MULTI-STAGE DRAWING TECHNIQUE FOR FORMING POROUS FIBERS

• Main Authors: TOWER, Theodore, T, TOPOLKARAEV, Vasily, A, SCHOLL, Neil, T, CARRILLO OJEDA, Antonio J, MCENEANY, Ryan, J
• Format: Patent
• Language: English; French; German
• Published: 03.02.2021
• Subjects: APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBONFILAMENTS; BRAIDING; CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS,THREADS, FIBRES, BRISTLES OR RIBBONS; COTTON-WOOL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS,NON-WOVEN FABRICS; FINISHING OR DRESSING OF FILAMENTS, YARNS, THREADS, CORDS,ROPES OR THE LIKE; KNITTING; LACE-MAKING; MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARYMATERIAL; MECHANICAL FINISHING OF YARNS OR ROPES; 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; WARPING OR BEAMING; YARNS

A method for forming porous fibers is provided. The fibers are formed from a thermoplastic composition containing a continuous phase, which includes a matrix polymer, and a nanoinclusion additive that is at least partially incompatible with the matrix polymer so that it becomes dispersed within the continuous phase as discrete nano-scale phase domains. The method includes traversing a bundle of the fibers through a multi-stage drawing system that includes at least a first fluidic drawing stage and a second fluidic drawing stage. The first drawing stage employs a first fluidic medium having a first temperature and the second drawing stage employs a second fluidic medium having a second temperature. The first and second temperatures are both lower than the melting temperature of the matrix polymer, and the first temperature is greater than the second temperature.