Injection molding part 3D texture out-of-mold rubbing method

Abstract

A 3D texture out-of-mold rubbing method for an injection molding part comprises the steps that firstly, a layer of rubbing UV liquid is sprayed on the outer surface of an injection molding part body, and IR heating is conducted; then, the outer surface of the heated injection molding part body is coated with a flexible 3D rubbing mold, and then vacuumizing and first-time UV curing are carried out; after the first UV curing is finished, the flexible 3D rubbing mold on the surface is torn off, and an injection molding part body with a 3D texture facing on the surface is obtained; and then the injection molding part body with the 3D texture facing on the surface after demolding is subjected to secondary UV curing, and an injection molding part product with 3D textures rubbed outside the mold is obtained. The injection molding part has the advantages that operation is convenient, the three-dimensional texture can be formed on the surface of the injection molding part body more clearly, and the surface hardness of the three-dimensional texture is improved.

Description

Technical Field

[0001] The present application relates to the technical field of product exterior finishes, and specifically to a method for off-mold rubbing of 3D textures (3D stereoscopic textures) of injection molded parts. Background Art

[0002] At present, for furniture and household appliances, realistic three-dimensional exterior finishing structures are required to meet the different requirements of consumers for product finishes; the preparation processes of three-dimensional exterior finishing of existing products are roughly divided into the following two types: the first process is to first prepare a structure with a three-dimensional texture finish, and then place the structure in an injection mold of the injection molded part body, and then inject the injection plastic into the mold to combine it with the three-dimensional texture finish by hot pressing, and then combine the three-dimensional texture finish with the injection molded part body to form an injection molded part body product with a three-dimensional texture surface; this process is to directly bond the three-dimensional texture layer structure to the injection molded part body. In this structure, the three-dimensional texture structure is combined with the injection molded part body material by hot pressing inside the injection mold. Due to the internal ring of the injection mold The complex environment and high temperature may cause the three-dimensional texture layer to deform, and the final three-dimensional texture display effect is not ideal; the second process is to place the three-dimensional texture layer structure in the mold cavity, and then inject the injection plastic and the three-dimensional texture finish into the hot pressing combination, transfer the three-dimensional texture in the three-dimensional texture layer structure to the surface of the injection plastic, tear off the three-dimensional texture layer structure, directly form a three-dimensional texture on the surface of the injection plastic, and then use the embossed three-dimensional texture directly as the external display surface without any other treatment; the above second method also realizes the hot pressing transfer of the three-dimensional texture inside the injection mold, the internal environment is not easy to control, and it may also cause the three-dimensional texture layer and the injection molded part body to be loosely attached, resulting in texture fracture.

[0003] In addition, the above-mentioned in-mold three-dimensional texture injection molding method has a low yield rate due to the different materials between the three-dimensional texture layer and the injection molded part body, as well as the limitations of the internal injection molding environment. The three-dimensional texture is easily deformed under the high-temperature in-mold injection molding environment, resulting in unclear texture formation; especially for the corresponding special-shaped injection molded part body structure, the in-mold injection molding process also allows for the three-dimensional texture layer and the injection molded part body to not fit fully, resulting in texture fracture; in addition, it may also lead to unsatisfactory hardness of the three-dimensional texture; and the existing in-mold injection molding requires the opening of multiple sets of molds, specifically a set of molds for forming injection molded parts, a set of molds for injection molded parts combined with 3D three-dimensional texture finishes, and the 3D three-dimensional texture finish needs to be hot-pressed by a set of hot pressing molds before being placed in the injection molded part mold. This requires the development of at least three molds, which greatly increases production costs. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the present application provides a method for rubbing 3D textures of injection molded parts outside the mold, which is easy to operate and can form three-dimensional textures more clearly on the surface of the injection molded part body and improve the surface hardness of the three-dimensional textures.

