JPS58119833A - Method of molding pad with different hardnesses - Google Patents

Abstract

PURPOSE:To prevent air from remaining around an insert member, by sticking a pipe through a vent of a mold into an insert member placed in the mold, injecting a raw liquid of a foamable resin in the cavity around the insert member, and foaming the resin. CONSTITUTION:An upper mold 1A is opened, and an insert member 2 molded from urethane tips or the like is placed in a desired position in a lower mold 1B, and is supported by known means. A pipe 11 whose tip is sharpened is mounted in a vent 4 in the upper mold 1A, and when the molds are clamped, the tip is inserted into the insert member 2. Then the raw liquid of foamable resin is injected into the cavity between the molds 1A, 1B, and is foamed and molded so that the pad 6 having different hardnesses wherein the insert member 2 and the pad member 3 are monolithically molded is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for molding pads of different hardness, and more specifically, a preformed insert material is inserted into a foam mold having vent holes, and then a stock solution of foamed synthetic resin is inserted into the foam mold. This invention relates to a method for forming pads of different hardness, which involves injecting into a foaming mold and foam-molding to form a pad material.

Conventionally, pads of different hardness are used in cushion pads for vehicles, etc., in which insert materials are inserted to form sections of different hardness, to improve the feeling of holding the seat or to obtain a cushion pad with good cushioning properties. ing. Porous materials such as urethane slab chips are often used as the insert material. However, as shown in Fig. 1, when the insert material 2 is inserted into the foam mold 1 and the stock solution of the foamed synthetic resin is injected to perform foam molding, if the insert material 2 is porous, the foamed synthetic resin is used. The undiluted resin solution easily impregnates the insert material 2, and the air in the mold 1 tends to be easily trapped around the insert material 2, and furthermore, the foaming speed of the undiluted solution of the foamed synthetic resin that comes into contact with the insert material 2 is slow, and the outside After the foaming of the foamed synthetic resin stock solution advances, the foaming of the foamed synthetic resin stock solution that comes into contact with the impregnated portion of the insert material 2 progresses, and the air accumulated around the insert material 2 and the air inside the insert material 2 and Foaming gas, etc. generated during foaming of the stock solution of foamed synthetic resin in contact with the insert material destroys the bubbles in the foamed outer pad material 3 and is discharged through the vent hole 4. 1
Air inside the insert material 2, air inside the insert material 2, foaming gas, etc. caused the pad material 3 to crack. In addition, the stock solution of the foamed synthetic resin leaks to the outside through the vent hole 4 of the foam mold 1, and debris of the foamed synthetic resin, called so-called urethane bread, is generated outside the vent hole 4. In order to prevent the occurrence of
There is a structure in which a degassing member 5 such as a non-woven fabric or a thin slab urethane is pasted on the inside of the vent hole 4 of the upper mold IA to prevent the generation of waste such as urethane bread.
When molding pads 6 of different hardness, gas venting members 5 made of non-woven fabric, thin slab urethane, etc. must be attached one by one, which increases costs.

The object of the present invention is to eliminate the risk of cracking in the padding material formed on the outside of the insert material, and to prevent the generation of scum from the foamed synthetic resin, while still allowing the foam molding of degassing materials such as nonwoven fabrics and slab urethane. This provides a method for forming pads of different hardness that does not require each piece of material to be pasted onto a mold, is highly economical, and furthermore, the quality of the foam-molded pad material is extremely good. It will become clear.

FIG. 2 shows an outline of an embodiment of the method for forming a pad of different hardness according to the present invention, and this embodiment will be explained as being applied to a cushion pad used for seats of automobiles, etc. , but not limited to this.

The upper mold IA of the foaming mold 1 is opened, and an insert material 2 formed from a urethane slab chip or the like is placed at a desired position in the lower mold IB in order to previously form a portion of different hardness.

In order to hold this insert material 2, conventionally known appropriate means are used. Further, a pipe 11 having an acute acicular tip is attached to the vent hole 4 formed in the upper die IA, and the tip of the pipe 11 is inserted into the insert material 2. Incidentally, the insert material 2 can also be held by the pipe 11 of the upper mold IA without being placed in the lower mold IB.

