3D printing device and method for coating by pushing liquid horizontally using a release film

Abstract

The present application relates to a 3D printing apparatus and method for coating a liquid by pressing horizontally with a release film. The 3D printing apparatus includes a liquid tank, a print platform, and a release film assembly. The liquid tank is used to contain liquid resin for printing and has a body region and a stretching region. The stretching region is located on one side of the top of the body region. The print platform is used to carry a print sample and enter the body region of the liquid tank. The release film assembly includes a release film and a release film drive assembly. The release film drive assembly is used to translate the release film so that the release film moves between the body region or the stretching region. The beneficial effects of the present invention are as follows: 1. Eliminate various errors caused by the introduction of a high-speed leveling member such as a hob, and improve the print quality. 2. A precise layer thickness can be obtained by pressing horizontally once with the release film, and improve the print efficiency. 3. When installing or removing the print platform, the release film moves to the stretching region of the liquid tank, eliminating the need for disassembly, making the work even easier.

Description

[Technical Field]

[0001] The present application relates to the technical field of photocuring 3D printing, and in particular to a 3D printing apparatus and method that uses a release film to horizontally press and coat a liquid. [Background technology]

[0002] Currently, high-precision photocuring 3D printing often uses a design with the light source positioned above the liquid vat below. The goal is to achieve higher accuracy by using thinner release films or self-leveling methods to project patterns more accurately onto the photosensitive resin. However, as the demand for larger print widths and higher viscosity liquid resins increases, even with the release film method, long leveling times are required to achieve the ideal layer thickness during actual printing. Therefore, BMF has developed a new hob high-speed leveling method to solve the problem of reduced efficiency due to long print leveling times. As shown in Figure 1, this is a diagram of the current 3D printing structure. The light path is located above the liquid vat 1, and the release film assembly 3 is fixed to the liquid vat 1. When the print platform 2 rises, the liquid resin 6 is pulled up, causing the release film assembly 3 to expand upward. At this time, the leveling hob 4 on the top surface of the release film assembly 3 rolls left and right to eliminate the expansion of the release film assembly 3. This method significantly reduces the waiting time for leveling during printing. This method also includes an air bubble scraper 5 that is attached to the underside of the release film assembly 3 and can slide left and right. The purpose is to remove air bubbles from the underside of the release film assembly 3, preventing them from affecting print quality. With the current method, before each print, the print platform 2 must be manually installed, then the release film assembly 3 must be manually installed, and finally the leveling hob 4 must be manually installed. After each print, the leveling hob 4 must be manually removed, then the release film assembly 3 must be manually removed, and finally the print platform 2 must be manually removed to obtain a printed sample.

[0003] Current methods use leveling hobs to solve the problem of high-speed leveling during large-area printing, but they also present several problems. The requirements for machining and assembling the leveling hob 4 are very high. It is difficult to maintain the leveling hob 4's motion plane parallel to the XY motion plane, resulting in some areas of the release film assembly 3 being excessively pressed down while other areas are not. It is very difficult to determine the exact positional relationship between the leveling hob 4 and the release film assembly 3 during use, which can result in the leveling hob 4 damaging the already molded sample during operation. When using hob leveling, the leveling hob often needs to be rotated multiple times at a very slow speed. The leveling hob 4 needs to be removed after each printing.

[0004] Currently, the drawbacks of this method are as follows: 1. The requirements for the processing and assembly precision of the leveling hob are high, which affects the print quality. 2. It is difficult for the moving surface of the leveling hob to remain parallel to the XY moving plane, which will affect the print quality. 3. It is difficult to determine the exact positional relationship between the leveling hob and the release film during use, which will affect the print quality. 4. When using hob leveling, it is often necessary to rotate the leveling hob multiple times at a very slow speed, which will affect printing efficiency. 5. After each print, the leveling hob needs to be removed, which is cumbersome. Summary of the Invention

[0005] The technical problem that the present invention aims to solve is to overcome the drawbacks of using a leveling hob for large-surface printing in the prior art, thereby providing a 3D printing apparatus and method that uses a release film to press and coat a liquid horizontally.

