CROSSLINKED POLYMERIC MATERIAL WITH ENHANCED STRENGTH AND PROCESS FOR MANUFACTURING

• Main Authors: HAWKINS, H. GENE, GUNTER, JAMES E, SCHROEDER, DAVID W, SALYER, BRIAN D, FREEDMAN, JORDAN H
• Format: Patent
• Language: English; French; German
• Published: 01.08.2007
• Subjects: AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F,C08G; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; BANDAGES, DRESSINGS OR ABSORBENT PADS; CHEMICAL ASPECTS OF BANDAGES, DRESSINGS, ABSORBENT PADS, ORSURGICAL ARTICLES; CHEMISTRY; COMPOSITIONS BASED THEREON; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF,TUBULAR STRUCTURES OF THE BODY, E.G. STENTS; DISINFECTION, STERILISATION, OR DEODORISATION OF AIR; FILTERS IMPLANTABLE INTO BLOOD VESSELS; FIRST-AID KITS; FOMENTATION; GENERAL PROCESSES OF COMPOUNDING; HUMAN NECESSITIES; HYGIENE; MATERIALS FOR BANDAGES, DRESSINGS, ABSORBENT PADS, OR SURGICALARTICLES; MEDICAL OR VETERINARY SCIENCE; METALLURGY; METHODS OR APPARATUS FOR STERILISING MATERIALS OR OBJECTS INGENERAL; ORGANIC MACROMOLECULAR COMPOUNDS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; PERFORMING OPERATIONS; PROSTHESES; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING; TREATMENT OR PROTECTION OF EYES OR EARS; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL; WORKING-UP

A radiation crosslinked (50 kGy), pressure-treated UHMWPE material has been developed by applying compressive force on a crosslinked polymer in a direction orthogonal to an axial direction. The deformed material is then cooled while held in a deformed state. The resulting material is anisotropic, with enhanced strength oriented along the axial direction. The directionally engineered material is oxidatively stable even after four weeks of accelerated aging in a pressure vessel containing five atmospheres of oxygen (ASTM F2003). Because of its oxidative stability, the deformation processed material is a suitable candidate for air-permeable packaging and gas sterilization, which has thus far been reserved for remelted highly crosslinked UHMWPEs.