JPH074871B2 - Cushion body manufacturing method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a manufacturing method for obtaining a cushion body suitable as a cushion pad material for a vehicle seat such as a vehicle or a furniture such as a sofa.

[Prior Art] Various materials have been conventionally used for cushion bodies used for automobile seats and the like. For example, it has been generally known that natural fibers such as palm rock and gummiher are used, or that synthetic resin foam such as urethane foam is used. More recently, the present inventors have developed a cushion body formed by binding the fibers of a linear fiber assembly made of crimped organic synthetic fibers with a resin binder as a substitute material. This kind of cushion body is molded into a predetermined shape by packing a predetermined amount of a fiber assembly to which a binder component such as urethane is attached in a molding die at a time and curing the binder component while compressing. Was common.

Usually, the outside of the cushion body is used while being covered with a cover material such as cloth or leather. In order to improve the appearance and finish after the covering, it is important to precisely shape the edge portion such as the ridgeline portion of the cushion body into the shape as designed.

[Problems to be Solved by the Invention] However, when a predetermined amount of fibers is packed in a mold and compression molded,
Formability is not good because pressure is not evenly applied between the inner surface of the mold and the fibers. For example, as shown in FIG. 8, in the suspending groove b of the cushion body a, the surface layer portion of the cushion body a did not adhere well to the mold c, and the shape was likely to be inaccurate. In particular, Gumiher, palm lock, curl lock mat, etc. have thick fibers and high rigidity, so the complicated and sharp shape such as the ridgeline part such as the hanging groove and cushion side is required as designed. It was difficult to shape it.

It is possible to solve the above problems to some extent by simplifying the shape of the cushion body as much as possible, but the vehicle seat has a complicated shape in order to improve the ride comfort and the seatability of the seated person. Inevitably, it is difficult to simplify the shape of the cushion body.

Therefore, it is an object of the present invention to provide a method for manufacturing a cushion body that can form a precise and sharp shape, particularly, a ridge line portion or a groove edge portion of the cushion body, and can cope with a complicated cushion shape.

[Means for Solving the Problems] In the method for manufacturing a cushion body invented by the present inventors in order to achieve the above object, the cushion surface layer portion is first formed in the first step, and then the cushion is formed in the second step. The main part is molded. In the first step, a thin sheet-shaped fiber aggregate containing a binder component is placed along the inner surface of a molding die and is pressed against the die by a pressing die. Then, the cushion surface layer portion is formed by curing the binder component. In the second step, a fiber aggregate containing a binder component is packed into the inner surface side of the cushion surface layer portion. Then, by curing the binder component in the mold, the cushion main portion is formed integrally with the cushion surface layer portion.

As the binder used for the cushion surface layer portion and the cushion main portion, for example, a material in which a urethane prepolymer solution is adhered to fibers and then the binder component is cured by blowing steam is adopted. Alternatively, a binder fiber having a softening point lower than that of the fiber may be mixed with the above fiber and heated to a temperature equal to or higher than the softening point of the binder fiber to bond the fibers to each other by the binder fiber.

[Operation] In the first step, only the cushion surface layer portion is accurately molded along the inner surface shape of the mold. Next, in the second step, the cushion main portion is integrally formed inside the cushion surface layer portion. In this way, the outer surface of the cushion main portion can be molded exactly as designed, so that the appearance after the covering is good and the cushion shape can be complicated.

[Example] As a material for the cushion surface layer, a sheet-like card cotton with a basis weight of 200 g / m ² is prepared as a fiber assembly in which crimped 6-denier polyester short fibers are three-dimensionally intertwined. The molding die 1 and the pressing die 2 shown in FIG. 2 are made of punching metal, and a large number of steam blowout holes are provided on the inner surface side. The above fiber assembly (thickness: several mm to several cm) is dipped in a urethane prepolymer (NCO% = 5%) of concentration 50% / tricene solution (trichloroethane), and then the excess urethane prepolymer is centrifuged. It is removed by force and adjusted so that the binder adhesion rate becomes 25 to 35%. The sheet-shaped fiber assembly 3a is pushed along the inner surface of the die 1 by the die 2
Push in gradually from above. Then, while the steam is blown from the steam introduction port 4 of the mold 1, the steam is introduced into the fiber assembly 3a through a large number of steam blowout holes on the inner surface side of the mold 1. After curing the urethane prepolymer, press die 2
To release. The cushion surface layer 3 (see FIG. 4) thus formed into a predetermined shape is one in which the entanglement points of the polyester fibers are bonded by a urethane binder, and has appropriate elasticity and excellent sag resistance and breathability. is doing. The above is the first step.

