Abstract: Microporous or open ultrafiltration poly (tetrafluoroethylene-co-perfluoro-(alkyl vinyl ether)) (PFA) or poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) film membrane or hollow fibers having open pores are formed from a melt blend of 10 to 35 weight percent of the PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and one or more surfaces of the shaped melt blend are coated with the solvent prior to phase separation of the melt blend. Coating the membrane with solvent during shaping results in membrane having larger pores on that membrane surface as compared to membranes not coated with solvent. The shaped melt blend is cooled to effect phase separation and crystallization of the PFA or FEP from the blend. The solvent is separated from the PFA or FEP by extraction and the porous PFA or FEP is heat set under restraint to prevent shrinkage.

Abstract: Microporous or open ultrafiltration poly (tetrafluoroethylene-co-perfluoro-(alkyl vinyl ether)) (PFA) or poly (tetrafluoroethylene-co-hexafluoropropylene) (FEP) film membrane or hollow fibers having open pores are formed from a melt blend of 10 to 35 weight percent of the PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and one or more surfaces of the shaped melt blend are coated with the solvent prior to phase separation of the melt blend. Coating the membrane with solvent during shaping results in membrane having larger pores on that membrane surface as compared to membranes not coated with solvent. The shaped melt blend is cooled to effect phase separation and crystallization of the PFA or FEP from the blend. The solvent is separated from the PFA or FEP by extraction and the porous PFA or FEP is heat set under restraint to prevent shrinkage.

Abstract: Microporous poly (tetrafluoroethylene-co-perfluoro (alkyl vinyl ether)) (PFA) or poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) membrane or hollow fibers are formed from a melt blend of 10 to 35 weight percent of PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and cooled to effect phase separation of the PFA or FEP from the blend. The solvent is removed from the PFA or FEP by extraction and the porous PFA or FEP is dried under restraint to prevent shrinkage.

Abstract: Microporous poly (tetrafluoroethylene-co-perfluoro (alkyl vinyl ether)) (PFA) or poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) membrane or hollow fibers are formed from a melt blend of 10 to 35 weight percent of PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and cooled to effect phase separation of the PFA or FEP from the blend. The solvent is removed from the PFA or FEP by extraction and the porous PFA or FEP is dried under restraint to prevent shrinkage.

Abstract: Microporous polypropylene membrane or hollow fibers is formed from a melt blend of 5 to 20 weight percent polypropylene and a solvent. The melt blend is shaped and cooled to effect solid phase separation of the polypropylene from the blend. The solvent is separated from the polypropylene by extraction and the porous polypropylene is dried under restraint to prevent shrinkage.

Abstract: Microporous membranes and methods for producing such membranes from ultrahigh molecular weight polyethylene are described. The method employs extrusion of a solution of UHMW-PE and porogen through a forming die followed by thermal phase separation of polymer and porogen. Microporous structures are created by removing porogen. Microporous membranes produced include membranes with good permeability to air and water making them particularly useful as filtration media and water-resistance breathable membranes.

Abstract: Microporous membranes and methods for producing such membranes from ultrahigh molecular weight polyethylene are described. The method employs extrusion of a solution of UHMW-PE and porogen through a forming die followed by thermal phase separation of polymer and porogen. Microporous structures are created by removing porogen. Microporous membranes produced include membranes with good permeability to air and water making them particularly useful as filtration media and water-resistant breathable membranes.

Abstract: Textile quality polymeric fibers and thin films that are highly sorbent for organic and other vapors, mists and solutes. The fibers and films comprise a polymeric matrix with a system of interconnecting micropores, and are highly loaded with particulate sorbents such as activated carbon. The fibers and films are manufactured by forming a melt blend of the sorbent particles, the polymer and a selected diluent, spinning or extruding and drawing down the fiber of film, and extracting the diluent. The diluent functions to permit a high spin or extrusion draw down, to permit the subsequent cold drawing of fibers highly-loaded with active carbon, and to permit the fiber or film to be porosified. Optionally, the diluent may be extracted after or before cold drawing, or without any cold drawing. The fibers and films are highly sorbent, are strong and durable and exhibit substantial strength over an appreciable degree of elongation.

Abstract: Textile quality polymeric fibers and thin films that are highly sorbent for organic and other vapors, mists and solutes. The fibers and films comprise a polymeric matrix with a system of interconnecting micropores, and are highly loaded with particulate sorbents such as activated carbon. The fibers and films are manufactured by forming a melt blend of the sorbent particles, the polymer and a selected diluent, spinning or extruding and drawing down the fiber or film, and extracting the diluent. The diluent functions to permit a high spin or extrusion draw down, to permit the subsequent cold drawing of fibers highly-loaded with active carbon, and to permit the fiber or film to be porosified. Optionally, the diluent may be extracted after or before cold drawing, or without any cold drawing. The fibers and films are highly sorbent, are strong and durable and exhibit substantial strength over an appreciable degree of elongation.

Abstract: Textile-quality multifilament yarns that are highly sorptive for organic vapors, mists and solutes are described. Each filament comprises a microporous polymeric sheath filled with a core of sorptive material. In a multifilament spinneret having a hollow needle in each orifice, a slurry containing the sorptive material is supplied to each needle, and a blend of a polymeric material and a pore-forming material is supplied to the orifice externally of the needle. The spun composite fibers are drawn and subsequently extracted to porosify the sheath and to activate the sorptive property of the cores.

Abstract: Textile-quality multifilament yarns that are highly sorptive for organic vapors, mists and solutes are described. Each filament comprises a microporous polymeric sheath filled with a core of sorptive material. In a multifilament spinneret having a hollow needle in each orifice, a slurry containing the sorptive material is supplied to each needle, and a blend of a polymeric material and a pore-forming material is supplied to the orifice externally of the needle. The spun composite fibers are drawn and subsequently extracted to porosify the sheath and to activate the sorptive property of the cores.

Abstract: An improved process is provided for simultaneously drawing and false-twist texturing of partially oriented polyester yarn. The process is of the type wherein the yarn from a supply source is passed through a yarn feed system; a heating zone in which the yarn is heated to a temperature of from about 175.degree. to about 235.degree. C; a cooling zone in which the yarn is cooled to a temperature below about 80.degree. C; a false-twisting means; and take-up means whereby the yarn is drawn to a desired draw ratio; to winding up means; and is characterized in that the yarn emerging from said heating zone and before entering said cooling zone is passed through a heat-maintenance zone, in which the yarn is maintained at a temperature and for a time sufficient to permit substantially complete crystallization of the yarn so that the fully-drawn textured yarn product has a tenacity of at least 3.5 gram per denier. Apparatus for carrying out said improved process is also provided.