| 摘要 |
In a cellular material a first panel having a series of lengthwise accordion folds across the width of the panel, alternate folds projecting toward the front of the panel and the back of the panel is attached to a second panel of material in a manner to create a series of P-shaped cells having a back, an upper cell wall and a lower cell wall in which the upper cell wall and the lower cell wall are curved in a same direction. |
