Patent ID: 8481157

Claim:
A melt extruded polymeric fiber comprising one or more polymers, and a lubricant provided on an entire outer surface of the fiber, wherein: (a) all polymers of which the fiber is comprised exhibit a melt flow index of less than 1 g/10 min measured at the condition specified for each of the one or more polymers by ASTM D 1238, and said polymers are selected from the group consisting of: ultra high molecular weight polyethylene, polypropylene, polycarbonates, styrenic block copolymers, ABS (acrylonitrile, butadiene, styrene copolymers), ethylene-propylene-nonconjugated diene copolymers grafted with a mixture of styrene and acrylonitrile (AES), styrene-acrylonitrile (SAN) copolymers, polyimides, norbornenes, polyphenylene sulfide, ionomers, polyesters, polyamides, polyurethanes, oriented syndiotactic polystyrene, acrylonitrile-styrene-acrylonitrile (ASA) copolymers; styrene-acrylonitrile copolymers, acrylonitrile-styrene-butylacrylate polymer, and multiphase polymers comprising macromolecules composed of different species that form separate phases within the same mass of material or a blend of one or more such polymers and one or more thermoplastic polymer; (b) the lubricant has a viscosity, at the temperature at which the polymer is delivered to the extrusion die from which the fiber was extruded, that has a ratio to the polymer viscosity at the same temperature of 1:40 or less; (c) the fiber comprises a continuous length at least 1000 times its width; and (d) the fiber has an average roughness (Ra) of about 1000 nanometers or less.