Method for producing spunbonded materials with improved tensile strength

• Main Author: YOU HEE-JU
• Format: Patent
• Language: English
• Published: 18.12.2002
• Edition: 7
• Subjects: APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTURE OF CARBONFILAMENTS; BRAIDING; CHEMICAL FEATURES IN THE MANUFACTURE OF ARTIFICIAL FILAMENTS,THREADS, FIBRES, BRISTLES OR RIBBONS; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; 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; METALLURGY; NATURAL OR ARTIFICIAL THREADS OR FIBRES; NON-WOVEN FABRICS; ORGANIC MACROMOLECULAR COMPOUNDS; SPINNING; TEXTILES; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRIMMINGS; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS; WADDING

Spin bonded material comprises: (a) adding additives to a propylene polymer material; (b) continuously extruding the propylene polymer material through a spinneret at greater than 500[deg]F to form discrete filaments; (c) drawing the filaments to molecularly orient the polymer filaments; and (d) depositing the filaments in a random manner onto a carrier belt to form a web. Polymer consists of: (i) a propylene homopolymer; or (ii) a random copolymer of propylene and ethylene containing less than 10%wt., having a melt flow rate of 3-30 g/10 min. Additives consist of: (i) 250-2500 pts. a pentaerythritol diphosphite; (ii) 250-2500 pts. a hindered phenol compound; (iii) 100-1500 pts. Ca stearate; and optionally (iv) 5-500 pts. a hydrotalcite compound. Preferably, the propylene polymer material has a melt flow rate of 3-20 g/10 min. and is extruded at greater than 525[deg]F. Material includes 745-1145 pts. (i), 800-1200 pts. (ii), 240-360 pts. (iii) and 55-85 pts. (iv).