JPH02208014A - Manufacture of foam with skin - Google Patents

Abstract

PURPOSE:To manufacture a foam with a skin, in which no crease is formed, simply at low cost by previously shaping a plastic film or sheet not bonded with a polyurethane foam raw material at the time of foaming onto the inner surface of the skin mounted to a cavity side-face section, injecting the raw material into the skin and bubble-forming the raw material. CONSTITUTION:A skin 54 is fitted onto a bottom-force cavity surface 52. A polyethylene sheet 56 with which a polyurethane foam raw material 58 at the time of foaming is not bonded is laminated and formed onto the inner surfaces of the sections A, A of the skin set up to both side faces 52b, 52b of a bottom- force cavity. The raw material 58 is injected onto the inner surfaces of the skin 54, and the raw material 58 is foamed without being cemented with the skin 54 covered with the sheets 56 on the cavity side-faces 52b shaped to the inner surface of the skin while the raw material 58 is bonded with the inner surface of the skin between cavity recessed-surfaces 52a, and contact-bonded with a cavity surface, thus forming a foam having a cavity shape. Both side faces 62b of the foam are covered with the sections A, A of the skin 54 not cemented with the foam, and the end sections of the sections A are engaged with the rear of the foam 62 or a sheet frame of the like.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a skinned foam used as a seat cushion or the like.

(Prior art) Seat cushions, etc., are mainly made of foam such as polyurethane foam covered with a skin, but the skin may shift from the surface of the foam during use, causing damage to the skin. In order to prevent wrinkles from forming on the skin, it is preferable that the skin and the foam are bonded together.

By the way, a foam with a skin, in which the skin and the foam are integrated, is manufactured in the following manner using the skin-body foam molding method, which has excellent workability.

First, as shown in FIG. 5, a skin 14 is placed on the cavity surface 12 of a mold 10 having a cavity of a predetermined shape. Then, the polyurethane foam raw material 16 is injected into the inner surface of the skin 14 and foamed, thereby forming a foam having substantially the same shape as the cavity shape on the inner surface of the skin. At this time, the foam is formed by adhering to the inner surface of the skin 14 due to the adhesive properties of the polyurethane foam raw material 16 generated during the foaming process, so that when the foam is removed from the mold, a desired foam with a skin can be obtained. .

The skinned foam obtained in this way has the skin and foam adhered on all sides including the sides, so
When the foam is compressed during use, the skin on the sides deforms together with the foam, causing wrinkles.

Furthermore, in the case of cushions for automobile seats, it is preferable to have cushions that can maintain the correct posture of the occupant.

Therefore, like the skinned foam 18 shown in FIG.
A foam body 24 with raised bank-like sides 20 and 22 covered with a skin 26 is widely used as an automobile seat seat.

However, when trying to manufacture a skinned foam 18 with raised bank-like sides on both sides using the skin-integrated foam molding method, as shown in FIG.
The skin must be placed on the cavity surface of the mold using a mold in which a deep concave surface 30.32 corresponding to the bulges of the foam sides 20.22 is formed, however,
Even if the plastic skin has been shaped into the desired cavity shape in advance by vacuum forming, etc., it is not easy to place the skin in close contact with the concave surface of a deep cavity, and the skin may float above the concave surface of the cavity. easy.

Therefore, when the polyurethane foam raw material injected into the epidermis fills the epidermis by foaming and forms a foam that adheres to the epidermis, the epidermis floating from the concave surface of the cavity is brought into close contact with the concave surface of the cavity by its foaming pressure. In this way, it becomes a foam with a skin.

However, with fabric skins that have been widely used in recent years, unlike plastic skins, it is difficult to shape the cavity surface in advance by vacuum forming, and it has to be made into a three-dimensional shape by sewing, so it is not necessarily the same as the cavity surface. There is a tendency that it does not become the epidermis of the shape.

As a result, when placed in the deep cavity concave surface,
The epidermis sagged, and when foam molding was performed, wrinkles often appeared in the sagging area.

In addition, attempts have been made to construct the fabric skin with fibers with excellent extensibility or tR (knitted) material and integrally mold the skin while stretching the skin during foam molding, but in the foam with the skin after demolding, Since tension is applied to the stretched skin so that it tends to shrink, the foam loses the contractile force of the skin and deforms, resulting in wrinkles in the skin at the chain parts.

In order to eliminate the above-mentioned disadvantages, it has conventionally been proposed to manufacture a skinned foam by the method shown in FIG. 8 or 9.

In the method shown in FIG. 8, the mold 36 can be divided at the concave surface 34 on the cavity side where wrinkles are likely to occur, the end 38a of the skin 38 is positioned outside the mold from the divided part, and the polyurethane resin is This is a method in which foam raw materials are injected into a mold and foamed together with the skin.

After removing the foam from the mold, cover the swollen portion of the side of the foam with the skin end 38a that was outside the mold, and lock the skin end to the back surface of the foam with a hook or the like. The desired product is obtained.

