Abstract: This invention relates to a new nonwoven material which has very high Frazier permeability while having substantial hydrostatic head liquid barrier properties. The material is comprised of fibers which are approximately one denier and finer fibers which have sufficient strength properties so as not to need a support scrim. The fabric is quite comfortable because of its breathability, quite soft because of its construction, and protective from liquids from rain to hazardous chemicals.

Abstract: This invention relates to a nonwoven sheet material with high air permeability and substantial hydrostatic head liquid barrier properties. The sheet material is comprised of at least 90%, by weight, melt spun substantially continuous filament polymer fibers having an average cross sectional area of less than about 90 square microns. The sheet material has a basis weight of less than 125 g/m2 and a grab tensile strength of at least 0.7 N/(g/m2). The invention is also directed to a process for melt spinning polymer fibers that can be used to make the nonwoven sheet material of the invention.

Abstract: The efficiency of electrostatic charging of polyolefin web in a process for flash-spinning polyolefin plexifilament from solution in a C4-C7 hydrocarbon, forming the plexifilament into a web, electrostatically charging the web, and laying the web down as a sheet is improved by having present in the electrostatic charging step environment a charge-improving compound, which can be any one of a number of specifically identified classes of charge-improving compounds. The charge improving compounds are present in an amount of at least 0.1 ppm of the atmosphere in that environment or more.

Abstract: A gas permeable package is provided that is comprised of a bonded, gas permeable, fibrous sheet material consisting of continuous lengths of bonded plexifilamentary fibril strands of a polyolefin polymer and a pigment. The polyolefin comprises at least 90% by weight of the fibril strands and the pigment comprises between 0.05% and 10% by weight of the fibril strands. The polyolefin polymer is preferably selected from the group of polyethylene, polypropylene, and copolymers comprised primarily of ethylene and propylene units, and is more preferably polyethylene. The pigment is preferably titanium dioxide. The fibrous sheet material has a basis weight of less than 85 g/m2, a delamination strength of at least 60 N/m, and an opacity of at least 90% if the sheet has a delamination strength less than 120 N/m, an opacity of at least 85% if the sheet has a delamination strength between 120 N/m and 150 N/m, and an opacity of at least 80% if the sheet has a delamination strength greater than 150 N/m.

Abstract: This invention relates to flash spinning copolymers which provide softness and quietness to nonwoven sheet structures formed of plexifilamentary film-fibril material. In particular, flash spinning polyethylene with an ethylene copolymer provides a substantial improvement in softness and quietness.

Abstract: Improved sheets of bonded plexifilamentary film-fibril strands spun from a polyolefin and a pigment are provided. The polyolefin comprises at least 90% by weight of the fibril strands, and the pigment comprises between 0.05% and 10% by weight of the fibril strands. The sheet has a high opacity and high smoothness, even when the sheet is bonded to a delamination strength greater than 120 N/m or when subjected to calendering. The sheet material is highly printable.

Abstract: This invention relates to a new nonwoven material which has very high Frazier permeability while having substantial hydrostatic head liquid barrier properties. The material is comprised of fibers which are approximately one denier and finer fibers which have sufficient strength properties so as not to need a support scrim. The fabric is quite comfortable because of its breathability, quite soft because of its construction, and protective from liquids from rain to hazardous chemicals.

Abstract: The efficiency of electrostatic charging of polyolefin web in a process for flash-spinning polyolefin plexifilament from solution in a C.sub.4 -C.sub.7 hydrocarbon, forming the plexifilament into a web, electrostatically charging the web, and laying the web down as a sheet is improved by having present in the electrostatic charging step environment a charge-improving compound, which can be any one of a number of specifically identified classes of charge-improving compounds. The charge improving compounds are present in an amount of at least 0.1 ppm of the atmosphere in that environment or more.