摘要 |
A method of producing an apertured structured material (10) for accommodating passage of fluids, particularly high viscosity fluids, through the apertured structured material (10). In one embodiment, the apertured structured material (10) is a composite material formed by differential shrinkage of a shrinkable second layer (30), for example an ethylene-propylene copolymer, which is laminated to a first layer (20), for example a polypropylene polymer. During the differential shrinkage process, a plurality of slits (44) which are formed in the second layer (30) open to form uniformly-shaped apertures (45). In another embodiment, an apertured structured heterogenous material is made of a heterogeneous mixture of at least two homogeneous fiber sets or components having different shrinkage extents. |