A structure for an in-mold injection molded metal pull-tab plastic film product

Abstract

The utility model belongs to the in-mold injection molding technical field discloses a kind of in-mold injection metal wire-drawing plastic film product structure, the plastic film includes the hardening layer, PET base material, wire-drawing coating and metal plating layer sequentially compounded from top to bottom;The hardening layer is attached to the upper surface of PET base material by coating curing process, the thickness of the hardening layer is 3-5 microns and surface hardness is greater than 2H;The thickness of the PET base material is 125 microns or 188 microns or 250 microns, the light transmittance of the PET base material is ≥90%, the haze of the PET base material is less than 1.5%;The wire-drawing coating is formed fine and dense stretch grain on the lower surface of the PET base material by UV transfer printing process;The utility model realizes product weight reduction and flexible molding by four-layer film combination IMD process, and metal texture is copied using vacuum plating layer and UV wire-drawing grain, replace traditional metal material.

Description

Technical Field

[0001] This utility model belongs to the field of in-mold injection molding technology, and more specifically, it relates to a structure suitable for in-mold injection molding of metal wire drawing plastic film products. Background Technology

[0002] With the trend towards high-end design in consumer electronics, surface treatment technologies that achieve a brushed metal finish have become an important means of enhancing product value. Traditional processes often use metal materials such as aluminum alloys and stainless steel to manufacture shell components through CNC machining or stamping. While these processes can present a good metallic texture, they have inherent drawbacks such as the high density of the material (aluminum has a density of approximately 2.7 g / cm³) and complex forming processes (requiring multiple cutting and surface treatment steps), resulting in a high overall product weight. This makes them particularly unsuitable for fields with strong lightweight requirements, such as wearable devices and ultra-thin electronic products.

[0003] In recent years, the industry has attempted to replace solid metal materials by combining in-mold molding (IMD) with surface metallization films. Current technologies commonly employ electroplating metal layers or coating with metallic inks on PET substrates; however, these methods have significant limitations: First, simple metal plating cannot replicate the three-dimensional luster of realistic brushed metal textures, resulting in a stiff surface texture and insufficient optical depth. Second, coatings formed by conventional metallic ink coating processes have poor abrasion resistance (generally lower than H grade pencil hardness), making them prone to peeling or texture deformation under the high temperature and pressure of injection molding. Third, existing composite film structures generally have light transmittance below 85% and haze greater than 2%, leading to significant optical distortion when applied to components such as transparent windows, severely restricting design freedom.

[0004] In addition, traditional metallized films have revealed many technical bottlenecks in the implementation of the IMD process: insufficient interfacial bonding strength between the metal coating and the injection molding resin (peel strength is mostly below 3N / cm), excessively high thermal shrinkage rate of the substrate during high-temperature injection molding (shrinkage rate generally exceeds 2% at 150℃) leading to interlayer misalignment, and difficulty in achieving both scratch resistance and hydrophobicity of the surface hardened layer. All these problems restrict the application of this technology in high-end products.

[0005] Therefore, this utility model provides a structure suitable for in-mold injection molded metal wire drawing plastic film products. Utility Model Content

[0006] In view of the above-mentioned problems of the existing technology, the purpose of this utility model is to provide a product structure suitable for in-mold injection metal brushed plastic film. By combining four layers of film with IMD process, the product weight is reduced and flexible molding is achieved. The metal texture is replicated by vacuum coating and UV brushed texture, replacing traditional metal materials.

[0007] The objective of this utility model can be achieved through the following technical solutions: A structure for in-mold injection molded metal wire drawing plastic film products, wherein the plastic film comprises, from top to bottom, a hardened layer, a PET substrate, a wire drawing coating, and a metal plating layer; The hardening layer is attached to the upper surface of the PET substrate by a coating and curing process. The thickness of the hardening layer is 3-5 micrometers and the surface hardness is greater than 2H. The PET substrate has a thickness of 125 micrometers, 188 micrometers, or 250 micrometers, a light transmittance of ≥90%, and a haze of <1.5%. The brushed coating is formed on the lower surface of the PET substrate by a UV transfer process to create fine stretching textures. The metal coating is applied to the surface of the brushed coating by vacuum magnetron sputtering of indium tin alloy or vacuum evaporation of aluminum, and the thickness of the metal coating is 50-150 nanometers. The total thickness of the plastic film is 200-450 micrometers, and the plastic film is hot-pressed together with the injection molding resin layer through an IMD process.

[0008] As a further preferred technical solution of this utility model, the stretch texture density of the brushed coating is 200-500 lines / cm, and the stretch texture direction of the brushed coating is unidirectional straight line, cross, or wavy.

[0009] As a further preferred technical solution of this utility model, the thickness of the metal coating is 50-120 nanometers, and the surface reflectivity is ≥85%.

