초록 ▼

A method for producing a structured material for accommodating passage of fluids, particularly high viscosity fluids, through the structured material. In one embodiment, the structured material is a composite material formed of a first layer, for example a polypropylene polymer, having a first shrin

A method for producing a structured material for accommodating passage of fluids, particularly high viscosity fluids, through the structured material. In one embodiment, the structured material is a composite material formed of a first layer, for example a polypropylene polymer, having a first shrinkage extent and a second layer bonded to the first layer, for example an ethylene-propylene copolymer, having a second shrinkage extent different from the first shrinkage extent. In another embodiment, a structured heterogenous material is made of a heterogeneous mixture of at least two homogeneous fiber sets or components having different shrinkage extents.

대표청구항 ▼

What is claimed is: 1. A method for producing a structured composite material for accommodating passage of viscous fluids through the structured composite material, the method comprising the steps of: forming a first layer having a first shrinkage extent, the first layer comprising a nonwoven web;

What is claimed is: 1. A method for producing a structured composite material for accommodating passage of viscous fluids through the structured composite material, the method comprising the steps of: forming a first layer having a first shrinkage extent, the first layer comprising a nonwoven web; forming a second layer having a second shrinkage extent different from the first shrinkage extent, the second layer comprising a film and having openings through the second layer; bonding the second layer to the first layer to form a composite material; and shrinking the second layer relative to the first layer, thereby forming a plurality of fiber loop pores in the first layer and shrinking the openings through the second layer to form a plurality of pores smaller than the fiber loop pores. 2. The method of claim 1, wherein the first layer comprises a propylene polymer and the second layer comprises an ethylene-propylene copolymer. 3. The method of claim 1, further comprising the step of heating the composite material to effect shrinkage of the second layer. 4. The method of claim 1, wherein the second layer is bonded to the first layer by one of thermal bonding, pin bonding and differential speed bonding. 5. The method of claim 1, further comprising the step of stretching the second layer before the second layer is bonded to the first layer. 6. The method of claim 5, wherein the second layer is stretched in a machine direction to about 1.5 to about 6.0 times an initial length. 7. The method of claim 5, wherein the second layer is stretched in a machine direction to about 2.0 to about 4.0 times an initial length. 8. A method for producing a structured composite material for accommodating passage of viscous fluids through the structured composite material, the method comprising the steps of: forming a first layer having a first shrinkage extent; forming a second layer having a second shrinkage extent different from the first shrinkage extent, the second layer comprising a film and having openings through the second layer; bonding the second layer to the first layer to form a composite material; creping the composite material; and shrinking the second layer relative to the first layer, thereby forming a plurality of fiber loop pores in the first layer and shrinking the openings through the second layer to form a plurality of pores smaller than the fiber loop pores. 9. A method for producing a composite material having a structure for accommodating passage of viscous fluids through the composite material, the method comprising the steps of: forming a first layer having a first shrinkage extent, the first layer comprising a nonwoven web; applying a second layer to the first layer to form the composite material, the second layer comprising a film, having a second shrinkage extent different from the first shrinkage extent and having openings through the second layer; and heating the composite material to produce the structure, wherein the second layer shrinks relative to the first layer, thereby forming a plurality of fiber loop pores in the first layer and shrinking the openings through the second layer to form a plurality of pores smaller than the fiber loop pores. 10. A method for producing a composite material having a structure for accommodating passage of viscous fluids through the composite material, the method comprising the steps of: forming a first layer having a first shrinkage extent; creping the first layer; applying a second layer to the first layer to form the composite material, the second layer having a second shrinkage extent different from the first shrinkage extent and comprising a film and having openings through the second layer; and heating the composite material to produce the structure, wherein the second layer shrinks relative to the first layer, thereby forming a plurality of fiber loop pores in the first layer and shrinking the openings through the second layer to form a plurality of pores smaller than the fiber loop pores. 11. The method of claim 9, further comprising the step of stretching the second layer before the second layer is applied to the first layer. 12. The method of claim 9, further comprising the step of pattern embossing the first layer to form thermal bonds which extend through the first layer.