A high-efficiency large-size light-curing forming apparatus and forming method

Abstract

The present application relates to a kind of high-efficiency large-size light-cured forming equipment and method, forming equipment includes material cylinder, forming module, oxygen supply module, printing substrate, Y-axis linear movement module and Z-axis linear movement module;Oxygen supply module is used to make the slurry between forming module and printing substrate form non-free liquid level;Forming module is realized by laser scanning along the direction of X axis from point to line forming, along the direction of Y axis movement realizes from line to plane forming;Printing substrate moves along the direction of Z axis, and layer-by-layer forming printing model on printing substrate.Utilize Y-axis linear movement module to drive forming module to move along the direction of Y axis to realize from line to plane forming, can increase printing size without reducing forming precision;The slurry between forming module and printing substrate forms non-free liquid level, can reduce liquid level flow leveling waiting time, using the light-cured forming mode of non-free liquid level line forming, guarantee high precision while realizing high-efficiency large-size printing.

Description

Technical Field

[0001] This invention belongs to the field of additive manufacturing technology, specifically relating to a high-efficiency large-size photopolymerization molding equipment and molding method. Background Technology

[0002] Photopolymerization is an additive manufacturing technology that is widely used in various industries, including aerospace, automotive manufacturing, biomedicine, and science education.

[0003] Currently, the two most common photopolymer 3D printing technologies are stereolithography (SLA) and digital light processing (DLP). SLA technology uses a point-to-line-to-surface scanning method, employing a focused laser beam under computer control to scan point by point according to the contour requirements, thus obtaining the shaped model. DLP technology uses a direct surface forming method, using slicing software to convert the 3D model into multiple layers of 2D planar images. Then, the DLP projection system projects these 2D images onto liquid photosensitive resin, where the resin solidifies at the pixel locations. Both technologies require a squeegee to spread the resin: after the first layer solidifies, the platform lowers by one layer's height, and the squeegee's reciprocating motion covers another layer of liquid resin on top of the solidified layer. The second layer is then scanned and solidified, adhering to the previous layer, and so on, until the final shape is formed. DLP and SLA technologies each have their advantages. DLP technology has a fast forming speed but lower printing accuracy, while SLA technology has high printing accuracy but a slower forming speed. In the photopolymer printing process, it is impossible to simultaneously achieve both printing efficiency and printing accuracy.

[0004] With the development of DLP technology, a bladeless continuous liquid surface growth technology (CLIP) based on DLP printing technology has emerged. CLIP technology is a revolutionary 3D printing technology developed by Carbon3D in the United States in 2015. Its principle is mainly to use a transparent and breathable Teflon membrane as the bottom of the resin tank, allowing light and oxygen to pass through. The oxygen entering the resin tank inhibits the solidification of the part of the resin closest to the bottom due to the oxygen inhibition effect, forming a "printing dead zone" tens of micrometers thick. The liquid below the "printing dead zone" forms a non-free liquid surface. The printing dead zone allows the printing platform to be continuously raised. During this process, there is no need for the reciprocating movement of the scraper, which greatly increases the printing efficiency.

[0005] The emergence of CLIP technology has injected new vitality into photopolymer 3D printing. However, the existing CLIP technology uses surface projection technology based on DMD chips. When printing large-sized parts, there is a problem of reduced accuracy due to insufficient resolution. It is difficult to meet the technical requirements of high precision and large size at the same time, resulting in poor overall printing performance. This shortcoming is more prominent when printing large-sized parts, which affects the further promotion of photopolymer 3D printing in the field of additive manufacturing. Summary of the Invention

[0006] In view of the technical problems existing in the prior art, one of the objectives of this invention is to provide a high-efficiency large-size photopolymerization molding device that can simultaneously meet the technical requirements of high precision and large size, and obtain good overall printing performance.

[0007] In view of the technical problems existing in the prior art, the second objective of the present invention is to provide a high-efficiency large-size photopolymerization molding method.

[0008] The objective of this invention is achieved through the following technical solution:

[0009] A high-efficiency, large-size photopolymerization molding equipment includes a frame, a material cylinder, a molding module, an oxygen supply module, a printing substrate, a Y-axis linear motion module, and a Z-axis linear motion module;

[0010] The material cylinder is fixed to the frame and is used to store the printing paste;

[0011] The printing substrate and the forming module are arranged sequentially from bottom to top in the material cylinder;

[0012] The oxygen supply module is connected to the forming module and is used to supply oxygen to the forming module so that the slurry between the forming module and the printing substrate forms a non-free liquid surface;

[0013] The forming module achieves point-to-line forming through laser scanning along the X-axis.

