Membrane for replacing UV photocuring coating of outer lampshade and forming process of membrane

Abstract

The invention discloses a diaphragm for replacing a UV photocuring coating of an outer lampshade and a forming process of the diaphragm. The diaphragm comprises a transparent bonding layer, a transparent middle layer and a transparent outer protective layer which are sequentially arranged in a stacked mode from inside to outside. Wherein the membrane is tightly attached to the surface of the outer lampshade through the transparent bonding layer and a vacuum compaction process to replace a UV light curing coating, the transparent middle layer is made of a material with impact resistance, ultraviolet resistance, light weight and high strength, and the transparent outer protective layer is made of a material with scratch resistance and high weather resistance. And the forming process is used for enabling the membrane to be tightly attached to the outer lampshade. According to the diaphragm scheme used for replacing the UV photocuring coating of the outer lampshade, the thought completely different from that of an existing UV photocuring coating is adopted, the UV photocuring coating does not need to be formed by spraying photocuring paint, and many defects existing in the photocuring paint spraying process are overcome.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive lighting, and particularly to a diaphragm for replacing the UV-curable coating of an outer lamp cover and its forming process. Specifically, the forming process is used to closely attach the diaphragm to the outer lamp cover of a vehicle lamp. Background Art

[0002] The spraying process of photocurable paint on the lamp cover of a vehicle lamp is a process for surface treatment of the lamp cover of a vehicle lamp using photocuring technology. By using photocurable paint, the curing of the coating can be achieved in a short time, so as to form a UV-curable coating on the surface of the lamp cover. The formed UV-curable coating can significantly improve the wear resistance, weather resistance and appearance quality of the lamp cover.

[0003] Currently, the spraying process of photocurable paint generally includes the following steps: (1) Pretreatment stage (removing static electricity & stress relief): Use an electrostatic dust removal rod or an electrostatic dust removal gun to remove dust and fine debris on the surface of the lamp cover, and at the same time use an annealing furnace or a stress relief drying tunnel to remove the residual stress inside the lamp cover to prevent cracking of the product or the paint layer after spraying; (2) Spraying stage (topcoat spraying or primer spraying): Use special photocurable paint for spraying, and ensure uniform coverage of the entire surface of the lamp cover during spraying to ensure consistent coating thickness; (3) Leveling stage (IR leveling): The lamp cover passes through a leveling chamber, and during the infrared heating process, the paint flows and spreads on the surface of the lamp cover to form a uniform paint film, forming a penetration layer on the surface of the lamp cover to volatilize the solvent in the paint; (4) Photocuring stage (UV lamp curing): Use the corresponding wavelength UVA in the UV lamp to excite the photosensitizer and initiator in the photocurable paint to promote the cross-linking polymerization reaction of resin molecules, so that the photocurable paint cures on the surface of the lamp cover and quickly forms a hard UV-curable coating; (5) Post-treatment: Check the uniformity and gloss of the UV-curable coating after curing, and if necessary, perform slight grinding and polishing to achieve an ideal appearance effect.

