| 摘要 |
PURPOSE:To obtain a foamed sheet having a nerve required at cutting and a softness required at packaging an article by specifying a ratio of a nerve in long side direction and a nerve in short side direction in a protrusion of a foamed sheet having a closed cell chamber and specifying a plurality of shapes of it. CONSTITUTION:A foamed sheet comprises a closed cell chamber made by connecting an upper layer sheet consisting of a thermoplastic resin film having a number of protrusions on its surface and a lower layer sheet consisting of a thermoplastic resin film having a flat surface. The protrusion of the foamed sheet consists of long sides and short sides. A ratio of a nerve S1 in the long side direction of the protrusion and a nerve S1 in the short side direction of the protrusion is 2.5<S1/S2. As for the shapes of a plurality of protrusions, a ratio of a length L1 of the long side of the protrusion and a length L2 of the short side of the protrusion is within a range of 1.2<=L1/L2<=20. The protrusions are arranged staggeringly in the short side direction and arranged linearly in the long side direction. Further, the short side direction of the protrusion is made to be the cross direction of the foamed sheet. |
