JP2003127151A - Method for producing pad for sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inexpensively without lowering moldability produce a pad for a sheet in which a surface layer material is molded integrally with a pad main body in a method for producing the pad in which a polyurethane raw liquid is injected into a molding mold and subjected to foaming. SOLUTION: The molding mold 10 having a lower mold 12 for molding the back side of the pad and an upper mold 16 which can be opened/closed in relation to the lower mold and molds the design surface side of the pad is used. The surface layer material 2 for forming at least a part of the design surface of the pad is arranged in the upper mold 16, and the polyurethane raw liquid M is injected into the molding mold 10 with the surface layer material 2 arranged so that the surface layer material 2 is integrated with the pad main body 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a seat pad, which is a cushion body mainly used for automobile seats.

[0002]

2. Description of the Related Art A seat pad called a cushion pad or a bag pad used for a seat portion or a back portion of an automobile seat is formed by pouring a polyurethane raw material solution into a molding die and foaming the same. It is manufactured by Specifically, the undiluted polyurethane solution is composed of a polyol and an isocyanate, and is usually injected into a mold while continuously mixing them according to a predetermined composition. The injected polyurethane undiluted solution is foamed and cured to a certain extent in a mold to foam-form a urethane foam sheet pad.

In such a seat pad, as shown in FIG. 2, a surface layer material (2) such as a soft slab which is softer than the pad body (1) is provided on the seating surface for the purpose of improving the comfort of sitting. There is a case. Conventionally, such a surface layer material (2) is attached to the pad body (1) with an adhesive, but in that case, a separate adhesion step is required after foam molding of the pad, which is costly, and It is difficult to control the process of the adhesive, and the surface layer material is easily peeled off.
Furthermore, there is a problem that the working environment is deteriorated by the solvent of the adhesive.

In order to solve these problems, it is conceivable to integrally form the surface layer material during foam molding of the pad body. FIG. 3 is a cross-sectional view of a molding die (50) used for conventional integral foam molding. The molding die (50) includes a concave lower die (51) and an upper die (52) which can be opened and closed with respect to the lower die (51).
The lower die (51) is used to mold the design surface side of the pad. Therefore, the lower mold (51) has left and right convex side portions (5) (5) of the cushion pad.
The left and right recesses (53) (53) forming the space and the relatively flat central portion (54) located therebetween are provided. When integrally molding using this mold (50), the lower mold (51)
A surface layer material (2) such as a soft slab that forms a part of the pad design surface is set in the central part (54) of the pad, and in that state, a polyurethane stock solution (M) is injected from the injection nozzle (55) into the molding die (50). Inject.

However, in such a conventional method, the undiluted polyurethane solution (M) easily penetrates into the surface layer material (2), and as a result, as shown in FIG. 2, the pad body (1) and the surface layer material (2). Thick impregnated cured layer at the interface with (3)
Was formed, and there was a problem that the comfort of sitting was impaired. In addition, the polyurethane undiluted solution permeates from the periphery of the surface layer material (2) to the surface side to form a cured layer (4), which causes a problem that defective products are likely to occur. In addition,
It is possible to laminate a film on the back surface of the surface layer material in order to prevent the generation of such an impregnated cured layer, but in this case,
The cost will be high.

The present invention has been made in view of the above problems, and an object of the present invention is to manufacture a sheet pad, in which a surface layer material is integrally molded with a pad body, at low cost without impairing moldability. And

[0007]

A method for producing a sheet pad according to the present invention is a method for producing a sheet pad by injecting a foaming undiluted solution into a molding die to perform foam molding.
The molding die comprises a lower mold for molding the back surface side of the pad, and an upper mold for molding the design surface side of the pad that can be opened and closed with respect to the lower mold, and the upper mold has at least the pad design surface. A pad body and the surface layer material are integrated with each other by arranging a surface layer material forming a part of the pad material and injecting a foaming undiluted solution into a molding die in a state where the surface layer material is arranged to perform foam molding.

