An INS injection molding method for automotive interior products

Abstract

This invention relates to the field of automotive interior and exterior trim manufacturing technology, specifically to an INS injection molding method and automotive interior products. The injection molding method includes: Step S1, pre-forming an INS film and then adjusting its shape to obtain an insert; Step S2, installing the insert into a cavity of a fixed mold plate, closing the fixed mold plate and a moving mold plate, injecting molten material into the cavity, and cooling to obtain the final product; wherein, the inner wall of the cavity is provided with brushed stripes, the brushed stripes comprising multiple strip-shaped protrusions spaced apart on the inner wall of the cavity, the height of the strip-shaped protrusions being 50-90 μm. Using the method of this invention, not only are the products produced having a strong tactile feel, but the breakage of the PMMA or ABS layer of the product can also be avoided, thereby preventing problems such as film breakage and failure in high and low temperature and light aging tests.

Description

Technical Field

[0001] This invention relates to the field of automotive interior and exterior trim manufacturing technology, and more specifically, to an INS injection molding method and automotive interior products. Background Technology

[0002] INS, also known as insert injection molding, is a process that uses thermoforming or high-pressure molding to stretch a transfer-printed film three times. The insert is then cut to fit the product's shape and precisely placed into the injection mold cavity for injection molding, resulting in a product with a decorative surface. Traditional INS processes only achieve a 2D effect, meaning only a pattern with little or no tactile feedback, and the high gloss and plasticky feel result in poor texture. To improve the tactile feel, current technologies use high-tactile films (PMMA layers with a brushed finish to create a strong tactile feel) to produce automotive interior products. However, because injection molding requires high temperatures (around 260°C) and high injection pressure, the surface texture of the film is flattened under high temperature softening and pressure, resulting in an unremarkable tactile effect. Summary of the Invention

[0003] The technical problem solved by this invention is that products obtained by existing INS injection molding methods have an unclear tactile feel.

[0004] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0005] An INS injection molding method, comprising:

[0006] Step S1: After preforming the INS film, adjust its shape to obtain the insert;

[0007] Step S2: Install the insert into the cavity of the fixed template. After closing the fixed template and the moving template, inject the molten material into the cavity. After cooling, the final product is obtained. The inner wall of the cavity is provided with brushed stripes. The brushed stripes include multiple strip-shaped protrusions spaced apart on the inner wall of the cavity. The height of the strip-shaped protrusions is 50-90μm.

[0008] Preferably, in step S2, the spacing between the strip-shaped protrusions is 5-10 μm.

[0009] Preferably, in step S2, the width of the strip-shaped protrusion is 5-15 μm.

[0010] Preferably, in step S2, the edges of the strip-shaped protrusions are all chamfered.

[0011] Preferably, the radius of the chamfer is 2-5 μm.

[0012] Preferably, in step S1, the preforming process includes thermoforming or high-pressure forming.

[0013] Preferably, the preforming process is high-pressure molding, and the pressure of the high-pressure molding is 2-3 MPa.

[0014] Preferably, in step S1, the thickness of the INS film is 0.5-0.8 mm.

[0015] Preferably, in step S2, the temperature of the molten material is 250-270°C.

[0016] The present invention also provides an automotive interior product, which is manufactured using the INS injection molding method described above.

[0017] Compared with existing technologies, this invention improves the tactile feel of the product by setting brushed stripes on the fixed template of the injection mold. The height of the raised stripes in the brushed stripes is set to 50-90 μm. This not only avoids the lack of noticeable tactile feel due to excessively small height (less than 50 μm), but also prevents the PMMA or ABS layer of the product from cracking due to excessively large height (greater than 90 μm). Therefore, the method of this invention not only produces products with a strong tactile feel, but also avoids cracking of the PMMA or ABS layer, thus preventing problems such as film breakage and failure in high / low temperature and light aging tests. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the INS injection molding method in an embodiment of the present invention;

[0019] Figure 2 A schematic diagram of the structure of the INS membrane in this embodiment of the invention;

[0020] Figure 3 A schematic diagram of the fixed template, insert, and moving template in a separated state in an embodiment of the present invention;

[0021] Figure 4 This is a structural diagram of a template;

[0022] Figure 5 for Figure 4 A magnified view of a portion of point A in the middle.

[0023] Explanation of reference numerals in the attached figures:

[0024] 1. PMMA layer, 2. Ink layer, 3. ABS layer, 4. Fixed template, 5. Insert, 6. Moving template. Detailed Implementation

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other. The terms "comprising," "including," "containing," and "having" are non-limiting, meaning that other steps and other components that do not affect the results can be added. The above terms cover the terms "composed of" and "substantially composed of." Unless otherwise specified, the materials, equipment, and reagents are commercially available.