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows: A 3D printing device that coats a liquid by pushing it horizontally using a release film, the vat is used to contain liquid resin for printing, and has a body region and a stretching region, the stretching region being disposed on one side of the top of the body region; the print platform is used to carry a print sample and enter the body region of the fluid reservoir; The release film assembly includes a release film and a release film drive assembly, and the release film drive assembly is used to translate the release film so that the release film moves between the main body region or the extension region.

[0007] Preferably, the 3D printing apparatus for horizontally pressing and coating a liquid with a release film according to the present invention further includes a bubble scraper disposed within the extension region and fixed to the bottom of the extension region of the liquid tank, closer to the main body region, with the top of the bubble scraper aligned with the bottom of the release film.

[0008] Preferably, in the 3D printing apparatus that coats a liquid by pushing it horizontally using a release film according to the present invention, the bubble scraper is attached to the bottom of the extension region of the liquid tank via a spring and a guide shaft.

[0009] Preferably, in the 3D printing apparatus for coating a liquid by horizontally pushing it using a release film according to the present invention, the release film assembly is a mounting substrate; a linear guide rail secured to the mounting substrate along a first direction along which the print platform moves between the body region and the extension region of the reservoir; a release film holder assembly mounted on the linear guide rail and movable along a first direction by being driven by a release film drive assembly, the release film holder assembly having a release film attachment jig member, and the release film attached to the release film attachment jig member.

[0010] Preferably, in the 3D printing apparatus that coats a liquid by horizontally pressing it using a release film according to the present invention, the release film holder assembly is a transmission frame connected to the linear guide rail via a slide block; A release film horizontal adjustment support column fixed to the transmission frame; and a horizontal adjustment frame connected to the release film horizontal adjustment column via a release film horizontal adjustment knob, to which the release film tensioning jig member is attached.

[0011] Preferably, in the 3D printing apparatus for coating a liquid by horizontally pushing it using a release film according to the present invention, the release film drive assembly is a step motor secured to the bottom of the mounting substrate; a synchronous belt connected to the step motor and the transmission frame to drive the transmission frame.

[0012] Preferably, in the 3D printing device for coating a liquid by horizontally pushing it using a release film according to the present invention, limit stoppers are further provided on the mounting substrate, which are arranged at the four corners of the mounting substrate and are used to prevent the movement of the transmission frame from exceeding the movement limit.

[0013] Preferably, the 3D printing device for coating a liquid by horizontally pushing it with a release film according to the present invention further includes a position sensor mounted on the mounting substrate. The sensor is attached to one edge of the mounting substrate and is used to sense the position of the transmission frame. The lateral movement position of the release film application jig member is limited by the position sensor.

[0014] A 3D printing method for coating a liquid by horizontally pushing it using a release film, using the above-mentioned 3D printing device, Step S1: moving the release film to the stretching area and attaching the print platform to the body area of ​​the liquid reservoir; Step S2: Controlling the print platform to rise and fall to a print start position, and ensuring that the distance between the print platform and the lower surface of the release film is one layer thick; Step S3 of controlling the release film to move to the main body region; Step S4: focusing the pattern on the release film by a UV lens, and performing exposure and curing to obtain a cured pattern; Step S5: controlling the print platform to descend and separating the cured print sample from the release film; Step S6: Controlling the release film to move laterally to the stretching region of the liquid tank; Step S7: repeating steps S2 to S6 until the sample printing is completed; and step S8 of controlling the release film to move laterally to the stretching region of the fluid reservoir and removing the print platform carrying the print sample.

[0015] Preferably, in the 3D printing method of the present invention in which a liquid is horizontally pressed and coated using a release film, an air bubble scraper is fixed to the bottom of the stretching area of ​​the liquid tank, and in step S6, the air bubble scraper removes air bubbles at the bottom of the release film.

