A multi-material printing apparatus and method to prevent cross contamination of powders

Abstract

The application provides a multi-material printing device capable of preventing powder cross contamination, comprising a workbench, a forming cylinder arranged in the middle of the workbench, a first powder cylinder and a second powder cylinder arranged on the workbench, wherein the first powder cylinder and the second powder cylinder are used for loading different kinds of powder, a first powder leakage groove and a second powder leakage groove arranged on the workbench, a first scraper powder suction assembly and a second scraper powder suction assembly with a moving function arranged on the workbench, a first iron block arranged on the workbench and used for sealing and blocking the first powder leakage groove, and a second iron block arranged on the workbench and used for sealing and blocking the second powder leakage groove. Through the powder supply structure of the two powder cylinders, the sealing and blocking design of the powder leakage groove and the movable iron block, the time and layer control logic, and the modular iron block switching mechanism driven by the linear motor and the electromagnet, the powder cross contamination is effectively prevented, the printing efficiency is improved, and the interlayer printing of two kinds of metal powder is realized.

Description

Technical Field

[0001] This invention relates to the field of printing equipment technology, and in particular to a multi-material printing device and method for preventing cross-contamination of powders. Background Technology

[0002] Metal 3D printing manufacturing technology is an emerging preparation technology that has been widely used in industries such as aerospace, biomedicine, automobile manufacturing, and military. Among them, the most widely used 3D printing manufacturing technology is selective laser melting (SLM). SLM technology is a technology that uses a high-energy laser beam to directly irradiate metal powder, causing it to melt rapidly and then cool and solidify into a shape. It can quickly achieve the melting and shaping of metal powder in the laser processing area, greatly improving the efficiency and quality of metal product forming. SLM technology does not require the use of molds and can directly convert 3D design models into solid parts, significantly shortening the R&D and manufacturing cycle. It is suitable for rapid prototyping and mass production.

[0003] As the manufacturing industry further enhances its requirements for the quality of parts manufacturing, it places higher demands on the quality, efficiency, and functional diversity of 3D printing. Currently, traditional metal 3D printing technology is often designed for the forming and processing of single metal materials, and the performance of metal products formed in this way is often quite limited.

[0004] To meet more complex design needs and achieve superior performance, multi-material 3D printing technology has emerged. However, in the process of multi-material 3D printing, the delivery, mixing, and forming of different metal powders can easily lead to powder cross-contamination. Powder cross-contamination can seriously affect the quality and performance of printed objects, causing the printed products to fail to meet the expected design requirements. For example, during the printing process, residues of different metal powders may mix with the powder being used, altering its composition and properties, leading to defects and unstable performance in the printed objects. More importantly, in most existing multi-material printing equipment, the remaining powder mixes together after printing, becoming waste powder that cannot be reused, requiring the purchase of new powder and increasing raw material costs. Existing equipment and methods struggle to effectively solve these problems, failing to ensure printing efficiency while simultaneously guaranteeing the quality and stability of multi-material printing and enabling powder recycling. Summary of the Invention

[0005] This invention proposes a multi-material printing device to prevent powder cross-contamination, thereby solving the problem of powder cross-contamination in the metal multi-material 3D printing process mentioned in the background art.

[0006] The technical solution of this invention is implemented as follows: A multi-material printing device for preventing cross-contamination of powders includes a worktable, a forming cylinder at the center of the worktable, a first powder cylinder and a second powder cylinder on the worktable for filling different types of powder, a first powder leakage trough and a second powder leakage trough on the worktable, a first scraper powder suction assembly and a second scraper powder suction assembly with movable function on the worktable, a first iron block for sealing and blocking the first powder leakage trough on the worktable, a second iron block for sealing and blocking the second powder leakage trough on the worktable, a first electromagnet for picking up and placing the first iron block on the worktable, a second electromagnet for picking up and placing the second iron block on the worktable, a first drive mechanism for driving the first electromagnet to move up and down on the worktable, and a second drive mechanism for driving the second electromagnet to move up and down on the worktable.

[0007] Preferably, the first driving mechanism includes a first linear motor for driving the first electromagnet to move up and down, and the second driving mechanism includes a first linear motor for driving the second electromagnet to move up and down.

