PRODUCTION OF HIGH STRENGTH BI-ABSORBABLE SUTURE BY EXTRUSION OF COPOLYMER AT TEMPERATURE CLOSED TO OR RELATIVELY LOWER THAN COPOLYMER MELTING POINT AT INITIAL STAGE AND THEN EXTENDING EXPOSURE TIME OF FILAMENTS TO TEMPERATURE HIGHER THAN FILAMENT MELTING POINT AT LAST STAGE AND SUTURE PRODUCED THEREBY

摘要

PURPOSE: A method of making a bio-absorbable suture fiber by extruding a copolymer at a temperature closed to or relatively lower than the melting point thereof at the initial stage and then extending the exposure time of filaments to a temperature higher than the melting point thereof at the last stage is provided. Thus obtained copolymer suture fiber has a fiber tenacity of between approximately 7.2 to 8.0 grams per denier and a fiber elongation between approximately 22% and 35%. CONSTITUTION: The suture fiber is prepared by the extrusion of PGA/PLA copolymer(14') with an extruder apparatus(10) having at least one heated zone that is maintained at a temperature of from 20 deg.C below the copolymer melting point to 5 deg.C above the copolymer melting point. The extruder apparatus has a metering pump(22) and a heated block(24) which are maintained at a temperature of no more than about 40 deg.C above the copolymer melting point, a spinneret(26) which is maintained at a temperature of 40 deg.C to 60 deg.C above the copolymer melting point, and an elongated heated sleeve(30) extending between 6 and 20 inches from the spinneret which is maintained at a temperature of at least about 60 deg.C above the copolymer melting point.