PROCESS FOR SPINNING UHMWPE, UHMWPE MULTIFILAMENT YARNS PRODUCED THEREOF AND PRODUCTS COMPRISING SAID YARNS

摘要

The invention relates to a gel-spinning process for producing a high tensile strength ultra high molecular weight polyethylene (UHMWPE) multifilament yarn comprising ultra-low dtex filaments, the process being characterized in that the draw ratio DRfluid applied to fluid filaments obtained by spinning a solution of UHMWPE through a spinneret and into an air gap, is at least 450, wherein DRfluid=DRsp*DRag, the DRsp and DRag being the draw ratios in the spinholes and in the air gap, respectively; and provided that DRag is at least 30. The UHMWPE multifilament yarns produced thereof were characterized by a tensile strength of at least 3.5 GPa and contained filaments having a dtex of at most 0.5. The invention further relates to products comprising said yarns, e.g. fabrics, medical devices and composite and ballistic articles.