JPS6221617B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to moldings, such as padded articles, particularly seats, made of naturally expanded polyurethane foam material or of said foam material and a facing material, and a method for producing the same.

The shape of a molded product using a polyurethane foam material is obtained by applying pressure in a mold, and is shaped by applying pressure and heating using a suitable foam block.

The present invention eliminates methods well known in this field, such as using a blend of certain aromatic and aliphatic isocyanates, as a molding process to obtain molded articles of thermoplastic material. Although not intended, the present invention requires the use of a foam that can be molded before polymerization and curing is complete. The invention, which can be used to obtain articles made by combining a finished surface and, if necessary, also a reinforcing base layer, is particularly suitable for the manufacture of chairs for the automotive and furniture industries. There is.

Hereinafter, a method for manufacturing a seat will be described as an example of the present invention, but the present invention is not limited to this and can be applied to articles of all shapes obtained by the method of the present invention.
Furthermore, the articles obtained by the method of the present invention are not limited to those whose surfaces are coated with a finishing material, or where other applicable retaining materials and reinforcing layers are provided. Moreover, the material used can be soft, semi-hard, or hard polyurethane foam. Currently, most seat padding uses soft or semi-rigid polyurethane foam and is made by molding or cutting out foam blocks.

An object of the present invention is to provide a new method for molding synthetic polyurethane foam moldings having the following characteristics.

That is, (1) supplying a polyurethane foam material onto a flat non-adhesive sheet-like member to obtain a foam block in which a uniform layer is formed; The thickness of this layer is determined by the final thickness of the polyurethane foam molding to be obtained. The lamination area of the polyurethane foam molded product is determined with respect to the area of the sheets to be obtained. The foamed polyurethane material is formulated so that the foam to be molded has good adhesion and plasticity even before complete polymerization. In addition, the foamed polyurethane raw material can be used for reinforcing layers such as thin filling layers,
It can be supplied on flexible polyurethane foam or on metal parts that are part of the entire seat.

(2) All raw materials should be allowed to foam naturally.

(3) After foaming has substantially ceased, cover the free surface of the foam with a facing material. Note that depending on the type of article, no surface material may be used. The surface material must have the ability to adhere to the polyurethane foam when foaming is substantially complete but polymerization is not complete.

(4) Applying a certain predetermined pressure to the surface material and the foam layer to bond them together before polymerization of the foam is completed.

(5) Transferring a combination article consisting of a soft foam with a facing material, which may also include reinforcement, into the cavity of a press supporting a pair of split molds, after which the foam is still intact. Applying pressure to the mold during the moldable stage to impart the desired final article shape.

(6) When the polyurethane foam becomes stable, demold the entire polyurethane foam. The physical and mechanical properties required of the foam are determined by the materials used and molding conditions in the above method, which is the object of the present invention.
In particular, the polyurethane foam must have adhesion properties when the polymerization is not completely completed and must be able to adhere accurately when the surface layer is applied. However, the foam must be sufficiently viscous to not pass through the weave, even if a coarse material such as cloth is used as the surface layer.

Alternatively, if a surface layer of a material that does not soak into the polyurethane foam material is used, or if necessary to improve the adhesion between the surface layer and the foam, a polyurethane foam material may be provided on the surface layer. can do. For example, when using PVC resin leather as a facing material, a polyurethane foam material is applied on top of the leather to allow it to foam naturally, and if reinforcement is required, the reinforcement is placed over the free foam surface of the foam, and then the foam is The necessary pressure is applied to achieve adhesion. Polyurethane foam has such plasticity that it allows plastic deformation of the entire polyurethane foam, surface material, and various other reinforcing layers when it is pressed, before curing is completely completed. must be maintained.

An example of a formulation of a polyurethane foam having the physical and mechanical properties required for the method of the present invention is shown below, but it is of course not limited thereto.

Polyoltriol M.W4800 (Daltocell type 32/75) 100pbw Triethanolamine 2 Water 2.8 Silicone oil (Type L-5305: Surfactant) 1 Triethylenediamine 0.15 Triethylamine 0.5 Dibutyltin dilaurate 0.02 Isocyanate 40 (Isocyanate is TDI80/20 and MDI 80/20
(mixed in the ratio of In the case of cloth, this does not need to be waterproof. This is because when the fabric is combined with the foam block to be molded, the foam has sufficient viscosity to avoid penetrating through the fabric. Both cloth and synthetic leather can be used as surface materials, but a more suitable surface material is 3~10m/
Foam layers having a final thickness of m may also be preassembled by standard frame lamination methods. Of course, the thickness is not limited to this.