Next, in the second step, after the urethane prepolymer solution is uniformly applied to the inner surface of the cushion surface layer portion 3 by spraying, the fiber aggregate to be the cushion main portion 6 is packed on the inner surface side of the cushion surface layer portion 3. Cushion main part 6
The fiber assembly used for is that the crimped polyester fiber cut into a predetermined shape is dipped in a urethane prepolymer solution with a concentration of 50%, and then excess urethane polymer is removed by centrifugal force. Adjusted to be 35%. This cut cotton is used for cushion surface layer 3
After setting it at a predetermined position inside, the molds 1 and 7 are closed as shown in FIG. Then, after curing the urethane prepolymer, it is taken out from the molds 1 and 7.
The above series of steps is shown in FIG. In the case of immediately shifting from the first step to the second step, it is not necessary to take out the cushion surface layer part 3 after molding from the mold 1. However, the cushion surface layer portion 3 after molding may be taken out from the mold 1.

The fibers used for the cushion surface layer 3 are 50
Fine single fibers having a denier or less, or those having 2 to 50 denier and a mixture of two or more kinds of fibers having different denier values may be used.

The cushion body obtained through the first step and the second step described above has an edge portion of the hanging groove 10 illustrated in FIG. 6, a tip ridge portion of the side support portion 11 illustrated in FIG. 7, and the like. As described above, the shape of the mold 1 can be accurately transferred at a place where sharpness is required, and the appearance finish after the covering is improved.

The cushion body has a continuous sheet-like cushion surface layer portion 3 at its surface, that is, a portion in contact with the cover material.
Since it is covered with, it is possible to weaken the force applied to the interface of the fibers of the sheet main portion 6 molded inside.
Therefore, good results can be obtained in terms of durability.

In addition, the hanging wire 13 used when covering
(See FIG. 3) may be integrally formed with the cushion surface layer portion 3. By doing so, the wire 13 is strongly bonded and held between the fibers of the cushion surface layer portion 3 and the fibers of the cushion main portion 6, and the hog ring or the like of the cover material is securely engaged without causing the wire 13 to peel off. Can be stopped.

As the fibers used for the cushion surface layer portion 3 and the cushion main portion 6, in addition to polyester, organic synthetic fibers such as polypropylene, nylon, acrylic, rayon, cupra, acetate, vinylon, vinylidene, polyvinyl chloride can be adopted. . Further, natural fibers such as wool, silk and cotton may be used, or these may be mixed with organic synthetic fibers and used.

In addition to the urethane prepolymer, the binder may be a rubber latex or solution type such as natural rubber, isoprene rubber, butadiene rubber, SBR, NBR, chloroprene rubber, and acrylic rubber, or water-soluble urethane or urethane. Emulsions can be used.

In addition, the above-mentioned organic synthetic fiber or natural fiber is mixed with a binder fiber having a lower softening point than this fiber, and heated to a temperature higher than the softening point of the binder fiber so that the entanglement points of the fibers are bound to each other. May be. Binder fibers include polyester, polypropylene,
Polyethylene, nylon, or the like can be used, that is, any fiber having a lower softening point than the fiber to be bound may be used.

[Effects of the Invention] According to the present invention, it is possible to accurately form a portion of a cushion body having a complicated shape, in which the shape is particularly required to have a sharp shape, according to the shape of the inner surface of the mold. improves. Further, since the surface in contact with the cover material is covered with the continuous sheet-like cushion surface layer portion which is bonded with the binder, the stress applied to the interface between the fibers of the cushion main portion inside thereof can be relieved and the durability is improved. .

[Brief description of drawings]

FIG. 1 is a flow chart showing steps of an embodiment of the method of the present invention, FIG. 2 is a schematic cross-sectional view showing a mold for molding, FIG. 3 is a schematic cross-sectional view showing a state at the time of molding the cushion surface layer portion, and FIG. Is a schematic cross-sectional view showing a cushion surface layer portion and a mold after molding, FIG. 5 is a schematic cross-sectional view showing a state at the time of molding the cushion main portion, and FIG. 6 is a cross-sectional view near a hanging groove formed by the method of the present invention. ,
FIG. 7 is a cross-sectional view of the side support portion formed by the method of the present invention, and FIG. 8 is a cross-sectional view near the hanging groove formed by the conventional method.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B29L 31:44

Claims (3)

[Claims] 1. A cushion surface layer portion is formed by causing a thin sheet-shaped fiber aggregate containing a binder component to be along an inner surface of a molding die and curing the binder component while being pressed against the die by a pressing die. 1 step, and a second step of forming a cushion main portion integrally with the cushion surface layer portion by packing a fiber assembly containing a binder component on the inner surface side of the cushion surface layer portion and curing the binder component. A method for manufacturing a cushion body, comprising: 2. The method for producing a cushion body according to claim 1, wherein a crimped organic synthetic fiber having a denier of 2 to 50 is used for the fiber assembly of the cushion surface layer and a urethane prepolymer is used as a binder component. 3. A cushion body according to claim 1, wherein a hanging wire for a cover ring is arranged between the cushion surface layer portion and the cushion main portion to integrally form the cushion main portion and the cushion surface layer portion. Method.