A mold structure and method for in-mold injection molding of exterior trim and double-sided diaphragm

Abstract

The present invention relates to a mold structure and method for in-mold injection molding of exterior trims and double-sided diaphragms. The mold structure includes a movable mold, a fixed mold, and a sloping top. The movable mold has a cavity, the fixed mold has a core, the sloping top is slidably connected to the fixed mold, and the double-sided diaphragm includes a functional diaphragm and a decorative diaphragm. The functional diaphragm is fixed in the cavity, and the decorative diaphragm is fixed on the core, forming a cavity between the functional diaphragm and the decorative diaphragm. A gate is provided on the sloping top, and the gate is connected to the cavity. The mold structure for in-mold injection molding of double-sided diaphragms of the present invention can be used for one-time injection molding of automotive exterior trims that have both heating and defrosting functions and customized decorative effects. The positioning structure allows the diaphragm to be positioned and pressed during the injection molding process, reducing the pushing of the molten resin on the diaphragm during the injection molding process, thereby avoiding wrinkles on the diaphragm. The special gate ensures that the end of the flow channel area of ​​the functional diaphragm can be clamped when the cavity and the core are closed, ensuring that the molten resin will not be back-packed when entering the cavity.

Description

Technical Field

[0001] The present invention relates to the field of in-mold injection molding, and more particularly to a mold structure and method for in-mold injection molding of exterior trim parts and double-sided diaphragms. Background Art

[0002] Currently, the existing automotive exterior trims for automatic cruise radars on the market use evaporation / sputtering plating processes to achieve the metallic effect and wave-transmitting function of the trims. The process is complex and there is no heating and defrosting function. In cold weather conditions, a frost layer is easily formed on the outside of the automatic cruise radar trim, causing the radar function to fail. To eliminate the impact of frost, the existing technology is to apply an anti-fog coating on the trim, but the cost is high and the defogger effect is not ideal. In addition, in order to achieve a colorful decorative effect, the trim needs to be masked and painted multiple times, the process path is complicated, and the production process is not environmentally friendly. Summary of the Invention

[0003] The object of the present invention is to provide a mold structure for in-mold injection molding of a double-sided diaphragm, through which an automobile exterior trim having both a heating and defrosting function and a customized decorative effect can be injection molded in one step.

[0004] To achieve the above-mentioned objectives, the present invention provides an exterior trim part on one hand, wherein a functional film sheet and a decorative film sheet are respectively provided on both sides of the exterior trim part, wherein the functional film sheet includes a heating base film and a plurality of heating wires evenly arranged on the heating base film, and the decorative film sheet includes a transparent film sheet and a plurality of ink layers of different colors arranged in sequence.

[0005] Furthermore, there are multiple heating wires, which are coiled on the entire surface of the heating base film.

[0006] The exterior trim of the present invention has both decorative and heating functions, and can be used for automatic cruise radar trim to avoid performance malfunction of functional trim in cold weather conditions.

[0007] On the other hand, the present invention provides a mold structure for in-mold injection molding of a double-sided diaphragm, comprising a movable mold, a fixed mold and a slanted top, the movable mold having a cavity, and the fixed mold having a core, the slanted top being slidably connected to the fixed mold, and is characterized in that the double-sided diaphragm comprises a functional diaphragm and a decorative diaphragm, the functional diaphragm being fixed in the cavity, the decorative diaphragm being fixed on the core, and a cavity being formed between the functional diaphragm and the decorative diaphragm; a gate is provided on the slanted top, and the gate is connected to the mold cavity.

[0008] Furthermore, positioning structures are provided on the mold cavity and the mold core, and the functional membrane and the decorative membrane are fixed on the mold cavity and the mold core respectively through the positioning structures.

[0009] Furthermore, the positioning structure is a positioning boss, and positioning holes are provided on the functional membrane and the decorative membrane, and the positioning boss is matched with the positioning hole with zero clearance.

[0010] Furthermore, the head of the positioning boss is provided with a guide taper.

[0011] Furthermore, the inclined roof includes a head and a runner area, a guide rod extends outward from the head, and the gate is arranged on the guide rod and communicates with the runner area.

[0012] Furthermore, the end portion of the decorative film extends to the flow channel region of the inclined roof, and the inclined roof presses the end portion of the decorative film onto the core.

