JPH02175232A - Preparation of trim part for car - Google Patents

Abstract

PURPOSE:To keep the beautiful appearance of a product without generating unevenness on the surface of the product by integrating a skin material molded by slash molding and a molten resin in a press bonding mold and absorbing the thickness irregularity of the skin material by the molten resin. CONSTITUTION:The skin material 12 of a door trim for a car consists of three layers of a skin layer 13, a foam layer 14 and a fiber material layer 15 in order from the outermost layer and both of the skin layer 13 and the foam layer 14 are molded by slash molding. The fiber material layer 15 is positioned on the side of the skin material 12 in contact with a molten resin, and the skin material 12 and a resin core material 11 are strongly bonded by anchor effect wherein the fiber material of the fiber material layer 15 penetrates the interior of the resin core material 11. Since even a resin material having no polarity like a polypropylene resin and poor in adhesiveness is strongly bonded by anchor effect, a resin material can be freely selected. The gas generated at the time of the molding of a resin is vented to the outside through the gaps between the fibers of the fiber material layer 5 and the surface of the skin material becomes smooth.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to automobile interior parts such as automobile door trims, and particularly to automobile interior parts using a skin material formed by slush molding to give a soft appearance. This invention relates to a method for manufacturing interior parts.

(Prior Art) Slash molding has been widely used as a method for manufacturing interior parts that require relatively good surface appearance and surface feel, such as automotive interior parts such as door trims and instrument pads.

This slush molding is one of the methods for molding skin materials. Normally, in order to manufacture interior parts such as door trims, in addition to the molding process of the skin material formed by slush molding, there is also the molding process of the core material and the molding process of the skin material. A process of integrating the core material and the core material is required.

For example, as shown in FIG. 9, a skin material 1 is molded using a slush molding apparatus, and a core material 2 to be bonded to the skin material 1 is press-molded in a separate process.

Then, in the next step, the skin material 1 and the core material 2 are crimped to complete the production of the door trim 3.

In addition, as another conventional example, after setting the skin material 1 which has been pre-molded into the product shape by slush molding into the urethane foam mold 4, and after injecting the hard urethane resin liquid 5 which will become the core material, the material is foamed and hardened. The production is completed by integrating the slash skin material 1 and the urethane core material.

(Problem to be solved by the invention) However, the former method requires three steps: a slush molding process for the skin material 1, a press molding process for the core material 2, and a crimping process for the skin material 1 and the core material 2. However, it has been pointed out that there is a problem that the number of steps increases, resulting in a significant increase in cost, and the thickness of the skin material 1 cannot be uniformly controlled by slush molding.
When integrated with the core material 2, there is a problem that variations occur in the product thickness of the door trim 3.
There is a drawback that air is present between the core material 2 and the core material 2, causing unevenness on the product surface, making it difficult to obtain a good product appearance.

In addition, the latter hard urethane resin liquid 5 is injected into the mold.
In the so-called mold forming method, the surface appearance of the product is maintained well, but there are problems with the strength of the core material made of hard urethane, and it must be made thick to obtain the necessary mechanical strength. First, it has the disadvantage of being restricted in terms of shape and being heavy.

Furthermore, the hard urethane core material requires large-scale specialized equipment for urethane injection and foaming, which has been pointed out as a problem that increases costs.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a method for manufacturing automobile interior parts using a skin material with good surface appearance and surface feel by slush molding. To provide a method for manufacturing interior parts for automobiles that does not cause unevenness on the surface, maintains a beautiful product appearance, and shortens the process to reduce costs.

(Means for Solving the Problems) In order to achieve the above object, the method for manufacturing automotive interior parts according to the present invention includes a skin layer formed by adhering resin powder to the mold surface of a slush molding die, It consists of a foam layer formed by laminating resin powder mixed with a foaming agent on the inner surface of the skin layer, and a fiber material layer with cellulose attached to the entire inner surface of this foam layer.After the foam layer is foamed by heating, A process of cooling and molding the skin material, and setting the skin material on the mold surface of the lower mold for crimping with the skin layer facing downward, and placing a resin core material on the top side of the skin material. After charging a certain molten resin, the upper mold for crimping and the lower mold for crimping are clamped, the resin core material is molded into the desired shape, and the resin core material and the skin material are integrally pressed. It is characterized by

(Operation) As is clear from the above configuration, according to the method of the present invention,
Since the skin material formed by slush molding and the molten resin are integrated within the compression mold, variations in the thickness of the skin material can be absorbed by the molten resin.