[0008] Preferably, both the first and second scraper dust suction components include a scraper and an anti-overflow shell mounted on the scraper for suction of powder. The anti-overflow shell is equipped with an air blowing nozzle and an air suction nozzle. The air blowing nozzle is mounted on an argon cylinder via a first retractable hose. A pressure regulating valve and a pulse solenoid valve are sequentially installed at the connection between the argon cylinder and the first retractable hose. The air suction nozzle is mounted on a dust collector via a second retractable hose. The dust collector is mounted on a suction machine via a connecting pipe.

[0009] Preferably, the workbench is further provided with two sliding mechanisms that guide the reciprocating movement of the first scraper powder suction component and the second scraper powder suction component, respectively. The sliding mechanism includes a slide rail fixedly installed on the workbench and a sliding rod slidably installed on the slide rail, and the scraper is fixedly installed on the sliding rod.

[0010] Preferably, a first sealing strip is fixedly installed on the top edge of the first iron block, and a second sealing strip is fixedly installed on the top edge of the second iron block.

[0011] Preferably, an air blowing component is installed on the worktable, an air suction component is installed on the worktable at a position symmetrical to the air blowing component, and a powder hopper is fixedly installed on the worktable at a position corresponding to the air suction component.

[0012] Preferably, the first powder leakage groove and the second powder leakage groove are located on both sides of the forming cylinder.

[0013] Preferably, the workbench is equipped with two lifting mechanisms for lifting the first powder cylinder and the second powder cylinder respectively.

[0014] Preferably, the workbench is equipped with a second lifting mechanism for driving the molding cylinder to rise and fall.

[0015] A multi-material printing method for preventing powder cross-contamination includes the following steps: S1. First, the first linear motor descends, driving the first electromagnet to descend synchronously. The first electromagnet is energized, tightly adsorbing the first iron block and transporting it to the position of the second powder leakage trough, blocking the second powder leakage trough. The upper surface of the first iron block is on the same plane as the workbench to prevent interference with the first scraper powder suction assembly. The first iron block is covered with a first sealing strip to ensure the sealing of the second powder leakage trough. Then, the first electromagnet is de-energized, and the first linear motor drives the first electromagnet to rise and reset. S2. Then, the first powder cylinder located on the same side as the first linear motor rises by one layer thickness. The first scraper powder suction component moves from the first powder cylinder towards the forming cylinder, spreading the powder in the first powder cylinder evenly on the forming cylinder and scraping the excess powder into the first powder leakage groove. The first scraper powder suction component returns to its position. After the laser prints one layer, the forming cylinder descends by one layer thickness, and the first powder cylinder rises by one layer thickness. This cycle repeats until the powder in the first powder cylinder is printed. Then, the scraper in the first scraper powder suction component, along with the anti-overflow shell, sucks away the powder from the surface of the second powder leakage groove and the forming cylinder, cleaning the powder. S3. The first linear motor descends, driving the first electromagnet to descend synchronously. The first electromagnet is energized, attracting the first iron block. Then the first linear motor moves upward to reset. S4. The second linear motor descends, causing the first powder leakage trough to be blocked and sealed by the second iron block. The upper surface of the second iron block is on the same plane as the worktable to prevent interference with the second scraper powder suction assembly. Then, the second linear motor rises and resets. The second powder cylinder located on the same side as the second linear motor rises. The scraper in the second scraper powder suction assembly moves from the second powder cylinder towards the forming cylinder, refilling the forming cylinder with powder. Excess powder is scraped into the second powder leakage trough. Then, the scraper returns to its position. After one layer is laser printed, the forming cylinder descends by one layer thickness. This cycle repeats until the powder in the second powder cylinder is printed. Then, the scraper in the second scraper powder suction assembly, along with the anti-overflow shell, sucks away the powder from the surface of the first powder leakage trough and the forming cylinder, cleaning the powder.

[0016] By adopting the above technical solution, the beneficial effects of the present invention are as follows: This invention effectively prevents cross-contamination of powders and enables interlayer printing of two types of metal powders through a two-powder cylinder collaborative powder supply structure, a sealed barrier design of the powder leakage trough and movable iron block, time-division layer control logic, and a modular iron block switching mechanism based on the collaborative drive of a linear motor and an electromagnet.

