| 摘要 |
A film or material which automatically controls its porous properties in relation to changes in its local environment comprises either two layers having different fluid absorption properties or a layer 1 having discrete surface areas 2 of different fluid absorption property. The film or material is cut to provide flaps 4a - 4d therethrough, so that the strain difference caused by the different absorption properties causes the flaps to bend and form openings. The discrete areas 2 are produced by attaching material or by treating with plasma, chemicals or radiation. Uses include clothing, bandages, wound dressings, food wrapping, tents and cloches. |