[0004] Although the UV-curable coating formed by the light-curing paint spraying process can improve the abrasion resistance, weather resistance, and appearance quality of the lamp shade, there are still some problems with the light-curing paint spraying process, including: (1) High equipment investment cost: Light-curing spraying requires special UV lamps or other light source equipment, and the initial investment and maintenance costs of these equipment are relatively high, which will cause greater economic pressure on enterprises; (2) Large floor area of the production line: The core parts of the light-curing production line include the conveying system, UV light source system, reflector, cooling system, control system, and exhaust system, all of which require a large amount of space and have a large floor area; (3) High process control requirements: Precise control of parameters such as spraying thickness, curing time, and operating environment temperature and humidity is required, and the process is difficult. Because if the spraying is uneven or the curing is insufficient, it will cause uneven curing of the coating, resulting in local softening or peeling, affecting product quality. At the same time, the temperature and humidity of the environment will affect the light-curing effect of the coating; (4) Poor adaptability to the substrate: Not all lamp shade substrates are suitable for using light-curing paint, and lamp shades of certain materials may affect the adhesion and curing effect of the coating; (5) Great harm to the environment: Ozone generated during the UV-curing process is a strong oxidant, which will pollute the atmospheric environment, especially in a poorly ventilated environment. At the same time, the waste of light-curing paint (such as uncured paint or cleaning agent) will also contain harmful chemical substances, which will pollute the soil and water body if not properly treated; (6) Great harm to the human body: The ultraviolet rays emitted by the UV-curing lamp have relatively high energy, and long-term exposure will cause skin burns, eye damage, immune system damage, etc.; at the same time, during the UV-curing process, short-wave ultraviolet rays react with oxygen to generate ozone, and inhaling ozone may irritate the respiratory tract, causing symptoms such as sore throat and cough, and long-term exposure may affect lung health; Components such as acrylate in the light-curing paint may also cause skin allergies or irritation, and long-term contact may lead to skin sensitivity or allergic reactions. Summary of the Invention

[0005] The object of the present invention is to: In view of the problems of the current solution of forming a UV-curable coating by the light-curing paint spraying process to improve the abrasion resistance, weather resistance, and appearance quality of the lamp shade, such as high upfront equipment investment, large floor area of the production line, high production process difficulty, poor substrate adaptability, great harm to the environment, and great harm to the human body, the present invention proposes a film for replacing the UV-curable coating of the outer lamp shade and its forming process, thereby solving the above problems.

[0006] To achieve the above object, the present invention is realized by the following technical solutions:

[0007] The present invention provides a film for replacing the UV-curable coating of an outer lamp cover. The film includes a transparent adhesive layer, a transparent intermediate layer, and a transparent outer protective layer that are sequentially stacked from the inside to the outside. Among them, the film is closely attached to the surface of the outer lamp cover through the transparent adhesive layer and a vacuum compaction process to replace the UV-curable coating. The transparent intermediate layer is made of a material with impact resistance, ultraviolet resistance, light weight, and high strength, and the transparent outer protective layer is made of a material with scratch resistance and high weather resistance.

[0008] Further, a film for replacing the UV-curable coating of an outer lamp cover: the thickness of the transparent adhesive layer is set to 0.1 - 0.5 mm.

[0009] Further, a film for replacing the UV-curable coating of an outer lamp cover: the transparent intermediate layer is made of polycarbonate (PC) material.

[0010] Further, a film for replacing the UV-curable coating of an outer lamp cover: the thickness of the transparent intermediate layer is set to 0.1 - 1.0 mm.

[0011] Further, a film for replacing the UV-curable coating of an outer lamp cover: the transparent outer protective layer is made of polymethyl methacrylate (PMMA) material.

[0012] Further, a film for replacing the UV-curable coating of an outer lamp cover: the thickness of the transparent outer protective layer is set to 0.1 - 1.0 mm.

[0013] The present invention also provides a forming process for a film for replacing the UV-curable coating of an outer lamp cover, which is used to make the film closely attached to the outer lamp cover.

[0014] This forming process uses a vacuum forming device, which includes a carrier, a forming upper box, and a forming lower box. The forming upper box and the forming lower box can be closed or separated. A fixed frame and a heating device are arranged in the forming upper box, and a lifting platform is arranged in the forming lower box.

[0015] This forming process includes the following specific steps:

[0016] S1. Provide an outer lamp cover and place it on the carrier, and the carrier has a structure adapted to the shape of the outer lamp cover.

[0017] S2. Move the carrier together with the outer lamp cover onto the lifting platform in the forming lower box, and fix the film on the fixed frame in the forming upper box. The film is located above the outer lamp cover but the two do not touch.

