A forming platform of a 3D printing device and a preparation method thereof

Abstract

The application discloses a forming platform of a 3D printing device and a preparation method thereof, and relates to the technical field of 3D printing. The forming platform is prepared from modified plastic material, the plastic material is optimized, the adhesion between a forming surface and a printing layer formed after exposure and curing of light-cured material can be significantly improved, and thus, the falling-off of the forming platform is reduced, and the printing success rate is improved.

Description

Technical Field

[0001] This invention relates to the field of 3D printing technology, and more specifically, to a molding platform for 3D printing equipment and its preparation method. Background Technology

[0002] 3D printing equipment requires a high degree of adhesion between the molding platform and the 3D printed part. If the initial print is not firmly bonded to the molding platform, the part is prone to detaching during subsequent printing, leading to print failure. Many molding platforms use injection molding platforms, which have the following problems during printing: the adhesion between the molding surface of the injection molding platform and the printed part is poor, making it easy for the part to detach during printing. For example, ABS, PP, PC, and PVA are all prone to this detachment problem.

[0003] The following improvement plan is proposed to address the board drop issue:

[0004] (1) Coatings can be applied to the molding surface of the ABS molding platform, but traditional coatings are not easy to dry, making transportation inconvenient, and the boards are still easy to fall off during the UV curing process.

[0005] (2) Chemical oxidation treatment of the molding surface of ABS molding platform. The most common method is to use chromic anhydride-sulfuric acid roughening solution to oxidize and etch the molding surface of ABS molding platform. The roughening solution is expensive, polluting and energy-intensive. Moreover, the improvement effect of using roughening solution on ABS molding platform is not good. It is still easy for the board to fall off during UV curing process, which has great limitations.

[0006] In view of this, the present invention is proposed. Summary of the Invention

[0007] One of the objectives of this invention is to provide a molding platform for a 3D printing device. The molding platform of the 3D printing device is prepared using the modified ABS material, which can significantly increase the adhesion of the molding platform.

[0008] The second objective of this invention is to provide a method for preparing a molding platform for a 3D printing device, which aims to improve the adhesion between the printed part and the molding surface of the molding platform, thereby reducing board drop and increasing the printing success rate.

[0009] This invention is implemented as follows:

[0010] In a first aspect, the present invention provides a molding platform for a 3D printing device, the molding platform having a molding surface for adhering a 3D printed part formed by exposure and curing of a photocurable material, wherein the molding platform is made of a modified plastic material, and the adhesive force between the molding surface and the printed layer formed by exposure and curing of the photocurable material satisfies not less than 1.5N per square centimeter.

[0011] In an optional implementation, the adhesion between the molding surface and the printed layer formed after exposure and curing of the photocurable material is not less than 3N per square centimeter.

[0012] In an optional embodiment, the plastic material is selected from at least one of ABS, PC, PP, POM, PA, PS, PBT, AS, PET, PVC, PEEK, PPSU, SAN, PE, TPE, PTFE, PES, and PVA.

[0013] In optional embodiments, the modification treatment includes at least one of grafting modification, blending modification, inorganic reinforcement modification, morphology and structure control modification, and crosslinking modification.

[0014] In an optional embodiment, the molding platform is made of modified ABS material, the raw materials of which include 70-80 wt% ABS resin, 5-20 wt% methacrylic resin, 5-10 wt% reinforcing fiber, and 1-5 wt% coupling agent.

[0015] In an optional embodiment, the raw materials for the modified ABS material include 73-78 wt% ABS resin, 10-15 wt% PMMA resin, 6-9 wt% reinforcing fiber, and 2-4 wt% coupling agent.

[0016] In an optional embodiment, the reinforcing fiber is selected from at least one of glass fiber, ceramic fiber, silica fiber, and boron fiber.

[0017] In an optional embodiment, the coupling agent is selected from at least one of silane monomers, styrene monomers, and titanate monomers;

[0018] The silane monomers are selected from at least one of vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-(methacryloyloxy)propyltrimethoxysilane.

[0019] In an optional embodiment, the methacrylate resin is selected from at least one of methyl methacrylate, polymethyl methacrylate (PMMA), polyurethane methacrylate, and n-butyl methacrylate.

[0020] In an optional embodiment, the shaped surface is obtained through surface treatment, which includes at least one of spraying, sandblasting, grinding, engraving, electroplating, coating, printing, texturing, polishing, painting, oiling, ion plating, and laser treatment.

[0021] Secondly, the present invention provides a method for preparing a molding platform for a 3D printing device, comprising:

[0022] Provide raw materials for the molding platform;

[0023] The raw materials are modified and shaped to obtain a molding platform made of plastic. The molding platform has a molding surface, which is used to adhere the 3D printed parts formed by exposure and curing of the photocurable material. The adhesion force between the molding surface and the printed layer formed by exposure and curing of the photocurable material is not less than 1.5N per square centimeter.

[0024] In an optional implementation, the adhesion between the molding surface and the printed layer formed after exposure and curing of the photocurable material is not less than 3N per square centimeter.

