3D printer based on liquid surface tension and printing method

Abstract

The invention belongs to the technical field of 3D printing, and particularly relates to a 3D printer based on liquid surface tension and a printing method. Comprising a light source used for providing curing light, a titration device used for providing a printing material, a film forming structure of the printing material and a printing platform. Wherein the thin film forming structure is provided with a through hole, and the through hole is located in the focal plane of the curing light and is parallel to the surface of the printing platform; the titration device is arranged above the thin film forming structure, the printing material is titrated on the surface of the thin film forming structure, and the thin film forming structure receives the printing material of the titration device and forms a liquid thin film at the through hole. According to the invention, the curing light directly irradiates on the film formed by the printing material for curing, so that the printing time is greatly shortened, the printing efficiency is improved, the overall energy consumption is reduced, the virtual focus problem is eliminated, and higher printing precision is ensured.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing, and in particular relates to a 3D printer and a printing method based on liquid surface tension. Background Art

[0002] Stereolithography is a traditional and relatively mature 3D printing technology that uses ultraviolet light or other forms of light sources to cure photosensitive resins and build three-dimensional objects by curing layer by layer. This technology is widely used in many fields such as medicine, engineering, and art due to its high resolution and fine printing quality. However, the printing process of traditional photocuring 3D printing technology relies on the light source to pass through the oxygen-permeable film or light-transmitting film at the bottom of the printing material pool. This design causes the intensity of light to be attenuated during transmission, and a higher-power projection light machine is required for 3D printing. In addition, due to the blocking of light by the film, the uniformity of the light is affected, resulting in a certain degree of defocus, which in turn has an adverse effect on the printing accuracy. Summary of the invention

[0003] In view of the light intensity attenuation and out-of-focus problems caused by the above-mentioned 3D printer passing through the oxygen-permeable film or the light-transmitting film, the purpose of the present invention is to provide a 3D printing device and a printing method. The 3D printing device performs curing printing by dripping printing materials and relying on the thin film formed by the surface tension of the liquid, which can achieve efficient light-curing printing and solve the out-of-focus problem.

[0004] In order to achieve the above-mentioned purpose of the invention, the first technical solution provided by the present invention discloses a 3D printing device, including a light source for providing curing light, a titration device for providing printing material, a film forming structure for printing material and a liftable printing platform; wherein the titration device is arranged above the film forming structure to titrate the printing material onto the surface of the film forming structure, a through hole is provided on the film forming structure, so that the printing material forms a liquid film at the through hole, and the printing platform is movably arranged corresponding to the through hole, so that the liquid film formed at the through hole is located in the focal plane of the curing light and is parallel to the surface of the printing platform.

[0005] Furthermore, the radial cross-sectional area of ​​the through hole is 5 to 25 mm. 2 .

[0006] Furthermore, the film forming structure is a ring.

[0007] Furthermore, the film forming structure is a ring.

[0008] Furthermore, the printing platform is arranged above the film forming structure, and the light source is arranged below the film forming structure.

[0009] Furthermore, the light source also includes a reflector, and the curing light reflected by the reflector passes through the through-hole focal plane.

[0010] Furthermore, the titration device is ≥1 and is detachable.

[0011] The second technical solution of the present application discloses a 3D printing method of the above 3D printing device, comprising:

[0012] The titration device extrude the printing material onto the surface of the film forming structure, so that it forms a uniform liquid film at the through hole;

[0013] The light source provides curing light to cure and print the liquid film, and the printing platform moves layer by layer perpendicular to the film to form a structure to achieve layer-by-layer stacking of materials.

[0014] Furthermore, the titration device ensures that the film is not broken by controlling the dropping frequency and the dropping amount during the curing printing process.

[0015] Furthermore, when the printing material needs to be replaced, the liquid film is broken by shaking or knocking the film-forming structure, and then cleaned, and then the titration device is replaced to achieve the replacement of the printing material.

[0016] The present invention has the following beneficial effects:

[0017] 1. The present invention performs curing by directly irradiating the curing light on the film formed by the printing material, thereby greatly shortening the printing time and improving the printing efficiency; at the same time, it avoids the problem of light intensity attenuation caused by the light source passing through the oxygen-permeable film or the light-transmitting film in the prior art, so that the curing process can be completed with lower light intensity, reducing the overall energy consumption; in addition, since the light does not pass through the light-transmitting or oxygen-permeable film, the influence of the film microstructure on the light is avoided, the out-of-focus problem is eliminated, and higher printing accuracy is guaranteed.

[0018] 2. If Figure 3 As shown, in the prior art, since the printing material is placed in the printing material pool, the printing platform can only be placed above the printing material pool. At the same time, in order to avoid physical interference between the printing platform and the printing material pool, it can only move up and down, which limits the degree of freedom. In the present application, since there is no printing material pool, the printing material forms a thin film through the through holes in the thin film forming structure and is directly cured by the light source. Therefore, the position of the printing platform will not be restricted, and it can be located above or below the thin film forming structure. The support structure of the printing platform can also be replaced with a robotic arm to freely control the horizontal, vertical and even rotational movement of the printing platform. When printing some special structures, the traditional light-curing printing method must add support. In the present application, since the printing freedom is not restricted, when printing these special structures, it is not necessary to add support, but the relative position of the printing material and the printing platform can be adjusted by the robotic arm.

