JPH09201831A - Mold and method for molding of urethane foam pad - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent urethane foam stock solution from creeping around a front side of a product by raising adhesion between resin and protruded wall by a method wherein a slit-forming protruded wall is provided so as to put an outer periphery of foamed synthetic resin to be integrally foamed between the protruded walls, and the slit forming protruded wall is made almost perpendicular to a seat. SOLUTION: Side slit-forming protruded walls inserting a slab foam 1 as integral foaming use between them are formed perpendicularly or in a reverse tapered shape. In order to obtain good moldability especially even at a terminal part of the slit forming protruded wall, a height of the slit forming protruded wall is sufficiently secured so as to reach at least 50% of a thickness of the slab foam. Adhesion between the slab urethane foam 1 and the slit forming protruded wall is raised to prevent the urethane foam stock solution to be poured later from going around. Further, the mold at a front end part of the pad is made vertical to raise adhesion to the slab urethane foam. Therefore, excellent foamed synthetic resin integrally molded product can be prepared.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a urethane foam molding die and a molding method for integrally foaming a synthetic foam resin.

[0002]

2. Description of the Related Art Conventionally, as a urethane foam molding pad for improving the comfort of an automobile seat occupant,
A layered different hardness pad has been proposed in which the surface layer of the pad is softened in order to relieve the pressure applied to the human body from the seat pad at the bottom of the buttocks and the backrest, and the lower portion is made of foam having relatively high rigidity. Specifically, a method of injecting two or more types of undiluted urethane blending liquids having different hardness into a mold at the same time or with a time difference, or a preformed urethane foam having a different hardness such as a slab urethane foam in advance. There is a method of setting inside and foaming integrally.

[0003]

As a method for producing the above-mentioned layered different hardness product, the slab urethane foam is set in advance in the mold on the surface of the pad, and the undiluted solution for the urethane foam pad for molding is injected into it. Then, the one that has been integrally foamed has been widely used, but there has been a problem that the injected urethane foam wraps around the surface side of the foamed synthetic resin such as slab foam. Especially with conventional dies, even if you try to sandwich slab urethane foam etc. between the projection walls for slit formation, the side walls of the projection walls for slit formation have a draft slope during molding, so there is a gap between the slab and urethane. As a result, a urethane foam undiluted solution wraps around to the surface of the slab foam without forming a close contact.

In the present invention, by devising a mold, the foamed synthetic resin such as a slab urethane foam that has been set and the outer peripheral wall of the slit forming projections are improved in adhesiveness and injected for later integral foaming. Obtaining a mold for preventing the urethane foam stock solution from wrapping around the surface side of the foamed synthetic resin (that is, the front side of the product), and using the mold, a method for obtaining a urethane foam pad solving this problem The purpose is.

[0005]

According to the present invention, as a means for solving the above-mentioned problems, first, as described in claim 1, a foamed synthetic resin preliminarily processed into a desired shape is set in a mold, and In a urethane foam molding die for injecting a molding urethane foam undiluted solution into an integrally foamed product, a slit forming projection wall or a mold inner wall portion is provided so as to sandwich the outer periphery of the foamed synthetic resin that is integrally foamed, Further, the urethane foam pad molding is characterized in that the slit forming projection wall on the side where the foamed synthetic resin and the mold are in contact with each other or the inner wall of the mold is made substantially perpendicular to the seating surface or is inversely tapered. As a mold for use in molding, as described in claim 2, 6 of the outer circumference of the foamed synthetic resin integrally foamed.
The slit forming projection wall or the mold inner wall portion is provided so as to sandwich 0% or more, preferably 80% or more, and at least the slit forming projection wall or the mold inner wall portion that is in contact with the foamed synthetic resin is provided with respect to the seat. The mold for urethane foam pad molding is characterized by being substantially vertical or having a reverse taper.

Further, as described in claim 3, in the molding die, the height of the slit forming projection wall for sandwiching the foam synthetic resin is at least 30% or more of the thickness of the foam synthetic resin for integrally foaming, It is preferably 50% or more, more preferably 80% or more. Further, in the molding die as described in claim 4, the height of the slit forming projection wall for sandwiching the foamed synthetic resin is at least 5 mm or more, preferably 10 mm or more, more preferably 15 mm.
The above is a mold for molding a urethane foam pad characterized by the above.

