Applied Extrusion Technologies, Inc.

Hercules Corporation

Joseph V Marra

Edward E Hovis

D Timothy Cullen

An apertured film extruded from a crystalline, thermoplastic, extrudable fluoroplastic material. The film includes spaced-apart strand segments defining apertures therebetween and has at least 10 strand segments per inch. The film has a thickness of 2-12 mils and a Frazier air permeability number in the range of 200-2,000. The invention includes a process for preparing an apertured thermoplastic film by a single-sided embossing method. The process includes the steps of extruding in the machine direction, a film of a molten, crystalline, thermoplastic, extrudable, fluoroplastic material. The molten extruded film is passed in the machine direction through the nip of two metal rollers. One of the rollers has a substantially smooth surface, having a convex configuration as viewed from a direction substantially parallel to the axis of the roll, such that the diameter in the center of the roll is in the range of 8-12 mils greater than the diameter at the ends of the roller for a 40 inch roller. The other roller includes a plurality of discrete, raised projections disposed in a pattern. Each of the projections terminates in a distal end. The ends are separated from each other and are completely surrounded by continuous surface regions located proximate of the distal ends. A sufficient pressure is applied at the nip to cause a plurality of small apertures and/or thin areas to be formed in the extruded film in substantially the same pattern as the pattern of discrete, raised projections of the other of the rollers. The film is stretched in both the cross-machine direction and in the machine direction to increase the open area of the apertures and cause the thin areas to open into apertures. The invention also includes a laminated structure.

Fluoroplastic apertured film fabric, structures employing same and

An adhesive hydrogel product includes a mixture comprising water, and a thermoplastic, water-soluble polymer extruded in a dry state. The thermoplastic, water-soluble polymer constitutes the principal water-soluble polymer of the mixture and is present in the mixture in a concentration, by weight, of at least 15 percent. The mixture having been exposed to a dose of radiant energy effective to provide an adhesive hydrophilic gel having a gel breaking strength of at least 10 p.s.i., and an absorption capacity per mil of thickness of the gel in excess of 10% by weight, and more preferably in excess of 30% by weight. The method includes the steps of directing a substrate including an extruded, thermoplastic, water-soluble polymer through a liquid bath at a speed for causing the substrate to absorb approximately 30 percent to about 80 percent, by weight, of said liquid to thereby convert said water-soluble polymer into a hydrogel; separating the substrate into discrete hydrogel products; packaging the discrete hydrogel products in moisture-impervious packages, and subjecting the packaged hydrogel products to a dose of radiation effective to provide an adhesive hydrogel having a gel breaking strength of at least 10 p.s.i., and an absorption capacity per mil of thickness of the gel in excess of 10%, by weight, and more preferably in excess of 30% by weight.

Hydrogel products and methods of producing same

A composite nonwoven fabric-like laminate which includes an integrated mat of polymeric microfibers having a diameter of less than 30 microns and a layer of nonwoven linearly oriented thermoplastic netting, the mat and netting being either continuously bonded or spot-bonded to produce a laminate with the desired properties.

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Wilmington, DE, United States of America

Joseph V Marra