Preparation process of transfer printing molded product and transfer printing molded product

Abstract

The invention provides a preparation process of a transfer-printing molded product and the transfer-printing molded product, and the preparation process specifically comprises the following steps: selecting a transfer-printing mold main body which is made of resin; a positioning assembly is arranged on the transfer mold main body, so that the transferred main body is accurately matched with the transfer mold main body; coating a layer of strippable material on a transfer printing main body, wherein the strippable material is weakly combined with the transfer printing mold main body; and when the transfer mold main body is in press-fit contact with the transferred main body, curing the strippable material by using a UV curing lamp, and constructing a permanent texture layer on the surface of the mold. According to the preparation process of the transfer printing molded product and the transfer printing molded product, the clean, easy and uniform demolding process is achieved, the mold loss is reduced, the problems that a traditional KMI / HTMI / TMI product is difficult to demold and large in mold loss are solved, the service life of the mold is prolonged by three times or above, and the product reject ratio is reduced to 4% or below.

Description

Technical Field

[0001] This invention relates to the field of transfer mold technology, and particularly to a preparation process for transfer molded articles and the transfer molded articles themselves. Background Technology

[0002] Transfer molds are an indispensable tool in production, directly determining the quality and production efficiency of transferred products. However, traditional transfer molds suffer from problems such as difficulty in demolding and high mold wear during production, leading to increased production costs. Specifically, in the production of traditional KMI (metal injection molding), HTMI (high temperature molding), and TMI (thermosetting molding) products, molds made of adhesive materials are difficult to peel off, resulting in product deformation rates as high as 15-20%. Forceful demolding can even cause scratches on the mold surface.

[0003] Chinese invention patent application number 2021103944607 discloses an environmentally friendly water-based release agent and its preparation method, which has a good demolding effect. However, after demolding, a small amount of release agent will remain on the mold or the transferred product, making subsequent cleaning inconvenient and even causing product contamination. In addition, the uniformity of the coating is difficult to control, with a certain thickness deviation, resulting in uneven demolding. Summary of the Invention

[0004] The purpose of this invention is to provide a preparation process for transfer-molded products and the transfer-molded products themselves, which solves the technical problem of how to cleanly produce transfer-molded products, achieves an easy and uniform demolding process, and reduces wear and tear on the mold.

[0005] A process for preparing a transfer-molded product specifically includes the following steps:

[0006] Step S1: Select the main body of the transfer mold. The main body of the transfer mold is made of resin.

[0007] Step S2: Set a positioning component on the main body of the transfer mold to ensure that the main body to be transferred is precisely matched with the main body of the transfer mold;

[0008] Step S3: Coat the transfer substrate with a peelable material, wherein the peelable material is weakly bonded to the transfer mold body;

[0009] Step S4: When the transfer mold body and the subject to be transferred are pressed into contact, the peelable material is cured with a UV curing lamp to build a permanent texture layer on the surface of the mold. Its bonding force with the mold (>3MPa) is much greater than the interfacial bonding force with the subject to be transferred (<0.5MPa), so that the peelable material separates from the transfer mold body and adheres to the subject to be transferred.

[0010] Preferably, the positioning component includes a camera, a printing laser engraving inspection system connected to the camera, and a PLC controller connected to the printing laser engraving inspection system.

[0011] Preferably, by mass fraction, the peelable layer comprises 60-70% siloxane polymer, 10-15% fluorocarbon resin, 5-10% silane coupling agent, 10-20% nano silica, and 3-5% structural adhesive.

[0012] Preferably, the peelable layer contains a mixed nano-ZnO / PTFE composite phase, and the ratio of ZnO / PTFE composite phase to peelable layer is 0.1-0.8.

[0013] Preferably, the molecular weight of the siloxane polymer is 5000-20000 g / mol, and the fluorocarbon resin is a dispersion of polyvinylidene fluoride or polytetrafluoroethylene.

[0014] Preferably, the transfer substrate is any one of KMI resin film, HTMI composite film, TMI thermosetting polymer film, and PET film.

[0015] Preferably, in step S1, the working surface of the transfer mold body is subjected to plasma or chemical activation treatment beforehand.

