Solvent-assisted centrifugal multi-material photocuring 3D printing device and method

Abstract

The invention provides a solvent-assisted centrifugal multi-material photocuring 3D printing device and method. The solvent-assisted centrifugal multi-material photocuring 3D printing device comprises a rack, a light path control device, a material changing device, a liquid tank assembly, a cleaning device, a lifting device and a printing platform. The light path control device, the material changing device and the lifting device are all arranged on the rack, the cleaning device is installed on the lifting device, the printing platform is installed on the cleaning device, and the cleaning device is used for driving the printing platform to rotate; the liquid tank assembly is installed on the material changing device, the material changing device is used for driving the liquid tank assembly to move transversely, the liquid tank assembly is arranged below the printing platform, and the light path control device is arranged below the liquid tank assembly. The organic solvent is used for cleaning the residual resin material, cross contamination of various materials is avoided, the residual resin material and the residual organic solvent are removed through centrifugal force generated by rotation of the motor, the influence of the organic solvent is reduced through secondary centrifugation, the multi-material printing precision is improved, the printing efficiency is effectively improved, and material waste is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a solvent-assisted centrifugal multi-material light-curing 3D printing device and method. Background Art

[0002] The core concept of 3D printing is to use digital models to create three-dimensional objects by adding materials layer by layer. This method allows the manufacture of complex structures and obtains structures that are difficult to achieve with traditional technologies. It has broad application prospects in many fields such as biomedicine, aerospace, construction and automobiles.

[0003] At present, polymer-based 3D printing technologies mainly include direct ink writing (DIW), melt extrusion molding (FDM), digital photocuring (DLP) and PolyJet. Among them, DLP technology uses ultraviolet light to cure materials such as photosensitive resins to manufacture 3D parts. As a high-resolution and fast 3D printing technology, it has been widely used in many fields. DLP printing technology has high precision and speed, which gives it a significant advantage in manufacturing three-dimensional objects with precise arrangement, different properties and functions. In recent years, the continuous liquid surface molding (CLIP) and large area rapid printing (HARP) methods based on DLP technology have significantly improved the printing speed and scale. CLIP achieves fast and high-precision printing by continuously curing the resin, which is suitable for the manufacture of complex geometric shapes. HARP uses multiple light sources and a large-area printing platform to produce multiple parts in a short time. These technological advances have promoted the widespread application of 3D printing in industries such as industry and medicine, and provided designers and engineers with more efficient solutions.

[0004] A major drawback of traditional DLP printing technology is that it can usually only be printed with a single material. This limits the flexibility and functionality of the design, and affects the application range and function of the final product. Therefore, one of the key issues in achieving integrated printing of multi-material components is how to avoid cross-contamination of multiple resin materials when changing materials, improve the resolution of multi-material distribution, and speed up the material change. At present, multi-material DLP printing equipment mainly switches materials by manually or automatically replacing the liquid tank, but simply adding multiple liquid tanks cannot effectively solve the problem of material cross-contamination. Therefore, it is usually necessary to use physical methods to remove residual resin liquid. However, there are some problems with this measure: physical methods often cannot completely remove all residual materials, especially in components with complex shapes, which are prone to leaving hidden resins. In addition, external force operations may cause damage to the surface of the component, especially on more fragile or delicate structures, which may lead to a decrease in surface quality. Therefore, the existing multi-material DLP printing technology urgently needs further improvement. Summary of the invention

[0005] In view of the defects in the prior art, the object of the present invention is to provide a solvent-assisted centrifugal multi-material light-curing 3D printing device and method.

[0006] The solvent-assisted centrifugal multi-material light-curing 3D printing device provided by the present invention includes a frame, an optical path control device, a material changing device, a liquid tank assembly, a cleaning device, a lifting device and a printing platform;

[0007] The optical path control device, the material changing device and the lifting device are all arranged on the frame, the cleaning device is installed on the lifting device, and the printing platform is installed on the cleaning device. The lifting device is used to drive the cleaning device and the printing platform to rise and fall, and the cleaning device is used to drive the printing platform to rotate;

[0008] The liquid tank assembly is installed on the material changing device, and the material changing device is used to drive the liquid tank assembly to move horizontally. The liquid tank assembly is correspondingly arranged below the printing platform, and the optical path control device is correspondingly arranged below the liquid tank assembly.

[0009] Preferably, the frame comprises an upper base plate, a first connecting rod, a middle base plate, a second connecting rod and a lower base plate;

[0010] The middle bottom plate is stacked and installed on the lower bottom plate through a plurality of second connecting rods, and the upper bottom plate is stacked and installed on the middle bottom plate through a plurality of first connecting rods;

[0011] The optical path control device is installed on the lower bottom plate, the material changing device is installed on the middle bottom plate, and the lifting device is installed on the upper bottom plate.

[0012] Preferably, the optical path control device comprises an adapter frame and a projector, and the adapter frame is fixedly mounted on the frame;

[0013] The projector is fixedly mounted on the adapter frame, and is used to realize light curing of printing materials on the printing platform.