[0005] In order to solve the above technical problems, the technical solution adopted in this application is: a method for rubbing 3D texture of injection molded parts outside the mold, the steps of the method include:

[0006] (1) First, a layer of UV rubbing liquid is sprayed on the outer surface of the injection molded part body, and IR heating is performed to volatilize and remove organic impurities in the UV liquid, thereby obtaining a viscous UV rubbing layer to achieve connection with the injection molded part body;

[0007] (2) then covering the outer surface of the heated injection molded body with a flexible 3D rubbing mold, and then evacuating the body so that the flexible 3D rubbing mold is completely attached to the outer surface of the IR heated injection molded body;

[0008] (3) performing a first UV curing on the injection molded part body after being bonded to the flexible 3D rubbing mold, so that the cured rubbing UV liquid curing layer and the 3D three-dimensional texture of the flexible 3D rubbing mold are transferred, and the 3D three-dimensional texture is transferred to the cured rubbing UV liquid curing layer;

[0009] (4) After the first UV curing is completed, the flexible 3D rubbing mold on the surface is torn off to obtain an injection molded part body with a 3D texture finish on the surface;

[0010] (5) Then, the injection molded part body having the 3D texture finish on the surface after demolding is subjected to a second UV curing to obtain an injection molded part product having the 3D texture printed outside the mold.

[0011] Furthermore, the temperature of the IR heating in step (1) is 50-350°C.

[0012] Furthermore, the temperature of the IR heating in step (1) is 50-150°C.

[0013] Furthermore, the first UV curing in step (3) is to set a plurality of UV lamps on the periphery of the injection molded part body after the flexible 3D rubbing mold is bonded, and then cure the injection molded part body after the flexible 3D rubbing mold is bonded by UV lamp irradiation.

[0014] Furthermore, the second UV curing described in step (5) is to set a plurality of UV lamps on the periphery of the injection molded part body having a 3D stereoscopic texture finish on the surface, and then cure the injection molded part body having a 3D stereoscopic texture finish on the surface by irradiating the UV lamps.

[0015] Furthermore, the flexible 3D rubbing mold is made of silicone material or PU (polyurethane) material.

[0016] Furthermore, the specific preparation process of the flexible 3D rubbing mold is as follows: the mold with a 3D three-dimensional texture is electroplated to form a plating layer (that is, a plating layer is formed on the surface of the three-dimensional texture), and then molten silicone material or PU (polyurethane) material is poured onto the plating layer, and allowed to stand for more than 24 hours to allow the molten silicone material or PU (polyurethane) material to solidify. The curing process transfers the 3D three-dimensional texture on the mold to the surface of the solidified silicone material or PU (polyurethane) material to form a flexible 3D rubbing mold.

[0017] Furthermore, after the molten silicone material or PU (polyurethane) material is poured onto the electroplating layer, it is vibrated and leveled, and then left to stand for more than 24 hours.

[0018] Furthermore, the hardness range of the silicone material or PU (polyurethane) material is 20-90 degrees hardness.

[0019] Furthermore, the hardness range of the silicone material or PU (polyurethane) material is 20-40 degrees hardness.

[0020] Furthermore, the thickness of the flexible 3D rubbing mold is 0.2-10 mm.

[0021] Advantages and beneficial effects of this application:

[0022] 1. The technical solution of the present application is to first obtain an injection molded part body of the required shape in a set of injection molds, and then directly coat the injection molded part body on the outside with a layer of UV liquid for IR heating, and then cover the flexible 3D rubbing mold to evacuate and adsorb for fitting, and perform the first UV curing on the whole, and then tear off the flexible 3D rubbing mold and perform the second UV curing; therefore, the preparation process of the present application only requires one set of molds to realize the rubbing of 3D stereoscopic texture, and it is carried out outside the mold of the injection molded part, and only the injection molded part body needs to be formed in the injection mold, thereby avoiding the shortcomings of the existing in-mold rubbing that may cause the three-dimensional texture to be not tight, easy to deform, and the need for multiple sets of mold opening molds due to the high temperature and in-mold environment; through the above process, the present application can obtain clearer three-dimensional texture, and is more suitable for the rubbing of three-dimensional texture on the surface of special-shaped injection molded parts, and is not prone to texture breakage, the texture fits more tightly, the transfer is more complete, and the operation process is simpler and more convenient.

