Process of making dimensionally-stable melt blown nonwoven fibrous structures

• Main Authors: Swan, Michael D, Moore, Eric M, Percha, Pamela A, Brostrom, Myles L, Talwar, Sachin, Christiansen, Randy L, Zillig, Daniel J, Romano, Michael D, Song, Liming
• Format: Patent
• Language: English
• Published: 03.09.2019
• Subjects: BRAIDING; COTTON-WOOL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS,NON-WOVEN FABRICS; KNITTING; LACE-MAKING; MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARYMATERIAL; MECHANICAL METHODS OR APPARATUS IN THE MANUFACTURE OFARTIFICIAL FILAMENTS, THREADS, FIBRES, BRISTLES ORRIBBONS; NATURAL OR ARTIFICIAL THREADS OR FIBRES; NON-WOVEN FABRICS; SPINNING; TEXTILES; TRIMMINGS; WADDING

A process and apparatus for producing a dimensionally stable melt blown nonwoven fibrous web. The process includes forming a multiplicity of melt blown fibers by passing a molten stream including molecules of at least one thermoplastic semi-crystalline (co)polymer through at least one orifice of a melt-blowing die, subjecting at least a portion of the melt blown fibers to a controlled in-flight heat treatment operation at a temperature below a melting temperature of the at least one thermoplastic semi-crystalline (co)polymer immediately upon exiting from the at least one orifice, and collecting at least some of the melt blown fibers subjected to the controlled in-flight heat treatment operation on a collector to form a non-woven fibrous structure. The nonwoven fibrous structure exhibits a Shrinkage less than a Shrinkage measured on an identically-prepared structure including only fibers not subjected to the controlled in-flight heat treatment operation, and generally less than 15%.