Water impervious materials

Claim 2

A water impervious laminated material comprising: a layer of conjugate fibers having a first face and an opposite face, said conjugate fibers being composed of a lower melting component and a higher melting component, wherein a substantial proportion of the surfaces of said conjugate fibers comprises said lower melting component; and a plastic laminated film which comprises a first layer and a second layer, said first layer of said film being thermoplastic and possessing a lower melt temperature than said second layer, the lower melting component of said conjugate fibers on said first face having been fuse bonded to said first layer of said plastic laminated film at a temperature below the melt temperature of said higher melting component of said fibers so that the latter component retains its initial fiber-like integrity.

Claim 3

The water impervious laminated material of claim 1, further comprising: a second layer of conjugate fibers of the type defined in claim 1, and a third layer on the plastic laminated film on the side of the second layer remote from the first layer, the third layer of said film being thermoplastic and possessing a lower melt temperature than said second layer, the lower melting component of said conjugate fibers on the first face of said second layer of conjugate fibers having been fuse bonded to said third layer of said laminated plastic film at a temperature below the melt temperature of said higher melting component of said fibers so that the latter component retains its initial fiber-like integrity.

Claim 4

The material of claim 1 or claim 2, in which the melt temperature of the first and, if present, the third layer of the laminated film is no more than 35°C higher or lower than that of the lower melting component of the conjugate fibers.

Claim 5

The material of any one of claims 1 to 3, in which the second layer of said laminated film comprises isotactic polypropylene.

Claim 6

The material of any one of claims 1 to 4, wherein the first layer and, if present, the third layer comprises independently ethylene/vinyl acetate copolymer, polyethylene, chlorinated polyethylene or polyvinyl chloride.

Claim 7

The material of claim 5 when dependent on claim 2, wherein the first and third layers are both either ethylene/vinyl acetate copolymer or polyethylene.

Claim 8

The material of any one of claims 1 to 6, wherein the conjugate fiber is a polyethylene/polyester sheath/core bi-component fiber.

Claim 9

The material of any one of claims 1 to 7, wherein said material has been bonded by means of a heated embossing calender or by passing the material through an oven while said material is held between two porous belts under light pressure.

Claim 10

The material of any one of claims 1 to 8, wherein the first layer and/or, if present, the second fiber layer comprises said conjugate fibers blended with non-conjugate fusible fibers, with the proviso that said first face thereof contains a plurality of conjugate fibers in said blend.

Claim 11

A process for preparing a water impervious laminated material according to any one of claims 1 to 9, comprising: forming an assembly of a first layer of conjugate fibers arranged with its first face adjacent the first layer of the plastic laminated film and, if the film comprises a third layer, a second layer of conjugate fibers arranged with its first face adjacent the third layer; subjecting said assembly to a temperature sufficient to fuse said lower melting component of said conjugate fibers which lie on said first face as well as the first and, if present, third layers of the film in contact with the fibers without fusing the higher melting component of said conjugate fibers nor the second layer of the film, while maintaining said assembly under minimal pressure; and cooling said assembly to resolidify said lower melting component of the fibers as well as said first and, if present, third layers of said film whereby said fibers are firmly bonded to said film without impairing the integrity of said higher melting component of said fibers.