| 摘要 |
PROBLEM TO BE SOLVED: To provide a method of manufacturing a vacuum heat insulating material superior in piercing resistant property, and to provide an outer packaging material for the vacuum heat insulating material.SOLUTION: There is provided a method of manufacturing a vacuum heat insulating material which includes: an outer packaging material for the vacuum heat insulating material, formed by successively stacking at least a protective layer, a gas barrier layer, and a thermally-welded layer; and a core material. The method includes steps of: covering the core material with the outer packaging material for the vacuum heat insulating material in a state that the thermally-welded layer side is positioned inside; keeping an inner portion in a vacuum state by decompression; and sealing an end portion of the outer packaging material for the vacuum heat insulating material by thermal welding. The thermally-welded layer is mainly composed of polypropylene, and stretched within a thermally-weldable range. |
