US4801419A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Solid phase deformation of thermoplastic tubes
Assignee: BTG International Ltd
•
Filing: 1986-07-15
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Granted: 1989-01-31
•
Expires: 2006-07-15
Abstract
Abstract A process for the deformation of a hollow workpiece comprising orientable, thermoplastic polymer by passage in the solid phase through a die having both an entry side and an exit side, which process comprises providing the hollow workpiece at the entry side of the die; applying to the hollow workpiece from the exit side of the die a tension insufficient to cause tensile failure of the workpiece but sufficient to deform the hollow workpiece by drawing it with reduction in its bulk cross-sectional area in the solid phase simultaneously through the die and over an internally positioned former having a cross-sectional area greater than the initial internal cross-sectional area of the hollow workpiece; and collecting the deformed hollow workpiece from the exit side of the die.
Inventors
- 👤 Ian M. Ward
- 👤 Alan Selwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 00:37
CPC Classifications
B; B29; B29C; B29C55/00; B29C55/30; B29C55/22; B29C55/26; B29K; B29K2027/00; B29K2027/12
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
134 words
A process for the deformation of a hollow workpiece comprising an orientable, thermoplastic polymer by passage in the solid phase through a die having both an entry side and an exit side, which process comprises providing the hollow workpiece at the entry side of the die; applying tension to the hollow workpiece from the exit side of the die where said tension is insufficient to cause tensile failure of the workpiece but sufficient to deform the hollow workpiece; thereby drawing said hollow workpiece with reduction in its bulk cross-sectional area in the solid phase simultaneously through the die and over an internally position former; said former having a cross-sectional area greater than the initial internal cross-sectional area of the hollow workpiece; and collecting the deformed hollow workpiece from the exit side of the die.
Claim 2
Dependent Claim
134 words
A process for the deformation of a hollow workpiece comprising an orientable, thermoplastic polymer by passage in the solid phase through a die having both an entry side and an exit side, which process comprises providing the hollow workpiece at the entry side of the die; applying tension to the hollow workpiece from the exit side of the die where said tension is insufficient to cause tensile failure of the workpiece but sufficient to deform the hollow workpiece; thereby drawing said hollow workpiece with reduction in its bulk cross-sectional area in the solid phase simultaneously through the die and over an internally position former; said former having a cross-sectional area greater than the initial internal cross-sectional area of the hollow workpiece; and collecting the deformed hollow workpiece from the exit side of the die.
Claim 3
Dependent Claim
17 words
A process according to claim 1 wherein the polymer comprising the hollow workpiece is a semicrystalline polymer.
Claim 4
Dependent Claim
28 words
A process according to claim 2 wherein the polymer is an unsubstituted or mono- or poly halo-substituted vinyl polymer, unsubstituted or hydroxy-substituted polyester, a polyamide or a polyacetal.
Claim 5
Dependent Claim
24 words
A process according to claim 3 wherein the polymer is a linear homo- or copolymer of ethylene or propylene with at least one comonomer.
Claim 6
Dependent Claim
24 words
A process according to claim 4 wherein the polymer is a linear homo- or copolymer of ethylene of M w from 50,000 to 500,000.
Claim 7
Dependent Claim
25 words
A process according to claim 5 wherein the hollow workpiece is heated to a temperature within 60° C. below the melting point of the polymer.
Claim 8
Dependent Claim
24 words
A process according to claim 4 wherein the polymer is a linear homo- or copolymer of propylene of M w from 150,000 to 800,000.
Claim 9
Dependent Claim
21 words
A process according to claim 7 wherein the hollow workpiece is heated to a temperature from 20° C. to 170° C.
Claim 10
Dependent Claim
12 words
A process according to claim 3 wherein the polymer is a polyoxymethylene.
Claim 11
Dependent Claim
21 words
A process according to claim 9 wherein the hollow workpiece is heated to a temperature from 80° C. to 170° C.
Claim 12
Dependent Claim
14 words
A process according to claim 3 wherein the polymer is a vinylidene fluoride polymer.
Claim 13
Dependent Claim
21 words
A process according to claim 11 wherein the hollow workpiece is heated to a temperature from 80° C. to 165° C.
Claim 14
Dependent Claim
12 words
A process according to claim 3 wherein the polymer is a polyester.
Claim 15
Dependent Claim
21 words
A process according to claim 13 wherein the hollow workpiece is heated to a temperature from 55° C. to 120° C.
Claim 16
Dependent Claim
13 words
A process according to claim 1 wherein the hollow workpiece comprises a filler.
Claim 17
Dependent Claim
15 words
A process according to claim 1 wherein the hollow workpiece is essentially unoriented before deformation.
Claim 18
Dependent Claim
19 words
A process according to claim 1 wherein the hollow workpiece is an open-ended elongate workpiece of substantially constant cross-section.
Claim 19
Dependent Claim
15 words
A process according to claim 17 wherein the hollow workpiece has an axis of symmetry.
Claim 20
Dependent Claim
19 words
A process according to claim 18 wherein the hollow workpiece has a circular, elliptical, square, rectangular or triangular cross-section.
Claim 21
Dependent Claim
38 words
A process according to claim 1 wherein at the die and downstream therefrom there is positioned within the hollow workpiece a former having a cross-sectional area of at least the initial internal cross-sectional area of the hollow workpiece.
Claim 22
Dependent Claim
11 words
A process according to claim 1 wherein the die is heated.
Claim 23
Dependent Claim
20 words
A process according to claim 1 wherein the oriented thermoplastic material passes through a heated chamber downstream from the die.
Claim 24
Dependent Claim
28 words
A process according to claim 1 wherein the hollow workpiece is drawn through the die in the solid phase at a nominal deformation ratio of at least 3:1.
Claim 25
Dependent Claim
18 words
A process according to claim 23 wherein the draw speed is greater than 50 cm min -1 .
Claim 26
Dependent Claim
9 words
A process according to claim 23 which is continuous.
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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) | 1992-01-31 | 1992-08-01 | 1993-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-01-31 | 1996-08-01 | 1997-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-01-31 | 2000-08-01 | 2001-01-31 | $7700.00 | Window Closed / Lapsed |