[0025] In an optional embodiment, the raw materials include at least one of ABS, PC, PP, POM, PA, PS, PBT, AS, PET, PVC, PEEK, PPSU, SAN, PE, TPE, PTFE, PES, and PVA.

[0026] In optional embodiments, the modification treatment includes at least one of grafting modification, blending modification, inorganic reinforcement modification, morphology and structure control modification, and crosslinking modification.

[0027] In an optional embodiment, the raw materials include 70-80 wt% ABS resin, 5-20 wt% methacrylic resin, 5-10 wt% reinforcing fiber, and 1-5 wt% coupling agent.

[0028] In an optional embodiment, the raw materials include 73-78 wt% ABS resin, 10-15 wt% methacrylic resin, 6-9 wt% reinforcing fiber, and 2-4 wt% coupling agent.

[0029] In an optional embodiment, the reinforcing fiber is selected from at least one of glass fiber, ceramic fiber, silica fiber, and boron fiber.

[0030] In an optional embodiment, the coupling agent is selected from at least one of silane monomers, styrene monomers, and titanate monomers;

[0031] The coupling agent is selected from at least one of vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-(methacryloyloxy)propyltrimethoxysilane.

[0032] In an optional embodiment, the methacrylate resin is selected from at least one of methyl methacrylate, polymethyl methacrylate (PMMA), polyurethane methacrylate, and n-butyl methacrylate.

[0033] In an optional embodiment, the preparation method further includes: surface treatment of the molded surface, the surface treatment including at least one of spraying, sandblasting, grinding, engraving, electroplating, coating, printing, texturing, polishing, painting, oiling, ion plating and laser treatment.

[0034] In an optional embodiment, the preparation method further includes: sandblasting the molding surface to control the surface roughness Ra of the molding platform to be 0.1μm-5μm.

[0035] In an optional embodiment, the abrasive used for sandblasting is a hard abrasive with angular edges, and the abrasive is selected from at least one of white corundum, brown corundum, glass sand and steel grit.

[0036] In an optional embodiment, the preparation method further includes: spraying the molding surface, wherein the raw materials used for spraying, by mass parts, include: 100 parts of light-curing resin, 80-150 parts of diluent and 0.05-2 parts of initiator;

[0037] The photocurable resin is selected from at least one of acrylates, allyl ethers and vinyl ethers, and the number average molecular weight of the photocurable resin is 4000-10W.

[0038] In an optional embodiment, the photocurable resin includes 50-90 parts of a first resin and 10-50 parts of a second resin, wherein the number average molecular weight of the first resin is 4,000-20,000 and the number average molecular weight of the second resin is 4W-10W.

[0039] The first resin is selected from at least one of RA3080, RA3081, RA3083, RA3091, 6071, 6175-3 and SD7508;

[0040] The second resin is selected from at least one of SD1000 and SWA20.

[0041] In an optional embodiment, the diluent is selected from either water or an organic solvent;

[0042] The organic solvent is selected from at least one of ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate.

[0043] In an optional embodiment, the initiator is selected from at least one of TPO, 819, and TPO-L; and / or

[0044] The raw materials used for spraying also include 0.05-1 part of additives; the additives are selected from at least one of CAB 551-0.01, CAB 551-0.2, CAB381-0.1 and CAB 381-0.5.

[0045] In an optional embodiment, the sprayed molding platform is dried to control the thickness of the dry film to be 20μm-30μm.

[0046] When the diluent is water, the drying temperature is controlled at 60℃-80℃ and the drying time is 10min-15min.

[0047] When the diluent is an organic solvent, control the drying temperature to 50℃-60℃ and the drying time to 3min-5min.

[0048] In an optional embodiment, the molding platform has a back side opposite to the molding surface, and the preparation method further includes: performing an opening process on the molding platform to form a plurality of through holes penetrating the molding surface and the back side of the molding platform, wherein the diameter of the through holes gradually increases from the molding surface to the back side.

[0049] In an alternative implementation, multiple through holes on the forming platform are arranged in an alternating manner.

[0050] The present invention has the following beneficial effects: the molding platform is prepared by using modified plastic material. By optimizing the plastic material, the adhesion between the molding surface and the printed layer formed after exposure and curing of the photocurable material can be significantly improved, thereby reducing board drop and improving the printing success rate. Attached Figure Description

[0051] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 A schematic diagram illustrating the application of coatings on a molding platform according to an embodiment of the present invention;

[0053] Figure 2 This is a schematic diagram of the molding platform of the 3D printing equipment provided in an embodiment of the present invention;

[0054] Figure 3 for Figure 1 Schematic diagram of the forming surface of the forming platform;

[0055] Figure 4 for Figure 1 A schematic diagram of the structure on the back of the forming platform;

[0056] Figure 5 for Figure 1 A cross-sectional view of the forming platform along HH.