[0023] 2. The preparation process of the present application uses a flexible 3D texture rubbing mold, so a more complete fit with the outer surface of the injection molded part can be achieved through vacuuming, and the 3D texture transfer is clearer.

[0024] 3. The present application only needs to realize the injection molding of the injection molded part body in the injection mold, so that the injection molded part body can be obtained with only one injection molding material in the mold injection process. Therefore, the obtained injection molded part body has stable mechanical properties and does not need to be hot-pressed with other materials in the injection mold, so the structure of the obtained injection molded part body is more complete. After the injection molding of the injection molded part body is completed, it is directly adsorbed with the flexible 3D rubbing mold by vacuuming in the outside world, and the texture of the flexible 3D rubbing mold is more completely transferred to the IR-heated UV liquid coating layer through vacuum pressure. Then, through two curing processes, the obtained injection molded part body with 3D texture has stronger hardness. The hardness of the 3D texture surface of this two-curing process can reach 5-7H. Therefore, the injection molded part body obtained by this process method can effectively improve its surface hardness, is more wear-resistant, and the 3D texture is not easy to wear, which effectively improves the service life of the overall injection molded part body with 3D texture. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of the structure of the injection molded part body, 3D texture layer and flexible 3D texture mold combined in this application.

[0026] Figure 2 Schematic diagram of the structure formed by the UV liquid coating layer of the present application.

[0027] Figure 3 Schematic diagram of the structure of the combination of the injection molded part body and the UV liquid coating layer of the present application.

[0028] Figure 4 Schematic diagram of the structure of the flexible 3D texture mold combined with the plastic part body and UV liquid coating layer in the present application.

[0029] Figure 5 Schematic diagram of the structure in which the flexible 3D texture mold of the present application is separated from the injection molded part body.

[0030] Figure 6 Schematic diagram of the structure of the injection molded part body obtained by the injection molded part 3D texture out-mold rubbing method of the present application.

[0031] Figure 7 Process flow chart of the 3D texture rubbing method for the injection molded part body in this application.

[0032] Figure 8 Image of the product obtained by the 3D texture off-mold rubbing method for injection molded parts.

[0033] As shown in the attached figure: 1. Injection molded part body, 2. 3D texture finishing layer, 3. Flexible 3D texture mold. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments. Obviously, the described embodiments are only preferred embodiments, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention;

[0035] It should also be noted that when a component is referred to as being "fixed to" (and other similar ways of "fixed to") another component, it may be directly on the other component or there may be another intermediate component, fixed through the intermediate component. When a component is considered to be "connected to" (and other similar ways of "connected to") another component, it may be directly connected to the other component or there may be another intermediate component at the same time. When a component is considered to be "set on" (and other similar ways of "set on") another component, it may be directly set on the other component or there may be another intermediate component at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by technicians in the technical field of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0036] As attached Figure 1-6 As shown, an injection molded part is obtained by a method of rubbing 3D texture of an injection molded part of the present application, and the structure of the injection molded part includes: an injection molded part body 1, the outer surface of the injection molded part body 1 is coated with a 3D texture finishing layer 2, the 3D texture finishing layer 2 is formed by a flexible 3D texture mold 3 coated on the outer surface, and the flexible 3D texture mold 3 is attached to the outer surface of the 3D texture finishing layer 2 by vacuuming. The injection molded part body formed by this structure does not need to be molded in the injection mold to combine the 3D texture finishing layer on the injection molded part body 1, but the obtained injection molded part body can be directly attached to the flexible 3D texture mold by vacuuming on the outside to achieve the formation of 3D texture, so it is easier to operate, saves processes and molds, and effectively reduces costs.

