Binder jet 3D printing equipment

Abstract

The invention discloses binder spraying 3D printing equipment, and belongs to the technical field of additive manufacturing. The powder spreading device comprises a powder spreading unit, preheating modules are arranged on the two sides of the powder spreading unit, and the preheating modules can preheat powder and a printing model before powder spreading of the powder spreading unit and preheat the powder after powder spreading of the powder spreading unit. According to the powder spreading unit, the single-roller design is adopted, the influence on a printing model can be avoided, the powder spreading unit adopts the working modes of preheating, powder spreading and heat preservation, caking among powder particles can be reduced, meanwhile, the temperature difference between powder and the printed model is reduced, the edge warping of the model is restrained, and the printing quality is improved.

Description

Technical Field

[0001] This application relates to the field of additive manufacturing technology, and in particular to a binder jetting 3D printing device. Background Technology

[0002] 3D printing is a manufacturing process that constructs three-dimensional solids by printing and stacking layers one by one, and can form complex shapes without molds. In practice, it is difficult to adjust the two powder-spreading rollers to be on the same horizontal plane. Even if they are initially on the same horizontal plane, during actual printing, due to the different heating conditions of the two powder-spreading rollers and the relationship between thermal expansion and contraction, the two powder-spreading rollers will not be on the same horizontal plane.

[0003] A high-speed 3D printing platform and method with publication number CN108312532A describes a printing component where, during printing, a front powder-spreading roller first spreads powder evenly on the worktable, a front infrared lamp preheats the powder, the print head sprays ink, and a rear infrared lamp cures the ink. However, after curing, the rear powder-spreading roller moves from the surface of the molten product and easily scratches the already formed model, thereby damaging the already formed surface and affecting the printed product, or even pushing the printed model away. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a binder jetting 3D printing device. The powder spreading unit adopts a single-roller design, which avoids affecting the printed model. The powder spreading unit uses a preheating, powder spreading, and heat preservation working method, which can reduce the agglomeration between powder particles and reduce the temperature difference between the powder and the printed model, thereby suppressing the warping of the model edges and improving the printing quality. The following technical solution is adopted: A binder jetting 3D printing device includes a powder spreading unit. The powder spreading unit is equipped with preheating modules on both sides. The preheating modules can preheat the powder and the printing model before the powder is spread by the powder spreading unit, and keep the powder warm after the powder is spread by the powder spreading unit.

[0005] Preferably, it also includes a printing unit, wherein heating modules are provided on both sides of the printing unit, the heating modules can heat and keep the powder warm before printing in the printing unit, and solidify and form after printing in the printing unit; More preferably, the heating module includes a first heating component and a second heating component, the first heating component being used to heat the powder and the printing model before spraying the adhesive, and the second heating component being used to spray the adhesive onto the printing unit for curing and shaping.

[0006] More preferably, the arrangement height of the first heating component is higher than that of the second heating component; this can greatly improve the model forming accuracy and quality.

[0007] Both the first heating component and the second heating component are provided with heat insulation components between themselves and the printing unit to block light from irradiating the printing unit.

[0008] Preferably, the preheating module includes a first preheating component disposed on the front side of the powder spreading unit and a second preheating component disposed on the rear side of the powder spreading unit.

[0009] Preferably, the printing unit includes an XY axis drive mechanism and a housing, as well as a printing component and an ink supply component disposed within the housing. The ink supply component is connected to the printing component, and the housing is connected to the XY axis drive mechanism.

[0010] Preferably, it further includes a cooling module for controlling the temperature inside the housing; The cooling module includes a cooling channel located within the printing unit, and a cooling medium circulates within the cooling channel.

[0011] Preferably, the powder spreading unit includes an X-axis drive mechanism and a mounting plate connected to the X-axis drive mechanism, wherein a rotatable powder spreading roller is connected to the mounting plate; A heat insulation cover is provided between the preheating module and the mounting plate, and the heat insulation cover is used to block the light that shines on the powder spreading roller.