On the other hand, the method shown in FIG.
A wall portion 40a with an end portion 38a of 8 erected on the inner surface of the upper mold 40.
In this method, the polyurethane foam raw material is sandwiched between the tip and the side inner surface 42a of the lower mold 42, and injected into the cavity, and the raw material is foamed integrally with the skin without touching the skin end 38a. After the foam is demolded, the sides of the foam are covered with the skin ends 38a to form a product.

According to the above two manufacturing methods, for the side parts of the foam where wrinkles are likely to occur, the skin is applied to the foam after foam molding, so the skin can be applied along the surface of the raised part of the foam, and the chain This can prevent wrinkles from forming on the epidermis. In addition, in the obtained skinned foam, since the skin is not adhered to the foam on both sides, the raised parts on both sides are compressed and the thickness of the foam decreases, and the skin may become loose at the chain parts. However, the tension of the fabric that makes up the epidermis causes the epidermis to contract and prevent wrinkles from forming.

However, the above two methods have the following problems.

First, the method shown in FIG. 8 has the problem that the structure of the mold is complicated, which not only takes time to handle the mold, but also takes a long time to manufacture the mold, and increases the price of the mold.

Further, in the method shown in FIG. 9, the side cavity surface becomes under-shaped. Then, when the mold is closed, the wall portion 40a hanging down from the inner surface of the upper mold collides with the side surface of the cavity of the lower mold, making it impossible to close the mold. Therefore, in order to prevent this inconvenience, the shape of the cavity surface is restricted, and there is a problem that the shape of the skinned foam cannot be freely designed.

Therefore, in view of the above-mentioned points, the present invention aims to provide a manufacturing method that can easily and inexpensively manufacture a foam with a skin that does not cause wrinkles on the skin, without impairing the freedom of external design. be.

(Means for solving problems) In order to achieve the above object, the present invention has the following configuration.

That is, in the method of manufacturing a foam with a skin that is adhesively integrated with the skin by providing a skin on the cavity surface, injecting a polyurethane foam raw material into the inner surface of the skin, and using the adhesiveness generated when the polyurethane foam raw material is foamed, A plastic film or seed that does not adhere to the polyurethane foam raw material at the time of foaming is provided in advance on the inner surface of the skin installed on the side surface of the cavity, and the polyurethane foam raw material is injected into the skin and foamed, thereby forming the skin on the side surface. The idea was to form a foam that was not bonded.

Note that the non-adhered skin on the side surface of the foam is stretched by locking its ends to a frame or the like on the back surface of the foam.

(Function) The polyurethane foam raw material injected into the epidermis foams while exhibiting adhesive properties. At this time, in the skin part where the inner surface is provided with a plastic film or sheet that does not adhere to the polyurethane foam raw material, that is, in the skin part located on the side surface of the cavity, the raw material foams without adhering to the inner surface of the skin, and other In the skin part, the raw material foams while adhering to the inner surface of the skin, forming a foam having a cavity shape.

Therefore, the foam that is integrated with the skin is removed from the mold, and the skin that is not bonded to the foam is stretched to cover the sides of the foam, and the ends of the skin are attached to the back of the foam. By locking it to a frame or the like, a desired wrinkle-free skinned foam can be obtained.

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

FIG. 1 is a sectional view of a mold for producing a skinned foam according to an embodiment of the present invention.

The mold 44 is for molding a skinned foam with raised bank-like sides, and is composed of an upper mold 46 and a lower mold 48. A cavity surface 50 is provided on the inner surface of the upper mold and the lower mold.
52 is formed. In addition, downwardly depressed concave surfaces 52a, 52a are formed on both sides of the lower mold cavity surface 52 in order to form a bank-like raised portion of the foam.

A skin 54 is provided on the lower mold cavity surface 52 of this mold 44. The skin 54 is made of a fabric-like material and usually has a structure as shown in FIG. 2 or 3.

The epidermis shown in FIG. 2 has the outermost layer 54a made of fabric.
The next inner layer 54b is made of flexible polyurethane foam, and the two are bonded or welded together to become one piece. The soft polyurethane foam in J'154b is used in order to enhance the soft feel of the skin 54 and to prevent the polyurethane foam raw material that will be injected into the inner surface of the skin later from impregnating and hardening into the fabric and impairing the soft feel of the skin.
and is provided to prevent the raw material from seeping onto the fabric surface and impairing the appearance of the skin.

On the other hand, the epidermis shown in FIG. 3 has the same outer layer 54a as above,
It consists of an inner layer 154b, and an innermost layer 54c made of a polyurethane film is further laminated on the inner layer M54b by flame welding (flame lamination). The polyurethane film of the innermost layer 54c is provided to prevent the polyurethane foam raw material that is later injected into the epidermis from impregnating the soft polyurethane foam of the inner layer 54b, thereby further enhancing the soft feel of the epidermis.

