Fibres et fils étirés de polypropylène hautement cristallisé et tissus à mailles tissus tissés et nappes de fibres obtenus à partir d'eux

摘要

A crystalline polypropylene of mean intrinsic viscosity 1.3-2.3 and of which at least 94% has a range of viscosity of 0.5-3.0 is used to prepare stretched fibres, threads and woven and non-woven fabrics. The polypropylene may be prepared by mechanically degrading, e.g. in a high shear gradient of a screw extruder, a polypropylene of mean intrinsic viscosity of at least 6 which may first be degraded by oxidation.