Further, as described in claim 5, 1 to 10 are set depending on the interval between the projection wall for forming slits or the inner wall of the mold in which the size of the foamed synthetic resin to be integrally foamed is set.
A method for molding a urethane foam pad, which is characterized by being made larger. Furthermore, as described in claim 6,
It is a method for producing a urethane foam pad molded article by using the urethane foam pad molding die according to any one of claims 1 to 5.

When defining the height of the projection wall for slit formation, the point is to make it possible to firmly seat the urethane foam foaming undiluted liquid between the projection wall for slit formation and the foamed synthetic resin, and this is an appropriate value. The height of the slit forming projection wall depends on the thickness of the foamed synthetic resin integrally foamed in the portion in contact with the slit forming projection wall.
In general, it is desirable to increase the height of the slit forming projection wall as the thickness of the foam synthetic resin increases, and the height of the slit forming projection wall is at least 30% or more of the thickness of the foam synthetic resin, preferably 50% or more, more preferably 80% or more is desired. However, when the thickness of the foamed synthetic resin that is integrally foamed is small (for example, about 10 mm), if the projection wall height for slit formation is defined by the ratio of the thickness of the foamed synthetic resin, sufficient sealing performance cannot be secured. Occurs. In this case, the height is not specified by the ratio, and the height of the slit forming projection wall is at least 5 mm or more, preferably 10 mm or more, and more preferably 15 mm or more.

It is ideal that the foamed synthetic resin to be integrally foamed is sealed by sandwiching the entire outer periphery thereof with the slit forming projection wall or the inner wall of the mold, but it is possible to form by molding only 60% or more of the entire outer periphery. May be possible. But,
In order to obtain a sufficiently good moldability, it is generally more preferable to sandwich 80% or more of the entire outer circumference.

As a method for making the slit forming projection wall vertical, if only one side of the slit forming projection wall is made vertical, it is also possible to make it vertical from the beginning during modeling. Further, as another method, a die is produced with a normal passing gradient, and then a slant portion of a wall for forming a slit is shaved by machining to make it vertical, or a projection for forming a slit formed vertically in advance. It is also possible to attach the wall later. However, the method for making the slit forming projection wall vertical is not limited to the three types mentioned here.

In order to prevent the injected urethane foaming undiluted solution from wrapping around to the pad surface side, it is considered more effective that the slit forming projection wall is provided with a reverse hand rather than a vertical wall. In addition, when the slab urethane foam etc. are integrally foamed when the slit forming projection wall is vertical, an impregnated cured layer of the urethane foaming stock solution is formed on the vertical surface of the outer periphery of the slab urethane foam that contacts the slit forming projection wall. However, since the hardened layer is present as a vertical vertical wall, there is a problem that it feels as if it were a foreign object when sitting. However, the reverse taper makes it difficult to form the impregnated hardened layer, and even if it can be done, it will not be perpendicular to the seating direction, but it will be a surface with a certain degree of inclination, so a feeling of foreign matter will be felt more than when it is vertical. Effects such as difficulty may be considered. A method of retrofitting the slit forming projection wall portion may be considered to give the slit forming projection wall an inverse taper, but the present invention is not limited to this method. Further, the present invention is not limited to making only one surface of the slit forming projection wall substantially vertical or inversely tapered, and both sides of the slit forming projection wall may be made substantially vertical or inversely tapered.

As the foamed synthetic resin, slab urethane foam is most commonly used as shown in claim 6, but other foams such as polyethylene, polystyrene and polypropylene are also conceivable. However, the present invention is not limited to the materials mentioned here.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, detailed examples thereof will be shown in Examples, but of course the present invention is not limited to these Examples.

[0014]

【Example】

[Example 1] According to the present invention, a side slit forming protrusion wall for sandwiching a slab foam for integral foaming is formed vertically,
Alternatively, sample cross-sections of the reverse tapered embodiment are shown in FIGS. 1-6, and in particular in FIGS. As shown in FIGS. 2 and 3, the slit forming projection wall height is 50% or more (more preferably 80% or more) of the slab foam thickness in order to obtain good formability, particularly in the slit forming projection wall end portion. The slab urethane foam and the wall of the slit forming projection are tightly adhered to each other so as to prevent the undiluted urethane foam liquid from wrapping around. FIG.
As shown in, the die at the front end of the pad is also vertical so that the adhesion with the slab urethane foam is enhanced.