[0027] like Figure 1 As shown, this embodiment of the invention provides an INS injection molding method, including:

[0028] Step S1: After preforming the INS film, adjust its shape to obtain the insert;

[0029] Step S2: Install the insert into the cavity of the fixed mold plate. After closing the fixed mold plate and the moving mold plate, inject molten material into the cavity. After cooling, the final product is obtained. The inner wall of the cavity is provided with brushed stripes, which include multiple strip-shaped protrusions spaced apart on the inner wall of the cavity. The height of the strip-shaped protrusions is 50-90 μm. Exemplarily, the brushed stripes include multiple strip-shaped protrusions spaced apart along the width direction on the inner wall of the cavity. It should be noted that the width direction of the cavity of the fixed mold plate is... Figure 4 The X-arrow indicates the direction.

[0030] For example, such as Figure 2 As shown, the INS film includes a PMMA layer 1, an ink layer 2, and an ABS layer 3.

[0031] Figure 3 This is a schematic diagram showing the fixed template 4, insert 5, and moving template 6 in a separated state. Figure 4 This is a structural diagram of a template. Figure 5 for Figure 4 A magnified view of a section at point A in the middle, from Figure 5 The distribution of the raised stripes in the brushed stripes can be seen.

[0032] like Figures 3 to 5 As shown, the fixed template 4 includes a fixed template body, on one side of which a cavity is formed. The inner wall of the cavity is provided with brushed stripes, which include multiple strip-shaped protrusions spaced apart on the inner wall of the cavity. The height of the strip-shaped protrusions is 50-90 μm. The movable template 6 includes a movable template body, on one side of which a protrusion structure matching the size and shape of the cavity is formed.

[0033] Compared with existing technologies, the embodiments of the present invention improve the tactile feel of the product by setting brushed stripes on the fixed template of the injection mold. The height of the raised stripes in the brushed stripes is set to 50-90 μm. This not only avoids the lack of noticeable tactile feel due to excessively small height (less than 50 μm), but also avoids the breakage of the PMMA or ABS layer due to excessively large height (greater than 90 μm). Therefore, the method of the present invention not only produces a product with a strong tactile feel, but also avoids breakage of the PMMA or ABS layer, thereby preventing problems such as film breakage and failure in high / low temperature and light aging tests.

[0034] In some embodiments of the present invention, in step S2, the spacing between the strip-shaped protrusions is 5-10 μm. When the spacing between the strip-shaped protrusions is less than 5 μm, the tactile feel of the resulting product is not obvious; when the spacing between the strip-shaped protrusions is greater than 10 μm, the membrane is prone to cracking.

[0035] In some embodiments of the present invention, in step S2, the width of the strip-shaped protrusion is 5-15 μm. When the width of the strip-shaped protrusion is less than 5 μm, the tactile feel of the resulting product is not obvious; when the width of the strip-shaped protrusion is greater than 15 μm, the film is prone to cracking.

[0036] In some embodiments of the present invention, in step S2, a chamfer is formed at the edge of each strip-shaped protrusion, and the radius of the chamfer is 2-5 μm. Specifically, "edge of the strip-shaped protrusion" refers to the edge of the top of the strip-shaped protrusion, such as... Figure 5 As shown, the top surface of the strip-shaped protrusion is elongated, and the connection between the top surface and the side surface is chamfered. Chamfering the edges of the strip-shaped protrusion helps to avoid sharp edges and membrane cracking. When the chamfer is greater than 5μm, the resulting product has a less pronounced tactile feel.

[0037] In some embodiments of the present invention, in step S1, the preforming process includes thermoforming or high-pressure forming.

[0038] In some embodiments of the present invention, the preforming process is high-pressure molding, and the pressure of the high-pressure molding is 2-3 MPa.

[0039] Specifically, the high-pressure molding process principle is as follows: After heating the INS film to a softening temperature, the mold shape is replicated by using high pressure (20kg / approximately 2MPa) and negative pressure -76mmHg vacuum method, thereby achieving the design appearance shape and size requirements.

[0040] In step S1, the shape adjustment includes cutting and forming. Cutting and forming involves placing the pre-formed INS film on a mold to remove excess material, similar in principle to the stamping process of metal parts. Specifically, the film is fixed on the lower die block, the mold begins to close, and the pressure core contacts the film in advance under the action of a spring, pressing and fixing the film. The upper die block continues to move to cut and separate the film, obtaining the desired shape.

[0041] In some embodiments of the present invention, in step S2, the temperature of the molten material is 250-270°C.

[0042] Specifically, the injection molding machine heats the plastic particles to a molten state, and then injects the molten plastic into the cavity of the fixed mold plate 4 through the gate. Under the huge injection pressure, the molten plastic can not only obtain various pattern effects of film on the surface of the product, but also make the product have a tactile texture.

[0043] This invention also provides an automotive interior product, manufactured using the INS injection molding method described above.

