A release film-free rapid light-curing 3D printing device and method

Abstract

The present invention provides a release film-free rapid light-curing 3D printing method, comprising the following steps: adding a photosensitive resin to the resin tank; fixing the printing chamber upside down in the resin tank so that a liquid level difference is generated between the liquid level in the printing chamber and the liquid level in the resin tank, and forming a positive or negative pressure air environment in the printing chamber; setting the printing parameters of the three-dimensional model through slicing software and importing them into a control system; exposing and curing the pattern displayed on the display screen of the projection device layer by layer at the liquid level in the printing chamber through the control system; after each layer of exposure is completed, the control system controls the servo motor to drive the lifting module to move, thereby driving the printing platform to descend a distance of the layer thickness; the liquid level in the printing chamber quickly stabilizes, repeating the above steps to expose and cure the next layer until the model is printed; removing the molded model from the printing platform and cleaning the residual resin on the surface through ultrasonic treatment. The release film-free rapid light-curing 3D printing method provided by the present invention can quickly stabilize the liquid level and avoid bubble generation during the 3D printing process, significantly improving the efficiency of 3D printing and the surface accuracy of the product. The present invention also provides a release film-free rapid light-curing 3D printing device.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a release film-free rapid light-curing 3D printing device and method. Background Art

[0002] In recent years, photocuring 3D printing technology has developed rapidly and has been widely used in fields such as medicine, electronics, aerospace, and industrial manufacturing. However, traditional photocuring 3D printing technology usually uses release film to assist molding, so the model needs to be separated from the release film and adhered to the building substrate through the reciprocating motion of the printing platform. This process significantly increases printing time and reduces printing efficiency. Continuous liquid interface curing technology (CLIP) solves the above problems by using a gas-permeable membrane, but the cost of the gas-permeable membrane limits the popularization and application of this technology. In addition, repeated use of the release film will cause surface wear, which in turn affects the stability of the printing process and even causes printing failure. Therefore, the maintenance and replacement of the release film further increases the production cost and operational complexity, which is not conducive to the promotion and application of photocuring 3D printing technology in industrial production.

[0003] In the prior art, in order to solve the problems existing in release film in 3D printing technology, sinking 3D printing technology has been promoted and applied. For example, Chinese patent application (CN111688187A) discloses a projection device, printer and light control method based on LCD liquid crystal display screen. This technology adopts sinking 3D printing technology and improves the printing success rate and efficiency of the product by optimizing the optical path structure. However, this technical solution has the common problems of sinking 3D printing technology: on the one hand, after completing one layer of printing, the lifting mechanism drives the printing platform to descend, and the liquid level will fluctuate during this process. It is necessary to wait for the liquid level to stabilize before printing the next layer, which affects work efficiency. If the next layer is printed when the liquid level is not stable, the printing thickness will be uneven, affecting the printing accuracy. On the other hand, because the 3D printing material used is light-curing resin, the fluctuation of the liquid level will generate bubbles on the liquid surface during the process of the lifting mechanism driving the printing platform to descend, which requires the degassing of the bubbles before printing the next layer, otherwise it will also affect the printing accuracy. The defoaming process of bubbles on the liquid surface takes a long time, especially bubbles generated by high-viscosity resins are more difficult to eliminate, which seriously affects the efficiency of 3D printing.

[0004] In view of this, it is necessary to provide a fast light-curing 3D printing process with high efficiency and high printing precision to solve the above technical problems. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a release film-free rapid light-curing 3D printing device and method. By adopting the sinking 3D printing technology, the technical defects of the release film in 3D printing are effectively overcome. At the same time, during the 3D printing process, the liquid surface can be quickly stabilized and no bubbles are generated, which significantly improves the efficiency of 3D printing and the surface accuracy of the product.

