Method of reducing the wall thickness of a PTFE tube and product formed thereby

• US 6,939,119 B2
• Filed: 09/23/2003
• Issued: 09/06/2005
• Est. Priority Date: 12/26/2000
• Status: Expired due to Fees

• Current Assignee: Lifeshield Sciences LLC (Acacia Research Corporation)
• Original Assignee: Scimed Life Systems Incorporated (Boston Scientific Corporation)
• Inventors: Hill, Jason P., Brown, Brian J., Lininger, James R.
• Primary Examiner(s): Mackey, James P.
• Application Number:
  US10/668,517
• Publication Number:
  US 20040056384A1
• Time in Patent Office: 714 Days
• Field of Search: 425/363, 425/365, 425/367, 425/374, 425/393
• US Class Current: 425/363
• CPC Class Codes: B29C 55/24 radial
• CPC Class Codes: B29C 67/0014 for shaping tubes or blown tubular films

Abstract

A thin wall PTFE tube is formed from an extruded green tube. The PTFE tube includes an inner tubular surface and an opposed outer tubular surface defining a tubular wall of a first thickness. The tubular wall is compressed to uniformly reduce the wall-thickness and circumferentially orient the tube. The PTFE tube is positioned over a first elongate roller with the inner tubular surface being in contact therewith. A second roller is positioned against the outer tubular surface of the PTFE tube. The pair of rollers are counter rotated so as to circumferentially compress the tubular wall between the rollers. This results in the uniform reduction in the tubular wall from the first thickness to a lesser second thickness and a circumferential orientation otherwise not occurring in an extruded PTFE paste extrusion.

Claims

1. An apparatus for reducing the thickness of the wall of a polymer tube comprising:

an inner luminal roller having an outer surface for supporting said tube thereabout;

an outer roller relatively movably positioned with respect to said inner roller to place said wall in compression therebetween;

means for relatively rotating said inner roller and outer roller to effect circumferential reduction in said thickness of said wall therebetween; and

a tensioning roller for supporting said tube thereabout, said tensioning roller being biased away from said inner roller for maintaining an outward radial tension on said tube.

2. An apparatus of claim 1 further including a supporting device for supporting said outer roller and wherein said inner roller is movably positioned with respect to said outer roller for movement into compressive engagement therewith.

3. An apparatus of claim 2 further including a warm water bath supporting said inner and outer rollers.

4. An apparatus for reducing the thickness of the wall of a polymer tube comprising:

an inner luminal roller having an outer surface for supporting said tube thereabout;

an outer roller relatively movably positioned with respect to said inner roller to place said wall in compression therebetween;

means for relatively rotating said inner roller and outer roller to effect circumferential reduction in said thickness of said wall therebetween;

a pair of tensioning rollers for supporting said tube thereabout, said pair of tensioning rollers being oppositely spring biased away from said inner roller for maintaining an outward radial tension on said tube.