[0017] This invention significantly improves the efficiency and quality of multi-material 3D printing. Precise powder supply and a sealed barrier design make the printing process more stable, reducing product defects caused by powder cross-contamination and improving the performance and stability of metal products. Furthermore, rapid material change response and intelligent control logic shorten printing time and increase overall production efficiency. More importantly, in most existing multi-material printing equipment, residual powder mixes together after printing, becoming waste powder that cannot be reused and requires the purchase of new powder, increasing raw material costs. This equipment, through precise powder supply, a sealed barrier design, and automatic powder cleaning, achieves powder recycling and reuse, greatly saving raw material costs. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a perspective view of the present invention; Figure 2 This is a front view schematic diagram of the present invention; Figure 3 This is a top view of the present invention; Figure 4 This is a top view of the anti-overflow shell of the present invention; Figure 5 This is a bottom view of the anti-overflow shell of the present invention.

[0020] in: 1. Workbench; 2. Forming cylinder; 3. First powder cylinder; 4. First powder leakage trough; 5. First scraper powder suction assembly; 501. Scraper; 502. Overflow prevention shell; 5021. Air blowing port; 5022. Air suction port; 503. Air blowing nozzle; 504. Air suction nozzle; 505. First retractable hose; 506. Argon cylinder; 507. Pressure regulating valve; 508. Pulse solenoid valve; 509. Second retractable hose; 510. Dust collector; 511. 6. Suction machine; 7. First iron block; 8. First sealing strip; 9. First electromagnet; 10. First linear motor; 11. Sliding mechanism; 12. Slide rail; 13. Sliding rod; 14. Air blowing component; 15. Suction component; 16. Powder hopper; 17. Second powder cylinder; 18. Second powder trough; 19. Second scraper powder suction assembly; 20. Second iron block; 21. Second sealing strip; 22. Second electromagnet; 23. Second linear motor. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] See Figure 1-5 This invention provides a multi-material printing device to prevent cross-contamination of powders, including a worktable 1, a forming cylinder 2 disposed in the middle of the worktable 1, a first powder cylinder 3 and a second powder cylinder 13 disposed on the worktable 1, the first powder cylinder 3 and the second powder cylinder 13 being used to fill different types of powders, a first powder leakage trough 4 and a second powder leakage trough 14 disposed on the worktable 1, a first scraper powder suction assembly 5 and a second scraper powder suction assembly 15 having a moving function disposed on the worktable 1, a first iron block 6 disposed on the worktable 1 for sealing and blocking the first powder leakage trough 4, a second iron block 16 disposed on the worktable 1 for sealing and blocking the second powder leakage trough 14, a first electromagnet 7 disposed on the worktable 1 for picking up and placing the first iron block 6, a second electromagnet 17 disposed on the worktable 1 for picking up and placing the second iron block 16, a first drive mechanism disposed on the worktable 1 for driving the first electromagnet 7 to move up and down, and a second drive mechanism disposed on the worktable 1 for driving the second electromagnet 17 to move up and down.

[0023] In this embodiment, the first driving mechanism is a first linear motor 8 with driving function, a lead screw module, and a servo motor, etc., and the second driving mechanism is a second linear motor 18 with driving function, a lead screw module, and a servo motor, etc. In this embodiment, the first driving mechanism is preferably a first linear motor 8 for driving the first electromagnet 7 to move up and down, and the first electromagnet 7 is driven to move up and down under the action of the first linear motor 8. In this embodiment, the second driving mechanism is preferably a second linear motor 18 for driving the second electromagnet 17 to move up and down. Under the action of the second linear motor 18, the second electromagnet 17 is driven to move up and down.

[0024] In this embodiment, both the first scraper powder suction assembly 5 and the second scraper powder suction assembly 15 include a scraper 501 and an anti-overflow shell 502 for suctioning powder mounted on the scraper 501. An air blowing nozzle 503 and an air suction nozzle 504 are mounted on the anti-overflow shell 502. The air blowing nozzle 503 is mounted on an argon cylinder 506 through a first retractable hose 505. A pressure regulating valve 507 and a pulse solenoid valve 508 are sequentially mounted at the connection between the argon cylinder 506 and the first retractable hose 505. The air suction nozzle 504 is mounted on a dust collector 510 through a second retractable hose 509. The dust collector 510 is mounted on a suction machine 511 through a connecting pipe. The anti-overflow housing 502 has an air inlet 5021 that communicates with the air nozzle 503, and an air inlet 5022 that communicates with the air suction nozzle 504. The first scraper powder suction component 5 or the second scraper powder suction component 15 moves to directly above the forming cylinder 2, completely covering the forming cylinder 2, that is, the first scraper powder suction component 5 or the second scraper powder suction component 15 can form a sealed cavity with the inside of the forming cylinder 2. Argon cylinder 506 is connected to pressure regulating valve 507 and pulse solenoid valve 508 to generate low-pressure pulse protection airflow. The low-pressure pulse protection airflow is blown into one side of the sealed cavity through air nozzle 503 and air outlet 5021, disturbing and blowing powder from the surface of parts and substrate. At the same time, air suction machine 511 works, and continuous negative pressure is generated at air suction nozzle 504. Metal powder is sucked into the interior of dust collector 510 through air intake 5022.