[0018] S3. Close the upper forming box and the lower forming box, then evacuate the inside of the vacuum forming device, and then heat the diaphragm through the heating device;

[0019] S4. Drive the lifting table to drive the outer lamp cover to move upward, so as to squeeze the diaphragm, and make the surface of the outer lamp cover in full contact with the transparent adhesive layer in the diaphragm;

[0020] S5. Restore the air pressure inside the vacuum forming device so that the diaphragm tightly adheres to the surface of the outer lamp cover;

[0021] S6. Take out the outer lamp cover after laminating, and cut off the redundant part, then the attachment and forming of the diaphragm on the outer lamp cover are completed.

[0022] Further, a forming process of a diaphragm for replacing the UV curable coating of the outer lamp cover: In step S3, evacuate to a pressure of -0.4 to -0.2 MPa inside the vacuum forming device.

[0023] Further, in step S3 of a forming process of a diaphragm for replacing the UV curable coating of the outer lamp cover, the heating temperature of the diaphragm is 150 to 170 °C.

[0024] Advantages of the present invention:

[0025] (1) The diaphragm solution proposed by the present invention for replacing the UV curable coating of the outer lamp cover adopts a completely different idea from the current UV curable coating. It does not need to spray the UV curable paint to form the UV curable coating, avoiding many defects existing in the UV curable paint spraying process. The diaphragm solution proposed by the present invention for replacing the UV curable coating of the outer lamp cover is a diaphragm that can be used to replace the UV curable coating on the traditional outer lamp cover. This diaphragm has good weather resistance and can improve the weather resistance, wear resistance, impact resistance and appearance quality of the outer lamp cover. At the same time, this diaphragm also has good light transmittance.

[0026] (2) The diaphragm solution proposed by the present invention to replace the UV-curable coating of the outer lamp cover is a technology that uses a three-dimensional vacuum surface forming process on the lamp cover instead of UV-curable spraying, which solves many problems existing in the current UV-curable spraying process. The solution of using a diaphragm to replace the UV-curable coating adopted by the present invention has the following advantages: ① It can reduce the upfront equipment investment: The upfront investment only includes the investment in the vacuum forming device, with fewer equipment investments and lower costs; ② Reduce the floor area of the production line: Only the vacuum forming device is needed for production, and the floor area of the equipment is much lower than that of the UV curing production line required by the UV spraying process; ③ Reduce the difficulty of the production process: Only the appropriate heating temperature of the diaphragm and the pressure during diaphragm attachment need to be set, and the operation is simple; ④ Improve the substrate adaptability: It can be applied to various lamp cover substrates (such as plastics, metals, etc.); ⑤ Reduce the harm to the environment: The present invention does not produce VOCs (volatile organic compounds) and wastewater, meeting the environmental protection requirements; ⑥ Reduce the harm to the human body: During use, there is no ultraviolet irradiation, and no VOCs (volatile organic compounds) and wastewater are produced, thus avoiding harm to human health.

[0027] (3) The diaphragm of the present invention for the outer lamp cover can effectively improve the weather resistance, wear resistance, and impact resistance of the lamp cover. There is a transparent adhesive layer on the back of the diaphragm, and the diaphragm can be attached using a three-dimensional vacuum surface forming process. The present invention uses a diaphragm to replace the UV-curable paint on the front lamp cover and uses a three-dimensional vacuum surface forming process to replace the light-curing spraying process. This diaphragm has good weather resistance, can improve the weather resistance, wear resistance, and impact resistance of the lamp cover, and at the same time, this diaphragm has good transmittance. Description of the Drawings

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0029] Figure 1 It is a schematic structural diagram of the diaphragm in Embodiment 1 of the present invention;

[0030] Figure 2 It is a schematic structural diagram after the diaphragm is attached to the outer lamp cover (substrate) in Embodiment 1 of the present invention, that is, the structural diagram of the outer lamp cover after film coating;

[0031] Figure 3 It is a schematic structural diagram of the vacuum forming device and the forming process flow chart of the diaphragm in Embodiment 1 of the present invention.