[0019] 3. When the printing material needs to be replaced, the prior art requires that the printing material in the original printing material pool be discarded, and then the printing material pool must be cleaned and dried before new printing material can be filled in. At the same time, the printing material pool and the oxygen-permeable or light-permeable film are easily damaged during the operation, and the replacement process is complicated and time-consuming. However, in the present application, since multiple titration devices can exist at the same time, different printing materials can be held at the same time, and the titration device is detachable, it is only necessary to rupture the liquid film on the film-forming structure by oscillation or knocking, and the printing material can be replaced after the new material is dripped in to form a film, which greatly saves the time consumed in switching the printing material pool.

[0020] 4. The printing materials of the prior art light-curing 3D printing equipment are generally placed in a printing pool, so only a small part of the printing materials can be used, and the rest will be wasted. Since there is no printing pool in the present application, the only material that may be wasted after printing is the material film formed on the film forming structure, and there is no material adhering to the periphery of the printing pool, so the utilization rate of the printing materials can be improved.

[0021] 5. In the traditional light-curing 3D printing process, as the printing progresses, the material liquid level will continue to drop, reducing the printing accuracy. However, in this application, there will be no problem of liquid level drop. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 , Figure 2 This is a schematic diagram of the three-dimensional structure of the 3D printing device provided by the present invention.

[0023] Markings in the figure:

[0024] 1. Light source;

[0025] 2. Support structure;

[0026] 3. Printing platform support structure;

[0027] 4. Motor;

[0028] 5. Titration device;

[0029] 6. Screw rod and its housing;

[0030] 7. Reflector;

[0031] 8. Light;

[0032] 9. Thin film formation structure;

[0033] 10. Printing materials;

[0034] 11. Printing platform;

[0035] 12. Print the finished product;

[0036] Attached Figure 3 It is the part with limited freedom in the existing 3D printing technology. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0039] In addition, in this application, spatial relative terms such as "under", "below", "under", "below", "above", "upper", "above", "higher", "side" (for example, in "side wall"), etc., are used to describe the relationship of one element to another (other) original as shown in the drawings. The spatial relative terms are intended to include different orientations of the device in use, operation and / or manufacture in addition to the orientation described in the drawings. For example, if the device in the drawings is turned over, the elements described as "under" or "below" other elements or features will then be defined as "above" the other elements or features. Therefore, the exemplary term "under" can include both above and below orientations. In addition, the device can be positioned otherwise (for example, rotated 90 degrees or at other orientations), so the spatial relative descriptors used herein are interpreted accordingly.

[0040] Figure 1-2 The 3D printing device provided by the present invention is shown, and the 3D printing device includes a light source 1 for providing curing light 8, a titration device 5 for providing printing material, a film forming structure 9 for printing material, and a printing platform 10.

[0041] like Figure 2 As shown, the film forming structure 9 is a closed loop structure with a through hole, which can be made into various closed loop shapes, such as a perfect circle, an ellipse, a square or other special shapes. When the titration device drops the printing material on the surface of the film forming structure, under the action of gravity and surface tension, the printing material will form a uniform liquid film at the through hole of the closed loop structure, so that it can be directly cured by a curing light source. Figure 1 As shown, the film forming structure is fixed and supported by a support structure 2 to provide a stable printing platform.

[0042] It can be understood that in this process, in order to form a liquid film, the size of the through-holes of the film-forming structure is affected by the properties of the printing material itself (surface tension, viscosity, etc.), and the size of its radial cross-sectional area is based on the liquid film that can just form a closed loop; for example, when the printing material is resin, its radial cross-sectional area is 5 to 25 mm 2 If the film forming structure is an arc-shaped closed loop structure, such as an ellipse or a perfect circle, the liquid film can be formed faster and more uniformly. A perfect circle is most preferred. When it is a perfect circle, the through hole diameter is 3-5 mm.

[0043] like Figure 1 As shown, the printing platform 10 is movably arranged corresponding to the through hole, so that the liquid film formed at the through hole is located at the focal plane of the curing light 8 and is parallel to the surface of the printing platform 10, so that the curing light can efficiently cure the film in the film forming structure. It can be understood that in this process, the light source can control the light intensity and fine-tune the angle through the program, so as to adjust the curing optical fiber to pass through the focal plane of the liquid film. This belongs to the conventional method in the field, and this application does not limit it, and only provides a preferred embodiment, for example Figure 1 The thin film forming structure is shown on its side, and then the curing light path is changed by a reflector 7 so that the thin film forming structure is located in the focal plane of the curing light.

