Process of making bioabsorbable filaments
View Patent ↗Methods for making bioabsorbable copolymer filaments are provided herein. The methods include drying the polymer pellets to be extruded, melt extrusion of copolymer components, stretching the filaments in one or more draw steps and permitting the drawn filaments to relax. The copolymer preferably contains units derived from glycolide or glycolic acid and units derived from an alkylene carbonate, such as, for example, trimethylene carbonate.
1. A process for manufacturing a monofilament suture from a block copolymer comprising from about 50 to about 80 weight percent glycolide, and about 20 to about 50 weight percent trimethylene carbonate, the method comprising: a) extruding the copolymer to provide a molten monofilament; b) quenching the molten monofilament to provide a solidified monofilament; c) drawing the solidified monofilament through a first oven maintained at a temperature of about 25° C. to about 40° C. at a draw ratio of about 2:1 to about 15:1; d) drawing the monofilament through a second oven maintained at a temperature of about 30° C. to about 150° C. at a draw ratio of about 1.1:1 to about 5:1; e) drawing the monofilament through a third oven maintained at a temperature of about 125° C. to about 165° C. at a draw ratio of about 0.5:1 to about 0.8:1; and f) annealing the monofilament.
2. The process of claim 1 wherein the step of extruding the copolymer comprises extruding the copolymer at a temperature from about 170° C. to about 240° C.
3. The process of claim 1 wherein the step of quenching the molten monofilament comprises utilizing a quench bath at a temperature from about 10° C. to about 80° C.
4. The process of claim 1 wherein the step of quenching the molten monofilament comprises utilizing a quench bath at a temperature from about 20° C. to about 30° C.
5. The process of claim 1 wherein the step of drawing the solidified monofilament through the first oven comprises drawing at a draw ratio of about 3:1 to about 12:1.
6. The process of claim 1 wherein the step of drawing the solidified monofilament through the first oven comprises drawing at a draw ratio of about 5:1 to about 7:1.
7. The process of claim 1 wherein the step of drawing the solidified monofilament through the second oven comprises drawing at a draw ratio of about 1.2:1 to about 3:1.
8. The process of claim 1 wherein the step of drawing the solidified monofilament through the second oven comprises drawing at a draw ratio of about 1.25:1 to about 1.5:1.
9. The process of claim 1 wherein the step of drawing the solidified monofilament through the third oven comprises drawing at a draw ratio of about 0.55:1 to about 0.75:1.
10. The process of claim 1 wherein the total draw ratio is from about 6.5:1 to about 8.5:1.
11. The process of claim 1 wherein the total draw ratio is from about 7:1 to about 8:1.
12. The process of claim 1 wherein the draw rate payoff may range from about 5 meters/minute to about 70 meters/minute.
13. The process of claim 1 wherein the step of drawing the solidified monofilament through the third oven comprises drawing the monofilament through a third oven maintained at a temperature of about 128° C. to about 150° C.
14. The process of claim 1 wherein the step of annealing the monofilament comprises subjecting the monofilament to temperatures ranging from about 100° C. to about 180° C.
15. The process of claim 1 wherein the step of annealing the monofilament comprises subjecting the monofilament to temperatures ranging from about 110° C. to about 150° C.
16. The process of claim 1 wherein the step of annealing lasts from about 9 to about 24 hours.
17. The process of claim 1 wherein the monofilament suture further comprises at least one medico-surgically useful substance.
18. The process of claim 1 wherein the at least one medico-surgically useful substance comprises a growth promoting factor.
19. The process of claim 1 wherein the at least one medico-surgically useful substance comprises an antimicrobial agent.
20. A process for manufacturing a monofilament suture from a block copolymer comprising from about 60 to about 70 weight percent glycolide, and about 30 to about 40 weight percent trimethylene carbonate, the method comprising: a) extruding the copolymer at a temperature from about 170° C. to about 240° C. to provide a molten monofilament; b) quenching the molten monofilament in a quench bath at a temperature from about 10° C. to about 80° C. to provide a solidified monofilament; c) drawing the solidified monofilament through a first oven maintained at a temperature of about 25° C. to about 40° C. at a draw ratio of about 3:1 to about 12:1; d) drawing the monofilament through a second oven maintained at a temperature of about 30° C. to about 150° C. at a draw ratio of about 1.25:1 to about 1.50:1; e) drawing the monofilament through a third oven maintained at a temperature of about 125° C. to about 165° C. at a draw ratio of about 0.55:1 to about 0.91:1; and f) annealing the monofilament at temperatures ranging from about 100° C. to about 150° C.
21. A process for manufacturing a monofilament suture from a block copolymer consisting essentially of about 50 to about 80 weight percent glycolide, and about 20 to about 50 weight percent trimethylene carbonate, the method comprising: a) extruding the copolymer to provide a molten monofilament; b) quenching the molten monofilament to provide a solidified monofilament; c) drawing the solidified monofilament through a first oven maintained at a temperature of about 25° C. to about 40° C. at a draw ratio of about 2:1 to about 15:1; d) drawing the monofilament through a second oven maintained at a temperature of about 30° C. to about 150° C. at a draw ratio of about 1.1:1 to about 5:1; e) drawing the monofilament through a third oven maintained at a temperature of about 120° C. to about 165° C. at a draw ratio of about 0.5:1 to about 0.9:1; and f) annealing the monofilament.
22. The process of claim 20 , wherein the block copolymer comprises from about 65 to about 67 weight % glycolide and about 33 to about 35 weight % trimethylene carbonate.
23. The process of claim 21 , wherein the block copolymer comprises from about 65 to about 67 weight % glycolide and about 33 to about 35 weight % trimethylene carbonate.