[0016] Preferably, in step S3, the thickness of the peelable material is 1-50 μm, ultrasonic vibration is applied simultaneously, and then it is cured at 50-150°C for 0.5-2 h to form a peelable layer.

[0017] Preferably, in step S4, under external force, the peelable layer is gradually pressured onto the substrate to be transferred, and then re-cured at the curing temperature of the substrate to be transferred, which is 80-120°C and the time is 20-30 seconds.

[0018] A transfer-molded article having a molded body layer with a microstructured surface and a residual peelable layer with a thickness of 0.5-5 μm attached to the surface of the body layer.

[0019] Preferably, the surface of the microstructure includes an embossed pattern or optical structure with an accuracy of ±0.5 μm.

[0020] This invention achieves the following significant effects:

[0021] (1) A peelable layer is coated on the outside of the transfer mold body, which greatly increases the demolding performance and reduces the peel strength to 0.1-0.4 N / cm (traditional process >2 N / cm). The number of stamping cycles of aluminum alloy molds is increased from 50,000 to 180,000, which improves the mold life. The surface defect rate is reduced from 18% to 2.0-3.5%. Compared with the release agent coating process in the existing technology, the cost per piece is reduced by 25-31%.

[0022] (2) The peelable layer includes siloxane polymer, fluorocarbon resin, silane coupling agent, nano silica, and structural adhesive. Their interaction achieves the following technical effects:

[0023] First, the combination of siloxane polymers and fluorocarbon resins results in a coating with extremely low critical surface tension, making it difficult for resin materials to wet and adhere to the surface. The siloxane polymers themselves also have low surface energy and can provide flexibility and film-forming properties, which, together with the fluorocarbon resins, further enhance the overall non-stickiness.

[0024] Secondly, the addition of silane coupling agents and nano-silica helps to improve the thermal stability and mechanical strength of the coating, making it suitable for high-temperature curing processes and maintaining stable demolding performance at high temperatures.

[0025] The addition of structural adhesive provides excellent bond strength and cohesion, ensuring that the release layer itself is strong and not easily damaged. At the same time, it greatly shortens the curing time at high temperatures.

[0026] Fourth, fluorocarbon resin / siloxane polymers, combined with ultrasonic vibration, help to form a continuous and smooth film layer, achieving a high-gloss mold surface replication effect.

[0027] (3) The addition of nano ZnO / PTFE composite phase helps to improve tribological properties. As the amount of nano ZnO / PTFE composite phase filler increases, the density, hardness and friction coefficient of the composite material also increase, which significantly reduces the wear of the composite material. That is, nano ZnO / PTFE composite phase helps to reduce the wear of the material.

[0028] (4) Special note: Silane coupling agents act as “molecular bridges”. One end (such as alkoxy groups) reacts with active groups such as hydroxyl groups on the surface of the mold substrate (metal, composite material, glass, etc.) to form strong chemical bonds; the other end (organic functional groups, such as amino, epoxy, vinyl groups) reacts with or physically entangles with polymers (siloxanes, fluorocarbon resins, structural adhesives) in the coating.

[0029] Combined with structural adhesive, it achieves strong adhesion, ensuring that the release layer adheres extremely firmly to the mold surface. It is not easy to peel, flake, or delaminate even under harsh chemical, thermal, and mechanical conditions, preventing the release agent from transferring onto the product and minimizing the transfer of release layer material to the surface of the molded product. This is crucial for subsequent coating, bonding, or appearance quality. Attached Figure Description

[0030] Figure 1 This is a flowchart of the preparation process of the transfer-printed molded product in this invention. Detailed Implementation

[0031] To more clearly illustrate the technical features of this solution, the following detailed implementation method will be used to explain the solution.

[0032] Example 1

[0033] A process for preparing a transfer-molded product specifically includes the following steps:

[0034] Step S1: Select the main body of the transfer mold. The main body of the transfer mold is made of resin.

[0035] Step S2: Set a positioning component on the main body of the transfer mold to ensure that the main body to be transferred is precisely matched with the main body of the transfer mold;

[0036] Step S3: Coat the subject to be transferred with a peelable material, which is weakly bonded to the transfer mold body;

[0037] Step S4: When the transfer mold body and the subject to be transferred are pressed into contact, the peelable material is cured with a UV curing lamp to build a permanent texture layer on the surface of the mold. Its bonding force with the mold (>3MPa) is much greater than the interfacial bonding force with the subject to be transferred (<0.5MPa), so that the peelable material separates from the transfer mold body and adheres to the subject to be transferred.