[0044] like Figure 2 As shown, the titration device 5 is arranged above the film forming structure 9, which is fixed by a supporting structure (not shown in the figure). The rate and amount of titration of the printing material by the titration device can be dynamically controlled according to the actual state of the film to avoid the film from breaking due to insufficient liquid. For example, when the surface tension of the printing material is insufficient, the integrity of the film can be maintained by increasing the dripping frequency. The thickness of the liquid film can also be controlled by adjusting the dripping speed of the dripper to meet different printing requirements. The titration process can be driven directly by a motor or by using an air compressor to adjust the air pressure, which is not particularly limited in this application.

[0045] In a preferred embodiment, the titration device 5 can be multiple, with different printing materials installed on it, and the titration device is detachable, so that the printing material can be quickly replaced. In the actual replacement process, it is only necessary to break the liquid film on the film forming structure, and then clean and dry the film forming structure, and then continue to drip another printing material. On the other hand, since the film forming structure is relatively simple and detachable, the film forming structure can also be directly removed and replaced with the film forming structure without material, and cleaned up uniformly after printing.

[0046] like Figure 1 As shown, the printing platform 11 is supported by the screw and its housing 6, and is driven to move by the motor 4, and the printing platform is parallel to the film forming structure; Figure 2 As shown, when one layer of printing is completed, the motor 4 drives the printing platform to move so that the finished layer contacts the liquid film, and the next layer of printing is performed. This step is repeated continuously, thereby achieving continuous stacking of materials to obtain a printed product.

[0047] In a preferred embodiment, the support structure screw rod and its housing 6 of the printing platform can be replaced by a mechanical arm, and the movement of the printing platform can be freely controlled by the mechanical arm, such as upward, downward, left, right, tilted to one side, rotated, flipped, etc. An embodiment of the present application discloses a printing method of the above-mentioned 3D printing structure, specifically: the titration device extrude the printing material to the surface of the film forming structure, so that it forms a uniform liquid film at the through hole; the light source provides curing light to cure the liquid film for printing, and at the same time, the printing platform moves layer by layer in the film forming structure to realize layer by layer stacking of materials, thereby obtaining a printed product.

[0048] It can be understood that in this process, the film forming structure 9 needs to be fixed on the support structure 2 first to ensure its stability, and then adjusted to be located in the focal plane of the curing light 8; then the printing platform is connected to its support structure, and then adjusted to be parallel to the film forming structure 9. At the same time, the printing material required for printing is added to the titration device. The titration device controls the dripping frequency and dripping amount during the curing printing process to ensure that the film is not broken. When the printing material needs to be replaced, the liquid film is broken by shaking or knocking the film forming structure, and cleaned, and then the titration device is replaced to achieve the replacement of the printing material.

[0049] In the above printing method, the droplet material needs to be continuously and evenly added to the printing material to form a uniform liquid film.

[0050] During printing, the support structure of the printing platform needs to be slowly moved so that the printing platform descends together with it until the surface of the printing platform contacts the liquid film.

[0051] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and the scope of protection of the present invention is defined by the attached claims, description and their equivalents.

Claims

1. A 3D printing device, characterized in that: The invention comprises a light source for providing curing light, a titration device for providing printing material, a film forming structure for the printing material and a printing platform; wherein the titration device is arranged above the film forming structure to titrate the printing material onto the surface of the film forming structure; a through hole is arranged on the film forming structure so that the printing material forms a liquid film at the through hole; the printing platform is movably arranged corresponding to the through hole so that the liquid film formed at the through hole is located in the focal plane of the curing light and is parallel to the surface of the printing platform.

2. The 3D printing device according to claim 1, characterized in that: The radial cross-sectional area of ​​the through hole is 5 to 25 mm 2 .

3. The 3D printing device according to claim 1 or 2, characterized in that: The film forming structure is a ring.

4. The printing device according to claim 3, characterized in that: The film-forming structure is a ring.

5. The 3D printing device according to claim 1, characterized in that: The printing platform is supported by a mechanical arm, and the mechanical arm can freely regulate the movement of the printing platform.

6. The 3D printing device according to claim 1, characterized in that: The light source further comprises a reflector, and the curing light reflected by the reflector passes through the through-hole focal plane.

7. The 3D printing device according to claim 1, characterized in that: The titration device is ≥1 and is detachable.

8. The 3D printing method according to any one of claims 1 to 7, characterized in that: include: The titration device extrude the printing material onto the surface of the film forming structure, so that it forms a uniform liquid film at the through hole; The light source provides curing light to cure and print the liquid film, and the printing platform moves layer by layer perpendicular to the film to form a structure to achieve layer-by-layer stacking of materials.

9. The 3D printing method according to claim 8, characterized in that: The titration device ensures that the film is not broken by controlling the dropping frequency and the dropping amount during the curing printing process.

10. The 3D printing method according to claim 8, characterized in that: When the printing material needs to be replaced, the liquid film is broken by shaking or knocking the film-forming structure, and then cleaned, and then the titration device is replaced to achieve the replacement of the printing material.

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