[0013] Furthermore, membrane positioning areas are symmetrically provided on both sides of the gate, and the membrane positioning areas have avoidance positions corresponding to the positioning holes.

[0014] Furthermore, the area of ​​the gate is smaller than the area of ​​the decorative film.

[0015] The mold structure for in-mold injection molding of a double-sided diaphragm of the present invention uses a positioning structure to position and press the functional diaphragm and the decorative diaphragm during the injection molding process, reducing the pushing of the molten resin on the diaphragm during the injection molding process, thereby avoiding wrinkles on the diaphragm; a special gate is used to ensure that the end of the flow channel area of ​​the decorative diaphragm can be clamped when the cavity and the core are molded, and the molten resin flow channel is at a certain distance from the edge of the functional diaphragm, ensuring that the molten resin will not be back-packed when entering the mold cavity, thereby allowing a double-sided diaphragm with heating and defrosting functions and customized decorative effects to be injection molded in one go.

[0016] Another aspect of the present invention provides a double-sided diaphragm in-mold injection molding method, comprising the following steps:

[0017] S1: A transparent film is formed into a decorative film with a pattern of exterior trim by screen printing;

[0018] S2: The decorative film is preformed under high pressure to form a shape having an exterior decorative part;

[0019] S3: embedding the heating wire into the heating base film to form a functional film sheet, and preforming the functional film sheet under high pressure to form a shape having an exterior trim;

[0020] S4: After high-pressure preforming, the decorative film and functional film are punched to form the shape required for the exterior parts to be covered;

[0021] S5: After punching, the decorative film and the functional film are respectively installed in the mold structure as described above, and the exterior decoration product is formed by double-sided film in-mold injection molding.

[0022] The double-sided diaphragm in-mold injection molding method of the present invention can perfectly solve the diaphragm positioning problems, vertical back-wrapping problems and diaphragm wrinkling problems during the injection molding process, ensuring that the molten resin smoothly enters the middle of the two layers of diaphragm, thereby forming a double-sided diaphragm with heating and defrosting functions and customized decorative effects in one injection molding. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic cross-sectional view of a layered decorative film according to an embodiment of the present invention;

[0024] Figure 2 is a schematic cross-sectional view of a layered heating film according to an embodiment of the present invention;

[0025] Figure 3 This is a diagram of the heating wire layout of a heating film according to an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of a mold structure for in-mold injection molding of a double-sided diaphragm according to an embodiment of the present invention;

[0027] Figure 5 yes Figure 4 A partial enlarged view of the mold structure for double-sided diaphragm in-mold injection molding;

[0028] Figure 6 yes Figure 4 AA cross-sectional view;

[0029] Figure 7 yes Figure 4 A partial enlarged view of the inclined top of the mold structure for double-sided diaphragm in-mold injection molding;

[0030] Figure 8 This is a flow chart of the manufacturing process of automotive exterior trim provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention are given below in conjunction with the accompanying drawings and described in detail.

[0032] The two sides of the automatic cruise radar exterior provided in an embodiment of the present invention have different functions. One side is a functional membrane with a heating function, which is used for heating and defrosting to prevent malfunction of the automatic cruise radar in cold weather; the other side is a decorative membrane, which is used to achieve a customized decorative effect.

[0033] like Figure 1 As shown, the decorative film includes a transparent PC film F1, ink layers F2, F3, and F5 of different colors, and a transparent adhesive ink F4. The ink layers F2, F3, and F5 of different colors serve as a decoration, and customized decorative effects can be achieved by changing their colors. The decorative film can be formed by screen printing.

[0034] like Figure 2 As shown, the functional film includes a transparent PC film F7 and a plurality of heating wires F6 evenly arranged on the PC film F7. The transparent PC film F7 is a heating base film, and the heating wires are embedded in the heating base film to form a functional film that can heat. The heating wires F6 are heated after being energized, thereby realizing the defrosting function. Figure 3 As shown, there are several heating wires F6, each of which is coiled around the entire PC diaphragm F7 like an electric furnace wire, thus extending the coverage area of ​​the heating wire F6. The heating diaphragm can be formed through a special implantation process, such as the ultrasonic implantation process, in which a copper wire vibrates at high frequency within the hole of an ultrasonic welding head to generate heat. Under the pressure of the welding head, the thermoplastic resin is implanted to form the heating diaphragm.

