JPH04107109A - Manufacture of product foamed integrally with skin - Google Patents

Abstract

PURPOSE:To get rid of positional displacement and wrinkles of a skin by a method wherein a plastic skin is placed on the face of a mold in such a way that a seal part of the skin is fitted to a seal part of the face of a mold and a liq. foaming material is injected and foamed while vacuum suction is performed. CONSTITUTION:At first, a slide mold 14b of a bottom force 14 and a bottom force main body 14a are combined and a skin 24 are fitted on the mold face 15 of the bottom force. In this case, the skin 24 is accurately fitted on the mold face 15 as a seal part 26 on the edge part of the skin is fitted to a seal part 22 of the mold face and is held on the mold face 15 of the bottom face by means of vacuum suction. In addition, as a gap between the skin 14 and the mold face 15 of the bottom force is surely sealed and air is not introduced from outside, the sealing is very tight. Therefore, there is no possibility that the skin 24 partly rises to the surface and the position thereof is displaced and the skin 24 is accurately brought into tight contact with the mold face 15 and is correctly held. Then, a liq. foaming raw material 28 such as a polyurethane foam raw material is poured on the inner face of the skin 24 held by suction on the mold face 15 of the bottom force and is integrally foamed with the skin 24 to mold an integrally foamed product with the skin.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for manufacturing a skin-integrated foamed product, in which skin-integrated foam molding is performed using a plastic skin formed by powder slush molding.

(Prior art) As a simple method for manufacturing foam products in which the surface of the foam is covered with a skin, a thin plastic skin that has been previously formed into a predetermined shape by vacuum forming is placed on the mold surface of a foam mold. There is a manufacturing method in which a liquid foaming material is injected into the inner surface of the skin and the foam is molded integrally with the skin, and products manufactured in this way are usually referred to as skin-integrated foam products.

In addition, in order to prevent the plastic skin from shifting or wrinkles during injection of the liquid foaming raw material and foaming, a vacuum suction hole is provided on the mold surface of the foam mold to vacuum the plastic skin against the mold surface. Injecting a liquid foaming raw material and foaming started to be carried out at the same time.

Furthermore, recently, there has been a demand for products with complex surface shapes or large skin-integrated foam products, and plastic skins formed by powder slush molding have come to be used for these products.

Powder slush molding involves putting thermoplastic plastic powder into a heated slush mold, melting and adhering it to the surface of the heated mold to a predetermined thickness to form a molten film, and then peeling off the cured film from the mold surface after curing. This is a method of obtaining a plastic film consisting of a mold surface shape (Japanese Unexamined Patent Application Publication No. 1983-1999).
-144913).

By the way, powder slush molding originally has the advantage of producing a thin plastic film, but
In areas where the mold surface changes in a complex manner, that is, in areas where the mold surface has a locally deep uneven shape, the plastic powder tends to adhere thickly, resulting in an increase in the thickness of the film. Furthermore, for large plastic films, it is necessary to make the entire film thick in order to prevent the film from tearing when it is peeled off from the mold surface of the slush mold. This is very different from the plastic skin formed by vacuum forming, which is stretched during vacuum forming and becomes thinner.

Therefore, when the skin formed by powder slush molding is integrally foam-molded, the complex shape and large thickness of the skin creates a gap between the end of the skin and the mold surface of the foam mold, and from that gap, external There is a problem in that air enters between the skin and the mold surface, impairing the vacuum state between the skin and the mold surface, making it difficult for the skin to adhere to the mold surface, and making the skin prone to wrinkles.

Furthermore, in the case of a large-sized skin, it is difficult to properly install it in a foaming mold, and there is also the problem of misalignment, poor suction to the mold surface due to the misalignment, and even wrinkles in the skin.

(Problems to be Solved by the Invention) Therefore, the present invention provides a skin-integrated foaming method that enables foam molding while holding the skin in the correct position on the mold surface in skin-body foam molding using a plastic skin formed by powder slush molding. It provides a method for manufacturing products.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides vacuum suction of a plastic skin of a predetermined shape formed by powder slush molding onto the mold surface of a foam molding die, while applying vacuum suction to the inner surface of the skin. In a method of manufacturing a skin-integrated foam product in which a liquid foaming raw material is injected and foam-molded integrally with the skin, a mold surface sealing portion consisting of bank-like protrusions or grooves surrounding the outer periphery of the product molding part on the mold surface of the foam mold. At the same time, a vacuum suction hole is also provided in the mold face sealing part, and a skin sealing part consisting of a groove is provided around the entire edge of the plastic skin, so that the plastic skin is connected to the mold face sealing part. We decided to place them on the mold surface so that they fit together, and to inject the liquid foaming raw material and foam while applying vacuum suction.