[0038] The positioning components include a camera, a printing laser engraving inspection system connected to the camera, and a PLC controller connected to the printing laser engraving inspection system.

[0039] The camera captures images of the area of ​​the subject to be transferred that is suitable for transfer, which are then transmitted to the printing laser engraving inspection system for image comparison to see if the area meets the requirements for transfer. If it does, the PLC controller starts to control the transfer mold body to press down and begin the transfer process. The working principle of the printing laser engraving inspection system is existing technology and will not be described in detail here.

[0040] By mass fraction, the peelable layer comprises 60-70% siloxane polymer, 10-15% fluorocarbon resin, 5-10% silane coupling agent, 10-20% nano silica, and 3-5% structural adhesive.

[0041] The exfoliable layer contains a mixed nano-ZnO / PTFE composite phase, and the ratio of ZnO / PTFE composite phase to exfoliable layer is 0.1-0.8.

[0042] The molecular weight of the siloxane polymer is 5000-20000 g / mol, and the fluorocarbon resin is a dispersion of polyvinylidene fluoride or polytetrafluoroethylene.

[0043] The substrate to be transferred can be any one of KMI resin film, HTMI composite film, TMI thermosetting polymer film, and PET film. In this Example 1, KMI resin film is selected as the substrate to be transferred.

[0044] In step S1, the working surface of the transfer mold body is subjected to plasma treatment beforehand.

[0045] In step S3, the thickness of the peelable material is 1 μm, and ultrasonic vibration is applied simultaneously. Then, it is cured at 50°C for 0.5 h to form a peelable layer.

[0046] In step S4, under external force, the peelable layer is gradually pressured onto the substrate to be transferred, and secondary curing is performed at the curing temperature of the substrate to be transferred, which is 80°C and the time is 20 seconds.

[0047] In this Example 1, the peelable layer is defined as comprising 65% siloxane polymer, 10% fluorocarbon resin, 10% silane coupling agent, 10% nano-silica, and 5% structural adhesive, and the following experimental group is designed:

[0048] Experimental group 1: ZnO / PTFE composite phase / peelable layer = 0.1;

[0049] Experimental group 2: ZnO / PTFE composite phase / peelable layer = 0.5;

[0050] Experimental group 3: ZnO / PTFE composite phase / peelable layer = 0.8;

[0051] Control group: No ZnO / PTFE composite phase in the peelable layer. Table 1 shows the test results for each test group in Example 1.

[0052] Table 1. Test results for each experimental group in Example 1.

[0053] Experimental group 1 Experimental group 2 Experimental group 3 control group Peel strength (N / cm) 0.29 0.23 0.12 0.35 Surface defects 2.7% 2.5% 2.0% 3.4% Unit cost reduction ratio 29% 30% 31% 28%

[0054] As can be seen from Table 1, the addition of the ZnO / PTFE composite phase to the peelable layer in this scheme helps to reduce peel strength, surface defects and unit cost.

[0055] Example 2

[0056] A transfer-molded article has a molded body layer with a microstructured surface and a residual peelable layer with a thickness of 0.5 μm attached to the surface of the body layer.

[0057] The microstructure surface contains embossed patterns or optical structures with an accuracy of ±0.5μm.

[0058] Example 3

[0059] The main body of the transfer mold is made of resin material. After ultrasonic cleaning with acetone, it is treated with Ar plasma for 10 minutes.

[0060] Spray-on peelable layer: includes 60% siloxane polymer, 15% fluorocarbon resin, 10% silane coupling agent, 10% nano silica, and 5% structural adhesive. The coating thickness is 20±2μm. It is pre-cured at 80℃ for 30min and then cured at 120℃ for 1h.

[0061] Pressure was applied to the HTMI silicon carbide composite film, and it was cured at 100℃ / 10MPa for 20s;

[0062] Manual peeling yields molded products with a smooth surface, with a demolding force only 18% of that of traditional processes, reducing the surface defect rate to 2.4%, and lowering the unit cost by 28% compared to the release agent coating process in existing technologies.