[0014] The Y-axis linear motion module is connected to the forming module and is used to drive the forming module to move along the Y-axis direction to achieve the forming from line to surface.

[0015] The Z-axis linear motion module is connected to the printing substrate and is used to drive the printing substrate to move along the Z-axis direction in order to form a printed model layer by layer on the printing substrate.

[0016] Furthermore, the forming module includes a forming window, a curing light source, an oxygen supply chamber, and a line forming optical module; the line forming optical module is located above the material cylinder and connected to the Y-axis linear motion module; the oxygen supply chamber is located below the line forming optical module; the forming window is located below the oxygen supply chamber and above the printing substrate, together with the line forming optical module and the oxygen supply chamber to form a closed space, and a non-free liquid surface is formed between the forming window and the printing substrate; the oxygen supply module is connected to the oxygen supply chamber; the curing light source is located above the forming window and is used to cure the paste printed on the printing substrate.

[0017] Furthermore, the lower part of the oxygen supply chamber is fitted and fixedly connected to the forming window.

[0018] Furthermore, the forming window includes an oxygen-permeable film and a porous glass support layer. The oxygen supply chamber, the porous glass support layer, and the oxygen-permeable film are connected and fixed sequentially from top to bottom, with the oxygen-permeable film correspondingly positioned above the printing substrate.

[0019] Furthermore, the line forming optical module includes a laser generator, a laser galvanometer, a field lens, and a drive motor. The laser generator is located between the laser galvanometer and the field lens and is used to emit laser light into the laser galvanometer. The laser light is reflected sequentially by the laser galvanometer and the field lens and then hits the printing substrate to form a point. The drive motor is used to drive the laser galvanometer to rotate rapidly so that the point moves back and forth rapidly on the printing substrate to form a line.

[0020] Furthermore, the laser galvanometer has a hexagonal prism structure, comprising six planar galvanometers connected end to end to form a closed structure, with the rotation axis of the laser galvanometer coinciding with the axis of the hexagonal prism.

[0021] Furthermore, the wire-forming optical module can be vertically and adjustablely connected to the upper part of the frame.

[0022] A high-efficiency large-size photopolymerization molding method, employing a high-efficiency large-size photopolymerization molding device, includes the following steps.

[0023] The lower end of the molding module is immersed in the slurry in the material cylinder;

[0024] The Z-axis linear motion module drives the printing substrate to move along the Z-axis direction, adjusts the distance between the forming module and the printing substrate, and supplies oxygen to the forming module through the oxygen supply module, so that the slurry between the forming module and the printing substrate forms a non-free liquid surface.

[0025] The forming module moves along the X-axis to form lines from points on the printing substrate;

[0026] The forming module is driven to move along the Y-axis by the Y-axis linear motion module, so as to achieve the forming from line to surface on the printing substrate;

[0027] The Z-axis linear motion module is used to drive the printing substrate to descend by one printing layer thickness. The above printing steps are repeated until the entire printing model is printed.

[0028] Furthermore, when printing adjacent upper and lower layers, the Y-axis linear movement module drives the forming module to move in opposite directions along the Y-axis.

[0029] Furthermore, when the printing substrate is driven to move along the Z-axis direction using the Z-axis linear motion module, the distance between the forming module and the printing substrate is adjusted to be greater than the sum of a printing dead zone and a printing layer thickness.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] This invention utilizes a Y-axis linear motion module to drive the forming module to move along the Y-axis direction to achieve line-to-surface forming, which can increase the printing size without reducing the forming accuracy. It also utilizes a Z-axis linear motion module to drive the printing substrate to move along the Z-axis direction, adjusting the distance between the forming module and the printing substrate. At the same time, it uses an oxygen supply module to form a non-free liquid surface between the forming module and the printing substrate, thereby reducing the waiting time for liquid surface leveling. By adopting a photopolymerization forming method with non-free liquid surface line forming, the scraping and light-emitting printing are simplified into one step, ensuring high accuracy while achieving high-efficiency large-size printing. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the planar structure of a high-efficiency, large-size photopolymerization molding device.

[0033] Figure 2 This is a schematic diagram showing the relative positions of the liquid surface, the forming window, and the printing substrate during printing.

[0034] Figure 3 This is a schematic diagram of the structure of a wire-forming optical module.

[0035] Figure 4 This describes the working steps of a high-efficiency, large-size photopolymerization molding equipment.

