Patent US3553471A successfully refreshed from Google Patents.
Patent US5246752A successfully refreshed from Google Patents.
US5246752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for drawing thermoplastic tubing
Assignee: Bayer Corp
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Filing: 1991-02-21
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Granted: 1993-09-21
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Expires: 2011-02-21
Abstract
Abstract The specification discloses a new method and apparatus for treating extruded teflon (fluoropolymer) tubing to significantly improve its dimensional and optical characteristics. Diameter tolerance is ±0.0002, concentricity rises to 95%, and optical clarity rises to the theoretical transmittance of the material. The tubing is first cleaned, and then heated to a transition temperature above 150°C. to soften and further homogenize the tubing. The tubing is then drawn through a polished diamond die and then rapidly cooled. The cooled tubing may be further stabilized by an annealing step. Both a batch mode and a continuous mode of operation are disclosed.
Inventors
- 👤 Jan Raczkowski
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:22
CPC Classifications
B; B29; B29C; B29C71/00; B29C71/02; B29C35/00; B29C35/02; B29C35/04; B29C35/06; B29C55/00; B29C55/30; B29C2071/022; B29C35/041; B29C35/16; B29K; B29K2027/00; B29K2027/12; B29K2027/18; B29L; B29L2023/00; B29L2023/22; Y; Y10; Y10T; Y10T428/00; Y10T428/13; Y10T428/1352; Y10T428/139; Y10T428/31504; Y10T428/3154; Y10T428/31544
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
25 words
An extruded and redrawn fluoropolymer tube having an outer diameter of 0.25 to 2.5 mm, and a dimensional accuracy throughout its length of ±0.0002 inches.
Claim 2
Dependent Claim
25 words
An extruded and redrawn fluoropolymer tube having an outer diameter of 0.25 to 2.5 mm, and a dimensional accuracy throughout its length of ±0.0002 inches.
Claim 3
Dependent Claim
27 words
An extruded and redrawn fluoropolymer tube as claimed in claim 1 having a uniform concentricity of inner and outer diameters and optical transmittance in excess of 90%.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-09-20 | 1997-03-22 | 1997-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-09-20 | 2001-03-22 | 2001-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-09-20 | 2005-03-22 | 2005-09-21 | $7700.00 | Window Closed / Lapsed |