[0006] The first aspect of the present invention is to provide a release film-free rapid light-curing 3D printing device, the technical solution of which is as follows:

[0007] A release film-free rapid light-curing 3D printing device, comprising a resin tank for containing photosensitive resin, a printing chamber, a projection device disposed in the printing chamber, a lifting module, a printing platform disposed at one end of the lifting module, a servo motor for controlling the operation of the lifting module, and a control system;

[0008] The printing chamber is a hollow structure with one end open. During operation, the open end of the printing chamber is fixed upside down above the resin tank, so that a liquid level difference is generated between the liquid level in the printing chamber and the liquid level in the resin tank, thereby forming a positive or negative pressure air environment in the printing chamber; the printing platform is located below the liquid level in the printing chamber;

[0009] The printing parameters of the three-dimensional model are imported into the control system, which uses a projection device to expose and cure the printed pattern layer by layer at the liquid surface in the printing chamber. After the exposure and curing are completed, the control system controls the servo motor to drive the lifting module to move, thereby driving the printing platform to move downward to expose and cure the next layer of graphics. The distance the printing platform descends each time is equal to the thickness of the corresponding printing layer.

[0010] Furthermore, the projection device includes an LCD screen and an ultraviolet light source, and the LCD screen is located above the liquid level in the printing chamber.

[0011] Furthermore, the wavelength of the ultraviolet light source is 405 nm.

[0012] Furthermore, the printing parameters include exposure time and layer thickness.

[0013] The second aspect of the present invention is to provide a method for rapid photocuring 3D printing without a release film, the technical solution of which is as follows:

[0014] A release film-free rapid light-curing 3D printing method, using the 3D printing device described in the first aspect, comprises the following steps:

[0015] Step S1, adding photosensitive resin into the resin tank;

[0016] Step S2, fixing the printing chamber upside down in the resin tank, so that a liquid level difference is generated between the liquid level in the printing chamber and the liquid level in the resin tank, and forming a positive pressure or negative pressure air environment in the printing chamber;

[0017] Step S3, setting the printing parameters of the three-dimensional model through the slicing software and importing it into the control system;

[0018] In step S4, the control system exposes and solidifies the pattern displayed on the display screen of the projection device layer by layer at the liquid surface of the printing chamber. After each layer is exposed, the control system controls the servo motor to drive the lifting module to move, thereby driving the printing platform to descend a distance of the layer thickness.

[0019] Step S5: The liquid level in the printing chamber quickly stabilizes, and step S4 is repeated to perform exposure and curing of the next layer until the printing of the model is completed;

[0020] Step S6: remove the molded model from the printing platform and clean the residual resin on the surface by ultrasonic treatment.

[0021] Furthermore, in step S3, a three-dimensional model is constructed using three-dimensional modeling software, and an STL file is exported, and the STL file is imported into a light-curing 3D printing slicing software to set printing parameters.

[0022] Furthermore, the printing parameters include exposure time and layer thickness.

[0023] Furthermore, the projection device includes an LCD screen and an ultraviolet light source, and the LCD screen is located above the liquid level in the printing chamber.

[0024] Furthermore, the wavelength of the ultraviolet light source is 405 nm.

[0025] Furthermore, in step S6, the ultrasonic cleaning step uses an ethanol solution for cleaning for 5 minutes.

[0026] Compared with the prior art, the release film-free rapid light-curing 3D printing device and method provided by the present invention have the following beneficial effects:

[0027] First, the release film-free, rapid, light-curing 3D printing device and method provided by the present invention secures the print chamber upside down above the resin tank, creating a level difference between the liquid level in the resin tank and the liquid level in the print chamber. This creates a positive or negative pressure air environment within the print chamber. Because the gas volume within the print chamber remains constant, the liquid level within the print chamber quickly stabilizes during light-curing 3D printing. This avoids uneven layer thickness and bubbles caused by an unstable liquid level during printing, improving the surface accuracy of the product. Because the liquid level within the print chamber can quickly stabilize, it saves adjustment time waiting for the liquid level to stabilize, thereby improving printing efficiency.