[0012] More preferably, it also includes a printing platform, the toner spreading unit is disposed on top of the printing platform for moving toner spreading, and the printing unit is disposed on top of the printing platform for moving printing; The printing platform includes a main powder chamber and a support platform, as well as powder supply chambers located on both sides of the main powder chamber. The support platform is disposed in the main powder chamber and the powder supply chamber to support the powder and the printing model.

[0013] More preferably, it also includes a temperature control module, which is used to control the temperature of the printing platform in zones; The temperature control module includes a mounting bracket and a detection component, as well as an arc-shaped reflector and several heating elements mounted on the mounting bracket. The heating elements divide the printing platform into several independent heating zones, and the detection component is used to provide real-time feedback on the temperature of each heating zone.

[0014] Compared with the prior art, the beneficial effects of this application are as follows: (1) The printing unit and the powder spreading unit are arranged independently in this application, and heating modules and preheating modules are arranged separately to ensure that the powder temperature is maintained, thereby avoiding the warping of the printed model; and the powder spreading unit adopts a single roller design, which can avoid damage or destruction to the printed model and greatly improve the quality of the printed model.

[0015] (2) The printing unit and the powder spreading roller module are arranged separately. The printing unit and some units can adjust their travel speed according to the process to meet the needs of different production processes. This is conducive to optimizing the printing process and improving product performance.

[0016] (3) The powder spreading unit can remove moisture or oil adsorbed on the powder surface during preheating by preheating, spreading powder and keeping it warm, reducing the clumping between powder particles and avoiding “void” or “uneven accumulation” during powder spreading. At the same time, the powder has reached the target preheating temperature during powder spreading, and the temperature difference with the already formed area below is very small, which can effectively suppress the warping of the model edge and improve the printing quality.

[0017] (4) Based on the above, a temperature control module is provided on the top of the printing platform, which can control the printing platform in zones, greatly improve the temperature control accuracy, and improve the quality of the printed model. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of this application; Figure 2 This is a schematic diagram of the printing module structure of this application; Figure 3 This is a schematic diagram of the powder-spreading unit structure of this application; Figure 4 This is a schematic diagram of the temperature control module structure of this application; Figure 5 This is a simplified schematic diagram of this application.

[0019] In the picture: 1. Printing platform; 11. Main toner chamber; 12. Toner supply chamber; 13. Support platform; 14. Toner collection chamber; 2. Printing unit; 20. XY axis drive mechanism; 21. Housing; 22. Printing assembly; 23. Ink supply assembly; 24. Cooling module; 241. Air inlet; 242. Air outlet; 3. Powder spreading unit; 30. X-axis drive mechanism; 31. Mounting plate; 32. Powder spreading roller; 33. Heat insulation cover; 4. Temperature control module; 41. Heating element; 42. Arc-shaped reflector; 43. Mounting bracket; 44. Detection component; 5. Heating module; 51. First heating component; 52. Second heating component; 53. Heat insulation component; 6. Preheating module; 61. First preheating component; 62. Second preheating component. Detailed Implementation

[0020] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described in this application are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0021] See Figures 1 to 5 To further elaborate on this application: A binder jetting 3D printing device includes a printing platform 1, and a powder spreading unit 3 and a printing unit 2, which are respectively used for powder spreading and printing, and are mounted on the top of the printing platform 1. The printing unit 2 can jet binder for printing patterns, and the powder spreading unit 3 is used for spreading powder on the printing platform 1.

[0022] The printing platform 1 includes a main powder chamber 11 and a support platform 13, as well as powder supply chambers 12 located on both sides of the main powder chamber 11. The support platform 13 is height-adjustable. The support platform 13 is disposed in the main powder chamber 11 and the powder supply chamber 12 to support the powder and the printing model.