(Function) The plastic skin placed on the mold surface of the foaming mold is vacuum-suctioned by the mold surface, so that it adheres closely to the mold surface. At this time, the plastic skin is properly attached to the mold surface by fitting the skin sealing part consisting of a groove on the edge with the mold face sealing part consisting of a protrusion or groove on the mold surface, and the vacuum suction of the mold surface sealing part. The sealing part of the replastic skin is attracted to the mold surface sealing part through the hole and tightly adheres to the mold surface, thereby preventing air from entering between the plastic skin and the mold surface from the outside. This ensures a reduced pressure between the skin and the mold surface, and prevents the skin from becoming misaligned or wrinkled.

(Example) Examples of the present invention will be described below.

Fig. 1 is a cross-sectional view of a plastic skin placed on a foaming mold in an embodiment of the present invention, Fig. 2 is an enlarged view of part A, Fig. 3 is an enlarged view of part B, and Fig. 4. is a cross-sectional view when foaming the liquid foaming raw material on the inner surface of the skin.

The foaming mold 10 consists of an upper mold 12 and a lower mold 14, and has a product-shaped cavity 16 between the upper mold 12 and the lower mold 14. The lower mold 14 is composed of a lower mold main body 1.4a and a slide mold 14b''c'n4 on the upper part of the lower mold main body 1.4a, and a product forming part 15a is formed on the edge of the mold surface 15 composed of the lower mold main body 14a and the slide mold 14b. A mold surface sealing portion 22 surrounding the outer periphery is formed as a clear seal.The slide mold 1.4b slides on the lower mold main body 14a during demolding of a skin-integrated foam product, and seals the mold surface 15. This is to release the undercut portion 17. The lower mold body 14a and the slide mold 1.4b are both hollow inside, and the suction vibrator 20 on the side of the lower mold 14 is connected to the lower mold body 14 through the hollow portion. Vacuum suction holes 18 on the mold surface 15 communicate with each other.The vacuum suction holes 18 on the mold surface are arranged at optimal intervals depending on the size, shape, etc. of the mold surface. , is also provided in the mold surface seal portion 22. The vacuum suction vibrator 20 is connected to a vacuum pump (not shown).

On the other hand, the plastic skin 24 placed on the mold surface of the lower mold 14 is molded into a predetermined product shape by powder slush molding, and the edge of the skin 24 corresponding to the mold surface seal portion 22 of the lower mold Skin seal part 2 consisting of grooves around the entire circumference
6 is formed. The material constituting the skin seal portion 26 is formed at the same time as the skin 24 is molded by forming protrusions on the mold surface (not shown) of a powder slush mold. Further, the shape of the outer layer constituting the skin seal portion 26 is such that it fits into the groove of the mold face seal portion 22.
The groove is formed into a substantially V-shaped groove that protrudes toward the lower die 14 side. Note that the width a of the skin seal portion 26 and the mold surface seal portion 22 is
is 1.0-3. OI, angle S is 90°, angle C is 45°
degree is suitable.

Using the foaming mold 10 and skin 24 thus formed, a skin-integrated foam product is molded in the following manner.

First, the slide mold 14b of the lower mold 14 and the lower mold main body 14
In combination with a, a skin 24 is placed on the lower mold surface 15. The device for the skin 24 is operated by aligning the skin seal portion 26 at the edge of the skin 24 with the mold surface seal portion 22 of the lower mold 14 and applying vacuum suction to the lower mold surface 15 by operating a vacuum pump. 24 on the lower mold surface 15. At this time, the skin 24 is accurately attached to the mold surface 15 by the skin sealing part 26 at the skin edge fitting into the mold surface sealing part 22, and the lower mold surface 1 is attached by the vacuum suction.
5 and held on the mold surface 15. In addition, the epidermis 24
The vacuum suction force that sucks the material to the lower mold surface 15 is generated by the fitting of the skin seal portion 26 at the skin edge with the mold surface seal portion 22 and the vacuum suction of the seal portion. This is a very large problem because the mold surface 27 is reliably closed and air does not flow in between the skin 24 and the lower mold surface 15 from the outside. As a result, the skin 24 can be accurately positioned on the mold surface 15 without being partially lifted or displaced from the mold surface 15.
It sticks to the surface and is held correctly.