[0025] The advantages of using low-pressure pulsed protective airflow in this embodiment are: low-pressure pulsed airflow can disturb and lift the metal powder in the sealed cavity; argon protective gas prevents powder oxidation, facilitates powder recycling and reuse, and eliminates the risk of metal dust combustion and explosion at the source.

[0026] Therefore, in this embodiment, the first scraper powder suction component 5 and the second scraper powder suction component 15 integrate powder spreading and powder suction functions, forming a sealed cavity with the forming cylinder 2. This solution solves the problem of inert gas environment damage and powder oxidation caused by the traditional powder collection method of opening the box, significantly improves powder utilization and equipment operating efficiency, reduces manual intervention and resource waste, and realizes a green, safe and efficient powder recycling process.

[0027] In this embodiment, two anti-overflow shells 502 for absorbing powder are respectively installed on opposite sides of the two scrapers 501.

[0028] In this embodiment, the workbench 1 is also provided with a sliding mechanism 9 that guides the movement of the scraper 501. The sliding mechanism 9 includes a slide rail 901 fixedly installed on the workbench 1 and a sliding rod 902 slidably installed on the slide rail 901. The scraper 501 is fixedly installed on the sliding rod 902. When the scraper 501 moves, it can drive the sliding rod 902 to slide on the slide rail 901. With the cooperation of the sliding rod 902 and the slide rail 901, the scraper 501 remains stable during the movement, so that the scraper 501 can stably scrape the powder on a plane.

[0029] In this embodiment, a first sealing strip 601 is fixedly installed on the top edge of the first iron block 6. When the first iron block 6 enters the interior of the second powder leakage trough 14, the first sealing strip 601 is also located inside the second powder leakage trough 14, and the tops of the first iron block 6 and the first sealing strip 601 are flush with the upper surface of the workbench 1. Under the action of the first sealing strip 601, a gap can be prevented between the first iron block 6 and the second powder leakage trough 14, thereby ensuring the sealing of the second powder leakage trough 14 and preventing powder from entering the interior of the second powder leakage trough 14.

[0030] In this embodiment, a second sealing strip 1601 is fixedly installed on the top edge of the second iron block 16. When the second iron block 16 enters the interior of the first powder leakage groove 4, the second sealing strip 1601 is also located inside the first powder leakage groove 4. The tops of the second iron block 16 and the second sealing strip 1601 are flush with the upper surface of the workbench 1. Under the action of the second sealing strip 1601, a gap can be prevented between the second iron block 16 and the first powder leakage groove 4, thereby ensuring the sealing of the first powder leakage groove 4 and preventing powder from entering the interior of the first powder leakage groove 4.

[0031] In this embodiment, an air blowing component 10 is installed on the worktable 1, an air suction component 11 is installed on the worktable 1 at a position symmetrical to the air blowing component 10, and a powder funnel 12 is fixedly installed on the worktable 1 at a position corresponding to the air suction component 11. The air blowing component 10 is used to blow air evenly, and the air suction component 11 is used to suction air. The air blowing component 10 is used to remove the powder splashes during the printing process, and the air suction component 11 blows the powder splashes during the printing process into the interior of the air suction component 11 under the suction action of the air suction component 11, and then enters the interior of the powder funnel 12 which is connected to the air suction component 11. In this embodiment, the blowing component 10 and the suction component 11 are used in conjunction with an external fan, which is prior art and will not be described in detail here.

[0032] In this embodiment, two lifting mechanisms are installed on the workbench 1 for lifting the first powder cylinder 3 and the second powder cylinder 13 respectively, and a second lifting mechanism is installed on the workbench 1 for driving the molding cylinder 2 to lift. The lifting mechanisms are identical in structure, and both are lead screw modules and servo motors, which can realize the lifting of the first powder cylinder 3, the second powder cylinder 13 and the molding cylinder 2.