[0057] Icons: 110-forming platform; 10-coating; 220-material tray; 310-optical machine; 001-forming surface; 002-back side; 003-through hole; 004-reinforcing rib. Detailed Implementation

[0058] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0059] This invention provides a method for preparing a molding platform for a 3D printing device, comprising:

[0060] S1. Provide the raw materials for the molding platform;

[0061] The raw materials can be general plastic materials, and can be selected from at least one of ABS, PC, PP, POM, PA, PS, PBT, AS, PET, PVC, PEEK, PPSU, SAN, PE, TPE, PTFE, PES and PVA.

[0062] In some embodiments, the raw materials include 70-80 wt% ABS resin, 5-20 wt% methacrylic resin, 5-10 wt% reinforcing fiber, and 1-5 wt% coupling agent.

[0063] It should be noted that by preparing modified ABS resin using ABS resin, methacrylic acid resin (PMMA resin), reinforcing fibers and coupling agents as raw materials, the modified ABS resin provided by this invention can be used to injection mold the molding platform of a 3D printing equipment, thereby improving the adhesion between the printed part and the molding surface of the molding platform, thus reducing board drop and improving the printing success rate.

[0064] Specifically, ABS resin is one of the five major synthetic resins, possessing excellent impact resistance, heat resistance, low-temperature resistance, chemical resistance, and electrical properties. Its chemical name is acrylonitrile-butadiene-styrene plastic. In the embodiments of this invention, ABS resin is the base material for modified ABS materials.

[0065] Specifically, the main functions of PMMA (polymethyl methacrylate) resin blending are: (1) to improve the heat resistance of ABS plastic and improve processing fluidity; (2) PMMA has good compatibility with polyurethane acrylate 3D photocurable resin, which can effectively improve the adhesion of the molding platform of plastic 3D printing equipment.

[0066] Specifically, because ABS is relatively soft, reinforcing fibers are used to enhance its strength, increase the flatness of the formed surfaces (0.1–0.15), improve surface roughness, and simultaneously increase adhesion. The role of reinforcing fiber blending is to effectively improve the rigidity and heat resistance of ABS plastic while reducing material shrinkage. Lower shrinkage ensures the dimensional accuracy and flatness of the molding platform in injection molding 3D printing equipment, while higher rigidity reduces deformation of the molding platform during the peeling process, ensuring a higher printing success rate.

[0067] Specifically, coupling agents can effectively improve the compatibility of ABS with PMMA and glass fiber, increase the yield of injection molded products and the uniformity of mixing, and prevent agglomeration and sedimentation.

[0068] Specifically, the mass fraction of ABS resin can be 70%, 72%, 74%, 76%, 78%, 80%, etc.; the mass fraction of methacrylic acid resin can be 5%, 10%, 15%, 20%, etc.; the mass fraction of reinforcing fiber can be 5%, 6%, 7%, 8%, 9%, 10%, etc.; and the mass fraction of coupling agent can be 1%, 2%, 3%, 4%, 5%, etc.

[0069] In a preferred embodiment, the raw materials include 73-78 wt% ABS resin, 10-15 wt% methacrylic resin, 6-9 wt% reinforcing fiber, and 2-4 wt% coupling agent. Optimizing the dosage of each component helps to further improve the adhesion of the molding surface of the molding platform obtained by injection molding of modified ABS resin to the printed parts.

[0070] In some embodiments, the methacrylate resin is selected from at least one of methyl methacrylate, polymethyl methacrylate (PMMA), polyurethane methacrylate, and n-butyl methacrylate, and may be one or more of these.

[0071] In some embodiments, the reinforcing fiber is selected from at least one of glass fiber, ceramic fiber, silica fiber, and boron fiber, and may be a mixture of one or more of them. All of the above reinforcing fibers can effectively improve the rigidity and heat resistance of ABS plastic, and also reduce material shrinkage.

[0072] In some embodiments, the coupling agent is selected from at least one of silane monomers, styrene monomers, and titanate monomers, and can be a commonly used coupling agent. Examples include, but are not limited to, vinyltrimethoxysilane (VTMS), vinyltriethoxysilane (VTES), 3-methacryloyloxypropyltrimethoxysilane (VMMS), γ-aminopropyltriethoxysilane (KH-550), and γ-(methacryloyloxy)propyltrimethoxysilane (KH-570).

[0073] It should be noted that, in the preparation of the modified ABS material of the present invention, ABS resin, PMMA resin, reinforcing fiber and coupling agent are used as raw materials according to the above-mentioned modified ABS material formula, and are mixed in proportion. Common plastic molding equipment and methods can be used for molding.

[0074] In some embodiments, a single-screw extruder can be used for co-extrusion, and the extruded product can be cut to a suitable size for subsequent injection molding to form a molding platform.