Furthermore, a fibrous material layer is located in the innermost layer of the skin material,
The fibrous material of the fibrous material layer is effectively bonded to the molten resin as an anchor, and the gas generated during molding of the resin core material can be extracted to the outside through this fibrous material layer, resulting in strong adhesion and a smooth surface. It becomes possible to form.

(Example) Hereinafter, a method for manufacturing an automobile interior part according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows an automobile door trim manufactured by applying the method of the present invention.
0 is roughly composed of a resin core material 11 and a skin material 12 that is integrally attached to the surface side of the resin core material 11. Furthermore, the skin material 12 has a three-layer structure, and the skin material 12 is formed from the outermost layer to the skin material 12. The layer 131 consists of a foam layer 14 and a fiber material layer 15.

The skin material 12 has a skin layer 13 and a foam layer 14 formed by slush molding, and has a good surface appearance and feel.

Further, as will be described later, the fiber material layer 15 located at the innermost layer of the skin material 12 is formed during molding of the resin core material 11.
It has the function of venting gas to the outside through the resin core material 11 and the foam layer 14, and the function of strengthening the bonding strength between the resin core material 11 and the foam layer 14 by the so-called anchor effect in which the cellulose material bites into both.

Next, the manufacturing process of the above automobile door trim 10 will be explained based on FIGS. 2 to 8.

First, FIGS. 2 to 4 show the process of forming the skin material 12 by slush molding, and FIG. 5 shows the skin material 12 formed by slush molding.

In FIG. 2, after heating the slush molding die 20 to a temperature higher than the melting point of PVC resin (230°C in this example), PVC resin powder is poured onto the inner surface of the slush molding die 20. By rotating both with the filled powder supply box 21 attached,
If PvC resin powder is attached to the mold surface of this slush molding mold 20 and this PVC resin powder is gelled, the soft skin layer 13 will be formed into a shape along the mold surface of the mold 20.
is formed. Note that the excess PVC resin powder is recovered by inverting the mold 20.

Next, as shown in FIG. 3, another powder supply box 22 (inside of which is filled with PVC resin powder mixed with a blowing agent such as azodicarbonamide) is fixed to the mold 20 and processed in the same manner. By rotating, the foam layer 14 is laminated on the inner surface of the skin layer 13. Similarly,
Excess powder is recovered by inverting the mold 20.

Next, as shown in FIG. 4, the supply box 23 filled with cellulose such as polyester fiber is attached to the slush molding mold 20 in which the skin layer 131 and the foam layer 14 are laminated, respectively, and the foam layer 14 is rotated. Cellulose is attached to the inner surface of 14.

At this time as well, the mold 20 may be reversed to collect excess cellulose.

Then, the foamed layer 14 is foamed by heating with a heater (not shown), and then cooled, and the skin material 12 shown in FIG.
Take out.

This skin material 12 consists of a skin layer 131 foam layer 14 from the outermost layer.
．． It consists of a three-layer structure of a fiber material layer 15 and a fiber material layer 15,
In this state, there is some variation in the thickness of the foam layer 14.

Next, FIGS. 6 to 8 show the process of integrating the skin material 12 and the resin core material 11. First, as shown in FIG. Set on the upper surface of the mold 30. At this time, the fibrous material layer 15, which is the innermost layer of the skin material 12, is set so as to face upward.

Thereafter, as shown in FIG. 7, the upper mold 31 for crimping is lowered by a lifting device (not shown), and simultaneously with this lowering, molten resin P such as polypropylene resin is charged. In this example, a path 32 for supplying molten resin P is provided inside the upper mold 31 for crimping, and this path 32 is connected to an external resin amount measuring mechanism (not shown). It is configured to automatically supply the required amount.

Furthermore, the molten resin P does not necessarily need to be supplied from the upper crimping mold W31, and if desired, a nozzle of an extrusion molding machine or the like may be positioned between the upper and lower crimping molds 30, 31, and the molten resin P is applied to the upper surface side of the skin material 12. P may also be input.

