Fibers and Nonwovens Including a Propylene Random Copolymer, and Processes for Producing the Fibers and Nonwovens

摘要

Fibers can include a polypropylene composition, which can include a metallocene random copolymer of propylene and a comonomer that is an alpha-olefin different from propylene. The metallocene random copolymer can have a comonomer content of from 1.2 wt % to 1.8 wt %, a molecular weight distribution of at least 1.0 and of at most 4.0 obtained without thermal or chemical degradation, and a melting temperature Tmelt of at most 140° C. A nonwoven can include the fibers, and a laminate can include the nonwoven. The fibers can be produced by polymerizing the propylene and comonomer in presence of a metallocene-based polymerization catalyst to obtain the metallocene random copolymer. The polypropylene composition can be melt-extruded to obtain a molten polypropylene stream, which can be extruded from capillaries of a spinneret to obtain filaments. A diameter of the filaments can be rapidly reduced to obtain a final diameter.