Abstract: The present invention relates to a die nosepiece for use in textile processes involving nonwoven melt blow fabrics. In a melt blown process, molten polymer resins are injected into a melt blown die and ejected from the die in the form of filaments. The present invention is directed to an improved die nosepiece comprising a slit with serrated edges through which resin filaments are ejected.

Abstract: A meltblown web is composed of fibers having a narrow fiber size distribution (expressed as % coefficient of variation of the average fiber diameter) and low packing density. The web is characterized as a soft lofty web and exhibits exceptional filtration capability. The web preferably comprises fibers having an average fiber size of between 3 and 10 microns and a packing density of between 5 to 15%, and a CV of 15 to 40%.

Abstract: A meltblowing die is provided with means for discharging crossflow air onto meltblown filaments to disrupt their shape and flow pattern between the die and the collector. The disruption enhances drag forces imparted by the primary meltblowing air and results in smaller diameter filaments.

Abstract: Melt blown non-woven mats prepared from thermoplastic polymer fibers and substantially completely free of polymer shot are produced at high polymer throughput rates in an improved melt blowing process in which thermoplastic polymer resins, preferably polypropylene, having initial intrinsic viscosities of at least 1.4, are degraded, optionally in the presence of a free radical source compound, to have both reduced intrinsic viscosities and an apparent viscosity in the melt-blowing nozzle orifices of from about 50 to about 300 poise.

Abstract: A battery separator and the process for preparing it, having excellent abrasion resistance, stiffness, porosity, pore size, and electrical resistance is produced by a process that includes degrading a fiber forming polymer, melt-blowing fibers from the degraded polymers and forming a non-woven mat of the fibers randomly laid and self-bonded. The non-woven mat is then compacted, in a critical manner, preferably at temperatures for polypropylene of from 290.degree. to 310.degree.F., using relatively low pressures, i.e. 10 psi/in.sup.2 or lss, to obtain a battery separator meeting precise and essential specifications.

Abstract: Battery separators are produced from nonwoven mats of thermoplastic fibers by wetting the fibers with a surfactant-water mixture to modify the surface properties of the fibers in the nonwoven mat, vaporizing the water while depositing the surfactant on the fibers, heating the nonwoven mat prior to compressing and then compressing to increase the fiber-to-fiber bonding as well as to form the desired structure. During compressing, ribs may be formed by using appropriate embossed rolls or press plate patterns. After the compressing step, slitting, cooling and cutting steps are carried out to produce a battery separator of the desired dimensions.