JPS58171921A - Manufacture of foam resin molded object shaped surface skin - Google Patents

Abstract

PURPOSE:To roll the end part of a surface skin to the back side of a base material, fusion-bond it and omit the treatment of the end part, by placing the surface skin of which the end is bent inside on the cavity face of a mold, then filling the space surrounded by the surface skin with foamable resin beads and foaming them. CONSTITUTION:At first, the surface skin 8 of which the end part 8a is bent inside is shaped by covering a sheet 6 on a mold 1, then reducing a pressure by a vacuum pump 3 and also heating it. The surface skin 8 is set on the cavity face 10 of a bottom force 9, then a top force 13 is clamped and the foamable resin beads 21 are filled in the space S surrounded by the surface skin 8 from a pouring pipe 20 and heat foamed, and the molded object 23 in which the surface skin 8 is fusion-bonded without a clearance to the surface of the base material 24 composed of foamed resin beads 21a...is obtained. EFFECT:A manufacturing process is simple and a manufacturing cost is low.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a molded article in which a skin is formed on the surface of a base material made of foamed resin beads, and particularly relates to a method in which the welding of the end portions of the skin is characterized.

Foamed resin molded products, which are made by heating and expanding resin beads containing a foaming agent in a mold cavity and molding them into a certain shape, are lightweight and have excellent heat insulation, impact resistance, sound absorption, etc. It is used in various parts such as packaging cushioning materials, insulation materials, and interior materials. Particularly when used as an interior material, it is necessary to attach a skin to the surface of the base material made of foamed resin beads in order to improve the feel and marketability.

By the way, in the past, when attaching a skin such as PVC or cloth to the surface of a plastic molded object, if the adhesive boundary of the skin exposed to the surface of the base material, it would not only be unsightly, but would also peel off from that area. Because it is easy, the end of the skin is rolled up to the back side of the base material and pasted. Therefore, there are disadvantages in that the number of steps increases and the work is troublesome. The same thing can be said in the case where the base material is formed by heating and foaming foamable resin beads.

The inventors of the present invention have developed the present invention to effectively solve the above-mentioned technical problems, and the purpose of the present invention is to solve the above-mentioned technical problems without involving the end portion of the epidermis into the back side of the base material.
To provide a foamed resin molded article in which the end part of a skin is wound to the right size and welded to the back side of a base material.

In order to achieve this object, the present invention sets a skin whose end portions are bent inward in advance on the cavity surface, and then inserts resin beads such as foamable polypropylene into the space surrounded by this skin. The gist is that the resin beads are filled, foamed by feeding steam, and the outer skin including the terminal portion is welded to a base material made of foamed resin beads.

An example of the implementation of the present invention will be explained in detail below based on the accompanying drawings.

Figure 1 shows a mold for producing a skin made of vinyl chloride or urethane, etc. The mold 1 has a seven-lunge shaped molding part 2 at the top, and has a space 4 connected to a vacuum pump 3 inside. In addition, there are many vacuum holes 5...
is bored so that one end faces the surface of the molded part 2 and the other end faces the space part 4.

This mold 1 is then covered with a sheet 6 that will serve as a skin, and while being evacuated, it is heated to about 150C to 170C and molded. Then, it is separated at the lower end 7 of the molded part 2,
As shown in FIG. 2, the end portion 8a forms a skin 8 that is bent inward.

Next, as shown in FIG. 3, it is set on the cavity surface 10 of the lower mold 9. This cavity surface 10 follows the shape of the skin 8. A space 11 connected to the vacuum pump is formed inside the lower mold 9, and this space 11
and the cavity surface 10 with a large number of vacuum holes 12...
・Communicate with

After the skin 8 is set in the lower mold 9 in this way, the upper mold 16 is molded as shown in FIG. This upper mold 16 has a hollow shape like the lower mold 9, and this hollow part 14 is divided into the left and right chambers 14a and 14b by a partition plate 15, and steam is sent to the left chamber 14H through a pipe 16. , right chamber 14
A pipe 17 for discharging this steam is attached to b. Each of the chambers 14a, 14b communicates with a cavity 19 formed during molding through communication holes 18. In addition, a resin bead injection pipe 20 is attached to the upper mold 16, and its tip is inserted into the cavity 1.
I'm making it to 9th.

