Abstract: A method of making a non-woven fibrous media, combining high vapor permeability and low liquid permeability, includes the steps of providing a non-woven fabric formed from fibers that are prematurely crystallized during fabric formation and have a wide heat of fusion range distribution, and calendering the fabric to soften the small polymer crystals therein of low heats of fusion, but not the relatively larger polymer crystals therein of relatively higher heats of fusion, thereby to retain high vapor permeability while providing low liquid permeability. The polymer is preferably isotactic polypropylene.

Abstract: A method of making a non-woven fibrous media, combining high vapor permeability and low liquid permeability, includes the steps of providing a non-woven fabric formed from fibers that are prematurely crystallized during fabric formation and have a wide heat of fusion range distribution, and calendering the fabric to soften the small polymer crystals therein of low heats of fusion, but not the relatively larger polymer crystals therein of relatively higher heats of fusion, thereby to retain high vapor permeability while providing low liquid permeability. The polymer is preferably isotactic polypropylene.

Abstract: A nonwoven fabric from spun fibers wherein the density of the spun fibers in the fabric varies between strips of relatively high density and strips of relatively low density. The strips extend along the length of the fabric in the machine direction in an alternating pattern, with the high density strips separated from each other by low density strips. The alternating high density and low density strips provide the fabric with a higher percent elongation in the cross direction than in the machine direction. The alternating pattern is achieved through use of a pattern screen defining a plurality of elongated air permeable regions separated by elongated substantially or relatively air impermeable regions, the elongated regions extending in the machine direction in an alternating pattern, with the air permeable regions separated from each other by the substantially or relatively air impermeable regions.

Abstract: A method of making a non-woven fibrous media, combining high vapor permeability and low liquid permeability, includes the steps of providing a non-woven fabric formed from fibers that are prematurely crystallized during fabric formation and have a wide heat of fusion range distribution, and calendering the fabric to soften the small polymer crystals therein of low heats of fusion, but not the relatively larger polymer crystals therein of relatively higher heats of fusion, thereby to retain high vapor permeability while providing low liquid permeability. The polymer is preferably isotactic polypropylene.

Abstract: A nonwoven fabric from spun fibers wherein the density of the spun fibers in the fabric varies between strips of relatively high density and strips of relatively low density. The strips extend along the length of the fabric in the machine direction in an alternating pattern, with the high density strips separated from each other by low density strips. The alternating high density and low density strips provide the fabric with a higher percent elongation in the cross direction than in the machine direction. The alternating pattern is achieved through use of a pattern screen defining a plurality of elongated air permeable regions separated by elongated substantially or relatively air impermeable regions, the elongated regions extending in the machine direction in an alternating pattern, with the air permeable regions separated from each other by the substantially or relatively air impermeable regions.

Abstract: A nonwoven fabric from spun fibers wherein the density of the spun fibers in the fabric varies between strips of relatively high density and strips of relatively low density. The strips extend along the length of the fabric in the machine direction in an alternating pattern, with the high density strips separated from each other by low density strips. The alternating high density and low density strips provide the fabric with a higher percent elongation in the cross direction than in the machine direction. The alternating pattern is achieved through use of a pattern screen defining a plurality of elongated air permeable regions separated by elongated substantially or relatively air impermeable regions, the elongated regions extending in the machine direction in an alternating pattern, with the air permeable regions separated from each other by the substantially or relatively air impermeable regions.

Abstract: A nonwoven fabric from spun fibers wherein the density of the spun fibers in the fabric varies between strips of relatively high density and strips of relatively low density. The strips extend along the length of the fabric in the machine direction in an alternating pattern, with the high density strips separated from each other by low density strips. The alternating high density and low density strips provide the fabric with a higher percent elongation in the cross direction than in the machine direction. The alternating pattern is achieved through use of a pattern screen defining a plurality of elongated air permeable regions separated by elongated substantially or relatively air impermeable regions, the elongated regions extending in the machine direction in an alternating pattern, with the air permeable regions separated from each other by the substantially or relatively air impermeable regions.