[0032] Markings in the figure: 1 - diaphragm, 2 - outer lamp cover, 3 - vehicle, 4 - upper forming box, 5 - lower forming box, 11 - transparent adhesive layer, 12 - transparent intermediate layer, 13 - transparent outer protective layer, 41 - fixing frame, 42 - heating device, 51 - lifting platform. Specific embodiments

[0033] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually illustrative only and in no way limits the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0034] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom", etc. is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. Moreover, the terms "first", "second", etc. are used to distinguish similar objects and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0035] Embodiment 1

[0036] As Figures 1 - 2 shown, Embodiment 1 of the present invention provides a diaphragm for replacing the UV - curable coating of the outer lamp cover. The diaphragm 1 includes a transparent adhesive layer 11, a transparent intermediate layer 12, and a transparent outer protective layer 13 which are sequentially stacked from the inside to the outside;

[0037] Among them, the thickness of the transparent adhesive layer 11 is set to 0.1 - 0.5 mm; the transparent intermediate layer 12 is selected from materials with impact resistance, UV resistance, light weight and high strength. Specifically, the transparent intermediate layer 12 is made of polycarbonate (PC) material, and the thickness of the transparent intermediate layer 12 is set to 0.1 - 1.0 mm; the transparent outer protective layer 13 is selected from materials with scratch resistance and high weather resistance. Specifically, the transparent outer protective layer 13 is made of polymethyl methacrylate (PMMA) material, and the thickness of the transparent outer protective layer 13 is set to 0.1 - 1.0 mm;

[0038] Among them, the diaphragm 1 is closely attached to the surface of the outer lamp cover 2 (substrate) through the transparent adhesive layer 11 and the vacuum compaction process, so as to replace the traditional UV light curing coating.

[0039] As Figures 1 - 3 shown, a forming process of a diaphragm for replacing the UV light curing coating of the outer lamp cover proposed in the above-mentioned Embodiment 1 is used to realize the close attachment of the diaphragm 1 to the outer lamp cover 2;

[0040] This forming process uses a vacuum forming device, which includes a carrier 3, a forming upper box 4 and a forming lower box 5. The forming upper box 4 and the forming lower box 5 can be closed or separated. A fixed frame 41 and a heating device 42 are arranged in the forming upper box 4, and a lifting platform 51 is arranged in the forming lower box 5;

[0041] This forming process includes the following steps:

[0042] S1. Provide the outer lamp cover (substrate) 2 and place it on the carrier 3. The carrier 3 has a structure adapted to the shape of the outer lamp cover 2;

[0043] S2. Move the carrier 3 together with the outer lamp cover 2 onto the lifting platform 51 in the forming lower box 5, and fix the diaphragm 1 on the fixed frame 41 in the forming upper box 4. The diaphragm 1 is located above the outer lamp cover 2 but does not touch it;

[0044] S3. Close the forming upper box 4 and the forming lower box 5 to form a closed vacuum forming device, then evacuate the inside of the vacuum forming device (evacuate to a pressure of -0.3 MPa inside the vacuum forming device), and then heat the diaphragm 1 to 160 °C through the heating device 42;

[0045] S4. Drive the lifting platform 51 to drive the outer lamp cover 2 to move upward, so that the outer lamp cover 2 fully presses the diaphragm 1 from bottom to top, and the entire surface of the outer lamp cover 2 is in complete contact with the transparent adhesive layer 11 in the diaphragm 1;

[0046] S5. Restore the air pressure inside the vacuum forming device to make the diaphragm 1 tightly adhere to the surface of the outer lamp cover 2;

[0047] S6. Take out the outer lamp cover 2 after laminating (as Figure 2 shown), cut off the redundant part, and then the attachment and forming of the diaphragm 1 on the outer lamp cover 2 is completed.

