COMPACTION OF POLYESTER FABRIC MATERIALS

• US 3,853,462 A
• Filed: 02/23/1972
• Issued: 12/10/1974
• Est. Priority Date: 02/23/1972
• Status: Expired due to Term

• Current Assignee: Ray E. Smith
• Original Assignee: Ray E. Smith
• Inventors: Smith, Ray E.
• Primary Examiner(s): Rosdol, Leon D.
• Assistant Examiner(s): Wolman, H.
• Application Number:
  US05/228,722
• Time in Patent Office: 1,021 Days
• Field of Search: 8/130.1,DIG.4 139/387R 66/170 3/DIG.1
• US Class Current: 8/130.1
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: D06M 13/08 with halogenated hydrocarbons
• CPC Class Codes: D06M 13/144 Alcohols; Metal alcoholates D06M13/11 takes precedence
• CPC Class Codes: D06M 13/152 having a hydroxy group bound to a carbon atom of a six-membered aromatic ring
• CPC Class Codes: Y10S 8/21 Nylon

Abstract

Knitted flat stock or tubing fabric material of a suitable polyester material such as polyethylene terephthalate is treated to reduce its porosity. The resulting product is useful as a synthetic inter-cardiac (e.g., vascular) prosthesis. Treatment is performed by immersing the knitted fabric material in a compacting solution containing a minor amount of an acidic organic component and a major amount of a halogenated aliphatic hydrocarbon having up to about 6 carbon atoms for a time sufficient to reduce the porosity of the knitted fabric material at least about 30 percent in the wale direction. A mixture containing about 90 to 98 percent by weight of methylene chloride and about 10 to 2 percent by weight of hexafluoroisopropanol is an example of a suitable compacting solution.

Claims

1. A PROCESS FOR PREPARING A SYNTHETIC VASCULAR PROSTHESIS COMPRISING THE STEPS OF:

A. PROVIDING A KNITTED SYNTHETIC LINEAR POLYESTER FABRIC TUBING MATERIAL HAVING A UNIFORM POROSITY, MEASURED ON THE WESOLOWSKI SCALE, ABOVE ABOUT 7,500 UP TO ABOUT 20,000 AND IN EXCESS OF THAT SUITABLE FOR LONG-TERM HEALING EFFECTS WITHOUT UNDUE HEMORRHAGING AT IMPLANTATION;

B. IMMERSING SAID POROUS KNITTED SYNTHETIC LINEAR POLYESTER FABRIC TUBING MATERIAL IN A COMPACTING SOLUTION CONSISTING ESSENTIALLY OF FROM ABOUT 2 TO ABOUT 10 PERCENT BY WEIGHT OF AN ACIDIC ORGANIC COMPONENT SELECTED FROM THE GROUP CONSISTING OF HEXAFLUOROISOPROPANOL, PHENOL, META-CRESOL, HEXAFLUOROACETONE PROPYLENE ADDUCT, TRICHLOROACETIC ACID, PARACHLOROPHENOL AND HEXAFLUOROACETONE SESQUIHYDRATE AND ABOUT 98 TO ABOUT 90 PERCENT BY WEIGHT OF A HALOGENATED ALIPHATIC HYDROCARBON SELECTED FROM THE GROUP CINSISTING OF METHYLENE CHLORIDE, CHLOROFORM, TETRACHLOROETHANE AND ETHYLENE DICHLORIDE UNITL SAID FABRIC MATERIAL UNIFORMLY SHINKS AT LEAST ABOUT 30 PERCENT MEASURED IN THE WALE DIRECTION AND THE POROSITY OF THE SAID FABRIC MATERIAL IS, MEASURED ON THE WESOLOWSHI SCALE, FROM ABOUT 30 TO ABOUT 5,000 AND SUITABLE FOR LONG-TERM HEALING EFFECTS WITHOUT UNDUE HEMORRHAGING AT IMPLANTATION;

C. REMOVING SAID COMPACTED FABRIC MATERIAL FROM SAID COM;

PACTING SOLUTION;

D. WASHING SAID COMPACTED FABRIC MATERIAL TO REMOVE ALL TRACES OF SAID COMPACTING SOLUTION;

AND E. FORMING SAID COMPACTED FABRIC MATERIAL INTO A VASCULAR PORSTHESIS.

2. The method of claim 1 wherein said acidic organic component is hexafluoroisopropanol and the said halogenated aliphatic hydrocarbon is methylene chloride.

3. The process of claim 2 wherein said compacting solution contains from about 4 to about 8 percent by weight of hexafluoroisopropanol and about 96 to about 92 percent by weight of methylene chloride.

4. The method of claim 1 wherein said polyester is polyethylene terephthalate.

5. The method of claim 1 wherein said compacting includes a shrinkage of at least about 40 percent in the wale direction.

6. The process of claim 1 wherein said forming of the prosthesis includes crimping of the compacted tubing.

7. The process of claim 1 wherein said fabric material is immersed in the said compacting solution for a time of from about 15 seconds to 30 minutes.