[0028] 2. The release film-free rapid light-curing 3D printing device and method provided by the present invention sets the printing parameters through slicing software and imports them into the control system. The control system accurately controls the exposure time of each layer and the distance the servo motor drives the printing platform to descend to ensure that the air pressure in the printing chamber remains unchanged, thereby ensuring the curing accuracy of each layer, reducing model defects and interlayer separation problems, and significantly improving the surface molding quality of the model.

[0029] 3. When the liquid level of the photocurable resin fluctuates, bubbles will be generated on the liquid surface, and the greater the viscosity of the resin material, the more difficult it is to eliminate the bubbles. The release-free film-free rapid photocuring 3D printing device and method provided by the present invention can quickly stabilize the liquid level in the printing chamber, thus avoiding the problem of bubbles generated by liquid level fluctuations. Therefore, it can be applied to photosensitive resins with different viscosity ranges, providing a wider range of material choices for various application scenarios, expanding the application field of photocuring 3D printing technology, and meeting diversified production needs. At the same time, the release-free film-free rapid photocuring 3D printing device and method provided by the present invention does not need to set up a bubble scraper to eliminate bubbles, making the structure of the printing device simpler and more capable of continuous operation, thereby ensuring printing efficiency.

[0030] 4. The release film-free rapid light-curing 3D printing device and method provided by the present invention do not require the use of a release film, thereby eliminating the purchase, maintenance and replacement costs of the release film, while simplifying the structure and maintenance operations of the equipment and reducing the overall production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. The drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0032] Figure 1 2. It is a schematic structural diagram of a release film-free rapid light-curing 3D printing device according to the present invention;

[0033] Figure 2 is a light microscope image of a molded part obtained by the method of Example 2;

[0034] Figure 3 3D printing device according to Example 3;

[0035] Figure 4 This is a light microscope image of the molded part obtained using the method of Example 3. DETAILED DESCRIPTION

[0036] In order to enable those skilled in the art to better understand the technical solutions in the embodiments of the present invention and to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific implementation methods of the present invention are further described below.

[0037] The endpoints of the ranges and any values ​​disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoints of each range, the endpoints of each range and individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0038] Example 1

[0039] See also Figure 1 , is a schematic diagram of the structure of the release-free, rapid, light-curing 3D printing device of the present invention. The release-free, rapid, light-curing 3D printing device of the present invention comprises a resin tank 1, a printing chamber 2, a projection device 3, a lifting module 4, a printing platform 5, a servo motor 6, and a control system (not shown).

[0040] The resin tank 1 is used to contain light-curing resin material. The use of light-curing resin is selected according to the application field and application scenario of the model.

[0041] Print chamber 2 is a hollow structure with one open end. When in operation, this open end is inverted over resin tank 1. The light-curable resin material within tank 1 seals print chamber 2, while air remains inside. Due to the pressure difference between the external air pressure and the air pressure inside the print chamber, a difference in liquid level occurs between the resin tank 1 and the print chamber. The depth of the inverted print chamber within the resin material determines the pressure of the air inside the print chamber, allowing for either positive or negative pressure.

[0042] The projection device 3 is arranged in the printing chamber 2, and includes a high-resolution LCD screen 31 and an ultraviolet light source 32. The LCD screen is located above the liquid surface in the printing chamber, and the wavelength of the ultraviolet light source is 405nm. A three-dimensional model is constructed using three-dimensional modeling software, and an STL file is exported. The STL file is imported into the photocuring 3D printing slicing software to set the printing parameters, and the printing parameters are imported into the control system. When working, the ultraviolet light source 32 is turned on, and a pattern corresponding to the printed model is displayed on the LCD screen. The ultraviolet light source is irradiated and exposed and cured at the liquid surface in the printing chamber. The exposed and cured pattern is the same as the pattern displayed on the LCD screen. When setting the printing parameters, the corresponding exposure time is designed according to the thickness of each layer and the information of the resin material used to accurately control the layer thickness of the printed model.

