The present invention provides a single-layer shape retaining material which is a fibrous, band-like, or sheet-like stretched formed material comprising 100 parts by weight of a high-density polyethylene resin having a weight-average molecular weight of 100,000 to 500,000 and a density of 0.945 to 0.960 g/cm.sup.3 and 3 to 50 parts by weight of an ethylene--olefin copolymer obtained by copolymerizing ethylene with an -olefin having 4 to 10 carbon atoms, the copolymer having a density of 0.935 to 0.960 g/cm.sup.3, the difference in density between the copolymer and the high-density polyethylene resin being 0.020 g/cm.sup.3 or less and a method for producing same.

The present invention provides a single-layer shape retaining material which is a fibrous, band-like, or sheet-like stretched formed material comprising 100 parts by weight of a high-density polyethylene resin having a weight-average molecular weight of 100,000 to 500,000 and a density of 0.945 to 0.960 g/cm.sup.3 and 3 to 50 parts by weight of an ethylene--olefin copolymer obtained by copolymerizing ethylene with an -olefin having 4 to 10 carbon atoms, the copolymer having a density of 0.935 to 0.960 g/cm.sup.3, the difference in density between the copolymer and the high-density polyethylene resin being 0.020 g/cm.sup.3 or less and a method for producing same.

A film material formed of thermoplastic polymer material is processed so as to have linearly extending regions (A) linked together by linearly extending webs (B), regions (A) and webs (B) each being oriented, the dominant direction of orientation in regions (A) forming an angle (V) to the direction on which (A) extends and webs (B) comprising arrays of linear furrows of thinner material or splits forming angles (U) higher than (V) to the direction in which (A) extends. The method of producing the new film involves passing an orientated film through a pair of intermeshing grooved rollers to cold-stretch the film in a direction at an angle to the predominant original orientation, at least one of the grooved rollers having crests with sharp edges to form the division between regions A and webs B and to stretch the material to form webs B while stretching the material less or not at all to form regions A. Preferably at least one of the grooved rollers has crests with a waved surface shape.

Multi-layer films include at least one cavitated core layer that is microporous and breathable, and at least one skin layer. The cavitated core layer includes a polyolefin and an inorganic filler dispersed in the polyolefin. Methods for forming polymeric films and articles of manufacture prepared therefrom are described.

Multi-layer films include at least one cavitated core layer that is microporous and breathable, and at least one skin layer. The cavitated core layer includes a polyolefin and an inorganic filler dispersed in the polyolefin. Methods for forming polymeric films and articles of manufacture prepared therefrom are described.

The present invention is directed to a method of incrementally stretching polymeric film formed from a blown film extrusion process. The present invention is further directed to a polymeric bag formed from an incrementally stretched polymeric film. The incremental stretching is performed on a collapsed polymeric bubble via a pair of intermeshing rollers. The incrementally stretched polymeric film may be stretched only along a portion of its width. The polymeric bag may be a drawstring trash bag with an extended hem where only the extended hem of the bag or the body of the bag comprises incrementally stretched polymeric film.

Methods for forming discrete deformations in web materials are disclosed. In some embodiments, the method involves feeding a web into an apparatus having nips that are formed between intermeshing rolls. The apparatus may be in the form of nested or other arrangements of multiple rolls, in which the web is maintained in substantial contact with at least one of the rolls throughout the process, and at least two of the rolls define two or more nips thereon with other rolls. In some embodiments, rolls can be used to expose a different side of the web for a subsequent deformation step. In these or other embodiments, the rolls can be used to transfer the web between rolls in such a manner that it may offset the rolls and/or web so that subsequent deformations are formed at a different cross-machine direction location than prior deformations.

Methods for forming discrete deformations in web materials are disclosed. In some embodiments, the method involves feeding a web into an apparatus having nips that are formed between intermeshing rolls. The apparatus may be in the form of nested or other arrangements of multiple rolls, in which the web is maintained in substantial contact with at least one of the rolls throughout the process, and at least two of the rolls define two or more nips thereon with other rolls. In some embodiments, rolls can be used to expose a different side of the web for a subsequent deformation step. In these or other embodiments, the rolls can be used to transfer the web between rolls in such a manner that it may offset the rolls and/or web so that subsequent deformations are formed at a different cross-machine direction location than prior deformations.

An apparatus for producing a stretchable sheet includes a pair of gear rolls each having a plurality of teeth arranged on a circumference thereof. The apparatus is configured to draw a raw sheet by passing the raw sheet through a gap between the pair of gear rolls. The raw sheet contains a plurality of types of fibers, and has a plurality of recessed sections formed by pressing. The recessed sections are formed collinearly at least along the drawing direction at a predetermined formation pitch in the drawing direction. An arrangement pitch of the teeth in the drawing direction is greater than the formation pitch and smaller than twice the formation pitch.

An apparatus for producing a stretchable sheet includes a pair of gear rolls each having a plurality of teeth arranged on a circumference thereof. The apparatus is configured to draw a raw sheet by passing the raw sheet through a gap between the pair of gear rolls. The raw sheet contains a plurality of types of fibers, and has a plurality of recessed sections formed by pressing. The recessed sections are formed collinearly at least along the drawing direction at a predetermined formation pitch in the drawing direction. An arrangement pitch of the teeth in the drawing direction is greater than the formation pitch and smaller than twice the formation pitch.