[0036] In the picture:

[0037] 1-Material cylinder, 2-Y-axis linear motion module, 3-Mounting partition, 4-Integral frame, 5-Oxygen supply chamber, 6-Line forming optical module mounting block, 7-Line forming optical module, 8-L-shaped support rod, 9-Z-axis linear motion module, 10-Air valve, 11-Air pipe, 12-Air pump, 13-Forming window;

[0038] 14-Curing light source, 15-Porous glass support layer, 16-Oxygen-permeable film, 17-Printing dead zone, 18-Printing model, 19-Printing substrate;

[0039] 20 - Field mirror, 21 - Laser generator, 22 - Laser galvanometer. Detailed Implementation

[0040] The present invention will now be described in further detail.

[0041] A high-efficiency, large-size photopolymerization molding equipment includes a frame, a material cylinder 1, a moving module, a molding module, an oxygen supply module, and a printing substrate 19.

[0042] The frame includes an overall frame 4 and a mounting partition 3, and the frame is divided into an upper part and a lower part by the mounting partition 3;

[0043] The material cylinder 1 is installed below the mounting partition 3, located at the lower part of the frame;

[0044] The moving module includes a Y-axis linear moving module 2 and a Z-axis linear moving module 9;

[0045] The forming module includes a forming window 13, an oxygen supply chamber 5, and a wire forming optical module 7;

[0046] The shaped window 13 includes an oxygen-permeable membrane 16 and a porous glass support layer 15, which are fixed to the lower part of the oxygen supply chamber 5.

[0047] The line forming optical module 7 is located directly above the material cylinder 1. The Y-axis linear motion module 2 is connected to the line forming optical module 7 and drives the line forming optical module 7 to move along the Y-axis direction, thereby increasing the printing size without reducing the forming accuracy.

[0048] The oxygen supply chamber 5 is installed directly below the line forming optical module 7, forming a closed space together with the line forming optical module 7 and the forming window 13. A non-free liquid surface is formed between the curing plane (the curing plane is the plane illuminated by the curing light source 14, which is the top surface of the printing substrate 19 in the first layer and the upper surface of the printed model 18 during the printing process) and the forming window 13, thereby reducing the waiting time for liquid leveling and improving printing efficiency.

[0049] The Z-axis linear motion module 9 is installed at the rear of the frame along the Z-axis direction, passing through the upper and lower parts of the frame. The Z-axis linear motion module 9 is connected to the printing substrate 19 and drives the printing substrate 19 to move along the Z-axis direction.

[0050] At the start of printing, the forming window 13 is immersed in the slurry in the material tank 1, located 0.5 mm below the slurry surface. The printing substrate 19 is located directly below the forming window 13, at a distance of 0.1 mm (approximately one printing dead zone 17 plus four printing layer thicknesses). With this structure, the liquid between the forming window 13 and the printing substrate 19 is constrained by the lower surface of the forming window 13 and the upper surface of the printed model 18 or the printing substrate 19, forming a non-free liquid surface. This prevents the liquid surface from fluctuating due to mechanical movement, thus ensuring a smooth and flat printing surface and reducing the waiting time for liquid leveling. Furthermore, during the printing of the first layer, because the distance between the printing substrate 19 and the forming window 13 is greater than one printing dead zone 17 plus one printing layer thickness, the slurry in contact with the printing substrate 19 does not solidify completely, thereby reducing the time required to remove the printed model 18 from the printing substrate 19 during post-processing.

[0051] The porous glass support layer 15 is the same size as the oxygen-permeable film 16. The porous glass support layer 15 is located above the oxygen-permeable film 16. The porous glass support layer 15 has mounting holes for connecting and fixing the oxygen supply chamber 5, the porous glass support layer 15 and the oxygen-permeable film 16 in sequence from top to bottom. The oxygen-permeable film 16 can transmit oxygen and ultraviolet light. The oxygen that passes through can enter the resin liquid and act as a polymerization inhibitor to prevent the curing reaction from occurring. A printing dead zone 17 with a thickness of about 20 micrometers is formed below the surface of the oxygen-permeable film 16, so that the photocuring reaction occurs in the area below the printing dead zone 17, thereby realizing the continuous liquid surface forming technology.

[0052] Mounting partition 3 is a large flat plate whose dimensions fit the XY plane of the frame. It is installed at the center of the frame, dividing the frame into upper and lower parts. A square through hole with the same size as the opening of the material cylinder 1 is opened at the center of mounting partition 3. Two symmetrical linear through holes are opened on both sides of the central square through hole along the Y-axis for the installation and movement of the linear forming optical module mounting block 6.