Next, the stock solution of foamed synthetic resin is injected into the lower mold IB of the foam mold 1, and foam molding is performed to obtain a pad material 3 integrally molded with the insert material 2. A pad 6 of different hardness is formed. Foaming of the foamed synthetic resin stock solution progresses gradually in the foaming mold 1 from around the center, and the air in the foaming mold 1 and the foaming gas generated during foaming are transferred to the pipe 11 inserted into the insert material 2. It is discharged to the outside of the vent hole 4 through.

At this time, the foaming gas generated when the raw solution of the foamed synthetic resin comes into contact with the insert material 2, where the foaming progresses slowly, is foam-molded, the air accumulated around the insert material 2, and the air inside the insert material 2 as the foaming progresses. The bubbles in the outer pad material 3 are destroyed and are not directly discharged from the vent hole 4.

In the above embodiment, the pipe 11 is attached to the upper mold IA in advance.
As described above, when the upper mold IA is closed and the upper mold IA is closed, the tip of the pipe 11 is inserted into the insert material 2.
After closing the upper mold IA, the pipe 11 may be inserted into the vent hole 4, and the tip of the pipe 11 may be inserted into the insert material 2.

The above is an outline of one embodiment of the method for molding a pad of different hardness according to the present invention. Foaming gas, etc., generated from the slow-foaming parts of the foamed synthetic resin stock solution, is transferred to the outside of the foaming mold through the pipe from the insert material without destroying the bubbles in the outer pad material where foaming has progressed. It is discharged. In addition, the foamed synthetic resin debris such as urethane pans that normally occur outside the vent hole will not be generated, and even if some foamed synthetic resin debris comes out of the pipe through the pipe, it will not reach the upper mold. It does not stick, and after foam molding, the pipe can be removed from the upper mold and easily disposed of. Further, the pad material on the outer periphery of the insert material of the pad material of different hardness made of the foam-molded pad material and insert material is not subjected to pressure inside the foam mold 1, so that a uniform molded product can be obtained.

In the above embodiment, the pipe 11 is attached to the king mold IA of the foaming mold 1 while maintaining liquid tightness, and the length of the pipe 11 that protrudes beyond the mold 1 is increased, and the upper mold IA and the lower mold IB are The foaming mold 1 is sealed in a liquid-tight manner, and the foaming mold 1 is immersed in a liquid kept at a predetermined temperature to heat it by immersion heating. There is no risk and it does not affect the foaming conditions.

FIG. 3 shows a different embodiment of the method for forming a pad of different hardness according to the present invention. In this embodiment, a pair of different hardness parts are added to both sides of the cushion pad to increase the side support function of the cushion pad. The insert materials 2a, 2b and 2c are placed in the lower mold IB of the foam mold 1, and the insert materials 2a, 2b and 2
pipes 11a attached to vent holes 4a, 4b, and 4c, respectively;

A pad of different hardness is molded in the same manner as in the above-mentioned embodiment except that 11b and llc are inserted.

According to the above embodiment, a plurality of insert materials are arranged in the lower mold, a plurality of pipes are inserted into the insert materials, and foaming gas and air inside the insert material are delivered to the foam molding mold through the pipes. There is no risk of the pad material being discharged to the outside and causing cracks, etc., and it is possible to form a high-quality pad of different hardness that has a side support function. Incidentally, the size and shape of the insert material are not limited to those shown in the drawings, and can be variously modified and changed.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional explanatory view of a foam molding die showing a conventional method for forming a pad of different hardness, and Figs. 2 and 3 show the application of the method of forming a pad of different hardness according to the present invention to an automobile seat cushion, respectively. It is a schematic cross-sectional explanatory view of a foaming mold in the case of doing so. In the figure, 1... Foaming mold, 2... Insert material, 3
... Pad material, 4 ... Vent hole, 6 ... Different hardness pad, 11 ... Pipe.

Claims (1)

[Claims] A pre-formed insert material is inserted into a foam mold having a vent hole, a stock solution of foamed synthetic resin is injected into the foam mold, and a pad material integrally molded with the insert material is formed by foam molding. In the method for forming a pad of different hardness, the foaming gas of the foamed synthetic resin generated during foam molding of the pad material and the air inside the insert material are channeled through a pipe provided between the vent hole and the insert material. A method for molding pads of different hardness, characterized by discharging the foam to the outside of the mold.