| 摘要 |
PURPOSE: To inexpensively massproduce a protective envelope capable of being held in compressed condition when not used and expanded into an impact- absorbing state when used, by holding a synthetic resin foam between the synthetic resin airtight sheets larger than the foam, compressing the foam between the sheets by pressing, and simultaneously heat sealing the ends of the sheets. CONSTITUTION: A synthetic resin foam 23 is held between the synthetic resin airtight sheets 24 having a length and a width larger than those of the foam 23, and pressed to be compressed between the sheets 24, and simultaneously the ends of the sheets 24 are heat sealed to keep the foam 23 in a compressed condition under vacuum to prepare an expandable member 22, then the member 22 is inserted between bag-shaped inner wall 15 and outer wall 12, and both walls are bonded thereafter. An article 19 is put in the inner wall 15, then a part 31 of the airtight coating is punctured to expose the expandable member 22 to the atmospheric air, so that the member 22 is expanded into an impact- absorbing state, and the fragile article 19 is wrapped in a state that it is surrounded by the member 22 through the inner wall 15. |