[0014] Preferably, the material changing device comprises a synchronous belt module, a synchronous belt motor, a first coupling, an optical axis, a supporting platform and a liquid tank frame;

[0015] There are two synchronous belt modules, which are symmetrically and parallelly installed on the frame, and the movement direction of the synchronous belt module and the projection direction of the projector of the optical path control device are in the same vertical plane;

[0016] The support platform is mounted on the synchronous belt module, and the motor is mounted at the end of the synchronous belt module to drive the support platform to reciprocate, and the rotating shafts of the two synchronous belt modules are connected to the same optical axis through a first coupling;

[0017] Both sides of the liquid tank frame are respectively installed on two supporting platforms, and the liquid tank assembly is installed on the top of the liquid tank frame.

[0018] Preferably, the liquid tank assemblies are multiple, and the multiple liquid tank assemblies are installed in parallel on the top of the liquid tank frame along the moving direction of the synchronous belt module.

[0019] Preferably, the liquid tank assembly comprises a base, light-transmitting glass, a pressure plate, a liquid tank body and a glass window, and the base is mounted on the material changing device;

[0020] The light-transmitting glass is installed in the base, the pressing plate is installed at the bottom of the liquid tank body and is used to fix the sealing film at the bottom of the liquid tank body, the liquid tank body is installed on the base, and the side wall of the liquid tank body is provided with a glass window.

[0021] Preferably, the lifting device comprises a right-angle adapter bracket and a stepper motor, and the transverse mounting plate of the right-angle adapter bracket is fixedly mounted on the frame;

[0022] The vertical mounting plate of the right-angle adapter bracket is provided with a slide rail and a slider structure that cooperate with each other, the cleaning device is fixedly mounted on the slider, and the stepper motor is mounted on the right-angle adapter bracket and is used to drive the slider to move in the vertical direction in the slide rail.

[0023] Preferably, the cleaning device comprises a support beam, a motor support beam, a bearing support beam, a servo rotary motor, a second coupling, a first thrust bearing, a rotating shaft, a deep groove ball bearing, a second thrust bearing and a housing;

[0024] The support beam is installed on the lifting device, the motor support beam and the bearing support beam are both installed on the support beam, and the bearing support beam is correspondingly installed below the motor support beam, and a servo rotating motor is installed on the top of the motor support beam;

[0025] The output shaft at the bottom of the servo rotary motor is connected to the rotating shaft through a second coupling, the first thrust bearing, the deep groove ball bearing and the second thrust bearing are sequentially sleeved on the outside of the rotating shaft from top to bottom and are located in a housing, and the housing is installed at the bottom of the bearing support beam;

[0026] The bottom end of the rotating shaft is fixedly connected to the printing platform.

[0027] Preferably, the printing platform comprises a bracket and a printing base, the bracket is connected to the cleaning device, and the printing base is fixedly mounted on the bottom of the bracket.

[0028] According to the solvent-assisted centrifugal multi-material light-curing 3D printing method provided by the present invention, the solvent-assisted centrifugal multi-material light-curing 3D printing device is used, and the following steps are included:

[0029] Step 1: Control the stepper motor of the lifting device to move the printing base of the printing platform to completely contact the liquid tank assembly, and then control the printing base to lift twice the preset slice layer thickness;

[0030] Step 2: Control the projector of the optical path control device to project the first layer of slice pattern onto the printing base to complete the curing of the current layer;

[0031] Step 3: After the curing of the current layer is completed, determine whether the printing process has been completed. If so, end the printing. If not, perform the following steps;

[0032] Step 4: Determine whether there are other materials in the current layer. If there are other materials, execute step 5a. If there are no other materials, execute step 5b.

[0033] Step 5a: Control the stepper motor to lift up so that the printed structure leaves the liquid surface, control the servo rotary motor in the cleaning device to rotate to remove the residual material to the current liquid tank, and control the stepper motor to lift up so that the printed structure leaves the liquid tank assembly;

[0034] The synchronous belt module of the material changing device is controlled to move to the cleaning tank in the liquid tank assembly, the stepper motor descends to immerse the printing structure in the organic solvent, the servo rotary motor rotates a preset number of circles, the stepper motor is lifted until the printing structure is exposed to the liquid surface, and the servo rotary motor rotates to further remove the residual resin and residual organic solvent;

[0035] Control the stepper motor to lift until the printing structure leaves the liquid tank assembly, the synchronous belt module moves to the liquid tank corresponding to the next material, and control the stepper motor to descend until the current layer is in close contact with the bottom of the liquid tank, and then execute step 2;

[0036] Step 5b: Determine whether the set material of the next layer is the same as the current layer. If different, control the stepper motor to lift so that the printed structure leaves the liquid surface, control the servo rotary motor in the cleaning device to rotate to remove the residual material to the current liquid tank, and control the stepper motor to lift so that the printed structure leaves the liquid tank assembly;