[0023] Combination Figure 1 In this embodiment, preheating modules 6 are provided on both sides of the powder spreading unit 3. The preheating modules 6 can preheat the powder and printing model before the powder spreading unit 3 spreads the powder, and keep the powder warm after the powder spreading unit 3 spreads the powder. Figure 3 The preheating module 6 includes a first preheating component 61 located in front of the powder spreading unit 3 and a second preheating component 62 located behind the powder spreading unit 3. When spreading powder from left to right, the powder supply chamber 12 on the left side provides powder. The first preheating component 61 first enters above the printing platform 1 and irradiates the powder and printing model on the printing platform 1 for preheating. Then, the powder spreading unit 3 spreads the preheated powder during its movement. The second preheating component 62 irradiates the surface of the spread powder again to keep it warm. Both the first preheating component 61 and the second preheating component 62 can be infrared lamps.

[0024] The powder spreading unit 3 described in this application can remove moisture or oil adsorbed on the powder surface during preheating by preheating, reducing the agglomeration between powder particles, and avoiding "voids" or "uneven accumulation" during powder spreading. At the same time, the powder has reached the target preheating temperature during powder spreading, and the temperature difference between it and the already formed area below is minimal, which can effectively suppress the warping of the model edges and improve the printing quality.

[0025] Combination Figure 1 The printing unit 2 has heating modules 5 on both sides, which are used to heat, solidify, and maintain the temperature of the powder and the printing model. Figure 2 The heating module 5 includes a first heating component 51 and a second heating component 52. The first heating component 51 heats the powder and the printing model before spraying the binder, and the second heating component 52 cures the binder sprayed by the printing unit 2. Both the first heating component 51 and the second heating component 52 can be infrared lamps. After the powder spreading unit 3 spreads the powder, when the printing unit 2 moves to print, the first heating component 51 first irradiates the powder. This keeps the powder warm and prevents it from cooling down quickly. It also re-baks the printed model to improve print quality. Subsequently, the printing unit 2 sprays the binder onto the powder surface to form a pattern. The second heating component 52 quickly cures the binder to reduce the outward diffusion of the binder on the powder surface and improves the forming accuracy. In this embodiment, the arrangement height of the first heating component 51 is higher than that of the second heating component 52. The first heating component 51 is a low-power infrared lamp, which avoids generating too much heat that could cause warping of the printed model. The second heating component 52 is a high-power infrared lamp to quickly cure and set the binder. Preferably, the second heating component 52 has a delayed irradiation time of no more than 0.5s for the new sprayed pattern, and its irradiation power density is greater than 15W / cm², specifically 15-30W / cm². The first heating component 51 maintains an irradiation power density of no more than 1.0W / cm² for the cured area, specifically 0.5-1.0W / cm². The height distance between the first heating component 51 and the second heating component 52 can be 50-100mm.

[0026] Combination Figure 5 In one feasible implementation, the printing unit 2 includes an XY-axis drive mechanism 20 and a housing 21, as well as a printing assembly 22 and an ink supply assembly 23 disposed within the housing 21. The ink supply assembly 23 is connected to the printing assembly 22 and is used to supply adhesive to the printing assembly 22. The housing 21 is connected to the XY-axis drive mechanism 20. The XY-axis drive mechanism 20 includes Y-axis linear drive assemblies arranged on both sides of the printing platform 1, and an X-axis linear drive assembly disposed between the Y-axis linear drive assemblies. The printing unit 2 is connected to the drive end of the X-axis linear drive assembly. The X-axis linear drive assembly and the Y-axis linear drive assembly can be a lead screw drive mechanism, a synchronous belt mechanism, or a linear motor module, etc.

[0027] A heat insulation component 53 is provided between the heating module 5 and the printing unit 2 to block light from irradiating the printing unit 2. Specifically, the heat insulation component 53 is provided between the first heating component 51 and the second heating component 52 and the printing unit 2. The heat insulation component 53 is made of heat-insulating material and can maintain a constant temperature for the printing component 22 and the ink supply component 23. The heat insulation component 53 can be made of ceramic fiber or aerogel felt; no specific limitation is made here.

