JPS646683A - Heat-insulating box body - Google Patents

Abstract

PURPOSE: To keep an initial thermal insulating property permanently at a thermal insulating box for a refrigerator by a method wherein a laminate bag composed of a metallic foil layer and a plastic layer is installed between an inner box and an outer box, and foam thermal insulating material is injected and foamed within the bag. CONSTITUTION: A laminate bag 9 comprised of a metallic foil layer and a polyethylene film is put into an outer box 2 with an opening end 13 being placed upward and its opening part 12 is inserted into and temporarily fixed to an injection port 4 of the outer box 2. Then, the inner box 1 is inserted with its protruded part being faced down and fixed, the inner box 1 and the outer box 2 are reversed from each other, an injection head is inserted into the opening 12 projected out of the injection port 4 and then foamed thermal insulating material 6 such as rigid urethane foam or the like is injected into the laminate bag 9. After waiting its volumetric expansion, the port 4 is pushed by a lid 14, internal air is discharged at an aeration sheet 15 at its lower surface, the lid 14 is taken out at the time of completion of foaming, an aluminum foil sheet 16 is adhered to prevent humidity at the port 4 so as to complete a thermal insulating box 7. In this way, it is possible to prevent moisture from entering into the foam thermal insulating material and keep an initial thermal insulating property permanently.