[0043] The lifting module 4 is controlled by a servo motor 6 and has the characteristics of high control precision. The servo motor 6 is controlled by a control system. One end of the lifting module 4 is connected to the printing platform 5, thereby driving the printing platform 5 to perform lifting and lowering movements. Among them, the printing platform is used to carry the printing model. After a layer of exposure and curing is completed, the servo motor drives the lifting module to work, driving the printing platform 5 to descend, and the descending height is equal to the thickness of the corresponding printing layer. In the present invention, the lifting module 4 is a combination of a screw and a nut, and its working principle is: the servo motor provides power, drives the pulley to rotate through the reducer, and the pulley then drives the screw to rotate, thereby causing the nut to produce linear motion. The printing platform 5 is connected to the nut through a connecting rod, so that the lifting and lowering linear motion of the printing platform can be realized. The present invention uses a servo motor to control the descending distance of the lifting platform, with high control precision, so that the layer thickness error can be controlled within the micron range.

[0044] When the model printing is completed, the printing chamber can be removed, and the lifting module can be driven up to expose the molded model to the resin liquid surface, so that the molded model can be taken out.

[0045] Example 2

[0046] Based on the release film-free rapid light-curing 3D printing device described in Example 1, the present invention further provides a release film-free rapid light-curing 3D printing method, which specifically includes the following steps:

[0047] Step S1, adding photosensitive resin into the resin tank;

[0048] Step S2, fixing the printing chamber upside down in the resin tank, so that a liquid level difference is generated between the liquid level in the printing chamber and the liquid level in the resin tank, and forming a positive pressure or negative pressure air environment in the printing chamber;

[0049] Step S3, setting the printing parameters of the three-dimensional model through the slicing software and importing it into the control system;

[0050] Specifically, a 3D model is constructed using 3D modeling software, and an STL file is exported. The STL file is then imported into the light-curing 3D printing slicing software to set the printing parameters, including layer thickness, exposure time of each layer, etc., to ensure the curing accuracy of the model.

[0051] In step S4, the control system exposes and solidifies the pattern displayed on the display screen of the projection device layer by layer at the liquid surface of the printing chamber. After each layer is exposed, the control system controls the servo motor to drive the lifting module to move, thereby driving the printing platform to descend a distance of the layer thickness.

[0052] Specifically, the control system turns on the projection device and the UV light source, displaying a pattern corresponding to the printed model on the LCD screen. The UV light source irradiates the liquid surface in the print chamber, exposing and curing the pattern. The cured pattern is identical to the pattern displayed on the LCD screen. The UV light source has a wavelength of 405 nm.

[0053] When the lifting module drives the printing platform down a layer thickness, the next layer can be exposed and cured.

[0054] Step S5: The liquid level in the printing chamber quickly stabilizes, and step S4 is repeated to perform exposure and curing of the next layer until the printing of the model is completed;

[0055] Step S6: remove the molded model from the printing platform and clean the residual resin on the surface by ultrasonic treatment. Specifically, the ultrasonic treatment cleaning step uses ethanol solution to clean for 5 minutes to remove the residual photosensitive resin on the surface of the printed model to ensure the cleanliness of the model.

[0056] The optical microscope image of the molded part printed in this embodiment is as follows Figure 2 As shown by Figure 2 It can be seen that the surface quality of the molded model is high and there is no obvious layer pattern.

[0057] Example 3

[0058] A rapid light-curing 3D printing method without release film, using Figure 3 The light-curing 3D printing device shown includes the following steps:

[0059] Step S1, adding photosensitive resin into the resin tank;

[0060] Step S2, importing the slice file into the control system;

[0061] Step S3: Using a sinking 3D printing technique, the photosensitive resin at the liquid surface is cured layer by layer. After one layer is exposed and cured, the lifting device drives the printing platform down, and then the next layer is exposed and cured until the model is printed.

[0062] Step S4: taking out the molded model and performing ultrasonic cleaning for 5 minutes.

[0063] The optical microscope image of the molded part printed in this embodiment is as follows Figure 4 As shown by Figure 4 It can be seen that the surface of the molded model has obvious layer patterns.

