| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a plastic film capable of preventing either external germs or moisture from entering and ensuring permeability due to increased pressure of gas generated inside. SOLUTION: A permeable resin film 2 with a thickness of about 3 to 10μm is applied to form and cover one surface of a porous film 1 having some fine holes 10 therein and then a non-permeable film 3 having some cut slits 30 is applied to cover the other surface of the porous film 1. Then, the non- permeable film 3 is applied outside to cause the cut slits 30 to be opened due to an increased pressure from inside and then gas flowed from inside escapes from some cut slits 30 opened through some fine holes 10 from the permeable resin film 2, resulting in that the film may become a gas permeable one.</p> |