[0037] As an example, the preparation material of the flexible 3D texture mold 3 described in the present application is made of silicone material or PU (polyurethane) material; the use of the above-mentioned flexible 3D texture mold can achieve a tighter and more complete fit with the 3D texture finishing layer under a vacuum environment, so that the final 3D texture is more realistic and complete; the specific preparation process of the flexible 3D texture mold can be achieved by pouring high-temperature molten silicone material or PU (polyurethane) material onto the three-dimensional texture surface of an existing metal texture 3D texture mold with a specific three-dimensional texture, or pouring high-temperature molten silicone material or The PU (polyurethane) material is poured onto the surface of the mold with a three-dimensional texture on a base layer formed of one of the materials selected from PUR (polyurethane), PMMA, PC, PET or ABS, and then a flexible 3D texture mold with a 3D texture surface is formed through leveling, standing, cooling and curing. The flexible 3D texture mold can be a flat structure or a flexible 3D texture mold with a curvature that matches the injection molded part body. Before pouring, electroplating can be performed on the surface of the mold with the three-dimensional texture side to form a layer of electroplating, so as to facilitate the flexible 3D texture mold in the subsequent stroke to be more complete and convenient to peel off.

[0038] As an example, the 3D texture finishing layer 2 described in the present application is formed by coating and curing the UV liquid or UV glue; adopting this solution, the UV liquid can be more firmly combined with the injection molded part body under curing conditions, and it is not easy to peel or warp; UV liquid or UV glue are both commercially available materials.

[0039] As an example, the curing described in the present application includes a first UV curing, and a second curing after removing the flexible 3D texture mold for a second time; through the above scheme, the hardness and wear resistance of the final 3D texture finishing layer can be effectively improved, and a more ideal three-dimensional texture display effect can be obtained; the temperature of the first IR heating can be maintained at 100-150°C, and the first UV curing is to set a plurality of UV lamps on the periphery of the injection molded part body after the flexible 3D rubbing mold 3 is bonded, and then the injection molded part body after the flexible 3D rubbing mold is bonded is cured by uniform irradiation of the UV lamp; the second curing after removing the flexible 3D texture mold is to set a plurality of UV lamps on the periphery of the injection molded part body, and then the injection molded part body is cured by uniform irradiation of the UV lamp.

[0040] As an example, the inner surface of the flexible 3D texture mold 3 described in the present application is not smaller than the outer surface of the 3D texture finishing layer 2; by adopting this solution, when vacuuming, the inner surface of the flexible 3D texture mold can be completely covered on the outer surface of the 3D texture finishing layer on the outer surface of the injection molded part body to be formed, and there will be no missing printing or texture loss.

[0041] As attached Figure 7 As shown, a 3D texture rubbing method of an injection molded part body of the present application comprises the following steps:

[0042] (1) first spray a layer of rubbing UV liquid (the UV liquid of the present application is a commercially available dual-curing UV liquid or a commercially available UV glue or UV liquid with dual curing function) on the outer surface of the injection molded part body 1, and then perform IR heating on the whole to volatilize the organic solvent and impurities in the rubbing UV liquid layer to form a viscous rubbing UV liquid layer (the thickness of the layer can be micron-level, such as between 0.001-1 micron, or 5-20 micron thickness), so as to achieve a tight connection with the injection molded part body 1; the temperature of the IR heating in step (1) is 100-150°C;

[0043] (2) The outer surface of the IR-heated injection mold body 1 is then covered with a flexible 3D rubbing mold 3, and then vacuumed (the degree of vacuum is adjusted according to the actual shape of the injection molded part to achieve a close fit with the outer surface of the injection molded part), so that the flexible 3D rubbing mold 3 is completely fitted on the outer surface of the cured injection molded part body 1; specifically, in a closed space, the flexible 3D rubbing mold 3 can be completely fitted on the UV liquid coating layer of the injection molded part body after IR heating by connecting it to an external vacuum pump body;

