JP2002210837A - Method for manufacturing heat insulating material- containing resin product - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a heat insulating material- containing resin product not having a joint or a joined part and excellent in waterproofness and heat insulating properties. SOLUTION: An outer skin 1 made of a resin and an inner skin 2 made of a resin are molded at the same time by a rotary molding method, and a foamable resin material is injected in the hollow part 4 formed between the outer skin 2 and the inner skin 3 and foamed to manufacture the resin product filled with an insulating material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a resin product containing a heat insulating material such as a waterproof / insulated tank having both waterproof and heat insulating properties.

[0002]

2. Description of the Related Art Many of the waterproof and heat-insulating tanks used in an air-conditioning heat storage system having both waterproof and heat-insulating properties have a gap between an outer wall (outer skin) and an inner wall (endothelium) constituting a skin. And the temperature of the liquid stored in the tank is maintained for a long time by adopting a structure in which the space is filled with a heat insulating material. Conventionally, such a waterproof / insulated tank is manufactured by combining a plurality of panels in which a foamed resin material such as urethane is lined with a plate made of FRP (glass fiber reinforced plastic) such that the foamed resin material is on the inside. I was

[0003]

However, since the above-mentioned conventional waterproof / insulated tank is an assembly, water leaks from the seam of the panel, or a heat bridge occurs at the joint between the FRP and the foamed resin material. There is a problem that the foamed resin material is deteriorated and the heat insulation performance is reduced.

The present invention has been made in view of the conventional problems, and an object of the present invention is to provide a method for producing a resin product containing a heat insulating material, which has no seams or joints, and has excellent waterproof and heat insulating properties. .

[0005]

According to a first aspect of the present invention, there is provided a method of manufacturing a resin product containing a heat insulating material, wherein a resin outer skin and an inner skin are simultaneously formed by a rotational molding method, and then the outer skin and the inner skin are formed. The foamed resin material is injected and foamed into the hollow portion formed between them, thereby producing a resin product in which the gap is filled with a heat insulating material made of the foamed resin material. According to a second aspect of the present invention, there is provided a method of manufacturing a resin product containing a heat insulating material, wherein the resin constituting the outer skin and the inner skin, which is a skin, is polyethylene. According to a third aspect of the present invention, there is provided a method of manufacturing a resin product containing a heat insulating material, wherein the foamed resin material is urethane.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In the method for producing a resin product containing a heat insulating material of the present invention, first, a double wall-shaped skin 1 as shown in FIG. 2 is formed using a rotational molding die 10 as shown in FIG. The outer skin 1 is housed in a foaming frame mold 20 as shown in FIG.
A resin material filled with a heat insulating material is manufactured by injecting and foaming a foamed resin material into a hollow portion 4 formed between the inner wall 3 and the inner wall 3. Hereinafter, in this example, a case of manufacturing a waterproof / insulated tank used in a heat storage system for air conditioning will be described.

The rotary molding die 10 is a substantially rectangular column-shaped die having a concave portion 12 provided with a hollow portion 11 for injecting a thermoplastic resin powder. After injecting thermoplastic resin powder from the mouth and sealing, for example, using a heat source such as gas burner Q,
While applying heat to the outer periphery of the mold 10, the rotation molding unit 10 is rotated in various directions by a rotating mechanism (not shown) to mold a resin product. The resin powder in the mold 10 is plastically deformed by the heat supplied from the heat source to increase fluidity, melts and melts, and
0 uniformly adhere to the inner wall. Thereafter, the rotary molding die 10 is cooled and the product is taken out to obtain a concave resin product having a uniform thickness in which the hollow portion 4 is formed between the outer skin 2 and the inner skin 3. . In this example, linear low-density polyethylene (LLD) is used as the thermoplastic resin.
Using PE), a polyethylene skin 1 having a hollow portion 4 formed between the outer skin 2 and the inner skin 3 was formed.

The foaming frame mold 20 comprises an outer frame 21 and an inner frame 22 held at a predetermined interval. An inlet 23 is provided at the top of the inner frame 22, and an air vent is provided at a lower portion of the outer frame 21. A hole 24 is formed, and the molded skin 1 is formed so that the outer skin 2 is in close contact with the inner peripheral surface 21S of the outer frame 21 and the inner skin 3 is in close contact with the outer peripheral surface 22S of the inner frame 22.
It is disposed in the foaming frame mold 20. Thereafter, urethane, which is a foamed resin material, is injected into the hollow portion 4 from the injection port 23 of the foaming frame mold 20 and foamed, thereby forming a gap between the outer skin 2 and the inner skin 3 as shown in FIG. A waterproof / insulated tank 6 filled with a heat insulating material 5 made of urethane resin can be obtained.

The waterproof / insulated tank 6 manufactured in this way is not an assembly as in the prior art, so it has no water leakage from the seam and is excellent in waterproofness. Since the foam (the heat insulating material) is not deteriorated due to the heat bridge since it is filled in close contact with the skin 1, heat insulation can be secured for a long time. Therefore, the waterproof / insulated tank 6 of this example can be suitably used for an air conditioning heat storage system that requires waterproofness and heat insulation.

In the above-described embodiment, the method of manufacturing the waterproof / insulated tank used in the heat storage system for air conditioning has been described. It is also applicable to resin products. Further, as a resin constituting the outer skin 2 and the inner skin 3 as the skin 1, in addition to polyethylene, for example, a thermoplastic resin such as polystyrene or polyamide, polycarbonate, polypropylene, cross-linked polypropylene, or the like may be used. Further, as the foam, a polyethylene foam, a polystyrene foam, a phenol foam, or the like can be used in addition to the urethane foam.

[0011]

As described above, according to the present invention,
After the resin outer skin and the inner skin are simultaneously formed by a rotational molding method, a foamed resin material is injected and foamed into a hollow portion formed between the outer skin and the inner skin to produce a resin product containing a heat insulating material. As a result, a resin product containing a heat insulating material having excellent heat insulating properties and no water leakage can be manufactured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a rotational molding die according to the present embodiment.

FIG. 2 is a cross-sectional view of a skin formed by a rotational molding method.

FIG. 3 is a diagram showing a configuration of a foaming frame die according to the present embodiment.

FIG. 4 is a sectional view showing an example of a resin product containing a heat insulating material according to the present invention.

[Explanation of symbols]

1 outer skin, 2 outer skin, 3 endothelium, 4 hollow part, 5 heat insulating material, 6 waterproof / insulated tank, 10 rotary mold, 11
Hollow part of mold, 12 concave part, 20 Frame mold for foaming, 21
Outer frame, 22 Inner frame, 23 Inlet, 24 Vent hole, Q gas burner.

Claims (3)

[Claims] 1. A method of manufacturing a resin product containing a heat insulating material, wherein a gap between a resin outer skin and an inner skin is filled with a heat insulating material.
A resin product containing a heat insulating material, wherein the resin product is manufactured by simultaneously molding the outer skin and the inner skin by a rotational molding method, and then injecting and foaming a foamed resin material into a hollow portion formed between the outer skin and the inner skin. Manufacturing method. 2. The method according to claim 1, wherein the resin constituting the outer skin and the inner skin is polyethylene. 3. The method for producing a resin product containing a heat insulating material according to claim 1, wherein the foamed resin material is urethane.