US4402900A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry spinning process with a gas flow amplifier
Assignee: EIDP Inc
•
Filing: 1982-11-01
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Granted: 1983-09-06
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Expires: 2002-11-01
Abstract
Abstract In conventional dry-spinning processes forming a hollow bundle of filaments, a heated inert gas is introduced to evaporate spinning solvent from the filaments, and a vacuum may be applied in the center of the bundle near the face of the spinneret to assist in drawing the heated inert gas through the filament bundle. A Coanda-flow entrainment device in the center of the bundle adjacent the spinneret face uses a small inlet gas flow directed along a Coanda surface. The device entrains gas, pulling it through the filament bundle and then directing it downward. This entrained flow can supplement or supplant the vacuum-induced flow through the filaments.
Inventors
- 👤 Walter C. Berry, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 05:44
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
94 words
In a spinning process that includes the steps of extruding a solution of polymer through a spinneret having orifices arranged in a pattern to form a hollow bundle of filaments and passing a first flow of heated inert gas downwardly around and inwardly through the bundle toward its hollow center to treat the filaments, the improvement comprising: introducing a second flow of inert gas along a Coanda surface centrally located within the bundle near the spinneret whereby a portion of said first flow of gas is entrained downwardly with said second flow of gas.
Claim 2
Dependent Claim
94 words
In a spinning process that includes the steps of extruding a solution of polymer through a spinneret having orifices arranged in a pattern to form a hollow bundle of filaments and passing a first flow of heated inert gas downwardly around and inwardly through the bundle toward its hollow center to treat the filaments, the improvement comprising: introducing a second flow of inert gas along a Coanda surface centrally located within the bundle near the spinneret whereby a portion of said first flow of gas is entrained downwardly with said second flow of gas.
Claim 3
Dependent Claim
38 words
The process as defined in claim 1, including the step of creating a vacuum in the center of the hollow bundle of filaments adjacent the spinneret face to assist said first flow of gas inwardly through the bundle.
References Cited (Backward Citations)
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US2131810A
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US1933587A
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US3521325A
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US4123208A
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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) | 1986-09-05 | 1987-03-07 | 1987-09-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-05 | 1991-03-07 | 1991-09-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-05 | 1995-03-07 | 1995-09-06 | $7700.00 | Window Closed / Lapsed |