THIN-WALLED CALENDERED PTFE

• US 20090252926A1
• Filed: 04/03/2008
• Published: 10/08/2009
• Est. Priority Date: 04/03/2008
• Status: Abandoned Application

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: Boston Scientific Scimed, Inc. (Boston Scientific Corporation)
• Inventors: Druma, Calin, Kebabjian, Matt, Noesner, Matthew, Henderson, Jamie S.
• Application Number:
  US12/061,898
• Publication Number:
  US 20090252926A1
• Time in Patent Office: Days
• US Class Current: 428/156
• CPC Class Codes: A61F 2/06 Blood vessels
• CPC Class Codes: A61L 27/16 obtained by reactions only involving carbon-to-carbon unsaturated bonds
• CPC Class Codes: A61L 27/56 Porous materials, e.g. foams or sponges
• CPC Class Codes: B29C 43/22 of articles of indefinite length
• CPC Class Codes: B29C 48/022 characterised by the choice of material
• CPC Class Codes: B29C 48/09 Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29K 2027/18 PTFE, i.e. polytetrafluorethene , e.g. ePTFE, i.e. expanded polytetrafluorethene
• CPC Class Codes: C08L 27/18 Homopolymers or copolymers or tetrafluoroethene
• CPC Class Codes: Y10T 428/24479 including variation in thickness

Abstract

The invention relates to prosthetic implants, and particularly those prosthetic implants which have an improved water entry pressure resistance. Particularly, the invention relates to a strong calendered PTFE tube and processes for making a strong calendered PTFE tube. The calendered PTFE tube may then be used to form a strong calendered expanded PTFE tube.

Claims

1. A prosthesis comprising:

a calendered tubular body comprising ePTFE having a densified node and fibril structure, said tubular body having a water entry pressure value of at least 20 psi, a thickness of between 50 to 100 microns, and a density of between about 0.5 g/cc to about 1.0 g/cc.

2. The prosthesis of claim 1, wherein said tubular body comprises an inner surface and an outer surface.

3. The prosthesis of claim 1, wherein said outer surface of said tubular body comprises a plurality of helical patterns.

4. The prosthesis of claim 1, wherein said outer surface of said tubular body comprises a plurality of cross-helical patterns.

5. A method for forming a PTFE tube comprising the steps of:

forming a green PTFE tube with an inner and outer surface;

positioning said green PTFE tube on a tubular support surface having an outer surface, wherein said inner surface of said green PTFE tube is associated with said outer surface of said tubular support surface; and

applying a compressive force along the length of said outer surface of said green PTFE tube.

6. The method of claim 5, wherein said compressive force is applied by a calendering mechanism comprising at least one rotatable roller, positioned about the outer surface of said green PTFE tube.

7. The method of claim 6, wherein said at least one rotatable roller is selected from the group consisting of cylindrical rollers, 3-dimensional tapered helical profiled rollers, and driven rollers.

8. The method of claim 6, wherein said at least one rotatable roller is advanced along at least a portion of the length of said green PTFE tube.

9. The method of claim 6, wherein said green PTFE tube is advanced along its longitudinal axis as it passes through said calendering mechanism.

10. The method of claim 6, wherein said calendering mechanism includes an iris attachment for positioning said at least one rotatable roller radially about said outer surface of said green PTFE tube.

11. The method of claim 6, wherein said green PTFE tube is advanced along its longitudinal axis through said iris attachment as said at least one rotatable roller rotates.

12. The method of claim 6, further comprising the step of heating said calendering mechanism.

13. The method of claim 5, wherein said application of compressive force is applied by shaping cam followers which rotate inline with the movement of the green tube along the tubular surface.

14. The method of claim 6, further comprising the step of creating a multitude of helical or cross-helical patterns on said outer surface of said green PTFE tube.

15. The method of claim 5, wherein said step of applying compressive force comprises rolling said tubular support surface against at least one external surface, wherein said at least one external surface contacts said outer surface of said green PTFE tube.

16. The method of claim 17, comprising two external surfaces, wherein said rolling tubular support surface is located between said external surfaces.

17. The method of claim 5, further comprising the step of expanding said PTFE tube after said step of applying a compressive force along the length of said outer surface of said green PTFE tube.