[0075] S2, Modification Treatment

[0076] The raw materials are modified and shaped to obtain a molding platform made of plastic. This platform has a molding surface for adhering to the 3D printed part formed by the exposure and curing of a photocurable material. Compared to conventional unmodified plastic injection molding platforms, the adhesion strength between the molding surface and the cured printed layer meets a requirement of not less than 1.5 N per square centimeter, whereas the adhesion strength of conventional unmodified plastic injection molding platforms is typically less than 1.5 N. Optimizing and modifying the plastic material significantly improves the adhesion strength between the molding surface and the printed layer. Furthermore, the optimization and modification of the plastic material in this application demonstrates that the actual test data shows the adhesion strength between the molding surface and the cured printed layer reaches not less than 3 N per square centimeter, and even not less than 4 N, 5 N, 6 N, or 7 N or more. This effectively improves the adhesion strength between the molding surface of the molding platform and the initial printed layer of the part, reduces the probability of board detachment, and increases the printing success rate.

[0077] In some embodiments, the modification treatment includes at least one of grafting modification, blending modification, inorganic reinforcement modification (using particle / fiber modification), morphology control modification, and crosslinking modification.

[0078] In some embodiments, the preparation method further includes: surface treatment of the molding surface, wherein the surface treatment includes at least one of spraying, sandblasting, grinding, engraving, electroplating, coating, printing, texturing, polishing, painting, oiling, ion plating, and laser treatment. Any of the above surface treatment methods are suitable for surface treatment of the molding surface, which is beneficial to further improve the adhesion between the molding surface and the printed layer.

[0079] Furthermore, the preparation method also includes: sandblasting the molding surface to control the surface roughness Ra of the molding platform to be 0.1μm-5μm. Sandblasting the molding surface of the modified ABS photocurable molding platform after injection molding can further improve the adhesion of the molding surface to the resin.

[0080] Specifically, sandblasting of the molding platform's surface is a mechanical roughening process. The injection-molded modified ABS molding platform is placed in an automated sandblasting line, and the sandblasting surface is fixed using fixtures. Compressed air is used to propel abrasive particles onto the molding surface of the platform that contacts the resin, resulting in the required uniform roughness. This improves the wettability of the photosensitive resin on the molding surface, enhancing bond strength. Furthermore, sandblasting cleans the molding surface, effectively removing residual mold release agent from the injection-molded part. Residual mold release agent can hinder the wetting of the photosensitive resin, reducing the risk of the resin detaching from the bond.

[0081] In some embodiments, the abrasive used for sandblasting is a hard abrasive with sharp edges, and the abrasive is selected from at least one of white corundum, brown corundum, glass sand and steel sand, and can be a hard abrasive with sharp edges.

[0082] It should be added that the surface treatment of the forming platform by sandblasting in the embodiments of the present invention does not generate a large amount of waste liquid and consumes less energy compared with chemical oxidation treatment and solvent erosion roughening, and the process is highly controllable; compared with surface painting modification, it has the advantages of low cost and good anti-aging performance.

[0083] In some embodiments, the preparation method further includes: spraying the molding surface, wherein the raw materials used for spraying, by mass parts, include: 100 parts of photocurable resin, 80-150 parts of diluent and 0.05-2 parts of initiator; wherein the photocurable resin is selected from at least one of acrylates, allyl ethers and vinyl ethers, and the number average molecular weight of the photocurable resin is 4000-10W.

[0084] Specifically, the structural formulas of acrylates are as follows:

[0085]

[0086] The structural formulas of allyl ethers are as follows:

[0087]

[0088] Vinyl ethers have the following structural formulas:

[0089]

[0090] This invention provides a 3D printing device, which includes the aforementioned 3D printing molding platform. The molding platform 110 is coated with a coating 10, and may further include... Figure 1 The optical engine 310, material tray 220 and other structures shown in the figure are used to hold resin in the material tray 220 to form a complete 3D printing device.

[0091] It should be noted that during 3D printing using the molding platform 110, ultraviolet light is used for photocuring, thereby firmly bonding the 3D printing molding platform 110 to the resin. Figure 1 As shown.

[0092] Specifically, the acrylate can be a (meth)acrylate, with the following structural formula:

[0093]

[0094] The double bonds in the modified coating can cross-link and cure with the (meth)acrylate double bonds in the printing resin (the reaction principle is as follows), so that the original coating and the initial cured layer of the printed part are integrated, resulting in better adhesion and less likelihood of board falling off.

[0095]

[0096] By utilizing the double bonds in acrylate, allyl ether, and vinyl ether resins to react with the photocurable resin that forms the printed part during photocuring, and by controlling the molecular weight of the photocurable resin, the coating can be made easy to surface dry, and can be used in 3D printing molding platforms.

[0097] Specifically, when the amount of photocurable resin is 100 parts, the amount of diluent can be 80 parts, 90 parts, 100 parts, 110 parts, 120 parts, 130 parts, 140 parts, 150 parts, etc.; the amount of initiator can be 0.05 parts, 0.1 parts, 0.2 parts, 0.5 parts, 0.8 parts, 1.0 parts, 1.2 parts, 1.5 parts, 1.8 parts, 2.0 parts, etc.