[0028] The powder spreading unit 3 includes an X-axis drive mechanism 30 and a mounting plate 31 connected to the X-axis drive mechanism 30. A rotatable powder spreading roller 32 is connected to the mounting plate 31. The powder spreading roller 32 is driven to rotate by a power component to spread powder, and its direction can be adjusted according to the powder spreading direction; the power component can be a motor. As a feasible implementation, the X-axis drive mechanism 30 includes X-axis linear drive components arranged on both sides of the printing platform 1; the X-axis linear drive components can be a lead screw drive mechanism, a synchronous belt mechanism, or a linear motor module, etc.

[0029] Combination Figure 5 In this embodiment, the printing unit 2 and the toner spreading unit 3 work alternately; thus, the printing unit 2 and the toner spreading unit 3 do not interfere with each other when they are working; the toner spreading unit 3 can achieve bidirectional toner spreading, which can greatly improve printing efficiency; specifically, when the printing unit 2 moves to the zero position, the printing unit 2 will not interfere with the toner spreading unit 3 spreading toner, and when the toner spreading unit 3 finishes spreading toner, it will move to one side of the printing platform 1 without affecting the printing unit 2 printing.

[0030] Combination Figure 2 In some embodiments, a cooling module 24 is also included, which is used to control the temperature inside the housing 21; the cooling module 24 provides cooling air to control the temperature inside the printing unit 2, preferably the cooling air temperature is 20℃-30℃. Closed-loop control and adjustment can be formed through the sensors of the printing assembly 22.

[0031] The cooling module 24 includes a cooling channel located within the printing unit 2, through which a cooling medium circulates. The cooling medium is cooling air; however, it can also be deionized water, an aqueous ethylene glycol solution, or silicone oil, etc. The cooling channel can be connected to an air supply mechanism to provide a cooling medium at a stable temperature; alternatively, the air supply mechanism can be used in conjunction with other heat exchange mechanisms to ensure the cooling air temperature, without limitation. The cooling channel includes an air inlet 241 and an air outlet 242 located on the housing 21, and the air inlet 241 and air outlet 242 are connected to the air supply mechanism.

[0032] Combination Figure 3 In some embodiments, a heat insulation cover 33 is provided between the preheating module 6 and the mounting plate 31. The heat insulation cover 33 is used to block the light shining on the powder spreading roller 32, so that the preheating module 6 will not shine directly on the powder spreading roller 32, and the heat of the preheating module 6 will not be directly or indirectly transferred to the powder spreading roller 32, thereby ensuring that the temperature of the powder spreading roller 32 is more stable, reducing the warping of the powder spreading roller 32 caused by temperature fluctuations, and improving the powder spreading quality and the quality of the printed model.

[0033] Combination Figure 4 In some embodiments, a temperature control module 4 is also included, which is used to control the temperature of the printing platform 1 in zones; it can compensate for the heat outside the powder spreading and printing process, maintain the powder at a stable temperature, prevent defects such as warping caused by cooling, effectively reduce the defect rate, and thus improve the printing quality.

[0034] The temperature control module 4 includes a fixed mounting bracket 43 and a detection component 44, as well as an arc-shaped reflector 42 and several heating elements 41 mounted on the mounting bracket 43. The heating elements 41 can be infrared lamps. The heating elements 41 divide the printing platform 1 into several independent heating zones. The detection component 44 is used to provide real-time feedback on the temperature of each heating zone. Each heating element 41 corresponds to a heating zone and can control the power of the heating element 41 based on the feedback from the detection component 44.

[0035] In some embodiments, the main powder cavity 11 and the support platform 13 are further provided with a powder preheating assembly (not shown) to control the powder temperature in the main powder cavity 11 and prevent the printed model from cooling down rapidly in the main powder cavity 11, which would cause warping.

[0036] In some embodiments, the printing platform 1 is further provided with powder collection chambers 14 around it, which are used to collect excess powder.

[0037] This application also discloses a 3D printing method, including the above-mentioned binder jetting 3D printing equipment, and further including the following steps: S1: The printing unit 2 moves to the zero position.

