JPS58171923A - Manufacture of foamed olefine resin molded object - Google Patents

Abstract

PURPOSE:To obtain the titled molded object to which a resin film is strongly fusion-bonded without an adhesive, by sticking a negatively charged olefine resin to a positively charged cavity face, then shaping a film by heat fusing and filling it with foamable beads and foam molding. CONSTITUTION:A negatively charged olefine resin powder 4 is blasted to the positively charged cavity face 2 of a mold 1, then the powder 4 is heat fused by using the heater 3 arranged in the mold 1 and a resin film 5 is shaped on the cavity face 2 on cooling. The foamable resin beads 13 of an olefine are filled in the cavity 9 in which the film 5 is shaped and the resin beads 13 are foamed, thereby obtaining the molded object 15 in which the resin film 5 is directly fusion-bonded to the surface of the base material 14 composed of foamed resin beads 13a.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a molded article in which a resin coating is attached as a skin to the surface of foamed polypropylene beads or the like.

Traditionally, resin sheets have been pasted on the surface of automobile instrument panels or inner panels to hide the plastic molded product that is the base material, improve the feel, enhance marketability, and even provide a cushioning function. ing.

Conventionally, in order to attach such a resin sheet, one sheet is cut to match the shape of the instrument panel, and an adhesive is applied to the back surface of the sheet before the resin sheet is attached. According to such a method, it is time-consuming to manufacture the paper due to the large number of steps, and separate equipment such as a cutting device is also required.
There are various disadvantages such as poor yield. This disadvantage also applies when using foamed resin to manufacture a member that requires a skin to be attached to the instrument panel or the like.

The present inventors have developed the present invention in order to effectively solve the above-mentioned problems when producing a molded article using foamable resin beads as a raw material and to which a skin must be attached. 4. Using an adhesive on the surface of the foamed olefin resin beads 9 by continuous processing using one mold 4. The resin film is firmly dissolved! The present invention provides a method for producing a molded article.

In order to achieve such an object, the present invention comprises a step of spraying negatively charged olefin resin powder onto a positively charged cavity surface of a mold, and a step of heating and melting the powder and then cooling it to form a resin coating. The gist of the process is to fill the cavity in which the resin coating has been formed with olefin-based foamable resin beads and heat and foam them.

An example of the implementation of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows the first step of the present invention, and 1 is the lower mold of the mold, and the upper surface of this lower mold 1 has a cavity surface that forms a cavity when the molds are mated with the upper mold. 2 is formed. Heaters 3 are disposed inside the lower mold 1 along the cavity surface 2. In the first step, the cavity surface 2 is positively charged, and the negatively charged polypropylene powder 4 is applied to the charged cavity surface 2.
・・Polypropylene powder 4 by full spraying, static electricity
... to be uniformly attached.

Next, the cavity surface 2t- is heated by the heater 6...
200tl? Heat the polypropylene powder to 4...
After about 5 minutes of complete melting, the molten polypropylene is cooled by spraying cold air or water to form a coating 5 as shown in FIG.

Then, as shown in FIG. 3, an upper mold 6 is placed on the lower mold 1 with the coating 5 formed on the cavity surface 2, and the mold is tightened. This upper mold 6 has a hollow shape, and the inside is divided by a partition plate 7, with a steam inlet pipe 8a on one side and a steam outlet pipe 8b on the other side.
- At the same time, the cavity 9 formed by the upper mold 6 and the lower mold 1 is communicated with the hollow part 10 of the upper mold 6 through the holes 11 . A resin bead injection pipe 12, 12 is attached to the upper mold 6 so that its tip faces into the cavity 9.

After the mold is set, as shown in FIG.
. Then, the steam enters the cavity 9 through the hole 11 on the right side, exits into the hollow portion 10 on the left side through the hole 11 on the left side, and is discharged to the outside through the outlet pipe 8t1. and Capitei 9
When steam is introduced into the foam, the foaming agent contained in the foamable polypropylene beads 13 decomposes and generates N2 gas, etc.
Beads 13 expand.

As a result, as shown in FIG. 5, a molded body 15 is obtained in which a polypropylene coating 5 is integrally welded to the surface of a base material 14 formed of foamed polypropylene beads 13a.

In addition, although the example using polypropylene as an olefin resin was demonstrated above, it is not limited to this and polyethylene etc. may be used. In short, it is sufficient that the coating formed by melting the resin powder and the foamed resin beads can be welded together without using an adhesive.

As is clear from the above description, according to the present invention, negatively charged olefin resin powder is sprayed onto the positively charged cavity surface, heated and melted, and then cooled to form a resin coating. The cavity where the coating was formed was completely filled with foamable olefin resin beads and heated and foamed, allowing the foamed resin to be molded into the base material through a continuous process using one mold without the use of adhesives. It is possible to obtain a molded product with a resin coating integrally formed on the surface of the persimmon, and has the advantages of reducing the number of steps and manufacturing at low cost compared to conventional methods.

[Brief explanation of the drawing]

The drawings show a preferred embodiment of the present invention, and FIG. 1 is a cross-sectional view showing the process of spraying olefin resin powder, FIG. 2 is a cross-sectional view of a state in which a film is formed, and FIG. FIG. 4 is a sectional view of the molded body filled with resin beads, and FIG. 5 is a sectional view of the molded body. In the drawings, 1 and 6 are molds, 2 is a cavity surface, 4 is olefin resin powder, 5Fi resin coating, 13 is olefin foam resin beads, and 14 is a base material. 15 is a molded body. Figure 2 5 Figure 4 Figure 5

Claims (1)

[Claims] Negatively charged olefin resin powder is sprayed onto the positively charged '-shaped cavity surface, then this powder is heated and melted and then cooled to form a resin film on the cavity surface. olefin-based foamable resin beads are filled into the expanded cavity, the resin beads are then foamed, and the resin coating is directly welded to the surface of a base material made of the foamed resin beads. A method for producing an olefin resin molded article.