[0044] (3) performing the first UV curing on the injection molded part body 1 after being bonded to the flexible 3D rubbing mold 3, so that the cured rubbing UV liquid-solid layer and the 3D three-dimensional texture of the flexible 3D rubbing mold are transferred, and the 3D three-dimensional texture on the flexible 3D rubbing mold 3 is transferred to the cured rubbing UV liquid layer from the beginning; the first UV curing described in step (3) is to set a plurality of UV lamps on the periphery of the injection molded part body after being bonded to the flexible 3D rubbing mold, and then cure the injection molded part body after being bonded to the flexible 3D rubbing mold by evenly irradiating and heating with the UV lamps;

[0045] (4) After UV curing is completed, the flexible 3D rubbing mold on the surface is torn off to obtain an injection molded part body 1 having a 3D texture finishing layer 2 on the surface;

[0046] (5) Then, the injection molded part body 1 having the 3D texture finishing layer 2 on the surface after demolding is subjected to a second UV curing; the second UV curing described in step (5) is to set a plurality of UV lamps on the periphery of the injection molded part body having the 3D texture finishing layer on the surface, and then cure the injection molded part body having the 3D texture finishing layer on the surface by evenly irradiating and heating with the UV lamp, thereby obtaining a final injection molded part product having the 3D texture finishing layer on the surface.

[0047] The flexible 3D rubbing mold described in the present application is made of silicone material or PU material.

[0048] The flexible 3D rubbing mold described in the present application has a specific preparation process as follows: electroplating a mold with a 3D texture (such as a metal mold with a 3D texture finish or a mold with an organic material base layer with a 3D texture finish), wherein the electroplating is a conventional process in the art, and a 0.001-1 micron thick electroplating layer is plated on one side of the 3D texture layer of the 3D mold, and then molten silicone material or PU material is poured onto the electroplating layer (a vibration tool can be used to vibrate and level the material), and the molten silicone material or PU material is allowed to stand for more than 24 hours, and the molten silicone material or PU material is solidified, and the 3D texture on the mold is transferred to the surface of the solidified silicone material or PU material to form a flexible 3D rubbing mold; the thickness of the flexible 3D rubbing mold is about 1 mm.

[0049] The preparation of the mold of the organic material base layer with a 3D stereoscopic texture finish used in the flexible 3D rubbing mold of the present application can be prepared by referring to the preparation method of the multi-channel 3D nano-textured mold in CN109465992A or a nano-textured mold disclosed in 201910529441.3, which is to transfer the texture pattern on the mold to the transfer glue, and the transfer glue is laminated with the carrier layer to form a three-dimensional texture on the surface of the carrier layer (a carrier layer made of one of PUR (polyurethane), PMMA, PC, PET or ABS) The transfer glue can be an ultraviolet-curing UV transfer glue, and the UV texture transfer glue and the carrier layer are tightly connected to form a whole through the curing effect; the electroplating layer is electroplated to the side with the mold three-dimensional texture, and the electroplating can be a conventional electroplating process in the industry. The electroplating is at a nanometer thickness and does not affect the texture trend and transfer of the 3D three-dimensional texture. In this way, when the molten silicone material or PU material is poured onto the electroplating layer and left to stand for more than 24 hours, it is easier to peel off the cured silicone material or PU material from the 3D three-dimensional texture finishing layer.