As described above, in the present invention, the relationship between the upper die and the lower die for the seat pad is reversed with respect to the prior art, and the design surface side of the pad, that is, the upper surface side of the cushion pad and the front surface of the bag pad are arranged. Try to mold the side with the upper mold,
A surface layer material is placed on the upper mold. Therefore, the foaming undiluted solution such as the injected polyurethane undiluted solution fills the mold while foaming, and when it reaches the surface layer material arranged in the upper mold, its fluidity is reduced due to foaming. . In this way, by lowering the fluidity of the foaming stock solution when contacting the surface layer material, that is, by increasing the viscosity, it is possible to suppress the excessive penetration of the foaming stock solution into the surface layer material, and to prevent the permeation from the surroundings of the surface layer material. You can prevent it from getting out.

Examples of the surface layer material include those formed of a material into which the undiluted foaming solution permeates, such as a preformed resin foam such as a polyurethane slab and various skins such as a nonwoven fabric and a woven or knitted fabric. The method of the present invention described above is suitable when the surface layer material made of the permeable material of the foaming stock solution is used.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a cross-sectional view of a molding die (10) in a method for manufacturing a sheet pad according to an embodiment of the present invention, (a) is when a polyurethane stock solution (M) is injected, and (b) is.
Indicates the time of foam molding.

The seat pad according to this embodiment is
A cushion pad used for a seat portion of an automobile seat, and like the conventional seat pad shown in FIG. 2, a polyurethane soft slab that is softer than the pad body (1) at the center of the seating surface that is the design surface. A substantially plate-shaped surface layer material (2) is integrally provided.

The mold (10) is a concave lower mold (12) which is held substantially horizontally and molds the back surface side of the cushion pad,
By rotating around a hinge part (14) arranged at one end of this lower mold (12), the lower mold (12) can be opened and closed by an upper mold (16) for molding the design surface side of a cushion pad. It is a mold.

The upper mold (16) includes left and right concave portions (18) and (18) forming left and right convex side portions (5) and (5) of the cushion pad, and a relatively flat central portion located therebetween. (20) and. A frame (22) for setting the surface layer material (2) is provided in the central portion (20). The frame (22) has a height equal to the thickness of the surface layer material (2) so as to completely cover the side surface of the surface layer material (2), and a protruding wall that surrounds the surface layer material (2) over the entire circumference. Is. The surface layer material (2) may be fixed in the frame (22) by using a jig or the like (not shown).

In the molding die (10), the mating surface (parting line) PL between the lower die (12) and the upper die (16) is from when the urethane stock solution (M) is injected until the upper die (16) is closed. It is set so that the foaming liquid does not overflow, and in this embodiment, as shown in FIG. 1B, it is set at a position higher than the mounting position of the surface layer material (2).

Reference numeral (30) is an injection nozzle for injecting the polyurethane stock solution (M) into the lower mold (12), which comprises an isocyanate supply section (32) for supplying an isocyanate component and a polyol supply section (for supplying a polyol component). 34) is connected to.

When manufacturing a cushion pad using the mold (10), first, as shown in FIG. 1 (a),
With the upper mold (16) open, the central part (20) of the upper mold (16)
Set the surface layer material (2) in the frame (22). Then, the polyurethane stock solution (M) is injected from the nozzle (30) into the lower mold (12) to close the upper mold (16). Then, Figure 1
As shown in (b), the polyurethane stock solution (M) is filled in the molding die (10), and the pad body (1) is integrally foam-molded on the surface layer material (2).

At this time, according to the present embodiment, the surface layer material (2) is set in the upper mold (16) for molding the design surface side of the pad so that the foam is integrally foamed. When the undiluted polyurethane solution (M) injected into the surface layer material (2) set in the upper mold (16) reaches the surface layer material (2), its fluidity is significantly reduced by foaming. Therefore, the polyurethane stock solution (M) hardly penetrates into the surface layer material (2), so that the impregnated layer formed at the interface between the surface layer material (2) and the pad body (1) becomes thin, which is caused by the impregnated layer. It is possible to prevent deterioration of sitting comfort. Further, it is possible to prevent the undiluted polyurethane solution (M) from seeping out from the periphery of the surface layer material (2) and reduce the defective rate.

