Abstract: Composite yarns having exceptional cut resistance are made by combining at least two different kinds of fiber, as follows: (a) a high modulus fiber having a modulus greater than about 200 gpd as measured by ASTM Test Method D-3822; and (b) a particle-filled fiber, which is made from a semi-crystalline polymer, such as poly(ethylene terephthalate), and hard particles having a Mohs Hardness Value greater than about 3.

Abstract: A process for producing a polyhalogenated microporous film having a very narrow pore size distribution and good temperature and chemical resistance. The process involves blending a polyhalogenated copolymer having a very small particle size with a binder polymer utilizing a solvent which is a nonsolvent for the polyhalogenated copolymer but a solvent for the binder polymer, forming a film from the blend, drying the film, heating the film to a temperature at or above the melting point of the polyhalogenated copolymer and under conditions such that the microparticulate particles at their points of mutual contact will neck together to form a relatively continuous matrix and extracting the binder polymer from the film utilizing a solvent for the binder particle to form a microporous film.

Abstract: Disclosed herein is a process for producing a polyhalogenated microporous film having a very narrow pore size distribution and good temperature and chemical resistance. The process involves blending a polyhalogenated copolymer having a very small particle size with a binder polymer utilizing a solvent which is a nonsolvent for the polyhalogenated copolymer but a solvent for the binder polymer, forming a film from the blend, drying the film, heating the film to a temperature at or above the melting point of the polyhalogenated copolymer and under conditions such that the microparticulate particles at their points of mutual contact will neck together to form a relatively continuous matrix and extracting the binder polymer from the film utilizing a solvent for the binder particle to form a microporous film.

Abstract: An improved process is provided for the formation of a high performance polyester (at least 85 mol percent polyethylene terephthalate) multifilament yarn. The product possesses a high strength (at least 7.5 grams per denier) and an unusually stable internal structure which renders it particularly suited for use in industrial applications at elevated temperatures. The filaments are melt spun and uniformly quenched under relatively high stress conditions (as described) to yield an as-spun filamentary material of relatively high birefringence (+9.times.10.sup.-3 to +70.times.10.sup.-3) which is passed in-line from the quench zone to a first draw zone where it is drawn at a draw ratio of 1.01:1 to 3.0:1, and subsequently is drawn (as described) to achieve at least 85 percent of the maximum draw ratio of the as-spun filamentary material. The resulting filamentary material exhibits unusually low shrinkage and hysteresis characteristics (i.e. work loss characteristics) as well as the high strength chatracteristics.

Abstract: An improved high performance polyester (at least 85 mol percent polyethylene terephthalate) multifilament yarn possessing a novel internal structure is provided. The multifilament yarn of the present invention possesses a high strength (at least 7.5 grams per denier) and an unusually stable internal structure which renders it particularly suited for use in industrial applications at elevated temperatures. As described in detail hereafter the subject multifilamentary material exhibits unusually low shrinkage and hysteresis characteristics (i.e. work loss characteristics) coupled with the high strength characteristics normally associated with polyester industrial yarns. Accordingly, when utilized in the formation of a tire cord and embedded in a rubber matrix, a highly stable tire may be formed which exhibits a significantly lesser heat generation uon flexing.