Patent ID: 7378045

Claim:
A process for producing suture fibers made of a glycolide and lactide copolymer in an extruder apparatus having a plurality of sequentially arranged and interconnected components including an extruder having at least one heated zone, a metering pump, a heated block, a spinneret having a plurality of capillary orifices and being located substantially vertically beneath the heated block, and a heated sleeve located substantially beneath the spinneret, a temperature control means being provided for each component for maintaining each component at a predetermined temperature, said process comprising the sequential steps of: feeding the copolymer having a copolymer melting point, defined as the DSC peak melting temperature thereof, to the extruder; maintaining the at least one heated zone of the extruder at a temperature of from about 20° C. below the copolymer melting point to about 5° C. above the copolymer melting point; maintaining the metering pump and the heated block at a temperature of no less than the copolymer melting point and no more than about 40° C. above the copolymer melting point, wherein the temperature of the metering pump and the heated block is greater than the temperature of the at least one heated zone of the extruder; maintaining the spinneret at a temperature from about 40° C. to about 60° C. above the copolymer melting point, wherein the temperature of the spinneret is greater than the temperature of the metering pump and the heated block; activating the metering pump to transfer the copolymer from the extruder to the heated block, whereupon the copolymer is substantially melted; forcing the substantially molten copolymer through the plurality of capillary orifices of the spinneret whereby filamentous copolymer fibers are formed; and maintaining the heated sleeve at a temperature of at least 60° C. above the copolymer melting point such that the period of time for which the copolymer fibers are substantially above the copolymer melting point is extended, the heated sleeve being positioned such that the copolymer filaments pass through the heated sleeve after formation in the spinneret, and the heated sleeve being between approximately six and eighteen inches long, the copolymer filaments having a denier per filament of about 2.0.