[0035] There is a transparent resin between the decorative film and the functional film. The circuit of the heating wire F6 is protected between the transparent PC film F7 and the resin. The ink layers F2, F3 and F5 of the decorative film are also protected between the PC film F1 and the resin.

[0036] In order to one-time injection molding of double-sided membrane products similar to the above-mentioned exterior parts, such as Figure 4 and 5 As shown, an embodiment of the present invention provides a mold structure for in-mold injection molding of a double-sided diaphragm, comprising a movable mold 5, a fixed mold and a slanted top 4, the movable mold 5 having a cavity, the fixed mold having a core 6, the top of the slanted top 4 being slidably connected to the fixed mold, the double-sided diaphragm comprising a functional diaphragm 7 and a decorative diaphragm 8, wherein the functional diaphragm 7 is provided with a heating wire, which has a heating function and is used for heating and defrosting, and is fixed in the cavity of the movable mold 5, the decorative diaphragm 8 is used to achieve a customized decorative effect, and is fixed on the core 6, and a cavity 10 is formed between the functional diaphragm 7 and the decorative diaphragm 8. During injection molding, the molten resin enters the cavity 10, thereby completing the in-mold injection molding of the double-sided diaphragm.

[0037] Specifically, positioning structures 1 and 2 are provided on the cavity and core 6, respectively. Functional film 7 is secured to the cavity via positioning structure 1, while decorative film 8 is secured to the core 6 via positioning structure 2. Positioning structures 1 and 2 respectively position functional film 7 and decorative film 8, preventing them from moving during the injection molding process, which could cause molten resin to enter between the film and the cavity or core and form backfill. Furthermore, since the film is positioned and pressed, the impact of molten resin on the film during the injection molding process is reduced, thereby preventing wrinkles in the film.

[0038] Positioning structures 1 and 2 can be configured as positioning bosses, with positioning holes provided on the functional diaphragm 7 and the decorative diaphragm 8 to cooperate with the positioning bosses. The positioning bosses and the positioning holes cooperate with each other with zero clearance, thereby achieving fixed positioning of the functional diaphragm 7 and the decorative diaphragm 8. Preferably, the positioning bosses are of a two-stage structure, with a cylindrical structure at the base having a diameter the same as the positioning hole, and a frustum-shaped structure at the head, with the top of the frustum smaller than the positioning hole, thereby forming a guide taper at the head, which facilitates smooth insertion of the diaphragm into the positioning hole and achieves precise positioning of the diaphragm.

[0039] The positioning structure 1 and the positioning structure 2 may also be other external ear-hanging positioning structures, which is not limited in the present invention.

[0040] like Figure 6 and 7 As shown, the inclined top 4 includes a head 42, a guide rod 41 extending outward from the head 42, a gate 3 is provided on the guide rod 41, and diaphragm positioning areas 45 are symmetrically arranged on both sides of the gate 3. The diaphragm positioning area 45 is defined by the diaphragm air avoidance boundary 44 and the gate 3. A positioning hole avoidance position 43 is provided in the diaphragm positioning area 45, which corresponds to the positioning hole of the decorative diaphragm 8. When the mold is closed, the positioning boss 2 can be inserted into the positioning hole avoidance position 43 of the decorative diaphragm 8, so that the inclined top 4 presses the decorative diaphragm 8 onto the core 6.

[0041] The end 9 of the decorative film 8 extends to the runner area 11 of the inclined top 4, and the area of ​​the gate 3 is smaller than the area of ​​the end 9 of the decorative film 8 at this location. This ensures that the inclined top 4 presses the decorative film 8 onto the core 6 when the mold is closed, and the molten resin enters the mold cavity 10 through the outer surface of the decorative film 8 without entering between the decorative film 8 and the core 6, thereby avoiding the formation of backpacking.

[0042] Since an actual molten resin flow channel is formed between the head 42 of the inclined top 4 and the decorative film 8 on the core 6, which is 2 mm away from the edge of the functional film 7, it can be ensured that the molten resin will not enter between the functional film 7 and the cavity to form a backflow.

