JPH0117847B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin molding method for a resin molded body used, for example, as an interior panel of an automobile.

FIG. 1 shows a type of automobile interior parts. This interior part 21 consists of a core material 2 such as a resin molded product.
A foam layer 23 is integrally formed on the surface of 2.

In manufacturing this interior component 21, first, a core material 22 is preformed by injection molding, press molding, etc., and then this core material 22 is molded into a core mold 25 and a cavity mold as shown in FIG. 26 is loaded into the core mold 25 of the foam molding mold 24, and then urethane resin is foamed and introduced into the cavity 28 of the cavity mold 26 from the mixing head 27, and before the foamed urethane resin solidifies, both of the above-mentioned Type 2
5 and 26 were closed and molded.

However, in such a resin molding method, the core material 2 is molded in a mold separate from the foam molding mold 24.
2 must be molded, which increases the product cost, and furthermore, the core material 22 must be molded from the mold for molding the core material.
When the core material 22 is removed, the core material 22 shrinks and deforms, creating a gap between the core material 22 and the core mold 25 when loaded into the core mold 25. There were disadvantages such as the urethane resin flowing in, resulting in defective products, and the need to remove the foamed urethane resin that had flowed in.

The present invention was made in order to eliminate the above-mentioned conventional drawbacks, and an object of the present invention is to provide a resin molding method in which a core material and a foam material can be molded in the same mold.

The present invention will be explained in detail below based on the embodiments shown in FIGS. 3 to 7.

1 is a polyol tank for the foam layer, 2 is a polyol tank for the core material, 3 is an isocyanate tank, 4 is a mixing head for the core material, and 5 is a mixing head for the foam layer. The polyol liquid in the core polyol tank 2 and the isocyanate liquid in the isocyanate tank 3 are circulated and supplied to the core mixing head 4 by a pump 6. Further, the polyol liquid in the foam layer polyol tank 1 and the isocyanate liquid in the isocyanate tank 3 are circulated and supplied to the foam layer mixing head 5 by a pump 6. Reference numeral 7 designates a switching valve for selectively allowing the isocyanate liquid to flow into either the core mixing head 4 or the foam layer mixing head 5. Reference numeral 8 denotes a molding die, and the molding die 8 is composed of a core mold 9 and a cavity mold 10, and the core mold 9 is equipped with a protruding plate 11 and a protruding rod 12 for releasing the mold. A cooling water passage 13 and a liquid injection port 14 are formed in the mold 10 .

Next, we will discuss resin molding using the mold 8. First, a pad 16 made of silicone rubber, which has been molded in advance, is loaded into the first cavity 15 of the cavity mold 10, and then the cavity is closed. The mold 10 and the core mold 9 are combined to form a second cavity 17 between the cavity mold 10 and the core mold 9, or more precisely between the upper surface of the part 16 and the core mold 9. Next, a mixture of the core material polyol tank and isocyanate is injected into the second cavity 17 from the liquid inlet 14 by the mixing head 4 (see FIG. 4). When the mixed liquid injected into the second cavity 17 reacts and the core material 18 is molded, the mold 8 is opened and the pad 16 is inserted into the first cavity 15.
(See Figure 5). Thus Patsto 1
After releasing the foam layer 6 from the mold, the foam layer is mixed by the mixing head 5 into the first cavity 15 formed by closing the mold 8 again, that is, into the space where the part 16 was located. By injecting a mixed solution of polyol and isocyanate through the injection port 14, the mixed solution reacts, and a foamed material 19 integral with the core material 18 is molded. After a certain molding time has elapsed, the mold 8 is opened and the molded product is released, whereby an interior panel 20 as shown in FIG. 7 is obtained. Therefore, according to this embodiment, the core material 18 and the foamed material 1 are formed using the same mold without releasing the core material 18 formed in the mold.
There is an effect that it is possible to obtain a molded product in which 9 and 9 are integrated. Note that a hard resin liquid may be injection molded instead of the foam material 19 in the above embodiment, and the order of molding the core material 18 and the foam material 19 in the above embodiment may be reversed.

As described above, in the present invention, the pad 16 is loaded into a part of the cavity 15 of the molding die 8, the mold is closed, and after the mold is closed, the first resin material 18 is injected into the other part of the cavity 15, thereby forming the mold. Then, the molding die 8 is opened, the pad 16 is removed from the inside of the cavity 15, the mold is closed, and after the mold is closed, a second resin material 19 is injected into the cavity where the pad 16 is located. Since this is a resin molding method characterized by molding the two resin materials 18 and 19 together, the present invention eliminates the need to release the primary molded core material. Because the core material and the mold surface are in close contact with each other without shrinkage deformation due to the material being released from the mold, when the foam layer forming liquid to be bonded to the core material is injected, there is a gap between the core material and the interface. There is no leakage of liquid, which eliminates defective products. In addition, when the core material is made in a separate mold and then this core material is set in another mold, there is a problem in that the temporary adhesion between the core material and the mold is difficult to be achieved due to the action of the mold release agent. However, according to the present invention, since it is not necessary to use a mold release agent, it is possible to improve the adhesion between the core material and the foam material. In addition, since the conventional core material is made using an injection mold, the mold has high rigidity, and is made of good material and has a good finish, making it an expensive mold, but it can be used in the molding method of the present invention. The practical benefits are great, such as the fact that low-pressure molding can be used for the molding, so an inexpensive molding can be used.

[Brief explanation of drawings]

Figure 1 is a cross-sectional view of a conventional automobile interior panel.
Fig. 2 is an explanatory diagram showing a conventional molding method for the interior panel, Fig. 3 is an explanatory diagram showing an example of an apparatus used in the molding method according to the present invention, and Fig. 4 is an explanatory diagram showing the core material molding according to this embodiment. Figure 5 is a cross-sectional diagram showing the part material being released from the mold, Figure 6 is a cross-sectional diagram showing the core material and foam material being integrally molded, and Figure 7 is the molding process. FIG. DESCRIPTION OF SYMBOLS 1...Polyol tank for foam layer, 2...Polyol tank for core material, 3...Isocyanate tank, 4...Mixing head for core material, 5...Mixing head for foam layer, 6...Pump, 7... Switching valve, 8... Molding mold, 9... Core mold, 10...
...Cavity type, 11...Protruding plate, 12...Protruding rod, 13...Cooling water passage, 14...Liquid inlet, 1
5...First cavity, 16...Pad, 17
...Second cavity, 18...Core material, 19...
Foam material, 20...interior board.

Claims (1)

[Claims] 1 Pad 16 in cavity 15 of molding die 8
After closing the mold, the first resin material 18 is injected into the cavity 15 and molded, and then the molding die 8 is opened and the pad 16
is removed from the cavity 15 and the mold is closed,
A resin molding method characterized in that after the mold is closed, a second resin material 19 is injected and molded, and both the resin materials 18 and 19 are joined together.