[0033] This invention also provides a multi-material printing method to prevent powder cross-contamination, implemented based on the aforementioned multi-material printing equipment for preventing powder cross-contamination, comprising the following steps: S1. First, the first linear motor 8 descends, driving the first electromagnet 7 to descend synchronously. The first electromagnet 7 is energized, tightly adsorbing the first iron block 6, and transporting the first iron block 6 to the position of the second powder leakage trough 14, blocking the second powder leakage trough 14. The upper surface of the first iron block 6 is on the same plane as the worktable 1 to prevent interference with the first scraper powder suction assembly 5. The first iron block 6 is covered with a first sealing strip 601 to ensure the sealing of the second powder leakage trough 14. Then, the first electromagnet 7 is de-energized, and the first linear motor 8 drives the first electromagnet 7 to rise and reset. S2. Then, the first powder cylinder 3 located on the same side as the first linear motor 8 rises by one layer thickness, and the first scraper powder suction component 5 moves from the first powder cylinder 3 to the forming cylinder 2, spreading the powder in the first powder cylinder 3 evenly on the forming cylinder 2, and scraping the excess powder into the first powder leakage groove 4. The first scraper powder suction component 5 returns to its position. After the laser prints one layer, the forming cylinder 2 descends by one layer thickness, and the first powder cylinder 3 rises by one layer thickness. This cycle repeats until the powder in the first powder cylinder 3 is printed. Then, the scraper 501 in the first scraper powder suction component 5, along with the anti-overflow shell 502, sucks away the powder from the surface of the second powder leakage groove 14 and the forming cylinder 2, cleaning the powder. S3. The first linear motor 8 descends, driving the first electromagnet 7 to descend synchronously. The first electromagnet 7 is energized, attracting the first iron block 6. Then the first linear motor 8 moves upward to reset. S4. The second linear motor 18 descends, causing the first powder leakage groove 4 to be blocked and sealed by the second iron block 16, and the upper surface of the second iron block 16 is on the same plane as the worktable 1 to prevent interference with the second scraper powder suction assembly 15. Then the second linear motor 18 rises and resets, and the second powder cylinder 13 located on the same side as the second linear motor 18 rises. The scraper 501 in the second scraper powder suction assembly 15 moves from the second powder cylinder 13 toward the forming cylinder 2, re-spreading the powder on the forming cylinder 2. Excess powder is scraped into the second powder leakage groove 14. Then the scraper 501 returns to its position. After one layer is laser printed, the forming cylinder 2 descends by one layer thickness. This cycle repeats until the powder in the second powder cylinder 13 is printed. Then the scraper 501 in the second scraper powder suction assembly 15, along with the anti-overflow shell 502, sucks away the powder from the surface of the first powder leakage groove 4 and the forming cylinder 2, cleaning the powder.

[0034] This invention utilizes a coordinated powder supply structure between the first powder cylinder 3 and the second powder cylinder 13. Through mechanical linkage, the first powder cylinder 3 and the second powder cylinder 13 are precisely coordinated with the two scrapers 501. This makes the supply and application of different metal powders more precise and efficient during the printing process. Compared with the traditional single powder cylinder supply method, it can better meet the needs of multi-material printing, greatly improve printing efficiency and quality, and realize the recycling of powder.

[0035] The time-sharing and layer-by-layer control logic ensures that the two materials are alternately spread and selectively melted in the forming cylinder 2 as needed. This intelligent control method can precisely control the powder spreading and melting process according to the characteristics of different materials and printing requirements, thereby realizing interlayer printing of the two materials. This not only improves the mechanical properties of metal products, but also expands the application of 3D printing technology in more fields.

[0036] The present invention utilizes a coordinated powder supply structure of the first powder cylinder 3 and the second powder cylinder 13 to achieve precise coordination between the first powder cylinder 3, the second powder cylinder 13 and the two scrapers 501 through mechanical linkage. Simultaneously, with the time-division layer control logic, it ensures that the two materials are alternately powdered and selectively melted in the forming cylinder 2 as needed, thereby enabling interlayer printing of the two materials.

[0037] This invention utilizes a sealing and barrier design between the second powder leakage groove 14, the movable first iron block 6, and the first sealing strip 601. During the powder spreading process, the movable first iron block 6, under the control of the first electromagnet 7, can precisely block the second powder leakage groove 14, and the movable second iron block 16, under the control of the second electromagnet 17, can precisely block the first powder leakage groove 4. This effectively prevents cross-contamination between the two powders during the powder spreading process. This sealing and barrier design fundamentally solves the problem of cross-contamination of powders during multi-material printing, making the printed metal products more stable and reliable in quality, and realizing the recycling and reuse of powders.