[0016] The beneficial effects of the present invention are as follows: 1. Eliminates various errors caused by the introduction of high-speed leveling components such as hobs, improving print quality. 2. One horizontal press with release film can achieve accurate layer thickness, improving printing efficiency. 3. When installing or removing the print platform, the release film moves to the stretching area of ​​the liquid tank, eliminating the need for disassembly, making the process even easier. [Brief explanation of the drawings]

[0017] The technical solutions of the present application are described in further detail below with reference to the accompanying drawings and examples. [Figure 1] This is a schematic diagram of the principle of conventional hob-leveling 3D printing. [Figure 2] FIG. 1 is a structural schematic diagram of a 3D printing device that uses a release film to horizontally press and coat a liquid, according to an embodiment of the present application. [Figure 3] FIG. 1 is a schematic diagram illustrating the operation steps of a 3D printing device that uses a release film to horizontally press and coat a liquid, according to an embodiment of the present application. [Figure 4] FIG. 1 is a perspective view of the overall structure of a 3D printing device that uses a release film to horizontally press and coat a liquid, according to an embodiment of the present application. [Figure 5] FIG. 1 is a side view of the overall structure of a 3D printing device that uses a release film to horizontally press and coat a liquid, according to an embodiment of the present application. [Figure 6] 1 is a schematic diagram of the overall structure of a release film assembly according to an embodiment of the present application. [Figure 7] 1 is a structural schematic diagram of a liquid tank member according to an embodiment of the present application. DETAILED DESCRIPTION OF THE INVENTION

[0018] Furthermore, where no contradiction exists, the embodiments and features in the embodiments of the present application can be combined with each other.

[0019] In describing the present invention, the orientations or positional relationships indicated by terms such as "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are based on the orientations or positional relationships shown in the drawings and are merely intended to facilitate the description of the present application. They do not necessarily indicate or suggest that the referenced devices or components have a specific orientation or are structured or operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present application. Furthermore, terms such as "first," "second," and the like are used for descriptive purposes only and cannot be understood as indicating or suggesting relative importance or implicitly indicating the number of technical features shown. Therefore, a feature qualified by "first," "second," etc. may explicitly or implicitly include one or more of the feature. In describing the present invention, unless otherwise specified, "plurality" means two or more.

[0020] In the description of this application, unless otherwise clearly defined and limited, the terms "attached," "coupled," and "connected" should be understood in a broad sense. For example, they may refer to a fixed connection, a detachable connection, or an integral connection. They may refer to a mechanical connection or an electrical connection. They may refer to a direct connection, an indirect connection via an intermediate medium, or an internal communication between two elements. Those skilled in the art can understand the specific meanings of the above terms in this application according to the specific circumstances.

[0021] The technical solutions of the present application are described in detail below with reference to the accompanying drawings and examples.

[0022] Example This example provides a 3D printing device that applies a liquid by horizontally pushing it onto a substrate using a release film. As shown in Figure 2, this device includes a liquid tank 1, a print platform 2, a release film assembly 3, and an air bubble scraper 5. The reservoir 1 is used to contain liquid resin 6 for printing and has a body region and a spread region, the spread region being located on either side of the top of the body region. The print platform 2 is used to carry a print sample 7 into the body region of the reservoir 1 . The release film assembly 3 includes a release film and a release film drive assembly, and the release film drive assembly is used to translate the release film so that the release film moves between the main body region or the extension region. The bubble scraper 5 is disposed in the stretching region and fixed to the bottom of the stretching region of the liquid tank 1 on the side closer to the main body region. The top of the bubble scraper 5 is aligned with the bottom of the release film.

