Abstract: A sheet comprising a plexifilamentary film-fibril network consisting essentially of high density polyethylene in an overlapping multi-directional configuration, the sheet, as-produced from a spin cell, having a normalized Frazier air permeability of between 0.002 and 0.2 m3/m2·minute at 50 gsm, a BET surface area of between 9 and 20 m2/gm, and a normalized hydrohead of between 150 and 250 cm at 50 gsm, wherein the plexifilamentary film-fibril network in an overlapping multi-directional configuration is flash-spun from a spin fluid comprising polymer and spin agent, the spin fluid temperature being 190° C. or greater, the spin agent comprising dichloromethane, the spin fluid having a polymer concentration of 12 to 14 weight percent.

Abstract: A process for the preparation of plexifilamentary film-fibril strands of polymer. The process includes the steps of generating a spin fluid containing (a) 5 to 30 wt. % containing one or more polymer types, (b) a primary spin agent selected from the group consisting of dichloromethane, cis-1,2-dichloroethylene and trans-1,2-dichloroethylene, and (c) a co-spin agent comprising 1H,6H-perfluorohexane or 1H-perfluorohexane or 1H-perfluoroheptane. The spin fluid is flash-spun at a pressure that is greater than the autogenous pressure of the spin fluid into a region of lower pressure to form plexifilamentary film-fibril strands of the polymer. The co-spin agent is present in the spin fluid in an amount sufficient to form an azeotrope-like composition with the primary spin agent in the presence of the one or more polymer types.

Abstract: A process for the preparation of plexifilamentary film-fibril strands of polymer. The process includes the steps of generating a spin fluid containing (a) 5 to 30 wt. % containing one or more polymer types, (b) a primary spin agent selected from the group consisting of dichloromethane, cis-1,2-dichloroethylene and trans-1,2-dichloroethylene, and (c) a co-spin agent comprising 1H,6H-perfluorohexane or 1H-perfluorohexane or 1H-perfluoroheptane. The spin fluid is flash-spun at a pressure that is greater than the autogenous pressure of the spin fluid into a region of lower pressure to form plexifilamentary film-fibril strands of the polymer. The co-spin agent is present in the spin fluid in an amount sufficient to form an azeotrope-like composition with the primary spin agent in the presence of the one or more polymer types.

Abstract: A sheet comprising a plexifilamentary film-fibril network consisting essentially of high density polyethylene in an overlapping multi-directional configuration, the sheet, as-produced from a spin cell, having a normalized Frazier air permeability of between 0.002 and 0.2 m3/m2·minute at 50 gsm, a BET surface area of between 9 and 20 m2/gm, and a normalized hydrohead of between 150 and 250 cm at 50 gsm, wherein the plexifilamentary film-fibril network in an overlapping multi-directional configuration is flash-spun from a spin fluid comprising polymer and spin agent, the spin fluid temperature being 190° C. or greater, the spin agent comprising dichloromethane, the spin fluid having a polymer concentration of 12 to 14 weight percent.

Abstract: A sheet having a plexifilamentary structure with a normalized Frazier air permeability of between 0.002 and 0.2 (m3/m2·minute)@50 gsm, and a normalized hydrohead of between 150 and 250 centimeters@50 gsm.

Abstract: A flash-spun plexifilamentary fiber strand having a BET surface area of less than 12 m2/g, a crush value of at least 0.9 mm/g wherein said fiber strand comprises predominantly fibers formed from polyethylene, said fibers having a total crystallinity index of less than 55%, said fiber strand having an elongation at break greater than 55% and sheets made thereof.

Abstract: A flash-spun plexifilamentary fiber strand having a BET surface area of less than 12 m2/g, a crush value of at least 0.9 mm/g wherein said fiber strand comprises predominantly fibers formed from polyethylene, said fibers having a total crystallinity index of less than 55%, and sheets made thereof.

Abstract: A flash-spun plexifilamentary fiber strand having a BET surface area of less than 12 m2/g, a crush value of at least 0.9 mm/g wherein said fiber strand comprises predominantly fibers formed from polyethylene, said fibers having a total crystallinity index of less than 55%, and sheets made thereof.

Abstract: A process for the preparation of plexifilamentary film-fibril strands of polymer. The process includes the steps of generating a spin fluid containing (a) 5 to 30 wt. % containing one or more polymer types, (b) a primary spin agent selected from the group consisting of dichloromethane, cis-1,2-dichloroethylene and trans-1,2-dichloroethylene, and (c) a co-spin agent comprising 1H,6H-perfluorohexane or 1H-perfluorohexane or 1H-perfluoroheptane. The spin fluid is flash-spun at a pressure that is greater than the autogenous pressure of the spin fluid into a region of lower pressure to form plexifilamentary film-fibril strands of the polymer. The co-spin agent is present in the spin fluid in an amount sufficient to form an azeotrope-like composition with the primary spin agent in the presence of the one or more polymer types.

Abstract: A flash-spun plexifilamentary fiber strand having a BET surface area of less than 12 m2/g, a crush value of at least 0.9 mm/g wherein said fiber strand comprises predominantly fibers formed from polyethylene, said fibers having a total crystallinity index of less than 55%, said fiber strand having an elongation at break greater than 55% and sheets made thereof.

Abstract: A sheet having a plexifilamentary structure with a normalized Frazier air permeability of between 0.002 and 0.2 (m3/m2·minute)@50 gsm, and a normalized hydrohead of between 150 and 250 centimeters@50 gsm.

Abstract: A fiber spinning process comprising the steps of providing a polymer solution, which comprises at least one weakly interacting polymer dissolved in at least one weakly interacting solvent to a spinneret; issuing the polymer solution in combination with a blowing gas in a direction from at least one spinning nozzle in the spinneret and in the presence of an electric field; forming fibers and collecting the fibers on a collector.

Abstract: The present invention is a fiber spinning process comprising the steps of providing a polymer solution, which comprises at least one polymer dissolved in at least one solvent with a vapor pressure of at least about 6 kPa at 25° C., to a spinneret, issuing the polymer solution in combination with a blowing gas in a direction away from at least one spinning nozzle in the spinneret and in the presence of an electric field wherein the polymer solution is discharged through the spinning nozzle at a discharge rate between about 6 to about 100 ml/min/hole, forming fibers, and collecting the fibers on a collector.

Abstract: A fiber spinning process comprising the steps of providing a polymer solution, which comprises at least one weakly interacting polymer dissolved in at least one weakly interacting solvent to a spinneret; issuing the polymer solution in combination with a blowing gas in a direction from at least one spinning nozzle in the spinneret and in the presence of an electric field; forming fibers and collecting the fibers on a collector.