[0038] Under the action of the blowing component 10, the powder splashes during the printing process can be carried away and blown into the interior of the suction component 11, and then enter the powder hopper 12 connected to the suction component 11. This can prevent the splashed powder from causing printing defects. At the same time, after each layer of powder printing is completed, the powder on the surface of the powder hopper and in the forming cylinder 2 is sucked away by the anti-overflow shell 502, which can clean the powder and avoid cross-contamination of powder.

[0039] The modular first iron block 6 switching mechanism, driven by the first linear motor 8 and the first electromagnet 7, achieves dynamic sealing and rapid material change response of the second powder leakage tank 14. The modular second iron block 16 switching mechanism, driven by the second linear motor 18 and the second electromagnet 17, achieves dynamic sealing and rapid material change response of the first powder leakage tank 4. This mechanism makes the switching between different metal powders faster and more accurate, greatly shortens the material change time, and improves printing efficiency. At the same time, the modular design also facilitates the maintenance and upgrading of the equipment.

[0040] In summary, this invention effectively prevents cross-contamination of powders and completes interlayer printing of two types of metal powders by employing a coordinated powder supply structure of the first powder cylinder 3 and the second powder cylinder 13, a sealed barrier design between the first powder leakage trough 4 and the second iron block 16, a time-division and layer-by-layer control logic, and a switching mechanism based on the modular first iron block 6 driven by the coordinated drive of the first linear motor 8 and the first electromagnet 7, and the modular second iron block 16 driven by the coordinated drive of the second linear motor 18 and the second electromagnet 17. This enables the recycling and reuse of powders.

[0041] This invention significantly improves the efficiency and quality of multi-material 3D printing. Precise powder supply and a sealed barrier design make the printing process more stable, reducing product defects caused by powder cross-contamination, improving the performance and stability of metal products, and enabling powder recycling and reuse. Simultaneously, rapid material change response and intelligent control logic shorten printing time and improve overall production efficiency.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-material printing device for preventing cross-contamination of powders, characterized in that: The system includes a workbench (1), a forming cylinder (2) located in the middle of the workbench (1), a first powder cylinder (3) and a second powder cylinder (13) located on the workbench (1), the first powder cylinder (3) and the second powder cylinder (13) being used to fill different types of powder, a first powder leakage trough (4) and a second powder leakage trough (14) located on the workbench (1), a first scraper powder suction assembly (5) and a second scraper powder suction assembly (15) having a moving function located on the workbench (1), and a device for cleaning the first powder leakage trough (4). The first iron block (6) is sealed and blocked. The workbench (1) is provided with a second iron block (16) for sealing and blocking the second powder leakage tank (14). The workbench (1) is provided with a first electromagnet (7) for picking up and putting down the first iron block (6). The workbench (1) is provided with a second electromagnet (17) for picking up and putting down the second iron block (16). The workbench (1) is provided with a first driving mechanism for driving the first electromagnet (7) to move up and down. The workbench (1) is provided with a second driving mechanism for driving the second electromagnet (17) to move up and down.

2. The multi-material printing device for preventing cross-contamination of powders according to claim 1, characterized in that: The first driving mechanism includes a first linear motor (8) for driving the first electromagnet (7) to move up and down, and the second driving mechanism includes a linear motor (18) for driving the second electromagnet (17) to move up and down.

3. The multi-material printing device for preventing cross-contamination of powders according to claim 1, characterized in that: The first scraper powder suction assembly (5) and the second scraper powder suction assembly (15) both include a scraper (501) and an anti-overflow shell (502) installed on the scraper (501) for suctioning powder. An air blowing nozzle (503) and an air suction nozzle (504) are installed on the anti-overflow shell (502). The air blowing nozzle (503) is installed on the argon cylinder (506) through the first retractable hose (505). A pressure regulating valve (507) and a pulse solenoid valve (508) are installed in sequence at the connection between the argon cylinder (506) and the first retractable hose (505). The air suction nozzle (504) is installed on the dust collector (510) through the second retractable hose (509). The dust collector (510) is installed on the suction machine (511) through the connecting pipe.