[0023] In this embodiment of the 3D printing apparatus, the print platform 2 is driven by a motion shaft (not shown), and the lifting and lowering of the print platform 2, the movement of the release film assembly 3, UV exposure, and other operations are controlled by control software on an industrial control computer. The control software controls the operation of each component according to the flowchart in Figure 3. The conventional system (shown in Figure 1) incorporates innovations to the liquid tank 1, release film assembly 3, leveling hob 4, and bubble scraper 5, as well as the specific printing process. The left side of the liquid tank 1 is increased in width, the release film assembly 3 is given a lateral movement function, the leveling hob 4 is eliminated, and the lateral movement function of the bubble scraper 5 is eliminated. When leveling is required for printing, the height of the print platform 2 is controlled to maintain a height distance of one layer thickness between the underside of the release film assembly 3 and the print surface. The release film assembly 3 moves from the left side of the print platform 2 to the right, and the right edge of the release film assembly 3 pushes the liquid resin above the print platform 2 horizontally to the right. The liquid surface that has already been pushed is immediately covered by the taut release film, ensuring the accuracy of the layer thickness between the lower surface of the release film and the surface waiting for printing.

[0024] This method differs from current self-leveling coating, release film coating, and hob-plus release film coating methods. All of these coating methods apply pressure perpendicular to the liquid surface to promote liquid leveling. In contrast, the above method applies a tangential force parallel to the liquid surface to promote liquid leveling, which is advantageous for quickly discharging excess liquid and quickly forming a precise layer thickness under the release film. For these reasons, the method of coating by pushing the liquid horizontally with a release film is characterized by high-quality and rapid coating.

[0025] The specific speed of the release film when the liquid is pressed horizontally to coat it is related to the print width, print layer thickness, and liquid viscosity, and the larger the print width, the smaller the print layer thickness, and the higher the liquid viscosity, the smaller the required speed of the release film. For various liquids, the specific horizontal pressing speed of the release film can be set according to the actual situation.

[0026] In this method, after adjusting the release film horizontally and focusing on the operation surface, when attaching the print platform 2 before printing or removing the print platform 2 after printing is completed, the print platform 2 can be easily attached or removed by simply moving the release film laterally to the left end of the liquid tank 1.

[0027] At the same time, the bubble scraper 5 can move slightly up and down within 2 mm under the action of the spring and guide shaft. When the release film moves laterally from side to side, the bubble scraper 5 moves laterally from side to side relative to the release film to complete the function of scraping off the bubbles. The bubble scraper 5 can be a one-way bubble scraper or a two-way bubble scraper. For information on one-way bubble scrapers, please refer to Patent Publication No. CN113942224A.

[0028] In the 3D printing apparatus of this embodiment, both the print platform 2 and the release film 3 are already leveled and focused before printing, as shown in Figure 3. The method used is as follows: Step S1: moving the release film to the stretching area and attaching the print platform 2 to the main body area of ​​the liquid tank 1; Step S2: Controlling the print platform 2 to move up and down to a print start position, and ensuring that the distance between the print platform 2 and the lower surface of the release film is one layer thick; Step S3 of controlling the release film to move to the main body region; Step S4: focus the pattern on the release film by the UV lens 8, and perform exposure (the exposure may be single projection exposure, multi-light projection exposure, or XY axis driven multi-projection exposure) and curing to obtain a cured pattern; Step S5: controlling the print platform 2 to descend and separating the cured print sample 7 from the release film; Step S6: Controlling the release film to move laterally to the stretching region of the liquid tank 1; Step S7: repeating steps S2 to S6 until the sample printing is completed; and step S8 of controlling the release film to move laterally to the stretching region of the liquid reservoir 1 and removing the print platform 2 carrying the print sample 7.

[0029] The bubble scraping function during the above process is achieved when the release film moves sideways. In actual application, the bubble scraper function can be used or not, and can be selected according to the actual situation. When in use, it is installed, and when not in use, it is removed.

[0030] 4, 5, and 7, in the 3D printing apparatus of this embodiment, the liquid tank member 200 of the liquid tank 1 is preferably hollow and can store liquid resin. As shown in Fig. 7, the right side is the main body region of the liquid tank 1, which is deeper, and the left side is the extension region of the liquid tank 1, which is shallower, and an air bubble scraper member 400 is fixed to the bottom of the edge on the side closest to the main body region.