[0048] The present invention relates to the technical field of automotive lighting. In Embodiment 1, the diaphragm 1 is used to replace the original UV light-curing coating on the outer lamp cover 2, and the three-dimensional vacuum surface forming process is used to replace the light-curing painting process. The diaphragm has good weather resistance, which can improve the weather resistance, wear resistance and impact resistance of the outer lamp cover 2. At the same time, the diaphragm also has good light transmittance.

[0049] The above are the preferred embodiments of the present invention, which are only used to explain the present invention and are not used to limit the present invention. Any obvious changes or variations derived from the technical solutions of the present invention are still within the protection scope of the present invention.

Claims

1. A film for replacing the UV light-curing coating of an outer lamp cover, characterized in that: The film (1) comprises a transparent adhesive layer (11), a transparent intermediate layer (12) and a transparent outer protective layer (13) which are stacked in sequence from the inside to the outside; The film (1) is tightly attached to the surface of the outer lampshade (2) through the transparent adhesive layer (11) and the vacuum compaction process to replace the UV light-curing coating, the transparent intermediate layer (12) is made of a material that is impact-resistant, UV-resistant, lightweight and high-strength, and the transparent outer protective layer (13) is made of a material that is scratch-resistant and highly weather-resistant.

2. A film for replacing the UV light-curing coating of an exterior lamp cover according to claim 1, characterized in that: The thickness of the transparent adhesive layer (11) is set to 0.1-0.5 mm.

3. The film for replacing the UV light-curing coating of the outer lamp cover according to claim 1, characterized in that: The transparent middle layer (12) is made of polycarbonate.

4. A film for replacing UV light-curing coating of an outer lamp cover according to claim 1 or 3, characterized in that: The thickness of the transparent intermediate layer (12) is set to 0.1-1.0 mm.

5. The film for replacing the UV light-curing coating of the outer lamp cover according to claim 1, characterized in that: The transparent outer protective layer (13) is made of polymethyl methacrylate.

6. A film for replacing UV light-curing coating of an outer lamp cover according to claim 1 or 5, characterized in that: The thickness of the transparent outer protective layer (13) is set to 0.1-1.0 mm.

7. A forming process for a film for replacing the UV light-curing coating of an outer lamp cover according to any one of claims 1 to 6, characterized in that: The process is used to achieve the goal of making the diaphragm (1) closely adhere to the outer lampshade (2); The forming process adopts a vacuum forming device, which comprises a carrier (3), an upper forming box (4) and a lower forming box (5); the upper forming box (4) and the lower forming box (5) can be closed or separated; a fixing frame (41) and a heating device (42) are arranged in the upper forming box (4); and a lifting platform (51) is arranged in the lower forming box (5); The molding process includes the following steps: S1. providing an outer lampshade (2) and placing it on a carrier (3), wherein the carrier (3) has a structure adapted to the shape of the outer lampshade (2); S2, moving the carrier (3) together with the outer lampshade (2) onto the lifting platform (51) in the lower molding box (5), fixing the membrane (1) on the fixing frame (41) in the upper molding box (4), wherein the membrane (1) is located above the outer lampshade (2) but does not touch it; S3, closing the upper forming box (4) and the lower forming box (5), then evacuating the interior of the vacuum forming device, and then heating the film (1) by the heating device (42); S4, driving the lifting platform (51) to move the outer lampshade (2) upward so as to make it contact with the transparent adhesive layer (11) in the film (1); S5, restoring the air pressure inside the vacuum forming device so that the membrane (1) is tightly attached to the surface of the outer lampshade (2); S6, taking out the coated outer lampshade (2), cutting off the excess part, and completing the attachment and molding of the film (1) on the outer lampshade (2).

8. The forming process of a film for replacing the UV light-curing coating of an outer lamp cover according to claim 7, characterized in that: In step S3, the vacuum forming device is evacuated to a pressure of -0.4 to -0.2 MPa.

9. The forming process of a film for replacing the UV light-curing coating of an outer lamp cover according to claim 7, characterized in that: The heating temperature of the membrane (1) in step S3 is 150-170°C.

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