JP2002210836A - 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 separately molded by rotary molding and subsequently housed in the predetermined gap (hollow part) 4 provided in a foaming retaining mold 20 and a foamable resin material is injected in the hollow part 4 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 a resin inner skin are separately molded by a rotational molding method. The outer skin and the inner skin are housed with a predetermined gap provided in a foaming frame mold, a foamed resin material is injected and foamed in the gap, and a heat insulating material made of the foamed resin material is provided in a gap between the outer skin and the inner skin. It is characterized in that a filled resin product is manufactured. 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, an outer skin and an inner skin, which are the skin of the resin product, are separately molded using a rotational molding die 10 as shown in FIG. The outer skin and the inner skin are housed in a foaming frame mold 20 as shown in FIG. 3, and a foamed resin material is injected into a gap between the outer skin 1 and the inner skin 2 to cause foaming, and a resin filled with a heat insulating material is provided. It manufactures products. 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 mold 10 is rotated in various directions by a rotation 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 uniformly adheres to the inner wall of the mold 10. Thereafter, the rotational molding die 10 is cooled to take out the product, whereby a concave resin product having a uniform thickness can be obtained. In this example, linear low density polyethylene (LLDPE) is used as the thermoplastic resin.
Then, a polyethylene outer shell 1 as shown in FIG. Further, the inner skin 2 made of polyethylene was molded separately from the outer skin 1 in the same manner as the outer skin 1.

As shown in FIG. 3, the foaming frame mold 20 includes an outer frame 21 and an inner frame 22 held at a predetermined interval.
An injection port 23 is formed at the top of the inner frame 22, and an air vent hole 24 is formed at a lower portion of the outer frame 21. The molded outer skin 1 is in close contact with the inner peripheral surface 21S side of the outer frame 21. Thus, the inner skin 2 is disposed in the foaming frame mold 20 so as to be in close contact with the outer peripheral surface 22S of the inner frame 22 corresponding to the inner peripheral surface 21S of the outer frame 21. The space between the outer frame 21 and the inner frame 22 is such that when the outer skin 1 and the inner skin 2 are set, a gap of a predetermined size (hereinafter referred to as a hollow portion) is formed between the outer skin 1 and the inner skin 2. ) 4 is set in advance so that 4 is formed. In this example, after the polyethylene outer skin 1 and the inner skin 2 formed using the rotational molding die 10 are set in the foaming frame mold 20 as described above, the foamed resin material is injected through the injection port 23. By injecting urethane into the hollow portion 4 and foaming the same, as shown in FIG. 4, the gap between the outer skin 1 and the inner skin 2 is filled with a heat insulating material 3 made of urethane resin.
An insulated tank 5 can be obtained.

Since the waterproof / insulated tank 5 manufactured in this manner is not an assembly as in the prior art, it does not leak from the seam and has excellent waterproof properties. Foam (heat insulation material) by heat bridge because it is filled in close contact with the outer skin (outer skin 1 and inner skin 2)
, And heat insulation can be ensured for a long period of time. Therefore, the waterproof / insulated tank 5 of this example can be suitably used for an air conditioning heat storage system that requires waterproofness and heat insulation.

In the above embodiment, the method of manufacturing the waterproof / insulated tank 5 used in the heat storage system for air conditioning has been described. However, the present invention is not limited to this. It is also applicable to filled resin products. Further, as the resin constituting the outer skin 1 and the inner skin 2 as the skin, in addition to polyethylene, for example, a thermoplastic resin such as polystyrene or polyamide, or polycarbonate, polypropylene, or cross-linked polypropylene 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 separately forming the resin outer skin and the resin inner skin by a rotational molding method, a foamed resin material is injected and foamed into a gap between the outer skin and the inner skin to manufacture a resin product containing a heat insulating material. Therefore, it is possible to manufacture a resin product containing a heat insulating material that has excellent heat insulating properties and does not leak water.

[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 sectional view of an outer 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 endothelium, 3 heat insulating material, 4 hollow portion, 5 waterproof / insulated tank, 10 rotary molding die, 11 die hollow portion, 12 concave portion, 20 foaming frame mold, 21 outer frame, 2
2 Inner frame, 23 inlet, 24 air vent, 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.
After the outer skin and the inner skin are separately formed by a rotational molding method, the outer skin and the inner skin are housed with a predetermined space provided in a foaming frame mold, and a foamed resin material is injected and foamed into the space to manufacture. A method for producing a resin product containing a heat insulating material. 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.