[0037] The synchronous belt module of the material changing device is controlled to move to the cleaning tank in the liquid tank assembly, the stepper motor descends to immerse the printing structure in the organic solvent, the servo rotary motor rotates a preset number of circles, the stepper motor is lifted until the printing structure is exposed to the liquid surface, and the servo rotary motor rotates to further remove the residual resin and residual organic solvent;

[0038] Control the stepper motor to lift the printing structure away from the liquid tank assembly, move the synchronous belt module to the liquid tank corresponding to the next material, control the stepper motor to the next layer height, and separate it from the bottom of the liquid tank by a set layer thickness distance, and execute step 2;

[0039] If the set material of the next layer is the same as that of the current layer, the stepper motor is directly controlled to the height of the next layer, which is separated from the bottom of the liquid tank by a set layer thickness distance, and step 2 is executed.

[0040] Compared with the prior art, the present invention has the following beneficial effects:

[0041] 1. The present invention has a simple structure and is easy to operate. The first centrifugation uses the centrifugal force generated by the rotation of the motor to preliminarily remove the residual resin and collect it in the stock liquid tank, which effectively improves the printing efficiency and reduces material waste. The residual resin material is cleaned with an organic solvent to avoid cross-contamination of multiple materials. The use of organic solvents reduces the rotation speed used for cleaning and reduces the damage to the structure caused by excessive centrifugal force. The second centrifugation uses the centrifugal force generated by the rotation of the motor to further remove the residual resin material and the residual organic solvent after cleaning, reducing the influence of the organic solvent on the subsequent structural cross-linking.

[0042] 2. The present invention adopts a servo rotary motor to achieve high-precision motion control, ensuring the consistency of the model position during printing, without the need for a limit device, which is conducive to miniaturization of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0044] Figure 1 It is a schematic diagram of the overall structure of the solvent-assisted centrifugal multi-material light-curing 3D printing device of the present invention;

[0045] Figure 2 It is a structural schematic diagram of the optical path control device in the present invention;

[0046] Figure 3 It is an explosion schematic diagram of the material changing device in the present invention;

[0047] Figure 4 is an exploded schematic diagram of the liquid tank assembly of the present invention;

[0048] Figure 5 is an exploded schematic diagram of the cleaning device of the present invention;

[0049] Figure 6 is an exploded schematic diagram of the printing platform in the present invention;

[0050] Figure 7It is a schematic diagram of the process of the solvent-assisted centrifugal multi-material light-curing 3D printing method of the present invention.

[0051] The figure shows:

[0052] Upper base plate 1 Liquid tank body 104

[0053] First connecting rod 2 Glass window 105

[0054] Midsole plate 3 Right angle adapter 11

[0055] Second connecting rod 4 Stepper motor 12

[0056] Lower base plate 5 Cleaning device 13

[0057] Projector 6 Servo Rotary Motor 131

[0058] Adapter 7 Second coupling 132

[0059] Synchronous belt module 8 First thrust bearing 133

[0060] Synchronous belt motor 81 Rotating shaft 134

[0061] First coupling 82 Deep groove ball bearing 135

[0062] Optical axis 83 Second thrust bearing 136

[0063] Support platform 84 Shell 137

[0064] Liquid tank frame 9 Bearing support beam 138

[0065] Tank assembly 10 Support beam 139

[0066] Base 101 Motor support beam 1310

[0067] Translucent glass 102 Bracket 14

[0068] Platen 103 Printing base 15 DETAILED DESCRIPTION

[0069] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0070] Research has found that one of the core issues in achieving integrated printing of multi-material components is how to avoid cross-contamination of multiple resin materials when changing materials and improve the resolution of multi-material distribution. At present, multi-material light-curing 3D printing equipment mainly switches materials by manually or automatically replacing the liquid tank, but simply adding multiple liquid tanks cannot effectively solve the problem of resin contamination. For this reason, physical methods are usually required to remove residual resin liquid. Such measures have the following problems: physical methods cannot completely remove all residual materials, especially in components with complex shapes, which are prone to leaving hidden resins. External forces may cause damage to the surface of the component, especially on more fragile or delicate structures, which may lead to a decrease in surface quality. Therefore, the existing multi-material light-curing 3D printing technology needs to be improved.

[0071] In view of the above problems, the present invention discloses a solvent-assisted centrifugal multi-material light-curing 3D printing device and method. The initial centrifugation uses the centrifugal force generated by the rotation of the motor to preliminarily remove the residual resin and collect it in the stock liquid tank, which effectively improves the printing efficiency and reduces material waste; the residual resin material is cleaned with an organic solvent to avoid cross-contamination of multiple materials. The use of organic solvents reduces the rotation speed used for cleaning and reduces the damage to the structure caused by excessive centrifugal force; the secondary centrifugation uses the centrifugal force generated by the rotation of the motor to further remove the residual resin material and the residual organic solvent after cleaning, reducing the influence of the organic solvent on the subsequent structural cross-linking.