A foam layer, preferably combined with a polyurethane foam, is placed over the free surface of the foam block to be molded as described in the third step of the process. Then, on the foam layer surface of the surface material, the foam block has finished foaming.
It is bonded to the surface of the foam block before the polymerization and curing are completely completed.

Embodiments of the present invention will be described below with reference to the drawings. The surface material 1 is composed of a synthetic resin finishing layer 2 of cloth or synthetic leather to which a foam layer 3 is laminated. This surface material 1 is joined to a form block 4 to be shaped, and this block 4
is held by a mold release material 5. Block 4
The foam material for making is supplied onto the mold release material 5. Moreover, this mold release material 5 can also be constituted by a reinforcing layer, and in this case, the form block 4
and the reinforcing layer are bonded to each other.

The area of the facing 1 is larger than the foam block 4 and the entire circumference of the edge projects beyond the block 4, the width of which is determined by the shape of the article to be molded.

FIG. 2 shows the manufacturing process of the method of the present invention. The station 1 is the position where the foam material is discharged by the metering unit 6 onto the mold release material 5 (or the reinforcing layer 5), and the foam material is specified by the mold 7 which forms the shape of the article to be molded. supplied within the area. At the station, the foamed material has almost completed foaming and has become a foam block 4. The facing 1 is held on the underside of the plate 8 by vacuum suction through the channel 9. Plate 8 is form block 4
It is pushed down by the piston 10 to the top. Light pressure is applied to help the adhesion between the facing material 1 and the foam block 4.

At the station, after stopping the vacuum suction from the channel 9 applied to the plate 8, the surface material 1 is removed from the plate 8 and the foam block 4 whose polymerization and hardening have not been completely completed is removed.
Cover the top. Next, preparations are made for moving the station under the press machine 11. The block 4 is a pair of split molds (upper and lower molds) 12, 1 of the press machine 11.
2', the outer surface of the facing 1 is placed in a recess of an upper mold 12 in the shape of the upper part of the seat.
The area of the foam block 4 is made slightly larger than the area of the mold so that wrinkles do not occur in the surface material 1 during press molding. Furthermore, avoid the appearance of wrinkles,
The recesses of the mold may also be connected to a vacuum suction chamber to facilitate air removal from the mold. Although it is necessary to use a large-capacity pump so that vacuum suction can be performed rapidly, the degree of pressure reduction does not need to be high. In reality, a reduced pressure of 650 mmHg is sufficient.

At the station, after being carried between the upper and lower molds 12 and 12' of the press 11, pressure is applied to the foam block 4 while it still has plasticity, and this pressure is maintained until the entire polymerization reaction of the foam is completed. Ru. To accelerate this polymerization, the foam block is preferably heated and aged at a temperature of 60 to 90°C. Of course, when Gold Your Foam is used, it can also be aged without heating. In this state, the molding time is about 3 minutes or less, and the time for applying pressure is 10 to 60 seconds.

FIG. 3 shows a typical example of a seat obtained by the above process. The foam is made thicker at the station and thinned at the station. According to this method, it is also possible to partially harden the station described above.

In the above embodiments, the molding process of soft or semi-rigid polyurethane foam has been described, but it goes without saying that the present invention can be applied to molding process of rigid polyurethane foam in exactly the same way. Moreover, many variations and modifications are possible within the scope of the technical idea of this invention.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of a foam block composed of multiple layers, Figure 2 is an explanatory diagram of the manufacturing process, and Figure 3 is a cross-sectional view of a foam block composed of multiple layers.
The figure is a sectional view showing an example of a molded product obtained by the method of the present invention. 1... Surface material, 2... Finishing layer (synthetic resin), 3... Foam layer, 4... Foam block, 5... Mold release material,
11...Press machine, 12, 12'...Mold.

Claims (1)

[Scope of Claims] 1. A foam block is formed by spontaneously foaming a polyurethane foam material, and when the foam material of the foam block is almost completely foamed and the polymerization hardening is not yet complete, the foam block is pressure-molded to form a desired shape. A method for producing a polyurethane foam molded product, characterized by forming it into an uneven shape. 2. A foam block made of naturally foamed polyurethane foam material and a surface material are bonded to each other while foaming of the foam material of the block is almost completed, polymerization is not yet completed and the surface is sticky, and the foam block and the surface material are bonded together. 1. A method for producing a polyurethane foam molded product, which comprises integrally press-molding the surface material and the surface material, and integrally bonding the surface material to a foam block and shaping it into a desired uneven shape. 3. A polyurethane foam material is supplied onto the adhesive surface material, and is allowed to naturally foam on the surface material to form a foam block. A method for producing a polyurethane foam molded product, which comprises press-molding an incomplete state to form a desired uneven shape.