射 | www.狠狠操.com| 日韩成人激情视频 | av不卡在线看 | 午夜免费av | 免费观看视频在线观看 | 毛片无限看 | 欧美日韩一区在线 | 中文字幕无码毛片免费看 | 天天看夜夜看 | 蜜桃久久精品成人无码av | 久久黄色免费视频 | 在线欧美亚洲 | 天天摸天天射 | 欧美日韩三级 | 强伦人妻一区二区三区 | 国产一区二区不卡在线 | 我的奴性朱竹清便器精厕贱奴视频 | 日韩伦理免费 | 136fldh精品导航福利 | 久久久午夜精品 | 玖草在线观看 | 一本一道波多野结衣一区二区 | 91综合在线 | 日韩激情在线观看 | 香蕉av在线| 欧美日韩激情在线 | 胸啊嗯~下面出水了 | 欧美视频亚洲 | 亚洲激情视频在线 | 精品视频在线一区 | 娇妻被恩人征服h版 | 日韩精品电影在线 | 亚洲精品成人a | 少妇熟女高潮流白浆 | 爽爽网| 蜜臀av网 | 一边亲嘴一边做好爽视频 | 任我爽在线视频 | 高h言情| 亚洲欧美天堂 | 国产免费a级片 | 91久久精品一区二区三区 | 日本在线不卡一区 | 黄瓜污视频 | 极品美女无套呻吟啪啪 | 本田岬在线观看 | 国产69页 | 手机在线观看免费av | 蜜臀久久99精品久久久无需会员 | 好吊妞这里只有精品 | 两男一女做2爱 | 在线色综合 | 91成人免费电影 | 国精产品一区一区三区mba下载 | 精品久久久久久中文字幕人妻最新 | 亲子乱对白乱都乱了 | hd极品free性xxx护士 | 欧美贵妇videos办公室 | 跪下被主人玩乳sm惩罚 | 免费看a级片 | 91tv在线观看 | 秋霞国产 | 伦理一级片 | 精品久久久久久中文字幕人妻最新 | 亚洲成人自拍 | 日本电视剧二人世界第十六集 | 黄色短视频在线观看 | 欧美成人aaa片一区国产精品 | 天堂资源在线播放 | 99re久久| 免费观看一区二区 | 米奇影院7777免费观看高清完整喜剧电影 | 国产性xxxx高清 | 欧美肥妇bwbwbwbxx| 成人欧美一区二区 | 一区二区三区四区视频 | 特级淫片aaaaaaa级 | 深夜福利一区二区三区 | 97精品| 国产黄拍 | 精品少妇| 国产精品一区二三区 | 日韩欧美网站 | 胸大被男同桌强解开胸罩床吻 | 四虎在线免费 | 9色视频| 久久精品久久久久 | 国产视频在线一区 | 中文久久乱码一区二区 | 狠狠久久 | 国产a级网站 | 亚洲日本免费 | 亚洲国产中文字幕在线 | 亚洲精品久久久 | av色噜噜 | 麻豆少妇水电工003 亚洲精选一区 | 欧美激情一区在线观看 | 国产久精品 | 日本一区二区中文字幕 | 国产盗摄一区 | 性做爰免费视频观看 | 日韩不卡av | 天天草视频 | 国产日韩在线一区 | 96视频在线观看 | 亚洲毛片视频 | 午夜老湿机 | 99精品欧美一区二区三区 | 欧美日韩激情在线 | 亚洲免费三区 | 在线播放一区二区三区 | 韩国做爰三级在线观看 | 男生操女生网站 | 极品嫩模炮交高潮叫床喷液 | 性色tv | 黄色片免费下载 | 福利影院在线观看 | 艳妇乳肉豪妇荡乳av无码福利 | 免费超碰在线 | 亚洲性综合 | 青青草91视频| 好逼天天操 | 艹男人的日日夜夜 | 韩国伦理在线 | 欧美大片一区二区三区 | 丁香花电影版免费观看第二季 | 超碰碰碰 | 太粗太长岳受不了 | spy3wc撒spy3wc撒 | 欧美爽爽爽 | 午夜爽爽视频 | 欧美三级一区二区三区 | 亚洲精品一区二区三区蜜桃久 | 日韩一区二区三区不卡 | 亚洲毛片视频 | 日本亚洲一区二区 | 自拍偷拍校园春色 | 日韩精品一区在线观看 | 成人免费视频国产免费麻豆 | 色婷婷丁香 | 一本大道久久 | 国产精品视频不卡 | 秋霞国产午夜精品免费视频 | 亚洲精品视频观看 | 兄弟的妈妈免费观看电视剧完整版中 | 91成人短视频 | 九九精品视频在线 | 男女www视频 | 免费看爱爱视频 | 深夜福利一区二区三区 | 久久久午夜精品 | 男女那个视频 | 男生操女生免费视频 | 中文字幕日本人妻久久久免费 | 亚洲精品三区 | 免费三片在线观看网站v888 | 91精品91久久久中77777 | www.