[0050] As attached Figure 8 As shown, it is a picture of a real product obtained by adopting the scheme described in the present application (the three-dimensional texture is a plurality of small three-dimensional grid structures similar to the thousand-hammer texture), which shows the structure of the injection molded part body with a transparent injection molding material as the background color; it can be seen that the surface of the injection molded part body presents a very clear three-dimensional texture layer, and the light effect produced by the three-dimensional texture can be observed from different angles; it shows that the off-mold rubbing method of the present application can obtain an injection molded product with a clear three-dimensional texture, the method process does not require the opening of multiple molds, and the off-mold rubbing operation is simpler and more convenient, and the use of a flexible 3D three-dimensional mold can be applied to the preparation of three-dimensional textures of more special-shaped injection molded parts, and the texture transfer and bonding is more complete.

Claims

1. A method for printing 3D texture of injection molded parts outside the mold, characterized in that: The steps of the method include: (1) First, a layer of UV rubbing liquid is sprayed on the outer surface of the injection molded part body, and IR heating is performed to volatilize and remove organic impurities in the UV liquid, thereby obtaining a viscous UV rubbing layer to achieve connection with the injection molded part body; (2) then covering the outer surface of the heated injection molded body with a flexible 3D rubbing mold, and then evacuating the body so that the flexible 3D rubbing mold is completely attached to the outer surface of the IR heated injection molded body; (3) performing a first UV curing on the injection molded part body after being bonded to the flexible 3D rubbing mold, so that the cured rubbing UV liquid curing layer and the 3D three-dimensional texture of the flexible 3D rubbing mold are transferred, and the 3D three-dimensional texture is transferred to the cured rubbing UV liquid curing layer; (4) After the first UV curing is completed, the flexible 3D rubbing mold on the surface is torn off to obtain an injection molded part body with a 3D texture finish on the surface; (5) Then, the injection molded part body having the 3D texture finish on the surface after demolding is subjected to a second UV curing to obtain an injection molded part product having the 3D texture printed outside the mold.

2. The method for rubbing the 3D texture of an injection molded part according to claim 1, characterized in that: The temperature of the IR heating in step (1) is 50-350°C.

3. The method for rubbing the 3D texture of an injection molded part according to claim 2, characterized in that: The temperature of the IR heating in step (1) is 50-150°C.

4. The method for rubbing the 3D texture of an injection molded part according to claim 1, characterized in that: The first UV curing described in step (3) is to set multiple UV lamps on the periphery of the injection molded part body after the flexible 3D rubbing mold is attached, and then cure the injection molded part body after the flexible 3D rubbing mold is attached by UV lamp irradiation.

5. The method for rubbing the 3D texture of an injection molded part outside the mold according to claim 1, characterized in that: The second UV curing described in step (5) is to set multiple UV lamps on the periphery of the injection molded part body with a 3D stereoscopic texture finish on the surface, and then cure the injection molded part body with a 3D stereoscopic texture finish on the surface by irradiating the UV lamps.

6. The method for rubbing the 3D texture of an injection molded part according to claim 1, characterized in that: The flexible 3D rubbing mold is made of silicone material or PU material.

7. The method for rubbing the 3D texture of an injection molded part according to claim 1, characterized in that: The specific preparation process of the flexible 3D rubbing mold is as follows: the mold with a 3D stereoscopic texture is electroplated to form an electroplating layer, and then molten silicone material or PU material is poured onto the electroplating layer, and allowed to stand for more than 24 hours to allow the molten silicone material or PU material to solidify, and the 3D stereoscopic texture is transferred to the surface of the solidified silicone material or PU material to form a flexible 3D rubbing mold.

8. The method for rubbing the 3D texture of an injection molded part according to claim 7, characterized in that: After the molten silicone material or PU material is poured onto the electroplating layer, it is vibrated and leveled, and then left to stand for more than 24 hours.

9. The method for rubbing the 3D texture of an injection molded part according to claim 7, characterized in that: The hardness range of the silicone material or PU material is 20-90 degrees hardness; the thickness of the flexible 3D rubbing mold is 0.2-10mm.

10. The method for rubbing the 3D texture of an injection molded part according to claim 9, characterized in that: The hardness range of the silicone material or PU material is 20-40 degrees hardness.

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