The flexible polyurethane foam of the inner skin layer 54b and the polyurethane film of the innermost layer 54c both have the property of adhering to the polyurethane foam raw material due to the adhesiveness exhibited by the polyurethane foam raw material during foaming.

In addition, a plastic film or sheet, such as a polyethylene sheet 56, to which the polyurethane foam raw material does not adhere during foaming, is sewn or double-sided to the inner surfaces of parts A and A of the skin provided on both sides 52b and 52b of the lower mold cavity. They are laminated and provided using adhesive tape or the like.

In addition, when the skin 54 formed in this manner is installed on the lower mold cavity surface, a portion of the skin 54 from the cavity concave surfaces 52a, 52a to the cavity side surfaces 52b, 52b may be in a state of floating from the cavity surface.

Then, a polyurethane foam raw material 58 is injected into the inner surface of the skin 54 provided on the cavity surface, and a foam with a skin is obtained in the following manner.

Polyurethane foam raw material 5 injected into the inner surface of the skin 54
No. 8 starts to react under closed mold conditions, exhibits adhesive properties, and foams. At that time, due to the adhesive property, the cavity concave surface 5
2a and 52a, the polyurethane foam raw material 58 adheres to the inner surface of the skin, while the polyethylene sheet 56.
56 are cavity side surfaces 52b and 5 provided on the inner surface of the skin.
2b, the polyurethane foam raw material 58 is foamed without adhering to its polyethylene sheet 56,56 and the skin 54 covered therewith. The polyurethane foam raw material 58 fills the skin 54 and forms the cavity concave surface 52a.

52a and the cavity side surfaces 52b, the skin of the 52b portion is pressed onto the cavity surface to form a cavity-shaped foam.

Thereafter, the foamed molded product is taken out from the mold, and FIG. 4 is a sectional view of the foamed molded product. The foamed molded product 60 thus obtained is made up of a foamed body 62 whose side parts 62a, 62a are raised in a bank-like shape, and an outer skin 54, in which both sides 62b of the foamed body are formed.

In 62b, parts A and A of the skin 54 are not adhered to the surface of the foam 62, while in the central part 62c of the foam, part B of the skin 54 is adhered to the surface of the foam 52.

Next, A of the skin 54 that is not adhered to the foam.

Both side surfaces 62b, 62b of the foam are covered with the A part, and the ends of the A and A parts of the skin are hooked to the back surface of the foam 62 or a seat frame, etc., to obtain a desired foam with a skin. At this time, it is preferable to remove the polyethylene sheet 56 on the inner surface of the skin A and the A part in order not to impair the soft feel of the skin A and the A part.

The skinned foam obtained in this way is formed without adhesion to the skin on both sides of the foam, so even if the skin is stretched during foaming, the foam will remain intact. After demolding, the side skin can be shrunk separately from the foam, without causing wrinkles in the side skin.

Also, since the skin and foam are not bonded on the sides,
Even when the raised portion is compressed, the looseness of the epidermis is absorbed by the expansion and contraction of fabrics, tsukus, etc. that make up the epidermis, and wrinkles do not occur.

(Effects) In this invention, a plastic film or sheet that does not adhere to the polyurethane foam raw material during foaming is provided in advance on the inner surface of the skin installed on the side surface of the cavity as described above, and the polyurethane foam raw material is injected into the skin. By performing skin-body foam molding, a foam with a skin without wrinkles can be produced.

Therefore, there is no need for the mold to have a complicated structure, and the foam manufacturing operation is not only simple, but also the manufacturing of the mold is not complicated at all, and the mold can be manufactured in a short period of time and at low cost.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a mold for manufacturing a foam with a skin according to an embodiment of the present invention, FIGS. 2 and 3 are sectional views showing an embodiment of the skin used in the invention, and FIG. The figure is a cross-sectional view of a skinned foam obtained by implementing the present invention. Furthermore, Fig. 5 is a cross-sectional view illustrating foam molding with an integrated skin, Fig. 6 is a cross-sectional view of a foam with a skin used for automobile seat cushions, and Fig. 7 is a foam with a skin that has raised banks on both sides. 8 and 9 are cross-sectional views illustrating a conventional manufacturing method. Figure 54: Epidermis, 56: Polyethylene sheet

Claims (1)

[Claims] In a method for manufacturing a foam with a skin that is adhesively integrated with the skin by providing a skin on the cavity surface and injecting a polyurethane foam raw material into the inner surface of the skin, the polyurethane foam raw material is bonded and integrated with the skin using the adhesive property that occurs when the polyurethane foam raw material is foamed. A plastic film or sheet that does not adhere to the polyurethane foam raw material at the time of foaming is provided in advance on the inner surface of the skin installed in the part, and the polyurethane foam raw material is injected into the skin and foamed.
A method for producing a foam with a skin, the method comprising forming a foam with no skin adhered to the side surfaces.