[0019]

EXAMPLES Example 1 and Comparative Example 1 were carried out using the formulations and molding dies shown in Table 1 below, and the moldability was evaluated. Here, Example 1 relates to the embodiment of the present invention shown in FIG. 1 described above, and Comparative Example 1 is based on the conventional manufacturing method shown in FIG.

The moldability was determined by the amount of impregnation, the comfort of sitting, and the presence / absence of submersion, and a comprehensive evaluation based on these was also performed. Here, the impregnation amount is 10% of the impregnation amount of polyurethane in the surface layer material in the cushion pad obtained in Comparative Example 1.
It was displayed as an index of 0. As for the sitting comfort, "○" means that there is no discomfort due to the impregnated hardened layer and that is comfortable to sit on, "△" means that there is some discomfort due to the impregnated cured layer, and "x" means that there is a large discomfort due to the impregnated cured layer. . The presence / absence of submersion refers to the presence / absence of leaching of the polyurethane stock solution from the periphery of the surface layer material to the surface side. In the comprehensive evaluation, a sample having excellent moldability was evaluated as “◯”, a sample having slightly poor moldability was evaluated as “Δ”, and a sample having poor moldability was evaluated as “x”.

[0021]

[Table 1]

[0022]

EFFECTS OF THE INVENTION According to the present invention, the surface layer material is arranged in the upper mold for molding the design surface side of the pad to perform integral foam molding, so that the fluidity of the foaming undiluted solution in contact with the surface layer material is improved. Since it can be lowered, it is possible to prevent the foaming undiluted solution from excessively permeating into the surface layer material, so that the impregnated and hardened layer formed at the interface between the surface layer material and the pad body is reduced and the sitting comfort is good. A pad for a seat can be manufactured. In addition, leaching from the periphery of the surface layer material to the surface side is also suppressed, and the product defect rate can be reduced. Further, since it is not necessary to separately provide an adhesion step after the foam molding and to laminate a film on the surface layer material, it is possible to manufacture a sheet pad excellent in moldability at low cost.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a foaming mold according to an embodiment of the present invention, in which (a) is a cross-section when a polyurethane raw material is injected,
(B) shows the cross sections at the time of foam molding.

FIG. 2 is a cross-sectional view of a seat pad.

FIG. 3 is a cross-sectional view of a molding die in a conventional foam molding method.

[Explanation of symbols]

(1) …… Pad body (2) …… Surface layer material (10) …… Mold (12) …… Lower mold (16) …… Upper mold (22) …… Frame (M) ... Polyurethane stock solution

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) B29L 31:58 B29L 31:58 (72) Inventor Fumihiro Kojima 1-17-18 Edobori, Nishi-ku, Osaka City, Osaka Prefecture F term in Toyo Tire & Rubber Co., Ltd. (reference) 3B084 CB01 4F204 AA42 AD08 AH26 EA01 EB01 EB13 EF01 EF05 EF27

Claims (2)

[Claims] 1. A method for manufacturing a sheet pad by injecting a foaming undiluted solution into a molding die for foam molding, wherein the molding die comprises a lower mold for molding the back surface side of the pad, and an opening / closing mechanism for the lower mold. An upper mold for molding the design surface side of the pad, which is capable of forming a surface layer material forming at least a part of the pad design surface on the upper mold, and the molding die with the surface layer material arranged. A method for manufacturing a pad for a sheet, characterized in that the pad main body and the surface layer material are integrated by injecting a foaming undiluted solution and performing foam molding. 2. The method for manufacturing a pad for a sheet according to claim 1, wherein the surface layer material is a resin foam-molded body that has been molded in advance.