[0044] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0045] Example 1

[0046] 1.1 After the INS film is subjected to high pressure forming, it is cut and shaped to obtain the insert; wherein, the pressure of the high pressure forming is 2MPa, and the INS film includes a PMMA layer 1, an ink layer 2 and an ABS layer 3, with a thickness of 0.6mm.

[0047] 1.2. The insert is installed in the cavity of the fixed mold plate. After the fixed mold plate and the moving mold plate are closed, the molten material is injected into the cavity. After cooling, the final product is obtained. The temperature of the molten material is 260°C. The inner wall of the cavity is provided with brushed stripes. The brushed stripes include a plurality of strip-shaped protrusions distributed at intervals along the width direction on the inner wall of the cavity. The spacing between the strip-shaped protrusions is 5μm, the height of the strip-shaped protrusions is 50μm, and the height difference between adjacent strip-shaped protrusions is not higher than 60μm. The width of the strip-shaped protrusions is 5μm, and the edges of the strip-shaped protrusions are all chamfered with a radius of 2μm.

[0048] The final product obtained in Example 1 has a strong tactile feel and no diaphragm cracking was observed.

[0049] Example 2

[0050] 2.1 After the INS film is subjected to high pressure forming, it is cut and shaped to obtain the insert; wherein, the pressure of the high pressure forming is 2MPa, and the INS film includes a PMMA layer 1, an ink layer 2 and an ABS layer 3, with a thickness of 0.8mm.

[0051] 2.2 The insert is installed in the cavity of the fixed mold plate. After the fixed mold plate and the moving mold plate are closed, the molten material is injected into the cavity. After cooling, the final product is obtained. The temperature of the molten material is 260°C. The inner wall of the cavity is provided with brushed stripes. The brushed stripes include a plurality of strip-shaped protrusions distributed at intervals along the width direction on the inner wall of the cavity. The spacing between the strip-shaped protrusions is 10μm, the height of the strip-shaped protrusions is 90μm, and the height difference between adjacent strip-shaped protrusions is no more than 60μm. The width of the strip-shaped protrusions is 15μm, and the edges of the strip-shaped protrusions are all chamfered with a radius of 5μm.

[0052] The final product obtained in Example 2 has a strong tactile feel and no diaphragm cracking was observed.

[0053] Comparative Example 1

[0054] The difference from Example 1 is that the height of the strip-shaped protrusions is 45 μm. The final product obtained in Comparative Example 1 has an imperceptible tactile feel.

[0055] Comparative Example 2

[0056] The difference from Example 1 is that the height of the strip-shaped protrusions is 120 μm. The membrane of the final product prepared in Comparative Example 2 showed cracking.

[0057] Comparative Example 3

[0058] The difference from Example 1 is that the spacing between the strip-shaped protrusions is 3 μm. The final product obtained in Comparative Example 3 has an imperceptible tactile feel.

[0059] Comparative Example 4

[0060] The difference from Example 1 is that the spacing between the strip-shaped protrusions is 12 μm. The membrane of the final product obtained in Comparative Example 4 showed cracking.

[0061] Comparative Example 5

[0062] The difference from Example 1 is that the width of the strip-shaped protrusion is 3 μm. The tactile feel of the final product obtained in Comparative Example 5 is not obvious.

[0063] Comparative Example 6

[0064] The difference from Example 1 is that the width of the strip-shaped protrusions is 17 μm. The membrane of the final product prepared in Comparative Example 6 showed cracking.

[0065] Comparative Example 7

[0066] The difference from Example 1 is that the radius of the chamfer is 6 μm. The tactile feel of the final product obtained in Comparative Example 7 is not obvious.

[0067] Furthermore, it should be noted that although the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. An INS injection molding method, characterized in that, include: Step S1: After preforming the INS film, adjust its shape to obtain the insert; Step S2: Install the insert into the cavity of the fixed mold plate. After closing the fixed mold plate and the moving mold plate, inject the molten material into the cavity. After cooling, the final product is obtained. The inner wall of the cavity is provided with brushed stripes, which include multiple strip-shaped protrusions spaced apart on the inner wall of the cavity. The height of the strip-shaped protrusions is 50-90 μm; the spacing between the strip-shaped protrusions is 5-10 μm; the width of the strip-shaped protrusions is 5-15 μm; and a chamfer is formed at the edge of each strip-shaped protrusion with a radius of 2-5 μm.

2. The INS injection molding method according to claim 1, characterized in that, In step S1, the preforming process includes thermoforming or high-pressure forming.

3. The INS injection molding method according to claim 2, characterized in that, The preforming process is high-pressure molding, and the pressure of the high-pressure molding is 2-3 MPa.

4. The INS injection molding method according to claim 1, characterized in that, In step S1, the thickness of the INS film is 0.5-0.8 mm.

5. The INS injection molding method according to claim 1, characterized in that, In step S2, the temperature of the molten material is 250-270℃.

6. An automotive interior product, manufactured using the INS injection molding method as described in any one of claims 1-5.

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