[0063] It should be noted that no ZnO / PTFE composite phase is added in this Example 3, and all other parameters not involved are the same as in Example 1.

[0064] Example 4

[0065] Microporous structures (pore diameter 10μm, depth 5μm) are etched on the surface of the mold.

[0066] Spray-on peelable layer: includes 70% siloxane polymer, 10% fluorocarbon resin, 5% silane coupling agent, 10% nano silica, and 5% structural adhesive. The coating thickness is 20±2μm. It is pre-cured at 150℃ for 20min and then cured at 120℃ for 0.5h.

[0067] Pressure is applied to the TMI resin film, and it is cured at 110℃ / 10MPa for 30s. After cooling, a mechanical interlocking structure is formed. After the TMI resin is molded, non-destructive demolding is achieved with the assistance of 40℃ warm water. The demolding force is only 16% of that of the traditional process, and the surface defect rate is reduced to 2.3%. Compared with the release agent coating process in the existing technology, the cost per piece is reduced by 27%.

[0068] It should be noted that no ZnO / PTFE composite phase is added in this Example 4, and all other parameters not involved are the same as in Example 1.

[0069] The technical features of this invention not described can be implemented by or using existing technology, and will not be repeated here. Of course, the above description is not a limitation of this invention, and this invention is not limited to the examples above. Any changes, modifications, additions or substitutions made by those skilled in the art within the scope of this invention should also be within the protection scope of this invention.

Claims

1. A process for preparing a transfer-molded article, characterized in that, Specifically, the steps include the following: Step S1: Select the main body of the transfer mold. The main body of the transfer mold is made of resin. Step S2: Set a positioning component on the main body of the transfer mold to ensure that the main body to be transferred is precisely matched with the main body of the transfer mold; Step S3: Coat the transfer substrate with a peelable material, wherein the peelable material is weakly bonded to the transfer mold body; Step S4: When the transfer mold body and the subject to be transferred are pressed into contact, the peelable material is cured with a UV curing lamp to build a permanent texture layer on the surface of the mold. Its bonding force with the mold is much greater than its interfacial bonding force with the subject to be transferred. When the peelable material separates from the transfer mold body, the peelable material adheres to the subject to be transferred.

2. The preparation process of a transfer-molded article according to claim 1, characterized in that, The positioning component includes a camera, a printing laser engraving inspection system connected to the camera, and a PLC controller connected to the printing laser engraving inspection system.

3. The preparation process of a transfer-molded article according to claim 1, characterized in that, By mass fraction, the peelable layer comprises 60-70% siloxane polymer, 10-15% fluorocarbon resin, 5-10% silane coupling agent, 10-20% nano silica, and 3-5% structural adhesive.

4. The preparation process of a transfer-molded article according to claim 1, characterized in that, The exfoliable layer contains a mixed nano-ZnO / PTFE composite phase by mass fraction, and the ratio of ZnO / PTFE composite phase to exfoliable layer is 0.1-0.

8.

5. The preparation process of a transfer-molded article according to claim 1, characterized in that, The transfer substrate is any one of KMI resin film, HTMI composite film, TMI thermosetting polymer film, and PET film.

6. The preparation process of a transfer-molded article according to claim 1, characterized in that, In step S1, the working surface of the transfer mold body is subjected to plasma or chemical activation treatment in advance.

7. The preparation process of a transfer-molded article according to claim 6, characterized in that, In step S3, the thickness of the peelable material is 1-50 μm, and ultrasonic vibration is applied simultaneously. Then, it is cured at 50-150°C for 0.5-2 hours to form a peelable layer.

8. The preparation process of a transfer-molded article according to claim 1, characterized in that, In step S4, under external force, the peelable layer is gradually pressured onto the substrate to be transferred, and then cured again at the curing temperature of the substrate to be transferred, which is 80-120℃ and takes 20-30 seconds.

9. A transfer-printed article, characterized in that, A molded main body layer with a microstructured surface, and a residual peelable layer attached to the surface of the main body layer, with a thickness of 0.5-5μm.

10. A transfer-molded article according to claim 9, characterized in that, The microstructure surface contains embossed patterns or optical structures with an accuracy of ±0.5μm.

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