Anti-deformation automobile interior part injection molding process

Abstract

The application discloses an anti-deformation automobile interior part injection molding process, which comprises providing an upper mold and a lower mold for injection molding, the upper mold and the lower mold are closed to form a cavity for forming the automobile interior part, and the cavity has a material injection channel, a first injection channel and a second injection channel; ABS material in a molten state is injected into the cavity through the material injection channel; pressurized gas is introduced, then foaming molten resin is injected into the cavity through the first injection channel; then non-foaming molten resin is injected into the cavity through the second injection channel; and the mold is opened to take out the cooled product. According to the application, the foaming molten resin and the non-foaming molten resin are continuously filled on the surface of the injection-molded ABS material to form a three-layer sandwich-like structure, the anti-deformation capability is improved, the shock absorption is reduced, the adhesion of the glue in the later stage is improved, and the stability is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of injection molding of automotive interior parts, and in particular relates to an anti-deformation injection molding process for automotive interior parts. BACKGROUND

[0002] The automotive interior part plates widely used in the market are applied to automotive instrument panels and door inner panels, and have a three-layer structure, i.e., a plastic layer as the inner layer, a glue layer as the middle layer, and a skin layer as the outer layer. The inner plastic layer is injection molded, i.e., the injection material is injected into the cavity of a mold, and after cooling and solidification, the product is demolded for the next process. Although this injection molding process only needs a mold to injection mold the injection material into a product, the product formed by this injection molding process has low surface strength, is prone to deformation, and has poor adhesion and easy separation in the later stage, resulting in poor quality of the finished automotive interior part. SUMMARY

[0003] Therefore, the present application aims to provide an anti-deformation injection molding process for automotive interior parts to avoid the problems of low surface strength, poor adhesion in the later stage, easy deformation, and poor product quality caused by the conventional injection molding process for automotive interior parts.

[0004] To solve the above technical problems, the present application discloses an anti-deformation injection molding process for automotive interior parts, which comprises the following steps:

[0005] Step a. providing an upper mold and a lower mold for injection molding, the upper mold and the lower mold being closed to form a cavity for molding the automotive interior part, and the cavity having an injection channel, a first injection channel, and a second injection channel;

[0006] Step b. injecting the ABS material in a molten state into the cavity through the injection channel, and then cooling to a semi-molten state;

[0007] Step c. introducing pressurized gas, and then injecting the foaming molten resin into the cavity through the first injection channel, the pressurized pressure being greater than the foaming expansion pressure of the foaming molten resin, and the pressurized gas being released after 2 minutes of pressure retention;

[0008] Step d. introducing pressurized gas, and then injecting the non-foaming molten resin into the cavity through the second injection channel, the pressurized pressure being greater than the foaming expansion pressure of the non-foaming molten resin, so that the non-foaming molten resin fills the entire cavity, and the pressurized gas is released after 2 minutes of pressure retention;

[0009] Step e. ensuring that the ABS material, the foaming molten resin, and the non-foaming molten resin are colloidically bonded to form the finished automotive interior part, and the mold is opened to take out the cooled product.

[0010] According to an embodiment of the present application, the first injection channel and the second injection channel are arranged in a V shape or an L shape.

[0011] According to an embodiment of the present application, the first injection channel and the second injection channel are provided with a gate valve at one end close to the cavity.

[0012] According to an embodiment of the present application, the injection pressure in steps c and d is 30-50 MPa.

[0013] According to an embodiment of the present application, the first injection channel and the second injection channel are arranged in a tapered recess in the inner wall of the cavity.

[0014] According to an embodiment of the present application, the pressurized gas is nitrogen.

[0015] Compared with the prior art, the present application can achieve the following technical effects:

[0016] By continuously filling the foaming molten resin and the non-foaming molten resin on the surface of the injection-molded ABS material, a three-layer sandwich-like structure is formed, the deformation resistance is improved, the shock absorption and buffering are reduced, the adhesion of the later glue is enhanced, and the stability is strengthened.

[0017] Of course, any product implementing the present application does not necessarily need to achieve all the technical effects described above. DETAILED DESCRIPTION

[0018] The embodiments of the present application will be described in detail below with reference to the embodiments, so that the implementation process of how the present application applies technical means to solve technical problems and achieve technical effects can be fully understood and implemented.