[0043] Similar to conventional molds, the mold structure of the present invention also includes mold feet, ejector pins and other components, the structure and connection method of which are well known in the art and will not be described in detail here.

[0044] like Figure 8 As shown, the manufacturing process of the automotive exterior parts of the present invention includes the following steps:

[0045] S1: PC film is screen-printed to form a decorative film with the pattern of automotive exterior parts;

[0046] S2: The decorative film is preformed under high pressure to form the shape of the automotive exterior part;

[0047] S3: The heating wiring membrane is preformed under high pressure to form a shape having an automobile exterior trim;

[0048] S4: The preformed film is punched to form the shape that the automotive exterior parts need to cover;

[0049] S5: The punched diaphragm is installed in the above mold structure, and the double-sided diaphragm is injected into the mold to form an automotive exterior product with both decorative and heating functions.

[0050] The PC film may also be replaced with other transparent films, which is not limited in the embodiment of the present invention.

[0051] The mold structure for in-mold injection molding of double-sided diaphragms provided in an embodiment of the present invention can be used for one-time injection molding of automotive exterior parts with heating and defrosting functions and customized decorative effects; through positioning structure 1 and positioning structure 2, the diaphragm is positioned and pressed during the injection molding process, reducing the pushing of the molten resin on the diaphragm during the injection molding process, thereby avoiding wrinkles on the diaphragm; through a special gate 3, it is ensured that the end 9 of the functional diaphragm runner area can be clamped when the cavity and the core 6 are closed, and the molten resin runner is at a certain distance from the edge of the functional diaphragm 7, ensuring that the molten resin will not be back-packed when entering the mold cavity 10.

[0052] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Various modifications are possible. In other words, any simple, equivalent changes and modifications made in accordance with the claims and description of the present invention are within the scope of protection of the patent claims. Anything not fully described in this invention constitutes conventional technology.

Claims

1. A method for forming an automatic cruise radar exterior part by double-sided film in-mold injection molding, characterized in that: The following steps are involved: S1, a transparent film and a plurality of ink layers of different colors are screen-printed to form a decorative film having a pattern of an exterior trim; S2, the decorative film is preformed under high pressure into a shape having an exterior decorative part; S3, uniformly embedding the heating wire into the heating base film to form a functional film sheet, and preforming the functional film sheet under high pressure to form a shape having an exterior trim; S4, the decorative film and functional film after high-pressure preforming are punched to form the shape required for the exterior decoration part to be covered; S5, provide a mold structure, which includes a movable mold, a fixed mold and a tilted top, the movable mold has a cavity, the cavity is provided with a first positioning structure, the fixed mold has a core, the core is provided with a second positioning structure, the tilted top is slidably connected to the fixed mold, the functional membrane after punching is fixed in the cavity by the first positioning structure, the decorative membrane after punching is fixed to the core by the second positioning structure, and a mold cavity is formed between the functional membrane and the decorative membrane; the tilted top includes a head and a runner area, a guide rod extends outward from the head, A gate is provided on the guide rod, and the gate is connected with the runner area. The end of the decorative film extends to the runner area of ​​the inclined top. The inclined top presses the end of the decorative film onto the core. The gate is connected with the mold cavity, and the molten resin enters the mold cavity, thereby completing the double-sided film in-mold injection molding to form an automatic cruise radar exterior part, wherein the automatic cruise radar exterior part includes a transparent resin located between the decorative film and the functional film, the ink layer is protected between the transparent resin and the transparent film, and the circuit of the heating wire is protected between the transparent resin and the heating base film.

2. The method according to claim 1, characterized in that There are a plurality of heating wires, which are wound on the entire surface of the heating base film.

3. The method according to claim 1, characterized in that The first and second positioning structures are positioning bosses, positioning holes are provided on the functional membrane and the decorative membrane, and the positioning bosses are matched with the positioning holes with zero clearance.

4. The method according to claim 3, characterized in that The head of the positioning boss is provided with a guide taper.

5. The method according to claim 3, characterized in that Diaphragm positioning areas are symmetrically arranged on both sides of the gate, and the diaphragm positioning areas have avoidance positions corresponding to the positioning holes.

6. The method according to claim 5, characterized in that The area of ​​the gate is smaller than the area of ​​the decorative film.

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