[0031] Preferably, as shown in FIGS. 4, 5 and 6, the release film assembly 3 is a mounting substrate 101; Linear guide rails 102, 103 fixed on a mounting substrate 101 along a first direction (a direction in which the print platform 2 moves between the main body region and the extension region of the reservoir 1); a release film holder assembly mounted on the linear guide rails 102, 103 and movable along a first direction by being driven by a release film drive assembly, the release film holder assembly having a release film application jig member 500, and the release film includes a release film holder assembly attached to the release film application jig member 500.

[0032] Preferably, as shown in FIGS. 5 and 6, the release film holder assembly comprises: a transmission frame 109 connected to the linear guide rails 102 and 103 via a slide block 124; release film level adjustment columns 110, 111, 112 fixed to the transmission frame 109; The horizontal adjustment frame 113 is connected to the release film horizontal adjustment posts 110, 111, 112 via release film horizontal adjustment knobs 120, 121, and the release film tensioning jig member 500 is attached to the horizontal adjustment frame 113.

[0033] This structure allows the release film holder assembly to move in the first direction. The horizontal adjustment frame 113 can be adjusted to a horizontal position using the release film horizontal adjustment knobs 120 and 121. Specifically, as shown in FIG. 6 , the transmission frame 109 and the horizontal adjustment frame 113 are rectangular, and the release film horizontal adjustment columns 110, 111, and 112 are attached to the three corners of the transmission frame 109 and the horizontal adjustment frame 113. Adjusting the horizontal position of the horizontal adjustment frame 113 is equivalent to adjusting the horizontal position of the release film attachment jig member 500, which ensures that the release film is parallel to the projection focal plane. The upper ends of the three release film horizontal adjustment columns are connected to the horizontal adjustment frame 113 via tension springs (not shown), horizontal adjustment knobs, and steel balls (not shown), ensuring that the horizontal adjustment of the horizontal adjustment frame 113 is achieved using the horizontal adjustment knobs. There are two horizontal adjustment knobs.

[0034] Preferably, the release film drive assembly comprises: a step motor 105 fixed to the bottom of the mounting substrate 101; and a synchronous belt (107) connected to the step motor 105 and the transmission frame 109 to drive the transmission frame 109. Optionally, the release film driving assembly may be any linear motion driving assembly, such as a method employing a step motor, a linear guide rail and a synchronous belt, or may be, for example, a servo motor + linear guide rail + lead screw, or any other assembly capable of realizing linear motion.

[0035] Preferably, limit stoppers 108 are further provided on the mounting substrate 101. The limit stoppers 108 are arranged at the four corners of the mounting substrate 101 and are used to prevent the movement of the transmission frame 109 from exceeding the movement limit. A position sensor 114 is further provided on the mounting substrate 101. The sensor 114 is attached to one edge of the mounting substrate 101 and is used to sense the position of the transmission frame 109. The lateral movement position of the release film attachment jig member 500 is limited by the position sensor 114.

[0036] Taking the above ideal embodiment of the present application as an indication, those skilled in the art can make various changes and modifications through the above description without departing from the technical idea of ​​the present application. The technical scope of the present application is not limited to the content of the specification, but should be determined based on the scope of the claims. [Explanation of symbols]

[0037] 1. Liquid tank, 2. Print platform, 3. Release film assembly, 4. Leveling hob, 5. Air bubble scraper, 6. Liquid resin, 7. Print sample, 8. UV lens, 122. Slide block, 124. Slide block, 101. Mounting board, 102, 103. Linear guide rail, 105. Step motor, 107. Synchronous belt, 108. Limit stopper, 109. Transmission frame, 110, 111, 112. Release film horizontal adjustment column, 113. Horizontal adjustment frame, 114. Position sensor, 120, 121. Release film horizontal adjustment knob, 500. Release film tension jig component, 200. Liquid tank component, 400. Air bubble scraper component

Claims

1. A 3D printing device that coats a liquid by horizontally pushing it using a release film, comprising a liquid tank (1), a print platform (2), and a release film assembly (3); The liquid reservoir (1) is used to contain liquid resin (6) for printing, and has a main body region and a stretching region, the stretching region being located on one side of the top of the main body region; The printing platform (2) is used to carry a printing sample (7) and enter the body region of the liquid reservoir (1); the release film assembly (3) includes a release film and a release film drive assembly, the release film drive assembly being used to translate the release film so that the release film moves between the main body region or the stretching region, and the release film assembly further includes an air bubble scraper (5), the air bubble scraper (5) being disposed in the stretching region and fixed to a bottom of the stretching region of the liquid bath (1) on a side closer to the main body region, and the top of the air bubble scraper (5) being aligned with the bottom of the release film.