[0053] The line forming optical module 7 includes a laser generator 21, a laser galvanometer 22, a field lens 20, and a drive motor. The laser generator 21 emits laser light, which is reflected sequentially by the laser galvanometer 22 and the field lens 20 onto the printing substrate 19 to form a point. The drive motor drives the laser galvanometer 22 to rotate rapidly, causing the point to reciprocate quickly on the printing substrate 19 to form a line. The laser galvanometer 22 consists of six planar mirrors forming a hexagonal prism, with its rotation axis coinciding with the axis of rotation. This structure effectively avoids the phenomenon of the laser galvanometer 22 rotating without travel, thus improving the conversion speed from point to line in line forming.

[0054] The Y-axis linear motion module 2 includes a stepper motor, a synchronous belt, a guide rail slider, and a line-forming optical module mounting block 6. The stepper motor and synchronous belt are mounted on the lower part of the frame, and the guide rail slider is mounted below the mounting partition 3, located outside the two linear through holes. The synchronous belt, guide rail slider, and line-forming optical module mounting block 6 are fixedly connected. The drive motor drives the synchronous belts on both sides to rotate, thereby moving the guide rail slider and the line-forming optical module mounting block 6 along the Y-axis direction.

[0055] The Z-axis linear motion module 9 includes a servo motor, a lead screw and nut pair, and a guide rail slider. The Z-axis linear motion module 9 is fixedly connected to two L-shaped support rods 8.

[0056] The line-forming optical module mounting block 6 has a gantry structure and is located at the top of the frame. A through-hole at the bottom connects it to the sliders on both sides, while a through-hole at the top crossbeam secures the line-forming optical module 7 to the center of the crossbeam via bolts. This structure allows adjustment of the bolt position to change the position of the line-forming optical module 7 along the Z-axis, thus ensuring the forming window 13 is at a suitable height.

[0057] The oxygen supply module includes an air pump 12, an air pipe 11, and an air valve 10. The air pump 12 is mounted on the frame. The air pump 12 draws in oxygen and inputs it into the oxygen supply chamber 5 through the air pipe 11. The air pump 12 is used to regulate the input rate of oxygen. The upper inlet of the oxygen supply chamber 5 has a mounting hole, which is fixedly connected to the lower end of the linear forming optical module 7. The middle part of the oxygen supply chamber 5 has an air inlet that is connected to the air pipe 11. The size of the lower outlet of the oxygen supply chamber 5 matches the size of the forming window 13 and is fixedly connected to it.

[0058] The opening of the material cylinder 1 is fixed in place with the square through hole of the mounting partition 3, and the material cylinder 1 is located at the bottom of the frame.

[0059] Two L-shaped support rods 8 are located directly above the material cylinder 1. The printing substrate 19 is fixed to the lower part of the L-shape of the L-shaped support rods 8 and is supported by the L-shaped support rods 8 to move up and down along the Z-axis in the material cylinder 1.

[0060] A high-efficiency large-size photopolymerization molding method, using the aforementioned high-efficiency large-size photopolymerization molding equipment, includes the following steps:

[0061] S1, the Z-axis linear motion module 9 drives the printing substrate 19 to rise until the upper surface of the printing substrate 19 is 0.6 mm away from the upper surface of the material cylinder 1;

[0062] S2, add slurry to the material cylinder 1 and adjust the position of the molding window 13 until the distance between the slurry liquid surface and the lower surface of the molding window 13 is 0.5 mm and the distance between the lower surface of the molding window 13 and the upper surface of the printing substrate 19 is 0.1 mm.

[0063] S3, turn on the air pump 12 and control the oxygen input rate by adjusting the air valve 10;

[0064] S4. Import the model into the computer, calculate the laser scanning path, and turn on the laser.

[0065] S5, the Y-axis linear motion module 2 drives the line forming optical module 7 to scan from the rear end to the front end along the Y-axis direction, and the curing light source 14 will cure the printing paste, thereby completing the printing of one layer;

[0066] S6, the Z-axis linear motion module 9 drives the printing substrate 19 to descend by one printing layer thickness;

[0067] S7, the Y-axis linear motion module 2 drives the line forming optical module 7 to scan from the front end to the rear end along the Y-axis direction. The curing light source 14 will cure the printing paste, thereby completing the printing of the next layer. When printing adjacent upper and lower layers, the Y-axis linear motion module 2 drives the line forming optical module 7 to move in opposite directions along the Y-axis direction, avoiding idle strokes and improving printing efficiency.

[0068] S8, the Z-axis linear motion module 9 drives the printing substrate 19 to descend by one printing layer thickness;

[0069] S9, repeat S5 to S8 until the entire model is printed.

