PROCESS FOR PRODUCING ARTICLES OF ULTRA HIGH MOLECULAR WEIGHT HIGH DENSITY POLYETHYLENE

• Main Author: CROCKER, ZENAS
• Format: Patent
• Language: English; French
• Published: 12.04.1983
• Edition: 3
• Subjects: AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; INDEXING SCHEME ASSOCIATED WITH SUBCLASS B29C, RELATING TO PARTICULARARTICLES; INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS; MAKING GRANULES OR PREFORMS; MIXING, e.g. DISSOLVING, EMULSIFYING, DISPERSING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; PREPARATION OR PRETREATMENT OF THE MATERIAL TO BESHAPED; RECOVERY OF PLASTICS OR OTHER CONSTITUENTS OF WASTE MATERIALCONTAINING PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDEDFOR; SHAPING OR JOINING OF PLASTICS; TECHNICAL SUBJECTS COVERED BY FORMER USPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ARTCOLLECTIONS [XRACs] AND DIGESTS; TRANSPORTING; WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE, IN GENERAL

A process for producing articles of ultra high molecular weight high density polyethylene is disclosed which avoids long heating and cooling cycles, and compacting pressures in the order of 3,000 to 4,000 lbs/sq. inch. The resin is intensively mixed and thermokinetically heated in an enclosed container with a plurality of blades attached to arms rotating about an axis with a blade tip speed of at least 18 m/sec. until the resin reaches a desired discharge temperature of at least 135.degree.C. After being discharged from the mixing step, the ultra high molecular weight resin is formed into the desired shape within a time such that degradation does not occur.