[0072] According to the solvent-assisted centrifugal multi-material light-curing 3D printing device provided by the present invention, Figure 1 As shown, it includes a frame; an optical path control device, which is arranged on the frame; a material changing device, which is arranged on the frame; a liquid tank assembly 10, which is arranged on the material changing device; a cleaning device 13, which is arranged on the lifting device; a lifting device, which is arranged on the frame; and a printing platform, which is arranged on the cleaning device 13. The present invention utilizes the centrifugal force generated by the rotation of the motor to remove the current residual resin liquid, avoid cross contamination of multiple materials, and improve the multi-material printing accuracy; in addition, organic solvent cleaning is added to further improve the cleaning effect. The present invention is of great significance in the fields of manufacturing multi-material soft robots, actuators, anisotropic mechanical metamaterials, etc.

[0073] Please also see Figures 1 to 7 , provides a preferred embodiment of the above solvent-assisted centrifugal multi-material light-curing 3D printing device.

[0074] like Figure 1As shown, this embodiment provides a solvent-assisted centrifugal multi-material light-curing 3D printing device, the frame includes an upper base plate 1, a 1.5-inch first connecting rod 2, a middle base plate 3, a 1.5-inch second connecting rod 4, and a lower base plate 5; the optical path control device includes a projector 6 and an adapter frame 7, both of which are arranged on the frame; the material changing device includes a synchronous belt module 8 and a liquid tank frame 9, both of which are arranged on the frame; the liquid tank assembly 10 is arranged on the material changing device, and the cleaning device 13 is arranged on the lifting device, the lifting device includes a right-angle adapter bracket 11 and a stepper motor 12, both of which are arranged on the frame, and the printing platform includes a bracket 14 and a printing base 15, which are arranged on the cleaning device 13.

[0075] Specifically, the cleaning device 13 includes a servo rotary motor 131 and related connecting parts. The servo rotary motor 131 accurately controls the speed and position of the driving printing base 15 to rotate, ensuring that the model position is consistent during the printing process, without the need for an additional positioning device, and the rotation error is 0.088 degrees. Its working process is as follows: the rotational motion of the servo motor 131 is accurately adjusted by the control system to ensure that the printing base 15 rotates at a set speed. When the platform starts to rotate, the centrifugal force acts on the residual materials attached to the surface, including residual resin, hydrogel and organic solvent, to move them outward to achieve a cleaning effect. In order to optimize the cleaning efficiency, the rotation speed and time can be adjusted according to different materials and printing parameters. During the rotation process, the residual material is quickly thrown off the printing surface, reducing the risk of cross contamination and ensuring the cleanliness of the printed components. Since the centrifugal cleaning method has the advantages of high efficiency and speed in the multi-material printing process, and the servo motor can achieve high-precision motion control to ensure printing accuracy, the rotating printing base 15 driven by the servo rotary motor 131 is selected as the cleaning device.

[0076] Specifically, in the material changing device, the synchronous motor 81 drives the synchronous belt module 8 to accurately move the liquid tank assemblies 10 arranged side by side on the liquid tank rack 9 to realize the switching of resin materials. The synchronous belt module 8 can quickly and accurately position the liquid tank of the required material to the printing position through the control of the motor 81. Since the material needs to be frequently changed during the multi-material printing process, the high precision of the motor ensures the stability of the position of the liquid tank at each switch, minimizing the positioning error. The liquid tank rack 9 is supported by a 13mm thick aluminum alloy frame structure. The frame is strong and not easy to deform, ensuring that the height of the liquid tank is consistent. With the transmission of the synchronous belt module, it can slide smoothly on the preset track. During the material changing process, the motor 81 drives the synchronous belt module to move quickly to ensure that different liquid tank assemblies 10 can be quickly switched to the printing area to improve printing efficiency and material utilization. This design makes multi-material printing operations more efficient and accurate.

[0077] Specifically, the tank assembly 10 includes a base 101, a highly transparent quartz glass, a tank body 104, a pressing plate 103, and four glass windows 105. The base 101 is the basic structure of the tank assembly and provides stable support. Its design takes into account seismic resistance and thermal stability to ensure that it can effectively resist external interference during the printing process. The highly transparent quartz glass is arranged on the base 101 as the bottom material of the tank. Due to its excellent light transmittance and chemical stability, it can effectively transmit the light source, so that the photopolymerization reaction in the photocuring process can proceed smoothly. The tank body 104 is located on the highly transparent quartz glass and is responsible for accommodating the resin material. The design of the tank body ensures the uniform distribution of the resin and the appropriate liquid level, so as to provide a stable material supply during the printing process. The pressing plate 103 is arranged on the tank body 104 to press the release film to prevent the resin from leaking and the release film from falling off. Finally, four glass windows 105 are arranged on the tank body 104 to facilitate the observation of the state of the internal resin.

