Patent ID: 8283426

Claim:
A process for the production of fibers and filaments comprising: (a) polymerizing propylene and one or more optional comonomers in presence of a Ziegler-Natta catalyst and an organoaluminium compound to produce a polypropylene having a molecular weight distribution M w /M n of at least 7; (b) feeding the polypropylene to an extruder; (c) subsequently melt-extruding the polypropylene to obtain a molten polypropylene stream; (d) extruding the molten polypropylene stream of step (c) through a number of fine capillaries of a spinneret, thus obtaining filaments of molten polypropylene; and (e) subsequently reducing the diameter of the filaments obtained in the previous step to a final diameter, wherein the polypropylene produced in step (a) is either a propylene homopolymer or a random copolymer of propylene with one or more comonomers, said comonomers being ethylene or a C 4 -C 10 alpha-olefin, said random copolymer comprising up to 6% by weight of comonomer, relative to the total weight of the random copolymer; and wherein the Ziegler-Natta catalyst comprises a titanium compound, which has at least one titanium-halogen bond, and an internal donor, both supported on a magnesium halide in active form, with the internal donor comprising at least 80 wt %, with respect to the total weight of the internal donor, wherein the internal donor is a di-ketone or a enamino-imine.