MANUFACTURE OF ULTRA-HIGH-MOLECULAR-WEIGHT POLYETHYLENE POROUS MATERIAL

• Main Authors: MASANO KOJI, WATANABE TAKAYUKI
• Format: Patent
• Language: English
• Published: 07.01.1997
• Edition: 6
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL PROCESSES OF COMPOUNDING; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

PURPOSE: To obtain a porous material having low bulk specific gravity, open cell pores of small ventilating resistance and excellent strength by passing composition mainly containing cauliflower-like ultra-high-molecular-weight polyethylene having specific mean particle size and viscosity-average molecular weight at a specific temperature as the part from an orifice remains melted. CONSTITUTION: As molding composition, composition containing cauliflower-like ultra-high-molecular-weight polyethylene having a mean particle size of 250 to 400μm and viscosity-average molecular weight of 500×10 to 650×10 as main body is used. This composition is passed from the orifices arranged at the end in a ram extruder at heating temperature of 150 to 300 deg.C as at least the part remains melted, and the partly melted positions are fusion bonded to each other in a mold interlocked to the orifices. Thus, hollow porous material having many open cell pores is sintered, and extrusion molded. In this manner, the porous material having a low bulk specific gravity and an excellent mechanical strength is continuously sintered and extrusion molded.