[0078] Before pouring different required resin materials, it is necessary to adjust the position and posture of each hardware and determine the initial position. Specifically, the optical path control device is adjusted so that the total length of the optical path is near the focal length of the projector 6. At this time, the projection pattern is focused on the upper surface of the release film at the bottom of the liquid tank assembly 10. On the other hand, the printing platform needs to be adjusted to the printing position, and the printing base 15 is adjusted to be flush with the liquid tank assembly 10, the printing platform is lowered to contact with the liquid tank bottom film, and the initial position of the printing platform is recorded.

[0079] Before printing, it is necessary to slice the model and determine the printing parameters for different materials. Specifically, slice the 3D model of the multi-material component, isolate the different material parts of the component, and slice the different material parts separately. The slice parameter settings must be the same each time and the coordinates must correspond to each other. Finally, several groups of slices corresponding to different material parts are obtained. When printing, the corresponding slice patterns are indexed by the number of layers and materials for projection. For example, when printing the 10th layer with three materials, first index the group of slices by the material, then index the current layer by the number of layers 10, and project the image to the liquid tank assembly 10. Due to different properties of different materials, the concentration of photoinitiator absorber is different, and the required printing parameters are also different. It is necessary to test the printing parameters of each material in advance to ensure that the molding thickness of each material is consistent under this combination of printing parameters.

[0080] During printing, the layers are stacked and formed in a projection curing-cleaning-replacing manner, which is specifically as follows: control the stepper motor 12 to move the printing platform to the initial position of the printing platform, then lift it up by one time to set the slice layer thickness, control the digital light processing projector 6 to project the first layer of slice pattern, complete the curing of the current layer, and appropriately increase the light exposure time to ensure that the initial layers are firmly adhered to the printing base 15. Determine whether it is finished, if it is finished, the printing is completed, if not, the following steps are performed.

[0081] Determine whether there are other materials in the current layer. If there are other materials, control the stepper motor 12 to lift a certain distance so that the printing structure leaves the liquid surface. The servo rotary motor 131 rotates at high speed to remove the residual materials to the current liquid tank. Control the stepper motor 12 to make the printing structure leave the liquid tank assembly 10. Control the synchronous belt module 8 to move to the cleaning tank. The stepper motor 12 descends to immerse the printing structure in the organic solvent. The servo rotary motor 131 rotates at a low speed for several circles. The stepper motor 12 is slightly lifted until the structure is exposed to the liquid surface. The servo rotary motor 131 rotates at high speed to remove the residual resin and organic solvent. Control the stepper motor 12 to lift until the printing structure leaves the liquid tank assembly 10, and the synchronous belt module 8 moves to the liquid tank corresponding to the next material. Control the stepper motor 12 to descend until the current layer is close to the bottom of the liquid tank, return to the projection step again, and repeat the cycle.

[0082] If there is no other material in the current layer, it is determined whether the set material of the next layer is the same as the current layer. If not, the above cleaning and material replacement steps are repeated to control the stepper motor 12 to the next layer height; if the material of the next layer is the same as the current one, the stepper motor 12 is directly controlled to the next layer height, and the distance from the bottom of the tank assembly to the set layer thickness is returned to the projection step again, and the digital light processing projector 6 is controlled to project the corresponding slice pattern, and so on, and finally the printing of the multi-material 3D model is completed.

[0083] It can be seen from the printing process that the present invention removes residual resin by a solvent-assisted centrifugal cleaning combined with an organic solvent cleaning method. The initial centrifugation uses the centrifugal force generated by the rotation of the motor to preliminarily remove the residual resin and collect it in the stock liquid tank, which effectively improves printing efficiency and reduces material waste; the residual resin material is cleaned with an organic solvent to avoid cross-contamination of multiple materials. The use of organic solvents reduces the rotation speed used for cleaning and reduces the damage to the structure caused by excessive centrifugal force; the secondary centrifugation uses the centrifugal force generated by the rotation of the motor to further remove the residual resin material and the residual organic solvent after cleaning, reducing the impact of the organic solvent on the structure.

[0084] See also Figure 2In a further implementation of an embodiment, the optical path control device includes: a projector 6 and an adapter frame 7. Before pouring different required resin materials into the liquid tank assembly 10, it is necessary to adjust the optical path control device so that the projection pattern is focused on the release film at the bottom of the liquid tank assembly 10, specifically: first install the projector 6 on the adapter frame 7, fix it with bolts, place the adapter frame 7 on the lower bottom plate 5, move the adapter frame 7 so that the projection axis of the projector 6 passes through the center of the liquid tank assembly 10, and the edge of the projection area is parallel to the edge of the liquid tank, loosen the bolts connecting the projector 6 and the adapter frame 7 appropriately, adjust the position of the projector up and down, so that the projection pattern is focused on the upper surface of the release film of the liquid tank assembly, and measure the total optical path length near the focal length of the projector 6. At this time, the image is clear and can be judged by receiving the image on the film surface with a CCD camera.