Then, a liquid foaming raw material such as a polyurethane foam raw material is injected into the inner surface of the skin 24 suctioned and held by the lower mold surface 15, and is foamed together with the skin 24 to form a skin-integrated foam product.

Thereafter, the skin-integrated foam product in the foam mold 10 is taken out from the foam mold 10, and the skin outside the product molding portion 15a is cut off to obtain a final product.

FIG. 5 is a sectional view of a foam mold and a skin material in another embodiment of the invention.

The foaming mold 30 consists of an upper mold 32 and a lower mold 34. The lower mold 34 is hollow inside, and the vacuum suction hole 38 of the mold surface 35 communicates with the vacuum suction vibrator 40 on the side, and the mold surface 35 surrounds the outer periphery of the product molding part 35a. A mold face seal portion 42 consisting of a bank-like protrusion is formed. Vacuum suction holes 38 in the lower mold surface 35 are not only formed at predetermined intervals in the product forming part 35a, but also in the mold surface sealing part 4.
2 are also formed at predetermined intervals. Further, a groove 43 is formed on the mold surface of the upper mold 32 corresponding to the mold surface seal portion 42 on the lower surface, and when the mold is closed, the mold surface seal portion 42 of the lower mold is connected to the groove 4 of the upper mold.
It is designed to be accommodated in 3.

On the other hand, the skin 44 is formed by powder slush molding, and a skin seal portion 46 is formed around the entire edge thereof. The skin seal portion 46 is formed of a groove having a protruding shape on the top so as to fit into the mold surface seal portion 42 of the lower mold.

Using the foaming mold 30 and skin 44 thus formed, a skin-integrated foam product is molded in the same manner as described above. At that time, the skin seal part 44 is fitted into the mold surface seal part 42 of the lower mold 34, and the skin 44 is attached to the lower mold surface 35 by vacuum suction.
The method of suctioning and holding is as described above.

In the above explanation, only an example was shown in which the mold face seal part provided on the foam mold was provided at the edge of the lower mold face, which is the mold mating surface with the upper mold. The position is not limited thereto, and may be inside the mold mating surface as long as it is on the outer periphery of the product molding part on the mold surface, and these positions are determined as appropriate depending on the shape of the skin-integrated foam product, the mold structure, etc.

(Effects) Since this invention consists of the above-mentioned refinement, the plastic skin formed by powder slush molding is vacuum-suctioned to a predetermined position on the mold surface of the foaming mold when the skin is integrally foam-molded. It can be placed in the correct position on the mold surface, prevents defects such as the skin lifting from the mold surface or wrinkles on the skin, and provides a good product appearance even with powder slush molded skins that are large in thickness or shape. This has the effect of making it possible to obtain a skin-integrated foamed product.

[Brief explanation of drawings]

Figures 1 to 4 relate to one embodiment of the present invention, in which Figure 1 is a cross-sectional view showing the case where the skin is installed on the mold surface of a foam mold, and Figures 2 and 3 are section A. , an enlarged view of part B, FIG. 4 is a sectional view showing the liquid foaming raw material during foaming, and FIG. 5 is a sectional view showing another embodiment of the present invention. 10.30: Foaming mold, 12.32 Upper mold, 14.3
4: Lower mold, 15.35: Mold surface, 15a, 35a: Product molding section, 16: Cavity, 18.38: Vacuum suction hole, 2
0.40: Vacuum suction vibrator, 22.42: Mold face seal part, 24.44 Niblastic skin, 26.46: Skin seal part

Claims (1)

[Claims] A plastic skin with a predetermined shape formed by powder slush molding is vacuum-suctioned onto the mold surface of a foaming mold, while liquid foaming raw material is injected into the inside of the skin, and foam molded integrally with the skin to produce a skin-integrated foam product. In this method, a mold face seal part consisting of bank-like protrusions or grooves surrounding the outer periphery of the product molding part is provided on the mold surface of the foam mold, and a vacuum suction hole is also provided in the mold face seal part, and a vacuum suction hole is provided in the mold face seal part. A skin seal made of grooves is provided around the entire edge,
The production of a skin-integrated foam product characterized by placing the plastic skin on a mold surface so that the skin seal part fits into the mold surface seal part, and injecting a liquid foaming raw material and foaming while vacuum suction is performed. Method.