[0098] In a preferred embodiment, the coating for the 3D printing platform comprises, by weight, 100 parts of UV-curable resin, 100-130 parts of thinner, and 0.2-0.5 parts of initiator. By optimizing the amount of each component in the coating, the surface drying rate is further improved, thereby enhancing the adhesion of the coating to the printed parts.

[0099] In some embodiments, the photocurable resin includes 50-90 parts of a first resin and 10-50 parts of a second resin. The number average molecular weight of the first resin is 4,000-20,000, and the number average molecular weight of the second resin is 4W-10W. By combining macromolecular resin and small molecule resin, leveling can be effectively controlled, and stringing problems can be prevented during spraying.

[0100] Furthermore, the first resin is selected from at least one of RA3081, RA3083, RA3091, 6071, 6175-3 and SD7508, and may be one or more of them; the second resin is selected from at least one of SD1000 and SWA20, and may be one or more of them. All of the above resins are commercially available materials, and the raw materials are readily available.

[0101] In some embodiments, the diluent is selected from water and organic solvents, and may be a mixture of one or more solvents. Using water as a solvent is more environmentally friendly, but it results in higher drying temperatures and greater energy consumption. Therefore, organic solvents are preferable, such as at least one of ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate. Considering solvent toxicity, solvents with lower toxicity and easier surface drying are preferable, such as a mixture of ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate.

[0102] In some embodiments, the initiator is selected from at least one of TPO, 819 and TPO-L, and the initiator can be a commonly used photocurable initiator, not limited to the above.

[0103] In some embodiments, the additive further includes 0.05-1 part of an auxiliary agent, such as 0.05 part, 0.1 part, 0.2 part, 0.3 part, 0.4 part, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1.0 part, etc., preferably 0.1-0.2 parts. The addition of the auxiliary agent can further improve the surface drying rate. The type of auxiliary agent may be, but is not limited to, at least one of CAB 551-0.01, CAB 551-0.2, CAB 381-0.1, and CAB 381-0.5 (all of the above auxiliary agents are cellulose acetate butyrate), and may be one or more.

[0104] Furthermore, the inventors optimized the mixing sequence by first mixing the diluent, initiator, and additives evenly, then mixing them evenly with the photocurable resin and filtering. In actual operation, the process can be divided into the following steps: (1) First, add the diluent to a suitable mixing vessel, turn on the stirring, and the speed is 500-1000 rpm. Then, add the initiator and additives in sequence and stir for 15-30 minutes until clear and transparent; (2) Add the resin and stir at a speed of 800-1500 rpm for 15-30 minutes until clear and transparent; (3) Stop stirring, filter with a 400-mesh filter cloth, and package.

[0105] In some embodiments, the sprayed molding platform is dried, and the thickness of the dried film is controlled to be 20μm-30μm, such as 20μm, 25μm, 30μm, etc.

[0106] When the diluent is water, the drying temperature should be controlled at 60℃-80℃, and the drying time at 10-15 minutes. Water-based coatings require a higher drying temperature to allow the water to evaporate quickly. As the temperature increases, the energy consumption for drying is greater, but it must not reach the softening temperature of ABS, otherwise the material will be damaged. Lower temperatures result in lower energy consumption, but require a longer drying time. Suitable drying temperatures for water-based coatings include 60℃, 70℃, and 80℃; suitable drying times include 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, and 15 minutes.

[0107] When the thinner is an organic solvent, control the drying temperature at 50℃-60℃ and the drying time at 3-5 minutes. For oil-based coatings, the drying temperature can be lower and the drying time shorter; under these conditions, the organic solvent can evaporate quickly to achieve surface dryness.

[0108] In some embodiments, such as Figure 2-5 As shown, the molding platform 110 has a molding surface 001 and a back surface 002 opposite to the molding surface 001. The preparation method further includes: making the molding platform open to form multiple through holes 003 that penetrate the molding surface and the back surface. The opening facilitates air permeability during the molding process. At the same time, the part passing through the hole after the resin is cured can form a hanging force, thereby improving the adhesion.

[0109] Furthermore, such as Figure 4-5 As shown, the inventors optimized the shape of the through hole 003. The diameter of the through hole 003 gradually increases from the forming surface to the back surface, and multiple through holes are staggered. The forming platform hole diameter is designed to be small on the forming surface and large on the opposite side of the forming surface, i.e., an inverted frustum shape, to increase the hanging force, improve the adhesion between the printed part and the forming platform, thereby reducing board drop and improving the printing success rate.

[0110] In some embodiments, such as Figure 1 As shown, a reinforcing rib 004 can also be provided on the back of the forming platform to increase the support strength.

[0111] In actual operation, the sandblasted forming platform is first cleaned and dried, and then the hole is opened. The drying process involves controlling the drying temperature at 65℃-70℃ and the drying time at 10min-30min. The sand on the surface of the forming platform is removed through cleaning and drying.

[0112] In some embodiments, cleaning can be done by washing with water to effectively remove sand from the surface of the forming platform. The washing method can be spraying, ultrasonic washing, etc.