[0085] See also Figure 3 In a further implementation of an embodiment, the material changing device includes: a synchronous belt module 8, a motor 81, two first couplings 82, an optical axis 83, two support platforms 84 and a liquid tank frame 9. The synchronous belt module 8 is arranged on the middle bottom plate 3, and its movement direction is in the same vertical plane as the projection direction of the projector 6. Before adjusting different resin materials, it is necessary to ensure that the positions of the two support platforms 84 on the synchronous belt module 8 are correct, so that the center point connection line is perpendicular to the movement direction of the synchronous belt module. The specific steps are: first, according to Figure 4 Install each component in the manner shown, ensure that the motor 81 is well connected to the synchronous belt module 8, and fix the optical axis 83 to the synchronous belt module through the first coupling 82. Next, adjust the position of the two support platforms 84 so that the line connecting their center points is perpendicular to the moving direction of the synchronous belt module, and ensure that the support platform is flush with the liquid tank frame 9. Finally, tighten the relevant bolts to fix the installation position of the support platform to ensure the stability and accuracy of the entire device.

[0086] See also Figure 4 In a further implementation of an embodiment, the liquid tank assembly includes: a base 101, a high-transmittance quartz glass, a liquid tank body 104, a pressure plate 103, and four glass windows 105. Before starting printing, it is necessary to install an nEFP release film between the liquid tank body 104 and the pressure plate 103, and the pressure plate 103 is tightened with a number of bolts. After that, the high-transmittance quartz glass 102 and the base 101 are installed. The quartz glass provides support for the nEFP release film to limit the downward deformation of the release film under the pressure of the liquid. At the same time, four glass windows 105 are installed to facilitate observation of the internal resin state. Finally, check the fixing state of each component to ensure that the liquid tank assembly can work stably during the printing process.

[0087] See also Figure 5In a further implementation of an embodiment, the cleaning device includes: a support beam 139, a motor support beam 1310, a bearing support beam 138, a servo rotary motor 131, a second coupling 132, a first thrust bearing 133, a rotating shaft 134, a deep groove ball bearing 135, a second thrust bearing 136 and a housing 137. Before starting cleaning, it is necessary to ensure that the installation position of each fixing plate is correct to ensure the stability and effectiveness of the cleaning device. The specific steps are: first, install the support beam 139 on the stepper motor 12 and ensure that it is firmly connected. Then, install the motor support beam 1310 on the support beam 139 to ensure that there is no gap between the two, and then install the servo rotary motor 131 on the motor support beam 1310. The deep groove ball bearing 135 is installed on the outside of the boss of the rotating shaft 134 by interference fit, the first thrust bearing 133 is installed above the rotating shaft boss, the second thrust bearing 136 is installed below the rotating shaft boss, the housing 137 is installed to the bearing support beam 138 and fixed with bolts, the rotating shaft 134 is installed on the second coupling 132, the bearing support beam 138 is installed on the support beam 139 and fixed with bolts to ensure that the entire cleaning device can operate smoothly and achieve an effective cleaning function.

[0088] See also Figure 6 In a further implementation of an embodiment, the printing platform includes: a bracket 14, a printing base 15. Before pouring different required resin materials, the printing platform should be adjusted to the printing position, and the printing base 15 should be adjusted to be flush with the liquid tank assembly, which is specifically: Figure 6 In the manner shown, the components are installed, the four bolts on the printing base 15 are loosened, the printing platform is lowered to contact the bottom of the liquid tank assembly 10, the printing base 15 is completely fitted thereto, and then the four bolts are tightened.

[0089] According to the present invention, a printing method of a solvent-assisted centrifugal multi-material light-curing 3D printing device is also provided, which is applied to the above-mentioned solvent-assisted centrifugal multi-material light-curing 3D printing device, such as Figure 7 As shown, the method includes the following steps: controlling the stepper motor 12 to move the printing platform to the initial position of the printing platform, and then lifting it up by one time to set the slice layer thickness, at which time the distance between the printing base 15 and the bottom of the liquid tank assembly 10 is approximately one slice thickness; controlling the digital light processing projector 6 to project the first slice pattern, completing the curing of the current layer, and appropriately increasing the illumination time to ensure that the initial layers are firmly adhered to the printing base 15. Determine whether it is finished, if it is finished, the printing is completed, if not, the following steps are performed.

[0090] Determine whether there are other materials in the current layer. If there are other materials, control the stepper motor 12 to lift a certain distance so that the printed structure leaves the liquid tank assembly 10. Control the synchronous belt module 8 to move to the alcohol tank, and the stepper motor 12 descends to immerse the printed structure in alcohol. The servo rotary motor 131 rotates at a low speed for several circles. The stepper motor 12 is slightly lifted until the structure is exposed to the liquid surface, and the servo rotary motor 131 rotates at a high speed to remove the residual material. Control the stepper motor 12 to lift until the printed structure leaves the liquid tank assembly 10, and the synchronous belt module 8 moves to the liquid tank corresponding to the next material. Control the stepper motor 12 to descend until the current layer is close to the bottom of the liquid tank, and then return to the projection step and repeat the cycle.