[0064] The release film-free rapid light-curing 3D printing device and method of the present invention fixes the printing chamber upside down in the resin material tank, so that a liquid level difference is generated between the liquid level in the printing chamber and the liquid level in the resin material tank. During the 3D printing process, the liquid level can be quickly stabilized and no bubbles are generated, which significantly improves the efficiency of 3D printing and the surface accuracy of the product.

[0065] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations made to these embodiments without departing from the principles of the present invention are still within the scope of protection of the present invention.

Claims

1. A rapid light-curing 3D printing device without release film, characterized in that: It includes a resin tank for containing photosensitive resin, a printing chamber, a projection device arranged in the printing chamber, a lifting module, a printing platform arranged at one end of the lifting module, a servo motor for controlling the operation of the lifting module, and a control system; The printing chamber is a hollow structure with one end open. During operation, the open end of the printing chamber is fixed upside down above the resin tank, so that a liquid level difference is generated between the liquid level in the printing chamber and the liquid level in the resin tank, thereby forming a positive or negative pressure air environment in the printing chamber; the printing platform is located below the liquid level in the printing chamber; The printing parameters of the three-dimensional model are imported into the control system, which uses a projection device to expose and cure the printed pattern layer by layer at the liquid surface in the printing chamber. After the exposure and curing are completed, the control system controls the servo motor to drive the lifting module to move, thereby driving the printing platform to move downward to expose and cure the next layer of graphics. The distance the printing platform descends each time is equal to the thickness of the corresponding printing layer.

2. The release film-free rapid light-curing 3D printing device according to claim 1, characterized in that: The projection device includes an LCD screen and an ultraviolet light source, and the LCD screen is located above the liquid level in the printing chamber.

3. The release film-free rapid light-curing 3D printing device according to claim 2, characterized in that: The wavelength of the ultraviolet light source is 405 nm.

4. The release film-free rapid light-curing 3D printing device according to claim 1, characterized in that: Printing parameters include exposure time and layer thickness.

5. A rapid light-curing 3D printing method without a release film, characterized in that: Using the 3D printing device according to claim 1, the 3D printing method comprises the following steps: Step S1, adding photosensitive resin into the resin tank; Step S2, fixing the printing chamber upside down in the resin tank, so that a liquid level difference is generated between the liquid level in the printing chamber and the liquid level in the resin tank, and forming a positive pressure or negative pressure air environment in the printing chamber; Step S3, setting the printing parameters of the three-dimensional model through the slicing software and importing it into the control system; In step S4, the control system exposes and solidifies the pattern displayed on the display screen of the projection device layer by layer at the liquid surface of the printing chamber. After each layer is exposed, the control system controls the servo motor to drive the lifting module to move, thereby driving the printing platform to descend a distance of the layer thickness. Step S5: The liquid level in the printing chamber quickly stabilizes, and step S4 is repeated to perform exposure and curing of the next layer until the printing of the model is completed; Step S6: remove the molded model from the printing platform and clean the residual resin on the surface by ultrasonic treatment.

6. The release film-free rapid light-curing 3D printing method according to claim 5, characterized in that: In step S3, a three-dimensional model is constructed using a three-dimensional modeling software, and an STL file is exported. The STL file is then imported into a light-curing 3D printing slicing software to set printing parameters.

7. The release film-free rapid light-curing 3D printing method according to claim 6, characterized in that: Printing parameters include exposure time and layer thickness.

8. The release film-free rapid light-curing 3D printing method according to claim 5, characterized in that: The projection device includes an LCD screen and an ultraviolet light source, and the LCD screen is located above the liquid level in the printing chamber.

9. The release film-free rapid light-curing 3D printing method according to claim 8, characterized in that: The wavelength of the ultraviolet light source is 405 nm.

10. The method for rapid photocuring 3D printing without release film according to any one of claims 5 to 9, characterized in that: In step S6, the ultrasonic cleaning step uses an ethanol solution for cleaning for 5 minutes.

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