[0113] Specifically, drying can be done by oven drying, with the internal temperature of the oven controlled at 65℃, 66℃, 67℃, 68℃, 69℃, 70℃, etc., and the drying time being 10min, 20min, 30min, etc.

[0114] This invention provides a molding platform for a 3D printing device. The molding platform has a molding surface for adhering a 3D printed part formed by exposure and curing of a photocurable material. The molding platform is made of a modified plastic material. By optimizing and modifying the plastic material, the adhesion between the molding surface and the printed layer formed by exposure and curing of the photocurable material can be significantly improved. Compared with the molding platform of unmodified plastic injection molding, the adhesion can meet the requirement of not less than 1.5N per square centimeter. For example, the adhesion between the molding surface and the printed layer formed by exposure and curing of the photocurable material can be not less than 1.5N, 2.0N, 2.5N, 3N, 3.5N, 4.0N, 4.5N, 5N, etc. per square centimeter, while the adhesion of conventional unmodified plastic injection molding platforms is usually less than 1.5N. Furthermore, by optimizing and modifying the plastic material using the proposed solution, test data shows that the adhesion between the molding surface and the printed layer formed after exposure and curing of the photocurable material reaches no less than 3N per square centimeter, and even no less than 4N, 5N, 6N, or 7N or higher. This effectively improves the adhesion between the molding platform and the initial printed layer of the part, reduces the probability of board detachment, and increases the printing success rate.

[0115] The type of plastic material is not limited. In some embodiments, the plastic material is selected from at least one of ABS, PC, PP, POM, PA, PS, PBT, AS, PET, PVC, PEEK, PPSU, SAN, PE, TPE, PTFE, PES and PVA. The type of plastic material can be selected from the above.

[0116] In some embodiments, the modification treatment includes at least one of grafting modification, blending modification, inorganic reinforcement modification (using particle / fiber modification), morphology control modification, and crosslinking modification.

[0117] In some embodiments, the molding platform is made of modified ABS material, the raw materials of which include 70-80 wt% ABS resin, 5-20 wt% methacrylic resin, 5-10 wt% reinforcing fiber, and 1-5 wt% coupling agent. The description of the modified ABS material is as described above in the specification and will not be repeated here.

[0118] In some embodiments, the molding surface is obtained through surface treatment, which includes at least one of spraying, sandblasting, grinding, engraving, electroplating, coating, printing, texturing, polishing, painting, oiling, ion plating, and laser treatment. Any of the above surface treatment methods are suitable for surface treatment of the molding surface, which helps to further improve the adhesion between the molding surface and the printed layer.

[0119] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0120] Example 1

[0121] This embodiment provides a method for preparing a molding platform for a 3D printing device, including the following steps:

[0122] (1) Preparation of modified ABS materials

[0123] Raw materials for modified ABS material: 72wt% ABS resin, 11wt% PMMA resin, 10wt% inorganic glass fiber, and 3wt% KH550 coupling agent.

[0124] After mixing the raw materials, they are fed into a twin-screw extruder for extrusion molding. The extrusion temperature is set to 200℃ for the first stage, 210℃ for the second stage, and 220℃ for the third stage. The extrusion speed is set to 40mm / s. After extrusion, the material is cut into granules with a length of 4mm and a diameter of 3mm.

[0125] (2) Injection molding

[0126] Using the modified ABS material prepared in step (1), a single-screw injection molding machine was used. The injection pressure was set to 100 MPa, the injection temperature of the first stage was 220°C, the second stage temperature was 235°C, the third stage temperature was 245°C, the holding time was 2.5 s, and the cold cutting time was 15 s.

[0127] (3) Sandblasting

[0128] The forming platform was sandblasted using 100-mesh white corundum at a pressure of 0.3 MPa and a distance of 50 mm.

[0129] Example 2

[0130] The only difference from Example 1 is that 40-mesh brown corundum is used, and the surface of the forming platform is sandblasted under a pressure of 0.5 MPa.

[0131] Example 3

[0132] The only difference from Example 1 is the raw material of the modified ABS material, as follows:

[0133] The composition consists of 70 wt% ABS resin, 15 wt% PMMA resin, 10 wt% inorganic glass fiber, and 5 wt% KH550 coupling agent.

[0134] Example 4

[0135] The only difference from Example 1 is the raw material of the modified ABS material, as follows:

[0136] The composition consists of 80 wt% ABS resin, 5 wt% PMMA resin, 14 wt% inorganic glass fiber, and 1 wt% KH550 coupling agent.

[0137] Comparative Example 1

[0138] The only difference from Example 1 is that the material of the forming platform is changed to aluminum.

[0139] It should be noted that aluminum molding platforms are commonly used platform materials for 3D printing photopolymerization, and various photosensitive resins can adhere to them well. Therefore, the performance measured in Comparative Example 1 can be used as the target performance of the plastic molding platform.

