HIGH STRENGTH POLYETHYLENE FIBER

PROBLEM TO BE SOLVED: To provide a high strength polyethylene fiber which has been difficult to produce by a conventional gel spinning method, in greatly high productivity. SOLUTION: This high strength polyethylene fiber is characterized in that the sizes of crystals originated from monoclinic crystals are ≥9 nm and the tensile strength of the fiber is ≥30 cN/dtex. The method for producing the high strength polyethylene fibers comprises dissolving ultrahigh mol.wt. polyethylene having an intrinsic viscosity of ≥8 dL/g in a solvent mixture comprising a good solvent for the polyethylene and a poor solvent in a weight ratio of 20:80 to 99:1 in a polyethylene concentration of 0.5 to 50 wt.%, extruding the formed polyethylene dope from orifices, cooling, and then drawing the filament-like products. The high strength polyethylene fiber contains the solvent having a viscosity index of ≤0.6 in a content of ≥5 ppm. COPYRIGHT: (C)2008,JPO&INPIT