Thereafter, as shown in FIG. 8, the upper and lower crimping molds 31 are lowered, and the upper and lower crimping molds 30 and 31 are clamped to mold the molten resin P into a desired shape and mold the resin core material 11. , the resin core material 11 and the skin material 12 are integrally fixed by pressing.

As shown in FIG. 1, the automobile door trim 10 molded in this way has slight variations in the thickness of the skin material 12 that are absorbed by the flow of the molten resin P, and the product thickness of the door trim 10 can be adjusted uniformly. Moreover, no unevenness occurs on the surface of the product.

Furthermore, the side of the skin material 12 in contact with the molten resin P is a fiber material layer 1.
5 is located, and the cellulose of the fiber material layer 15 is located in the resin core material 1.
The skin material 12 and the resin core material 11 are firmly joined by the so-called anchor effect that bites into the inside of the resin core material 11. In particular, even a resin material such as polypropylene resin, which has no polarity and has extremely poor adhesiveness, can be bonded more firmly due to the anchor effect, so the resin material can be freely selected.

In addition, gas is generated during resin molding, but the fiber material layer 15
Since gas escapes to the outside through the gaps between the fiber elements in the resin core material 11 and the skin material 12, no air pockets are generated between the resin core material 11 and the skin material 12, and the surface of the skin material 12 forms a smooth surface.

In this example, the method for manufacturing the automobile door trim 10 has been described above, but any automobile interior parts using slush-molded skin material may be applied to instrument pads, etc. in addition to the door trim 10. .

(Effects of the Invention) As described above, according to the method of the present invention, the skin material obtained by slush molding and the molten resin are integrally fixed with a press, so that the slush molded skin material and the molded core material can be bonded together. Compared to the conventional method of integrating, the process can be shortened, and variations in the wall thickness of the skin material due to slush molding can be absorbed by the flow of the molten resin, so unevenness does not appear on the product surface and products with uniform wall thickness can be provided. This has the effect of reducing costs and improving the appearance design. Furthermore, compared to the urethane resin injection method, the equipment is not large-scale, the strength of the resin core material can be guaranteed, and there are advantages in that it is inexpensive and lightweight.

Furthermore, in the present invention, after forming a skin layer and a foam layer by slush molding, a fiber layer is formed by attaching a fiber layer to the foam layer, so the skin material and the resin core material are formed within the resin. The skin material and the core material can be firmly bonded due to the so-called anchor effect in which the fibers bite into the fibers, and air can be released to the outside through the gaps between the fibers, so there is no air accumulation and the bond between the skin material and the core material is It has the effect of producing a beautiful product with excellent bonding strength, no internal air pockets, and a smooth surface.

In particular, even when a resin material such as polypropylene resin, which is advantageous in terms of cost and strength but has poor adhesion, is used as the core material, the bonding strength is strengthened by this fibrous material layer, making it practical for overlaying. In this way, the degree of freedom in selecting resin materials can be greatly expanded.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view showing an automobile door trim manufactured by the method of the present invention, FIGS. 2 to 4 are cross-sectional views showing the forming process of the skin material in the method of the present invention, and FIG. 6 to 8 are cross-sectional views showing the integral pressing process of the resin core material and the skin material in the method of the present invention, and FIGS. 9 and 10 are slush-molded skin materials. FIG. 2 is an explanatory diagram showing a simplified example of a conventional method for manufacturing interior parts for automobiles using the method. 14... Foaming layer 15... Fibrous material layer 20... Slash molding mold 21.22.23... Supply box 30... Lower mold for crimping 31... Upper mold for crimping Patent application People Kasai Kogyo Co., Ltd.

Claims (1)

[Claims] 1. A skin layer (13) formed by adhering resin powder to the mold surface of a slush molding die (20), and a resin powder containing a foaming agent on the inner surface of this skin layer (13). The foam layer (14) is formed by laminating the foam layer (14).
) forming a skin material (12) by foaming the foam layer (15) by heating and then cooling the foam layer (15); (12) on the mold surface of the lower mold for crimping (30),
After setting the skin layer (13) facing downward and pouring the molten resin, which is the material of the resin core material (11), onto the top side of the skin material (12), the upper mold for crimping (31) is crimped. The resin core material (11) is molded into the desired shape by clamping the lower mold (30), and the resin core material (11) and the skin material (1) are molded together.
2) A method for producing automotive interior parts, characterized by comprising the step of integrally pressing.