| 摘要 |
PCT No. PCT/GB92/00537 Sec. 371 Date Jan. 21, 1994 Sec. 102(e) Date Jan. 21, 1994 PCT Filed Mar. 24, 1992 PCT Pub. No. WO92/16434 PCT Pub. Date Oct. 1, 1992A bilayer laminated material has a gas permeability increasing greatly with temperature, achieved by cutting a star-shaped hole in it when it is relaxed and flat. On warming, the leaves between the radial cuts curl and disproportionately increase the hole size. Such a material, if flat at 5 DEG C. and wide open at 20 DEG C., is useful for packaging vegetable produce. |