[0038] S2: The powder supply chamber 12 on the left side is raised to supply powder, the powder spreading unit 3 moves in the first direction, the preheating module 6 on the right side preheats the powder, and then the powder spreading unit 3 evenly spreads the powder in the main powder chamber 11. At the same time, the preheating module 6 on the left side reheats and keeps the spread powder warm. The preheating temperature of the powder by the preheating module 6 is 40-80℃, preferably 60℃.

[0039] S3: The printing unit 2 moves along the first direction. The heating module 5 on the right first heats and keeps the powder warm. Then, the printing unit 2 sprays adhesive onto the powder surface. After that, the heating module 5 on the left immediately irradiates and cures the adhesive. The printing is completed and the unit returns to the zero position.

[0040] S4: The powder supply chamber 12 on the right side is raised to supply powder, the powder spreading unit 3 moves in the second direction, the preheating module 6 on the left side preheats the powder, and then the powder spreading unit 3 spreads the powder evenly in the main powder chamber 11. At the same time, the preheating module 6 on the right side reheats and keeps the spread powder warm.

[0041] S5: Repeat S3. At this time, the heating module 5 on the right side will heat and keep the powder warm, and at the same time, it will re-bake the previous layer of printed model.

[0042] S6: Repeat S1 to S5.

Claims

1. A binder jetting 3D printing device, characterized in that: It includes a powder spreading unit, and preheating modules are provided on both sides of the powder spreading unit. The preheating modules can preheat the powder and the printing model before the powder spreading unit spreads the powder, and keep the powder warm after the powder spreading unit spreads the powder.

2. The binder jetting 3D printing equipment according to claim 1, characterized in that: It also includes a printing unit, which has heating modules on both sides. The heating modules can heat and keep the powder warm before printing and solidify it after printing.

3. The binder jetting 3D printing equipment according to claim 2, characterized in that: The heating module includes a first heating component and a second heating component. The first heating component is used to heat the powder and the printing model before spraying the adhesive, and the second heating component is used to spray the adhesive onto the printing unit for curing and shaping.

4. The binder jetting 3D printing equipment according to claim 3, characterized in that: The first heating component is arranged at a higher height than the second heating component; Both the first heating component and the second heating component are provided with heat insulation components between themselves and the printing unit to block light from irradiating the printing unit.

5. The binder jetting 3D printing equipment according to claim 1, characterized in that: The preheating module includes a first preheating component located on the front side of the powder spreading unit and a second preheating component located on the rear side of the powder spreading unit.

6. The binder jetting 3D printing equipment according to claim 2, characterized in that: The printing unit includes an XY axis drive mechanism and a housing, as well as a printing component and an ink supply component disposed within the housing. The ink supply component is connected to the printing component, and the housing is connected to the XY axis drive mechanism.

7. The binder jetting 3D printing equipment according to claim 6, characterized in that: It also includes a cooling module for controlling the temperature inside the housing; The cooling module includes a cooling channel located within the printing unit, and a cooling medium circulates within the cooling channel.

8. The binder jetting 3D printing equipment according to claim 1, characterized in that: The powder spreading unit includes an X-axis drive mechanism and a mounting plate connected to the X-axis drive mechanism, and a rotatable powder spreading roller is connected to the mounting plate. A heat insulation cover is provided between the preheating module and the mounting plate, and the heat insulation cover is used to block the light that shines on the powder spreading roller.

9. The binder jetting 3D printing equipment according to claim 2, characterized in that: It also includes a printing platform, with the toner spreading unit located on top of the printing platform for moving and spreading toner; the printing unit is located on top of the printing platform for moving and printing. The printing platform includes a main powder chamber and a support platform, as well as powder supply chambers located on both sides of the main powder chamber. The support platform is disposed in the main powder chamber and the powder supply chamber to support the powder and the printing model.

10. The binder jetting 3D printing equipment according to claim 9, characterized in that: It also includes a temperature control module, which is used to control the temperature of the printing platform in zones; The temperature control module includes a mounting bracket and a detection component, as well as an arc-shaped reflector and several heating elements mounted on the mounting bracket. The heating elements divide the printing platform into several independent heating zones, and the detection component is used to provide real-time feedback on the temperature of each heating zone.

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