[0070] In step S5, the laser scanning path mainly describes the forming stage from point to line along the X-axis, and the motion of the Y-axis linear motion module 2 mainly describes the forming stage from line to surface along the Y-axis.

[0071] This invention employs a non-free liquid surface line forming photopolymerization molding method, simplifying scraping and light emission printing into a single step, ensuring high precision while achieving high-efficiency large-size printing.

[0072] The above embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present invention shall be considered equivalent substitutions and shall be included within the protection scope of the present invention.

Claims

1. A large-size photopolymerization molding device, characterized in that: It includes a frame, a material cylinder, a forming module, an oxygen supply module, a printing substrate, a Y-axis linear motion module, and a Z-axis linear motion module; The material cylinder is fixed to the frame and is used to store the printing paste; The printing substrate and the forming module are arranged sequentially from bottom to top in the material cylinder; The oxygen supply module is connected to the forming module and is used to supply oxygen to the forming module so that the slurry between the forming module and the printing substrate forms a non-free liquid surface; The forming module achieves point-to-line forming through laser scanning along the X-axis. The Y-axis linear motion module is connected to the forming module and is used to drive the forming module to move along the Y-axis direction to achieve the forming from line to surface. The Z-axis linear motion module is connected to the printing substrate and is used to drive the printing substrate to move along the Z-axis direction in order to form a printed model layer by layer on the printing substrate.

2. A large-size photopolymerization molding device according to claim 1, characterized in that: The forming module includes a forming window, a curing light source, an oxygen supply chamber, and a line forming optical module; The line forming optical module is located on the upper part of the material cylinder and connected to the Y-axis linear motion module; The oxygen supply chamber is located below the line forming optical module; the forming window is located below the oxygen supply chamber and above the printing substrate, together with the line forming optical module and the oxygen supply chamber to form a closed space, and a non-free liquid surface is formed between the forming window and the printing substrate. The oxygen supply module is connected to the oxygen supply chamber; the curing light source is located above the forming window and is used to cure the paste printed on the printing substrate.

3. A large scale light solidification forming apparatus according to claim 2, wherein: The lower part of the oxygen supply chamber fits into the shaped window and is fixedly connected.

4. A large scale light solidification forming apparatus according to claim 2, wherein: The forming window includes an oxygen-permeable membrane and a porous glass support layer. The oxygen supply chamber, the porous glass support layer, and the oxygen-permeable membrane are connected and fixed in sequence from top to bottom, with the oxygen-permeable membrane correspondingly positioned above the printing substrate.

5. A large scale light solidification forming apparatus according to claim 1, wherein: The line forming optical module includes a laser generator, a laser galvanometer, a field lens, and a drive motor. The laser generator is located between the laser galvanometer and the field lens and is used to emit laser light into the laser galvanometer. The laser light is reflected sequentially by the laser galvanometer and the field lens and hits the printing substrate to form a point. The drive motor is used to drive the laser galvanometer to rotate rapidly so that the point moves back and forth rapidly on the printing substrate to form a line.

6. A large scale light solidification forming apparatus according to claim 5, wherein: The laser galvanometer has a hexagonal prism structure, consisting of six planar galvanometers connected end to end to form a closed structure. The rotation axis of the laser galvanometer coincides with the axis of the hexagonal prism.

7. A large scale light solidification forming apparatus according to claim 1, wherein: The wire-forming optical module can be adjusted vertically and connected to the upper part of the frame.

8. A large scale stereolithography method characterized by: The large-size photopolymerization molding equipment according to any one of claims 1-7 includes the following steps: The lower end of the forming module is immersed in the slurry in the material cylinder; The Z-axis linear motion module drives the printing substrate to move along the Z-axis direction, adjusts the distance between the forming module and the printing substrate, and supplies oxygen to the forming module through the oxygen supply module, so that the slurry between the forming module and the printing substrate forms a non-free liquid surface. The forming module moves along the X-axis to form lines from points on the printing substrate; The forming module is driven to move along the Y-axis by the Y-axis linear motion module, so as to achieve the forming from line to surface on the printing substrate; The Z-axis linear motion module is used to drive the printing substrate to descend by one printing layer thickness. The above printing steps are repeated until the entire printing model is printed.

9. A method of large scale photocuring according to claim 8, wherein: When printing adjacent upper and lower layers, the Y-axis linear movement module drives the forming module to move in opposite directions along the Y-axis.

10. A method of large scale photocuring according to claim 8, wherein: When the Z-axis linear movement module drives the printing substrate to move along the Z-axis direction, the distance between the forming module and the printing substrate is adjusted to be greater than the sum of one printing dead zone and one printing layer thickness.

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