4. The multi-material printing device for preventing cross-contamination of powders according to claim 3, characterized in that: The workbench (1) is also provided with two sliding mechanisms (9) that guide the reciprocating movement of the first scraper powder suction assembly (5) and the second scraper powder suction assembly (15). The sliding mechanism (9) includes a slide rail (901) fixedly installed on the workbench (1) and a sliding rod (902) slidably installed on the slide rail (901). The scraper (501) is fixedly installed on the sliding rod (902).

5. A multi-material printing device for preventing cross-contamination of powders according to claim 1, characterized in that: The top edge of the first iron block (6) is fixedly installed with a first sealing strip (601), and the top edge of the second iron block (16) is fixedly installed with a second sealing strip (1601).

6. The multi-material printing device for preventing cross-contamination of powders according to claim 1, characterized in that: An air blowing component (10) is installed on the workbench (1), an air suction component (11) is installed on the workbench (1) at a position symmetrical to the air blowing component (10), and a powder hopper (12) is fixedly installed on the workbench (1) at a position corresponding to the air suction component (11).

7. A multi-material printing device for preventing cross-contamination of powders according to claim 1, characterized in that: The first powder leakage groove (4) and the second powder leakage groove (14) are located on both sides of the forming cylinder (2).

8. A multi-material printing device for preventing cross-contamination of powders according to claim 1, characterized in that: The workbench (1) is equipped with two lifting mechanisms for lifting the first powder cylinder (3) and the second powder cylinder (13) respectively.

9. A multi-material printing device for preventing cross-contamination of powders according to claim 1, characterized in that: The workbench (1) is equipped with a lifting mechanism 2 for driving the molding cylinder (2) to rise and fall.

10. A multi-material printing method for preventing powder cross-contamination according to claim 1, implemented based on the multi-material printing equipment for preventing powder cross-contamination according to any one of claims 1-9, characterized in that: Includes the following steps: S1. First, the first linear motor (8) descends, and the first linear motor (8) drives the first electromagnet (7) to descend synchronously. The first electromagnet (7) is energized and tightly attracts the first iron block (6), transporting the first iron block (6) to the position of the second powder leakage trough (14) to block the second powder leakage trough (14). The upper surface of the first iron block (6) is on the same plane as the worktable (1) to prevent interference with the first scraper powder suction assembly (5). The first iron block (6) is covered with a first sealing strip (601) to ensure the sealing of the second powder leakage trough (14). Then the first electromagnet (7) is de-energized, and the first linear motor (8) drives the first electromagnet (7) to rise and reset. S2. Then the first powder cylinder (3) located on the same side as the first linear motor (8) rises by one layer thickness, and the first scraper powder suction component (5) moves from the first powder cylinder (3) toward the forming cylinder (2), spreading the powder in the first powder cylinder (3) evenly on the forming cylinder (2), and scraping the excess powder into the first powder leakage groove (4). The first scraper powder suction component (5) returns to its position. After the laser prints one layer, the forming cylinder (2) descends by one layer thickness, and the first powder cylinder (3) rises by one layer thickness. This cycle repeats until the powder in the first powder cylinder (3) is printed. Then the scraper (501) in the first scraper powder suction component (5) carries the anti-overflow shell (502) to suck away the powder on the surface of the second powder leakage groove (14) and in the forming cylinder (2), cleaning the powder. S3. The first linear motor (8) descends, driving the first electromagnet (7) to descend synchronously. The first electromagnet (7) is energized, attracting the first iron block (6). Then the first linear motor (8) moves upward to reset. S4. The second linear motor (18) descends, causing the first powder leakage trough (4) to be blocked and sealed by the second iron block (16), and the upper surface of the second iron block (16) is on the same plane as the worktable (1) to prevent interference with the second scraper powder suction assembly (15). Then the second linear motor (18) rises and resets, and the second powder cylinder (13) located on the same side as the second linear motor (18) rises. The scraper (501) in the second scraper powder suction assembly (15) moves from the second powder cylinder (13) to the forming cylinder. (2) Move in the direction to refill the powder in the forming cylinder (2). Excess powder is scraped into the second powder leakage groove (14). Then the scraper (501) returns to its position. After the laser prints one layer, the forming cylinder (2) drops by one layer thickness. This cycle repeats until the powder in the second powder cylinder (13) is printed. Then the scraper (501) in the second scraper powder suction assembly (15) carries the anti-overflow shell (502) to suck up the powder on the surface of the first powder leakage groove (4) and in the forming cylinder (2) and clean the powder.

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