The following materials were used as the materials used here. Injection urethane foam: Density: 0.050 g / cm3 25% Hardness: 25 kgf / φ200 Slab foam material: Made by Bridgestone Product name: XY-RD Density: 0.060 g / cm3 25% Hardness: 4.5 kgf / φ200

[Comparative Example 1] For comparison, FIG. 7 shows a cross-sectional view in the case where a slab urethane foam which is integrally foamed is set in a mold having a slope on a conventional slit forming projection wall. As shown in the figure, a gap is created between the slab urethane foam and the mold slit forming projection wall, and the urethane undiluted solution enters from this gap and wraps around to the slab surface side.

[0017]

As described above in detail with respect to the present invention, when the mold of the present invention is used, a foamed synthetic resin previously processed into a desired shape is set in the mold to integrally foam urethane foam. When the pad is obtained, it is possible to produce a good foam synthetic resin-integral molded article without the urethane foam stock solution injected later going around the surface of the foam synthetic resin.

[Brief description of drawings]

FIG. 1 is a perspective view of a sample in which a slab urethane foam is integrally foamed with a slit forming projection wall being substantially vertical.

FIG. 2 is a lateral cross-sectional view of a part of the sample corresponding to the AA ′ cross section in FIG. 1 of the pad.

FIG. 3 is a pad diagram.

FIG. 4 is a lateral cross-sectional view of a die corresponding to a section taken along the line BB ′ in FIG. 3 when the slit forming projection wall is substantially vertical.

FIG. 5 is a cross-sectional view of a die of a portion corresponding to the BB ′ cross section in FIG. 3, the pad when the slit forming projection wall is reversely tapered.

FIG. 6 is a vertical cross-sectional view of a mold corresponding to a CC ′ cross section of the pad in FIG. 3 when the slit forming projection wall is made substantially vertical.

FIG. 7 is a cross-sectional view of a mold when the integrally foamed slab urethane foam is set in a mold having a projection wall for forming a normal slit.

[Explanation of symbols]

1 Slab urethane foam that is integrally foamed 2 Slit surface of vertically molded pad 3 Slit forming projection wall end 4 Mold 5 Slit forming projection wall with one side vertical 6 Slit forming projection with one side reverse taper Wall 7 Slit forming projection wall with both sides vertical 8 Mold front end with vertical contact surface with slab 9 Rear mold end with vertical contact surface with slab 10 Normal slit forming projection wall 11 Gap between the slab foam and the projection wall for slit formation

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B29K 105: 04 B29L 9:00 31:58

Claims (7)

[Claims] 1. A urethane foam pad molding die in which a synthetic foam resin which has been processed into a desired shape is set in advance in a mold, and a urethane foam stock solution for molding is injected into this to mold an integrally foamed product. A slit forming projection wall or a mold inner wall portion is provided so as to sandwich the entire outer circumference or a part of the foamed synthetic resin to be foamed, and at least the slit forming projection wall or the mold inner wall portion on the side in contact with the foam synthetic resin is provided. A mold for urethane foam pad molding, which is characterized by being almost vertical or inversely tapered with respect to the seat. 2. A slit forming projection wall or a mold inner wall portion is provided so as to sandwich 60% or more, preferably 80% or more of the outer periphery of the integrally foamed synthetic resin, and at least the side in contact with the synthetic resin foam. 2. The urethane foam pad molding die according to claim 1, wherein the slit forming projection wall or the inner wall portion of the die is made substantially vertical to the seat or has an inverse taper. 3. The mold according to claim 1, wherein the height of the slit forming projection wall sandwiching the foamed synthetic resin is at least a portion of the foam which is in contact with the slit forming projection wall. A urethane foam pad molding die characterized in that the thickness of the synthetic resin is 30% or more, preferably 50% or more, and more preferably 80% or more. 4. The mold according to any one of claims 1 to 3, wherein the height of the slit forming projection wall that sandwiches the foamed synthetic resin is at least 5 mm or more, preferably 10 mm.
mm or more, more preferably 15 mm or more, a urethane foam pad molding die. 5. The molding die according to claim 1, wherein the dimension of the foamed synthetic resin to be integrally foamed is set to be 1 to 10% larger than the slit forming projection wall interval. A urethane foam pad molding method characterized in that 6. The urethane mold pad molding die and method according to claim 1, wherein a soft slab urethane foam is used as the foamed synthetic resin to be integrally foamed. Urethane foam pad molding method. 7. A method for molding a urethane foam pad, which comprises using the mold for molding a urethane foam pad according to any one of claims 1 to 6.