2. 2. The 3D printing device for coating a liquid by horizontally pushing it using a release film, as described in claim 1, characterized in that the bubble scraper (5) is attached to the bottom of the extension area of ​​the liquid tank (1) via a spring and a guide shaft.

3. The release film assembly (3) is a mounting substrate (101); Linear guide rails (102, 103) fixed on a mounting substrate (101) along a first direction from the main body region toward the extension region of the liquid tank (1); a release film holder assembly mounted on the linear guide rails (102, 103) and movable along a first direction by being driven by a release film drive assembly, the release film holder assembly having a release film attachment jig member (500), and the release film being attached to the release film attachment jig member (500); 2. A 3D printing device that coats a liquid by horizontally pushing it using the release film according to claim 1.

4. The release film holder assembly includes: a transmission frame (109) connected to the linear guide rails (102, 103) via a slide block (124); Release film level adjustment columns (110, 111, 112) fixed to the transmission frame (109); a horizontal adjustment frame (113) connected to the release film horizontal adjustment columns (110, 111, 112) via release film horizontal adjustment knobs (120, 121) and having the release film tensioning jig member (500) attached thereto; 4. A 3D printing device that coats a liquid by horizontally pushing it using the release film according to claim 3.

5. The release film drive assembly a step motor (105) fixed to the bottom of the mounting substrate (101); 5. The 3D printing device for coating a liquid by horizontally pushing it using a release film according to claim 4, further comprising: a synchronous belt (107) connected to the step motor (105) and to the transmission frame (109) to drive the transmission frame (109).

6. 5. The 3D printing device for coating a liquid by horizontally pushing it using a release film according to claim 4, characterized in that limit stoppers (108) are further provided on the mounting substrate (101), and the limit stoppers (108) are arranged at the four corners of the mounting substrate (101) and are used to prevent the movement of the transmission frame (109) from exceeding the movement limit.

7. 5. A 3D printing device for coating a liquid by pushing it horizontally using a release film, as described in claim 4, characterized in that a position sensor (114) is further provided on the mounting substrate (101), the sensor (114) is attached to one edge of the mounting substrate (101) and is used to sense the position of the transmission frame (109), and the lateral movement position of the release film application jig member (500) is limited by the position sensor (114).

8. A 3D printing method for coating a liquid by horizontally pushing it using a release film, the method comprising using the 3D printing apparatus according to any one of claims 1 to 7, Step S1: moving the release film to the stretching area and attaching the print platform (2) to the body area of ​​the liquid tank (1); Step S2: Controlling the print platform (2) to move up and down to the print start position, and ensuring that the distance between the print platform (2) and the lower surface of the release film is one layer thick; Step S3: Controlling the release film to move to the main body region; Step S4: focusing the pattern on the release film by a UV lens (8), and performing exposure and curing to obtain a cured pattern; Step S5: Controlling the print platform (2) to descend and separating the cured print sample (7) from the release film; Step S6: Controlling the release film to move laterally to the stretching region of the liquid tank (1); Step S7: repeating steps S2 to S6 until the printing of the sample is completed; and step S8 of controlling the release film to move laterally to the stretching region of the liquid tank (1) and removing the print platform (2) carrying the print sample (7).

9. 9. The 3D printing method for coating a liquid by horizontally pushing it using a release film according to claim 8, wherein an air bubble scraper (5) is fixed to the bottom of the stretching region of the liquid tank (1), and in step S6, the air bubble scraper (5) removes air bubbles at the bottom of the release film.

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