| 摘要 |
PURPOSE:To shorten the time of expansion for an expansible heat insulator by using a system in which an air vent hole having a gradually enlarged diameter is provided from the upstream side of the expansible heat insulator toward its top as a final expansion place on the back wall turned upwards of an outer box when the heat insulator is expanded inside the heat-insulating box of a refrigerator, etc. CONSTITUTION:The back wall 3a of an outer box 3 is turned upwards and the outer box 3 is connected with an inner box 2. Then, a raw liquid is injected into between both the boxes 2 and 3, and the injection hole 21 is closed with a sealing member 23. As the raw liquid expands, air and gases are pushed out, as shown by arrows representing the magnitude of speed gradient, from air vent holes 20A, 20B, and 20C, and an expandible heat insulator 4 partly leaks from the smallest air vent hole 20A, solidifies, and closes the hole 20A and then closes the holes 20B and 20C in sequence. After the solidification of each hole, inner and outer jigs are removed, the expansible heat insulator leaked and solidified from the holes 20A, 20B, and 20C is removed, and the holes are covered with a sealing member 22. By this, a heat-insulating box is completed. Thus, if the removal of air and gases is completely performed, the formation of honeycombs by the stagnation of air in the expanded heat insulator 4 can be avoided. |