[0091] If there is no other material in the current layer, it is determined whether the set material of the next layer is the same as the current layer. If not, the above cleaning and material replacement steps are repeated to control the stepper motor 12 to the next layer height; if the material of the next layer is the same as the current one, the stepper motor 12 is directly controlled to the next layer height, and the distance from the bottom of the tank assembly to the set layer thickness is returned to the projection step again, and the digital light processing projector 6 is controlled to project the corresponding slice pattern, and so on, and finally the printing of the multi-material 3D model is completed.

[0092] The present invention has the following beneficial effects: the first centrifugation uses the centrifugal force generated by the rotation of the motor to preliminarily remove the residual resin and collect it in the stock liquid tank, effectively improving the printing efficiency and reducing material waste; the residual resin material is cleaned with an organic solvent to avoid cross-contamination of multiple materials. The use of organic solvents reduces the rotation speed used for cleaning and reduces the damage to the structure caused by excessive centrifugal force; the second centrifugation uses the centrifugal force generated by the rotation of the motor to further remove the residual resin material and the residual organic solvent after cleaning, reducing the influence of the organic solvent on the cross-linking of subsequent layers. At the same time, a servo rotary motor is used to achieve high-precision motion control to ensure the consistency of the model position during printing without the need for a limit device.

[0093] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0094] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A solvent-assisted centrifugal multi-material light-curing 3D printing device, characterized in that: It comprises a frame, an optical path control device, a material changing device, a liquid tank assembly (10), a cleaning device (13), a lifting device and a printing platform; The optical path control device, the material changing device and the lifting device are all arranged on the frame, the cleaning device (13) is installed on the lifting device, and the printing platform is installed on the cleaning device (13). The lifting device is used to drive the cleaning device (13) and the printing platform to rise and fall, and the cleaning device (13) is used to drive the printing platform to rotate; The liquid tank assembly (10) is installed on the material changing device, and the material changing device is used to drive the liquid tank assembly (10) to move horizontally. The liquid tank assembly (10) is correspondingly arranged below the printing platform, and the optical path control device is correspondingly arranged below the liquid tank assembly (10).

2. The solvent-assisted centrifugal multi-material light-curing 3D printing device according to claim 1, characterized in that: The frame comprises an upper base plate (1), a first connecting rod (2), a middle base plate (3), a second connecting rod (4) and a lower base plate (5); The middle bottom plate (3) is stacked and installed on the lower bottom plate (5) via a plurality of second connecting rods (4), and the upper bottom plate (1) is stacked and installed on the middle bottom plate (3) via a plurality of first connecting rods (2); The optical path control device is mounted on the lower base plate (5), the material changing device is mounted on the middle base plate (3), and the lifting device is mounted on the upper base plate (1).

3. The solvent-assisted centrifugal multi-material light-curing 3D printing device according to claim 1, characterized in that: The optical path control device comprises an adapter frame (7) and a projector (6), wherein the adapter frame (7) is fixedly mounted on the frame; The projector (6) is fixedly mounted on the adapter frame (7), and the projector (6) is used to realize light curing of the printing material on the printing platform.

4. The solvent-assisted centrifugal multi-material light-curing 3D printing device according to claim 1, characterized in that: The material changing device comprises a synchronous belt module (8), a synchronous belt motor (81), a first coupling (82), an optical axis (83), a supporting platform (84) and a liquid tank frame (9); There are two synchronous belt modules (8), which are symmetrically and parallelly mounted on the frame, and the movement direction of the synchronous belt modules (8) and the projection direction of the projector (6) of the optical path control device are in the same vertical plane; The support platform (84) is mounted on the synchronous belt module (8), and the motor (81) is mounted at the end of the synchronous belt module (8) to drive the support platform (84) to reciprocate, and the rotating shafts of the two synchronous belt modules (8) are connected to the same optical axis (83) through a first coupling (82); The two sides of the liquid tank frame (9) are respectively mounted on two supporting platforms (84), and the liquid tank assembly (10) is mounted on the top of the liquid tank frame (9).

5. The solvent-assisted centrifugal multi-material light-curing 3D printing device according to claim 4, characterized in that: There are multiple liquid tank assemblies (10), and the multiple liquid tank assemblies (10) are installed in parallel on the top of the liquid tank frame (9) along the moving direction of the synchronous belt module (8).

6. The solvent-assisted centrifugal multi-material light-curing 3D printing device according to claim 1, characterized in that: The liquid tank assembly (10) comprises a base (101), a light-transmitting glass (102), a pressing plate (103), a liquid tank body (104) and a glass window (105); the base (101) is installed on the material changing device; The light-transmitting glass (102) is installed in the base (101), the pressing plate (103) is installed at the bottom of the liquid tank body (104) and is used to fix the sealing film at the bottom of the liquid tank body (104), the liquid tank body (104) is installed on the base (101), and the side wall of the liquid tank body (104) is provided with a glass window (105).