[0019] The present application discloses an anti-deformation automobile interior part injection molding process, which comprises:

[0020] Step a. providing an upper mold and a lower mold for injection molding, the upper mold and the lower mold are closed to form a cavity for forming an automobile interior part, and the cavity has an injection channel, a first injection channel and a second injection channel;

[0021] Step b. injecting ABS material in a molten state into the cavity through the injection channel, and then cooling to a semi-molten state;

[0022] Step c. introducing a pressurized gas, then injecting a foaming molten resin into the cavity through the first injection channel, the pressurizing pressure is greater than the foaming expansion pressure of the foaming molten resin, the pressurized gas is released after 2 min of pressure maintaining;

[0023] Step d. After the pressurized gas is introduced, the non-foaming molten resin is injected into the cavity through the second injection channel, and the pressurized pressure is greater than the foaming expansion pressure of the non-foaming molten resin, so that the non-foaming molten resin fills the entire cavity, and the pressurized gas is released after 2 min of pressure maintaining;

[0024] Step e. Ensure that the ABS material, the foaming molten resin, and the non-foaming molten resin are colloidically bonded, and the automobile interior part product is formed.

[0025] In an embodiment of the present application, the upper mold and the lower mold form a cavity for molding the automobile interior part by clamping, and the cavity has a material injection channel, a first injection channel, and a second injection channel connected by pipelines, for filling the corresponding ABS material, the foaming molten resin, and the non-foaming molten resin, respectively.

[0026] Specifically, the ABS material is injection molded to form the basic framework of the automobile interior part. The foaming molten resin is injected onto the surface layer of the ABS material, and solidification and shrinkage form a protective inner layer with a larger density and a foamed outer layer with a smaller density, providing the automobile interior part with shock absorption and shock resistance. Then the foamed outer layer is combined with the foaming molten resin continuously injected to form a cured interlayer, greatly improving the strength and anti-deformation ability of the internal ABS material, and the resin has good adhesion, which is beneficial to the later gluing of the skin to form the external decoration.

[0027] When injecting the foaming molten resin and the non-foaming molten resin, pressurized gas needs to be introduced to remove possible bubbles and ensure product quality, and the pressurized gas may be discharged after injection is completed. Preferably, the pressurized gas is nitrogen, which is an inert gas and is convenient to use.

[0028] The first injection channel and the second injection channel of the present application are arranged in a V shape or an L shape, forming a broken line arrangement, which can avoid backflow of injection material and increase the stroke, thereby improving cooling efficiency and molding performance during the specific injection and solidification process.

[0029] The first injection channel and the second injection channel are provided with gate valves at one end close to the cavity, which can be closed in time to avoid mutual interference of injection material.

[0030] The injection pressure in steps c and d is 30-50 MPa, which has good injection filling effect and meets the pressure required for resin solidification and molding.

[0031] In addition, the first injection channel and the second injection channel are arranged in a tapered recess on the inner wall of the cavity, which increases the outlet area, facilitates flow guidance, and improves efficiency.

[0032] In summary, the application improves the anti-deformation ability, shock absorption, enhances the later glue adhesion and strengthens the stability by forming a three-layer sandwich structure similar to the three-layer sandwich structure by continuously filling the foaming molten resin and non-foaming molten resin on the surface of the injection molded ABS material.

[0033] The foregoing description shows and describes several preferred embodiments of the application, but it is understood that the application is not limited to the forms described, but is capable of modifications and adaptations in various other combinations, modifications and environments, and capable of being practiced or being carried out in various other combinations, modifications and environments without departing from the spirit and scope of the application as described in the specification and as claimed. Any changes and modifications that come within the meaning and range of equivalents of the claims are to be embraced within the scope of the application.

Claims

1. A process for injection molding a deformation-resistant automotive interior part, characterized in that, The method comprises the following steps: Step a. providing an upper mold and a lower mold for injection molding, the upper mold and the lower mold are closed to form a cavity for molding an automotive interior part, and the cavity has a material injection channel, a first injection channel and a second injection channel; Step b. injecting ABS material in a molten state into the cavity through the material injection channel, and then cooling to a semi-molten state; Step c. injecting a foaming molten resin into the cavity through the first injection channel after introducing a pressurized gas, the pressurized pressure is greater than the foaming expansion pressure of the foaming molten resin, the pressurized gas is released after 2 minutes of pressure maintaining; Step d. injecting a non-foaming molten resin into the cavity through the second injection channel after introducing a pressurized gas, the pressurized pressure is greater than the foaming expansion pressure of the non-foaming molten resin, so that the non-foaming molten resin fills the entire cavity, and the pressurized gas is released after 2 minutes of pressure maintaining; Step e. ensuring that the ABS material, the foaming molten resin, and the non-foaming molten resin are colloidically bonded to form an automotive interior part product, and the product is taken out after cooling; wherein the first injection channel and the second injection channel are arranged in a V shape or an L shape; and wherein the first injection channel and the second injection channel are provided with a gate valve at one end close to the cavity.

2. The anti-deformation automotive interior part injection molding process according to claim 1, wherein, The injection pressure in steps c and d is 30-50 MPa.

3. The anti-deformation automotive interior part injection molding process according to claim 1, wherein, The first injection channel and the second injection channel are located in a tapered recess on the inner wall of the cavity.

4. The anti-deformation automotive interior part injection molding process according to claim 1, wherein, The pressurized gas is nitrogen.