| 摘要 |
PROBLEM TO BE SOLVED: To prevent discoloration by the ultraviolet ray, etc., by opening a plurality of holes in a non-crosslinked polyolefine resin foamed body, and to easily form the cushioning material having flexibility, deformability, and shape restoration by providing the cell structure of semi-continuous bubbles. SOLUTION: The cushioning material 7 is formed by foaming the polyolefine resin without using the crosslinking agent, and a hole 8 is opened after foaming. Cells K2 having continuous openings are formed in the hole 8 for the cell structure which is of closed cell foam K1 to realize the semi-continuous foam. Holes are opened by the needle driving operation to drive the needle surface of a needle plate on which innumerable needles are planted. The hole opening density is determined by arbitrarily selecting the needle density of needles to be planted on the needle plate, or the needle driving number to regulate the flexibility, deformability, and shape restoration of the cushioning material 7. |