7. The solvent-assisted centrifugal multi-material light-curing 3D printing device according to claim 1, characterized in that: The lifting device comprises a right-angle adapter bracket (11) and a stepping motor (12), wherein the transverse mounting plate of the right-angle adapter bracket (11) is fixedly mounted on the frame; The vertical mounting plate of the right-angle adapter bracket (11) is provided with a slide rail and a slider structure that cooperate with each other, the cleaning device (13) is fixedly mounted on the slider, and the stepping motor (12) is mounted on the right-angle adapter bracket (11) and is used to drive the slider to move in the slide rail along the vertical direction.

8. The solvent-assisted centrifugal multi-material light-curing 3D printing device according to claim 1, characterized in that: The cleaning device (13) comprises a support beam (139), a motor support beam (1310), a bearing support beam (138), a servo rotary motor (131), a second coupling (132), a first thrust bearing (133), a rotating shaft (134), a deep groove ball bearing (135), a second thrust bearing (136) and a housing (137); The support beam (139) is installed on the lifting device, the motor support beam (1310) and the bearing support beam (138) are both installed on the support beam (139), and the bearing support beam (138) is correspondingly installed below the motor support beam (1310), and a servo rotary motor (131) is installed on the top of the motor support beam (1310); The output shaft at the bottom of the servo rotary motor (131) is connected to the rotating shaft (134) through a second coupling (132); the first thrust bearing (133), the deep groove ball bearing (135) and the second thrust bearing (136) are sequentially sleeved on the outside of the rotating shaft (134) from top to bottom and are located in a housing (137); the housing (137) is installed at the bottom of the bearing support beam (138); The bottom end of the rotating shaft (134) is fixedly connected to the printing platform.

9. The solvent-assisted centrifugal multi-material light-curing 3D printing device according to claim 1, characterized in that: The printing platform comprises a bracket (14) and a printing base (15), the bracket (14) is connected to the cleaning device (13), and the printing base (15) is fixedly mounted on the bottom of the bracket (14).

10. A solvent-assisted centrifugal multi-material light-curing 3D printing method, characterized in that: The solvent-assisted centrifugal multi-material light-curing 3D printing device according to any one of claims 1 to 9 comprises the following steps: Step 1: Control the stepper motor (12) of the lifting device to move the printing base (15) of the printing platform to completely contact the liquid tank assembly (10), and then control the printing base (15) to lift twice the preset slice layer thickness; Step 2: Control the projector (6) of the optical path control device to project the first layer of slice pattern onto the printing base (15) to complete the curing of the current layer; Step 3: After the curing of the current layer is completed, determine whether the printing process has been completed. If so, end the printing. If not, perform the following steps; Step 4: Determine whether there are other materials in the current layer. If there are other materials, execute step 5a. If there are no other materials, execute step 5b. Step 5a: Control the stepper motor (12) to lift up so that the printing structure leaves the liquid surface, control the servo rotary motor (131) in the cleaning device (13) to rotate to remove residual materials to the current liquid tank, and control the stepper motor (12) to lift up so that the printing structure leaves the liquid tank assembly (10); The synchronous belt module (8) of the material changing device is controlled to move to the cleaning tank in the liquid tank assembly (10), the stepper motor (12) descends to immerse the printing structure in the organic solvent, the servo rotary motor (131) rotates a preset number of times, the stepper motor (12) is lifted until the printing structure is exposed to the liquid surface, and the servo rotary motor (131) rotates to further remove residual resin and residual organic solvent; Control the stepper motor (12) to lift until the printing structure leaves the liquid tank assembly (10), the synchronous belt module (8) moves to the liquid tank corresponding to the next material, and control the stepper motor (12) to descend until the current layer is in close contact with the bottom of the liquid tank, and then execute step 2; Step 5b: Determine whether the set material of the next layer is the same as the current layer. If they are different, control the stepper motor (12) to lift up so that the printing structure leaves the liquid surface, control the servo rotary motor (131) in the cleaning device (13) to rotate to remove the residual material to the current liquid tank, and control the stepper motor (12) to lift up so that the printing structure leaves the liquid tank assembly (10); The synchronous belt module (8) of the material changing device is controlled to move to the cleaning tank in the liquid tank assembly (10), the stepper motor (12) descends to immerse the printing structure in the organic solvent, the servo rotary motor (131) rotates a preset number of times, the stepper motor (12) is lifted until the printing structure is exposed to the liquid surface, and the servo rotary motor (131) rotates to further remove residual resin and residual organic solvent; Control the stepper motor (12) to lift the printing structure away from the liquid tank assembly (10), the synchronous belt module (8) moves to the liquid tank corresponding to the next material, and control the stepper motor (12) to the height of the next layer, which is separated from the bottom of the liquid tank by a set layer thickness distance, and execute step 2; If the set material of the next layer is the same as that of the current layer, the stepper motor (12) is directly controlled to the height of the next layer, which is separated from the bottom of the liquid tank by a set layer thickness distance, and step 2 is executed.

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