羞羞漫画 | 欧美日韩精品一区二区三区视频播放 | 性欧美巨大乳 | 六月婷婷网 | 国产视频成人 | 开心激情站 | 国产极品视频 | 网址av| 日本 奴役 捆绑 受虐狂 | 深夜福利一区二区三区 | 免费观看视频在线观看 | 狠狠狠狠狠干 | 乳色吐息免费观看 | 欧美日韩一级二级 | 吊侵犯の奶水授乳羞羞漫画 | 五月天综合激情网 | 亚洲国产小视频 | 国产精品毛片久久久久久 | 生活一级片 | 电影女教师日记 | 91色交| 噼里啪啦免费看 | 一本一道久久a久久精品蜜桃 | 污的视频在线观看 | 国内精品久久久 | 69天堂网 | 日本亚洲视频 | 午夜电影免费看 | 9人人澡人人爽人人精品 | 欧美日韩在线电影 | 亚洲精品大全 | 狠狠爱婷婷 | 精品人妻一区二区三 | 精品一区在线视频 | a视频免费在线观看 | 99中文字幕在线观看 | 日本性网站 | 老师…好紧蕾丝丝袜和我做 | 高清视频一区二区三区 | 天堂视频免费 | 黄频在线免费观看 | 不穿衣服的网站 | 久久亚洲国产成人精品性色 | 在线观看国产网站 | 极品美女无套呻吟啪啪 | 精品久久久久久中文字幕人妻最新 | 啪啪福利社 | 亚洲视频在线一区 | 少妇高潮露脸国语对白 | 91麻豆成人精品国产免费网站 | 91在线免费视频观看 | 怡红院在线播放 | 久久久久91| 午夜精品视频在线观看 | 日本少妇videos高潮 | 神马午夜888| 青娱乐国产盛宴 | 国产欧美另类 | 妇女主任大腚耸动着 | 精品人妻一区二区免费视频 | 五月天激情影院 | 国产不卡一区二区视频 | 国产网红无码精品视频 | 九九99久久| 韩国一级电影 | 色网在线 | 女人与公拘交酡zozo | 1024国产精品 | 精品国产一 | 国产a级网站 | 自拍偷拍校园春色 | 国精产品一区一区三区有限在线 | 亚洲一区二区视频在线观看 | 午夜18视频在线观看 | 99在线观看精品视频 | 日韩成人精品一区二区 | 调教h视频 | 老女人做爰全过 | 日韩精品成人免费观看视频 | 肥胖女人做爰视频 | 色福利网 | 日本成人久久 | 操碰97| 免费网站18 | 成人在线观看视频网站 | 青青草福利 | 午夜欧美视频 | 免费一级黄色 | 亚洲精品区 | 一起草av在线| 亚洲va韩国va欧美va精品 | 日本黄a三级三级三级 | 亚洲av成人精品日韩在线播放 | 老外几下就让我高潮了 | 扒开腿 | 日韩精品在线观看免费 | 亚洲综合另类小说 | 六月丁香婷婷综合 | 亚洲丁香花色 | 初尝黑人巨炮波多野结衣电影 | 寡妇毛片一区二区三区 | 久草超碰在线 | 娇妻被恩人征服h版 | 亚洲精品伦理 | 久久福利小视频 | 波多野吉衣毛片 | 国产a级网站 | 正在播放久久 | 性欧美精品男男 | 好看的h文| 久久国产精品波多野结衣av | 国产美女主播 | 91网在线观看 | 久久精品视屏 | 另类小说五月天 | 午夜老司机福利 | 亚洲欧美国产毛片在线 | 亚洲福利视频一区 | 中文字幕黑人 | 欧美精品一区在线 | 女生叉开腿让男生捅 | 狠狠撸视频 | 欧美mv日韩mv国产网站app | 风间由美av在线 | 好看的h文 | 日精品 | 好逼天天操 | 久久精品无码专区 | 欧美精品久久久久久久久 | 欧美爽爽爽 | 一本大道久久东京热无码av | 她享受粗啪滋嗯大爷轻点视频 | 伊人一区 | 中文字幕一区二区av | 91麻豆精品国产91久久久久久 | 日韩精品自拍 | 国产三级电影 | 亚洲精品二 | 久久av影视 | 亚洲青涩 | 亚洲网站视频 | 韩国r级《瑜伽教练》在线 国产乡下妇女三片 | 天天精品视频 | 亚洲无毛 | 狠狠爱婷婷 | 国产欧美精品一区二区三区 | 无码人妻av免费一区二区三区 | 午夜av福利| 小泽玛利亚一区二区三区视频 | 考逼视频 | 亚洲最大福利网 | 长河落日 | 福利视频一区二区三区 | 国产三级a | 我和岳疯狂性做爰视频 | 日本不卡一区 | 肉肉h | 欧美日韩视频在线 | 桃色av| 国产www视频 | 亚洲一区在线观看视频 | 操操操操操操操操 | 国产一区二区不卡在线 | 日本少妇性高潮 | 午夜av毛片 | 91色国产 | 肥胖女人做爰视频 | 性做爰免费视频观看 | 国产专区视频 | 亚洲涩情 | 国产视频在线一区 | 日韩精品人妻中文字幕 | 亚洲成人三级 | 日韩一级精品 | 一级片黄色片 | 亚洲蜜臀av乱码久久精品蜜桃 | 鬼六终极篇之镣铐女犯人第二部 | mm131丰满少妇人体欣赏图 | 日韩精品中文在线 | 欧美日韩一级大片 | 日本黄色小说 | 日韩伦理在线播放 | 女人的天堂av在线 | 狠狠操狠狠操狠狠操 | 免费看污黄网站在线观看 | 狠狠干免费视频 | 在线欧美一区 | 波多一区 | 五月天中文字幕 | 黄色网址最新 | 久久福利视频导航 | 欧美日韩免费 | 国产精品久久综合 | 91色国产| 天天人人 | 粉嫩欧美一区二区三区 | 偷拍视频网 | 毛片基地免费 | 综合在线观看 | 爱草视频| 一级片国产 | 一区二区三区视频在线播放 | 黑人巨大精品欧美一区 | 少妇高潮久久久久久潘金莲 | 欧洲一区二区在线观看 | 在线综合网| 欧美xxxxx自由摘花 | 成人免费av网站 | 国产精品久久综合 | 沈芯语老师家访麻花视频 | 九九视频在线观看 | 中文字幕一区二区三区四区视频 | 精品国产aⅴ一区二区三区东京热 | 国产男男gaygay网站xnxx | 国产精品扒开腿做爽爽爽视频 | 奇米四色网 | 狠狠干少妇 | 国产精品久久综合 | 蜜臀av网| 中文字幕第6页 | 五月婷婷开心 | 啊啊啊好爽在线观看 | 91国内精品久久久久 | free性hd另类医生 | 免费人成 | 日韩日b视频| 久久精品视频网站 | 在线看一区二区 | 无码人妻av免费一区二区三区 | 亚洲视频在线一区 | 欧美国产激情 | 国产情侣av在线 | 欧美最猛黑人xxxx黑人猛交 | 国产福利电影网 | 八戒,八戒电影在线观看 | 手机看片福利永久 | 啊啊啊好爽在线观看 | 两根一起进蹂躏3p | 91高跟黑色丝袜呻吟在线观看 | 日本黄色大片在线观看 | 理论片中文字幕 | 99re国产精品视频 | 亚洲国产成人91精品 | 午夜看黄神器 | av激情在线| 亚洲福利视频一区 | 精品国产一区二区三 | 国产精品国产三级国产aⅴ9色 | 日本黄色小说 | 久久久久久亚洲中文字幕无码 | 后进极品白嫩翘臀在线视频 | 亚洲精品国产精品乱码不卡√香蕉 | 日本高清视频在线播放 | 欧美黄色免费视频 | 天堂视频免费 | 天天干夜夜做 | 国产古装艳史毛片hd | 边添小泬边狠狠躁视频 | 狠狠爱婷婷 | 国产又爽又黄免费视频 | 办公室大战高跟丝袜秘书经理ol | 黄色免费毛片 | 成人免费久久 | 色婷婷免费视频 | 森泽佳奈在线播放 | 欧美日韩五区 | 91视频在线观看 | 日本美女啪啪 | 久热伊人| 久久久精品网站 | 中文字幕福利视频 | 午夜一区二区三区免费观看 | 欧美色老太 | 丁香综合| 超碰色人阁| 琪琪久久 |