[0010] As a further preferred technical solution of this utility model, the PET substrate is a biaxially oriented polyester film, the elastic modulus of the PET substrate is ≥4GPa, and the heat shrinkage rate of the PET substrate is ≤1.5% at 150℃ / 30min.

[0011] As a further preferred technical solution of this utility model, a transition layer is provided between the metal coating and the brushed coating, and the transition layer is a silicon dioxide or aluminum oxide layer with a thickness of 10-20 nanometers.

[0012] As a further preferred technical solution of this utility model, the surface of the hardened layer is provided with a microstructure texture, the depth of which is 0.5-2 micrometers and the width is 5-20 micrometers.

[0013] As a further preferred technical solution of this utility model, the outer surface of the metal coating is formed with a nanoscale uneven structure by plasma treatment, and the surface roughness Ra of the metal coating is 0.1-0.3μm.

[0014] As described above, the structure of the in-mold injection molded metal wire drawing plastic film product provided by this utility model has the following beneficial effects: 1. This utility model utilizes the above-mentioned structure of a metal wire drawing plastic film product suitable for in-mold injection molding. Compared with the prior art, due to the adoption of this structure, a four-layer composite film structure is used: a hardening layer, a PET substrate, a wire drawing coating, and a metal plating layer to replace traditional metal materials. The thickness is only 200-450 micrometers. Combined with the IMD process, it achieves hot-press bonding with the resin layer, reducing the product weight by 60%-80%. At the same time, it has the processing flexibility of injection molding and can manufacture complex curved surface shapes, breaking through the limitations of metal material molding.

[0015] 2. This utility model utilizes the above-mentioned structure for in-mold injection molded metal brushed plastic film products. Compared with the prior art, due to the adoption of this structure, a 50-150 nanometer metal coating (reflectivity ≥85%) is formed by vacuum magnetron sputtering of indium tin alloy or evaporation of aluminum. Combined with a 200-500 line / cm brushed texture (containing nano titanium dioxide particles to enhance optical scattering) printed by UV transfer, the unique three-dimensional luster of metal brushing is replicated while retaining 90% light transmittance of the PET substrate. The visual texture is indistinguishable from real metal.

[0016] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a structural diagram of a metal wire drawing plastic film product applicable to in-mold injection molding, as per this utility model application.

[0019] Summary of figure labels and their descriptions: 100, Hardened layer; 200, PET substrate; 300, Brushed coating; 400, Metal plating. Detailed Implementation

[0020] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.

[0021] It should be noted that the structures, proportions, and sizes depicted in the accompanying drawings are merely for illustrative purposes and to aid those skilled in the art. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, provided they do not affect the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention. Specific structures can be described with reference to the accompanying drawings of the patent application.

[0022] This utility model provides a structure suitable for in-mold injection molded metal wire drawing plastic film products. Please refer to [link / reference]. Figure 1 As shown, the plastic film comprises, from top to bottom, a hardened layer 100, a PET substrate 200, a wire-drawing coating 300, and a metal plating layer 400. The hardening layer 100 is attached to the upper surface of the PET substrate 200 by a coating and curing process. The thickness of the hardening layer 100 is 3-5 micrometers and the surface hardness is greater than 2H. The PET substrate 200 has a thickness of 125 micrometers, 188 micrometers, or 250 micrometers, a light transmittance of ≥90%, and a haze of <1.5%. The brushed coating 300 forms fine stretch textures on the lower surface of the PET substrate 200 through a UV transfer process; The metal coating 400 is applied to the surface of the brushed coating 300 by vacuum magnetron sputtering of indium tin alloy or vacuum evaporation of aluminum, and the thickness of the metal coating 400 is 50-150 nanometers. The total thickness of the plastic film is 200-450 micrometers, and the plastic film is hot-pressed together with the injection molding resin layer through an IMD process.

[0023] It should be noted that by replacing metal materials with ultra-thin films of 200-450 micrometers, the product weight is reduced by 60%-80%, while still meeting the requirements for injection molding of complex curved surfaces. Furthermore, through the synergistic effect of vacuum-plated indium tin alloy / aluminum layers (50-150 nanometers) and UV transfer brushed texture, the three-dimensional luster of brushed metal is reproduced, with a light transmittance of ≥90% and a haze of <1.5%, achieving a highly realistic visual effect. In addition, the combination of the 200 biaxial tensile properties of the PET substrate (elastic modulus ≥4GPa) and the surface hardness of the 100 hardened layer >2H ensures both impact resistance and wear resistance.

[0024] The hardened layer 100 is a functional coating formed by coating and curing a fluorine-containing or organosilicon-modified resin composition. The surface water droplet angle of the hardened layer 100 is ≥100°, which significantly improves the hydrophobic and anti-fouling properties, reduces fingerprint residue, and maintains high hardness and scratch resistance.