[0140] Comparative Example 2

[0141] The only difference from Example 1 is that the material of the molding platform is changed to ABS 757.

[0142] Comparative Example 3

[0143] The only difference from Example 1 is that the material of the molding platform is changed to PC+ABS material, with PC110 having a mass fraction of 30% and ABS 757 having a mass fraction of 70%.

[0144] Comparative Example 4

[0145] The only difference from Example 1 is that the surface treatment of the forming platform is changed from sandblasting to chemical roughening. The chemical roughening solution is formulated with 400 g / L chromic anhydride and 350 g / L sulfuric acid, and the process conditions are immersion at 60°C for 30 min.

[0146] Comparative Example 5

[0147] The only difference from Example 1 is that no surface treatment is applied to the forming platform.

[0148] Test case

[0149] The molding platforms prepared in the examples and comparative examples were tested. After measuring the surface roughness and flatness, the models were printed using a Hegtech Chairside photopolymerization 3D printer. Four materials were used: Hegtech high-precision dental model resin, Hegtech temporary crown and bridge resin, Hegtech surgical guide resin, and Hegtech removable denture base resin. After printing, the models were subjected to pull-out tests while still attached to the molding platform. The test results are shown in Table 1.

[0150] Example and comparative test environment conditions: placed at room temperature for 24 hours, test temperature 23℃, relative humidity 50%, the specific test method is as follows:

[0151] (1) Surface roughness of the forming platform: The surface roughness of the four corners and the center point of the forming platform is tested and the Ra value is recorded.

[0152] (2) Flatness of the forming surface of the forming platform: The flatness of the forming surface of the forming platform is tested at 20 points, and the maximum difference in flatness is recorded.

[0153] (3) Adhesion test of the molding platform: An adhesion test model was printed using a molding platform. The model was positioned at the four corners and the center of the molding platform. The adhesion area between the molding surface of the molding platform and the printed layer of the model after exposure and curing of the photocurable material was 65 cm². 2 After printing, a pull-out test was performed using a universal testing machine, and the force (N) used when the model was peeled off the molding platform at 5 points was recorded.

[0154] Table 1. Performance test results of the molding platforms in the embodiments and comparison examples.

[0155]

[0156]

[0157] According to the data in Table 1, the bonding strength achieved by modifying ABS material and using sandblasting (Examples 1 and 2) is close to or even exceeds that of the metal platform (Comparative Example 1), which can meet normal printing requirements. Replacing the material with plastic (such as Comparative Examples 2-3) will cause the printing plate to fall off, rendering the solution unusable; or replacing it with a surface roughening process (such as Comparative Example 4) will result in a much lower bonding strength than Examples 1-2 and Comparative Example 1, posing a risk of printing plate falling off.

[0158] In summary, this invention provides a molding platform for a 3D printing device and its preparation method. The molding platform is obtained by injection molding with modified ABS material, and then the molding surface of the platform is sandblasted to improve the roughness of the molding surface. Furthermore, the holes of the molding platform are optimized, which can significantly increase the adhesion between the molding surface of the molding platform and the printed part, thereby overcoming the phenomenon of board falling off. This invention represents a significant improvement in adhesion in the field of plastic molding platforms.

[0159] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A molding platform for a 3D printing device, characterized in that, The molding platform has a molding surface for adhering a 3D printed part formed by exposure and curing of a photocurable material. The molding platform is made of a modified plastic material, and the adhesion force between the molding surface and the printed layer formed by exposure and curing of the photocurable material is not less than 1.5N per square centimeter. The molding platform is made of modified ABS material, the raw materials of which include 70-80 wt% ABS resin, 5-20 wt% methacrylic acid resin, 5-10 wt% reinforcing fiber and 1-5 wt% coupling agent. The raw materials are modified and molded to obtain the molding platform.

2. The molding platform according to claim 1, characterized in that, The adhesion between the molding surface and the printed layer formed after the photocurable material is exposed and cured must be no less than 3N per square centimeter.

3. The molding platform according to claim 1, characterized in that, The plastic material is selected from at least one of ABS, PC, PP, POM, PA, PS, PBT, AS, PET, PVC, PEEK, PPSU, SAN, PE, TPE, PTFE, PES, and PVA.

4. The molding platform according to claim 1, characterized in that, The modification treatment includes at least one of grafting modification, blending modification, inorganic reinforcement modification, morphology and structure control modification, and crosslinking modification.

5. The molding platform according to claim 1, characterized in that, The reinforcing fiber is selected from at least one of glass fiber, ceramic fiber, silica fiber and boron fiber.

6. The molding platform according to claim 1, characterized in that, The coupling agent is selected from at least one of silane monomers, styrene monomers, and titanate monomers; The silane monomer is selected from at least one of vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-(methacryloyloxy)propyltrimethoxysilane.

7. The molding platform according to claim 1, characterized in that, The methacrylate resin is selected from at least one of methyl methacrylate, polymethyl methacrylate, polyurethane methacrylate, and n-butyl methacrylate.

