UHMWPE spinning process, UHMWPE multifilament threads produced by it and their use

摘要

A process for spinning gel of UHMWPE yarns of high tensile strength comprising ultra-low dtex filaments, the process comprising the steps of: a) preparing a solution of a UHMWPE in a solvent; b) spinning through a row and in an air space of the solution of step a) to form fluid filaments, the row containing multiple spinning holes and wherein each spinning hole comprises at least one area with a gradual decrease in diameter and where the diameter downstream of the spinning hole from which the solution is delivered to the air gap is comprised between 0.1 and 1.5 mm; c) stretching of the fluid filaments with a fluid draw ratio DRfluid = DRsp x DRag, where DRsp and DRag are the draw ratios in the spinning holes and in the air space, respectively; and d) cooling the fluid filaments to form solvent-containing gel filaments; and e) at least partial removal of the remaining solvent from the gel filaments to form solid filaments, before, during or after the stretching of the solid filaments with a solid DR ratio of at least 4, characterized in that the fluid filaments are stretched by a fluid draining ratio of at least 450 fluid, provided that DRag is at least 30.