8. A process for preparing a synthetic vascular prosthesis which comprises the steps of:

a. providing a uniformly porous, knitted polyethylene terephthalate tubing having a wall thickness between about 0.1 and 0.3 mm. and a porosity, measured on the Wesolowski scale, above about 7,500 up to about 20,000;

b. immersing said porous, knitted polyethylene terephthalate tubing in a compacting solution consisting essentially of from about 4 to about 8 percent by weight hexafluoroisopropanol and from about 96 to about 92 percent by weight of methylene chloride for from about 5 to about 15 minutes to uniformly compact the tubing, said compacted tubing having a porosity, measured on the Wesolowski scale, of from about 30 to about 5, 000;

c. removing said compacted tubing from the compacting solution;

d. washing and drying said compacted tubing to remove all traces of the compacting solution and wash liquid; and

e. crimping said dried compacted tubing.

9. A process for reducing the porosity of a uniformly porous knitted synthetic linear polyester fabric material which comprises contacting said fabric with a compacting solution containing a minor proportion of a solvent for the polyester and a major proportion of a shrinking agent for the polyester for a time sufficient to uniformly compact said fabric at least about 30 percent measured in the wale direction of the fabric, said solvent being selected from the group consisting of hexafluoroisopropanol, phenol, meta-cresol, hexafluoroacetone propylene adduct, trichloroacetic acid, parachlorophenol and hexafluoroacetone sesquihydrate, and said shrinking agent being selected from the group consisting of methylene chloride and chloroform, said solution having a solubility parameter approximately that of the polyester, said solubility parameter of the solution being defined in accordance with the following:

Ss V1S1 + V2S2 where Ss is the solubility parameter of the solution, V1 is the volume fraction of the solvent component, S1 is the solubility parameter of the solvent component, V2 is the volume fraction of the shrinking agent component and S2 is the solubility parameter of the shrinking agent component; and

removing all traces of said compacting solution from said compacted fabric.

10. The process of claim 9 wherein said compacting solution contains from about 2 to about 10 percent by weight of the solution of the solvent for the polymer and from about 98 to about 90 percent by weight of the shrinking agent for the polymer.

11. The process of claim 10 wherein said compacting solution contains from about 4 to about 8 percent by weight of the solution of the solvent for the polymer and from about 96 to about 92 percent by weight of the shrinking agent for the polymer.

12. The process of claim 9 wherein said polyester is polyethylene terephthalate.

13. A process for reducing the porosity of a uniformly porous, relatively smooth-surfaced knitted synthetic linear polyester tubing which comprises immersing said tubing in a compacting solution for a time sufficient to uniformly compact said tubing at least about 30 percent measured in the wale direction of the tubing without appreciable distortion of the smooth surface of the tubing, said compacting solution containing a mixture of from about 2 to about 10 percent by weight of hexafluoroisopropanol and from about 90 to about 98 percent by weight of methylene chloride;

and removing all traces of said compacting solution from said compacted fabric.

14. The process of claim 13 wherein said tubing is immersed in the said compacting solution for from about 30 seconds to about 30 minutes.

15. The process of claim 14 wherein said tubing is immersed in the said compacting solution for from about 5 to about 15 minutes.

16. The process of claim 13 wherein said solution contains from about 4 to about 8 percent by weight of hexafluoroisopropanol and from about 96 to about 92 percent by weight of methylene chloride.

17. The process of claim 13 wherein the polyester is polyethylene terephthalate.

18. The process of claim 13 wherein the yarn in said tubing has a denier of 40.

19. The process of claim 13 wherein the yarn in the tubing has a denier of 70.

20. A process for preparing a synthetic inter-cardiac prosthesis comprising the steps of:

a. providing a knitted synthetic linear polyester fabric material having a uniform porosity, measured on the Wesolowski scale, above about 7,500 up to about 20,000 and in excess of that suitable for long-term healing effects without undue hemorrhaging at implantation;

b. immersing said porous knitted synthetic linear polyester fabric material in a compacting solution consisting essentially of from about 2 to about 10 percent by weight of an acidic organic component selected from the group consisting of hexafluoroisopropanol, phenol, meta-cresol, hexafluoroacetone propylene adduct, trichloroacetic acid, parachlorophenol and hexafluoroacetone sesquihydrate and about 98 to about 90 percent by weight of a halogenated aliphatic hydrocarbon selected from the group consisting of methylene chloride, chloroform, tetrachloroethane and ethylene dichloride until said fabric material uniformly shrinks at least about 30 percent measured in the wale direction and the porosity of the said fabric material is, measured on the Wesolowski scale, from about 30 to about 5,000 and suitable for long-term healing effects without undue hemorrhaging at implantation;

c. removing said compacted fabric material from said compacting solution; and

d. washing said compacted fabric material to remove all traces of said compacting solution.