[0025] The brushed coating 300 has a stretch texture density of 200-500 lines / cm. The stretch texture of the brushed coating 300 can be unidirectional straight, cross, or wavy. By using unidirectional / cross / wavy textures, the visual effects of different metal brushing processes (such as straight lines, random lines, and snowflake patterns) can be accurately simulated, thus broadening the diversity of product design.

[0026] The metal coating 400 has a thickness of 50-120 nanometers and a surface reflectivity of ≥85%. While ensuring the metallic texture, it avoids the brittle cracking problem caused by excessively thick coatings and improves the hot-pressing bonding stability during IMD injection molding.

[0027] The PET substrate 200 is a biaxially oriented polyester film. The elastic modulus of the PET substrate 200 is ≥4GPa, and the heat shrinkage rate of the PET substrate 200 is ≤1.5% at 150℃ / 30min. The biaxially oriented polyester film gives the substrate excellent dimensional stability. Its deformation rate is lower than that of traditional PET film in the injection molding environment at 150℃, which prevents interlayer misalignment caused by high temperature hot pressing.

[0028] A transition layer is provided between the metal plating layer 400 and the brushed coating layer 300. The transition layer is a silicon dioxide or aluminum oxide layer with a thickness of 10-20 nanometers. The provision of the transition layer improves the adhesion of the metal plating layer 400 and solves the problem of interface peeling caused by the difference in thermal expansion coefficients between the metal layer and the organic coating.

[0029] The brushed coating 300 contains nano-sized inorganic particles. The surface of the brushed coating 300 with its stretch texture forms a micro-rough structure that enhances light scattering through the nano-particles. The nano-sized inorganic particles dispersed in the brushed coating 300 enhance the gloss and layering of the metal plating 400 through the light scattering effect, and the particle size matches the brushed texture to avoid abnormal surface roughness of the coating.

[0030] The surface of the hardened layer 100 is provided with a microstructure texture, the depth of which is 0.5-2 micrometers and the width is 5-20 micrometers; the microstructure texture reduces specular reflectivity through diffuse reflection.

[0031] The outer surface of the metal coating 400 is formed with a nanoscale uneven structure through plasma treatment, and the surface roughness Ra of the metal coating 400 is 0.1-0.3μm. By forming a nanoscale uneven structure with Ra 0.1-0.3μm through plasma treatment of the metal coating 400, the mechanical bonding strength with the injection molding resin is enhanced, and the softness of the metallic texture is optimized through diffuse reflection.

[0032] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A structure suitable for in-mold injection molded metal wire drawing plastic film products, characterized in that, The plastic film comprises, from top to bottom, a hardened layer, a PET substrate, a wire-drawing coating, and a metal plating layer; The hardening layer is attached to the upper surface of the PET substrate by a coating and curing process. The thickness of the hardening layer is 3-5 micrometers and the surface hardness is greater than 2H. The PET substrate has a thickness of 125 micrometers, 188 micrometers, or 250 micrometers, a light transmittance of ≥90%, and a haze of <1.5%. The brushed coating is formed on the lower surface of the PET substrate by a UV transfer process to create fine stretching textures. The metal coating is applied to the surface of the brushed coating by vacuum magnetron sputtering of indium tin alloy or vacuum evaporation of aluminum, and the thickness of the metal coating is 50-150 nanometers. The total thickness of the plastic film is 200-450 micrometers, and the plastic film is hot-pressed together with the injection molding resin layer through an IMD process.

2. The structure of an in-mold injection molded metal wire drawing plastic film product according to claim 1, characterized in that, The stretch texture density of the brushed coating is 200-500 lines / cm, and the stretch texture direction of the brushed coating is unidirectional straight line, cross, or wavy.

3. The structure of an in-mold injection molded metal wire drawing plastic film product according to claim 1, characterized in that, The thickness of the metal coating is 50-120 nanometers, and the surface reflectivity is ≥85%.

4. The structure of an in-mold injection molded metal wire drawing plastic film product according to claim 1, characterized in that, The PET substrate is a biaxially oriented polyester film, the elastic modulus of the PET substrate is ≥4GPa, and the heat shrinkage rate of the PET substrate is ≤1.5% at 150℃ / 30min.

5. The structure of an in-mold injection molded metal wire drawing plastic film product according to claim 1, characterized in that, A transition layer is provided between the metal plating layer and the brushed coating layer, and the transition layer is a silicon dioxide or aluminum oxide layer with a thickness of 10-20 nanometers.

6. The structure of an in-mold injection molded metal wire drawing plastic film product according to claim 1, characterized in that, The surface of the hardened layer is provided with a microstructure texture, the depth of which is 0.5-2 micrometers and the width of which is 5-20 micrometers.

7. The structure of an in-mold injection molded metal wire drawing plastic film product according to claim 1, characterized in that, The outer surface of the metal coating is formed with a nanoscale uneven structure through plasma treatment, and the surface roughness Ra of the metal coating is 0.1-0.3 μm.

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