Novel solvent system to produce polyethylene fibres having a high tensile strength and a high modulus by means of gel spinning and stretching in a plurality of phases

摘要

Described is a novel solvent system comprising a first solvent and a second solvent for use in a process for producing polyethylene fibres having a high tensile strength and a high modulus from gel spinning. Cycloalkane, cycloalkene or a mixture thereof is chosen as the first solvent to dissolve ultra-high molecular- weight polyethylene, and a volatile solvent such as cyclohexanone or a mixture thereof is chosen as the second or extracting solvent. The solvent system specified in the present invention allows the extracted fibres to be stretched directly after the spinning step, without an intervening coiling step being required. The resulting polyethylene fibres according to the present invention have a tensile strength greater than 15 g/denier, a modulus greater than 350 g/denier, a breaking elongation of less than 10% and a crystallinity greater than 60%. IMAGE