| 摘要 |
PURPOSE:To adjust bonding strength freely by deforming mouth edges within the wall thickness of a base plastic film in the molten state, pseudo-bonding two films and finishing them into one film. CONSTITUTION:A base film 4 consisting of a pored plastic film 1 with small pores 2 having mouth edges 3 of crater shape and a polypropylene resin film in the molten state just after extrusion film forming is faced a polyethylene resin film by the vacuumizing method, which are clamped between clamping rolls, and mouth edges 3 of small pores 2 are bitten into the wall thickness of the plastic film 4, crushed and deformed. In the case of enhancing pseudo- bonding strength, the diameter L and the height H are increased and the number of small pores 2 is increased. Out of said three conditions, only H or L or only said number can be increased to enhance strength, which is determined by the problem of breathing volume at the time of opening the pores, the problem of through-view inside or the like. Pseudo-bonding strength can be adjusted by said arrangement. |