8. The molding platform according to any one of claims 1 to 7, characterized in that, The shaped surface is obtained through surface treatment, which includes at least one of spraying, sandblasting, grinding, engraving, electroplating, coating, printing, texturing, polishing, painting, oiling, ion plating, and laser treatment.

9. A method for preparing a molding platform for a 3D printing device, characterized in that, include: The raw materials for the molding platform are provided; the raw materials include 70-80 wt% ABS resin, 5-20 wt% methacrylic resin, 5-10 wt% reinforcing fiber, and 1-5 wt% coupling agent. The raw materials are modified and shaped to obtain a plastic molding platform. The molding platform has a molding surface for adhering a 3D printed part formed by exposure and curing of a photocurable material. The adhesion force between the molding surface and the printed layer formed by exposure and curing of the photocurable material is not less than 1.5N per square centimeter.

10. The preparation method according to claim 9, characterized in that, The adhesion between the molding surface and the printed layer formed after the photocurable material is exposed and cured must be no less than 3N per square centimeter.

11. The preparation method according to claim 9, characterized in that, The modification treatment includes at least one of grafting modification, blending modification, inorganic reinforcement modification, morphology and structure control modification, and crosslinking modification.

12. The preparation method according to claim 9, characterized in that, The raw materials include 73-78 wt% ABS resin, 10-15 wt% methacrylic resin, 6-9 wt% reinforcing fiber, and 2-4 wt% coupling agent.

13. The preparation method according to claim 9, characterized in that, The reinforcing fiber is selected from at least one of glass fiber, ceramic fiber, silica fiber and boron fiber.

14. The preparation method according to claim 9, characterized in that, The coupling agent is selected from at least one of silane monomers, styrene monomers, and titanate monomers; The coupling agent is selected from at least one of vinyltrimethoxysilane, vinyltriethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-(methacryloyloxy)propyltrimethoxysilane.

15. The preparation method according to claim 9, characterized in that, The methacrylate resin is selected from at least one of methyl methacrylate, polymethyl methacrylate, polyurethane methacrylate, and n-butyl methacrylate.

16. The preparation method according to any one of claims 9 to 15, characterized in that, The preparation method further includes: performing surface treatment on the molded surface, wherein the surface treatment includes at least one of spraying, sandblasting, grinding, engraving, electroplating, coating, printing, texturing, polishing, painting, oiling, ion plating and laser treatment.

17. The preparation method according to any one of claims 9 to 15, characterized in that, The preparation method further includes: sandblasting the molding surface to control the surface roughness Ra of the molding platform to be 0.1μm-5μm.

18. The preparation method according to claim 17, characterized in that, The abrasive used in the sandblasting is a hard abrasive with sharp edges, and the abrasive is selected from at least one of white corundum, brown corundum, glass sand and steel sand.

19. The preparation method according to any one of claims 9 to 15, characterized in that, The preparation method further includes: spraying the molded surface with a coating, wherein the raw materials used for spraying, by mass parts, include: 100 parts of photocurable resin, 80-150 parts of diluent and 0.05-2 parts of initiator; The photocurable resin is selected from at least one of acrylates, allyl ethers and vinyl ethers, and the number average molecular weight of the photocurable resin is 4000-10W.

20. The preparation method according to claim 19, characterized in that, The photocurable resin comprises 50-90 parts of a first resin and 10-50 parts of a second resin, wherein the number average molecular weight of the first resin is 4000-20000 and the number average molecular weight of the second resin is 4W-10W. The first resin is selected from at least one of RA3080, RA3081, RA3083, RA3091, 6071, 6175-3 and SD7508; The second resin is selected from at least one of SD1000 and SWA20.

21. The preparation method according to claim 19, characterized in that, The diluent is selected from either water or an organic solvent; The organic solvent is selected from at least one of ethyl acetate, butyl acetate, and propylene glycol methyl ether acetate.

22. The preparation method according to claim 19, characterized in that, The initiator is selected from at least one of TPO, 819, and TPO-L; and / or The raw materials used for spraying also include 0.05-1 parts of additives; the additives are selected from at least one of CAB 551-0.01, CAB 551-0.2, CAB381-0.1 and CAB 381-0.

5.

23. The preparation method according to claim 19, characterized in that, The coated molding platform is then dried, with the dry film thickness controlled to be 20μm-30μm; wherein... When the diluent is water, the drying temperature is controlled at 60℃-80℃ and the drying time is 10min-15min; When the diluent is an organic solvent, the drying temperature is controlled at 50℃-60℃ and the drying time is 3min-5min.

24. The preparation method according to any one of claims 9 to 15, characterized in that, The molding platform has a back side opposite to the molding surface. The preparation method further includes: performing an opening process on the molding platform to form a plurality of through holes penetrating the molding surface and the back side of the molding platform, wherein the diameter of the through holes gradually increases from the molding surface to the back side.

25. The preparation method according to claim 24, characterized in that, The plurality of through holes on the forming platform are arranged in an alternating manner.

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