) After molding the upper mold 16 and lower mold 9 as described above, the skin 8
Fill the space S formed by the foaming polypropylene beads 21 through the injection pipe 20, and
The state is as shown in the figure. Next, 120 tons was passed through the entire pipe 16 to the left chamber 14H. Fully introduce superheated steam at a degree,
Steam is sent into the space S through the communication hole 18, and further discharged to the outside through the right chamber 14b'r.

In this process, the foaming agent in the expandable polypropylene beads 21 is decomposed by the heat of the steam, generating organic gas, N2 gas, etc., and the beads 21 expand.

After that, the cooling water is poured into the cooling pipe 22... and the mold 9゜1
6 is separated and the molded body 26 is taken out. Molded body 2 taken out
In No. 3, the skin 8 is integrally welded to the surface of the end portion 1f of the base material 24 consisting of foamed polypropylene beads 21a... without any gaps.

FIG. 7 shows another embodiment, and when this mold is used, a series of steps can be performed with one mold.

That is, the mold 25 includes, in addition to the upper mold 13 and lower mold 9 similar to those described above, a slide mold 26 that can be inserted into and removed from the end portion of the molded body 23.

In the manufacturing process, first, the sheet 6 that will become the skin 8 is set on the cavity surface 10 of the lower mold 9, and the sheet 6
Slide mold 2 was inserted so that the terminal end of the
Then, the upper mold 13 and the lower mold 9 are molded, and the resin beads 21 are completely filled in the same manner as described above and heated and foamed. After the molding is completed, the upper mold 13 and the slide mold 26 are removed, and the sheet 6 is placed at an appropriate location 27.
A desired molded body can be obtained by separating the molded body.

In the above embodiments, polypropylene was used as the foamable resin beads, but the present invention is not limited to this, and polystyrene, polyethylene, or the like may also be used. However, when polypropylene is used, it has superior oil resistance, chemical resistance, impact resistance, etc. compared to other resins, so polypropylene is recommended when using molded products for automobile instrument panels or side panels. is preferable, and the material of the outer skin is not limited, but for example, when using foamable polypropylene beads, it is possible to use an olefin resin as the material, or to use an adhesive by laminating an olefin resin on the back surface. Can be welded without any damage.

As is clear from the above description, according to the present invention, a skin whose end portions are bent inward in advance is set on the cavity surface, and the space formed by this skin is filled with foamed resin beads. Then, I heated and foamed it, so
It is possible to obtain a molded article in which the end portions are wrapped and welded on the back side 1 of the base material without performing any end treatment on the skin.

Further, since the manufacturing process is extremely simple, it has many advantages such as being able to be manufactured at low cost.

[Brief explanation of the drawing]

The drawings show an example of the implementation of the present invention, and FIG. 1 is a cross-sectional view of a mold for molding the skin, FIG. 2 is a side view of the skin, and FIGS. 3 to 5 are molded articles according to the present invention. FIG. 6 is a cross-sectional view of the same molded product, and FIG. 7 is a cross-sectional view showing another embodiment. In the drawings, 8 is the skin, 8a is the end portion, and 9.13° 26Fi type, 10 is a cavity surface, 21 is a foamed resin bead, 21a is a foamed resin bead, 23
is a molded body, and 24 is a base material. Patent applicant Honda Motor Co., Ltd. Tokyo Seat Co., Ltd. Agent Patent attorney Yoichi Shimoda Patent attorney Kunihiko Ohashi Figure 1 Figure 2 θ Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] After setting the skin with the terminal part bent inward on the capy surface of the mold, the space surrounded by the skin was filled with foamable resin beads, and then the foamable resin beads were heated and foamed to foam the skin. A method for producing a foamed resin molded article having a skin formed thereon, characterized in that the foamed resin molded article is welded to a base material made of resin beads without any gaps.