US4268464A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic pinning of extruded polyamide film
Assignee: Toyobo Co Ltd
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Filing: 1979-08-16
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Granted: 1981-05-19
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Expires: 1999-08-16
Abstract
Abstract A process for production of a sheet of a polyamide material which comprises extruding the polyamide material in a melt state in the form of sheet and bringing the extruded sheet in a melt state into contact with the surface of a moving chill body for quenching to give an undrawn film, characterized in that a direct current of high voltage is applied between an electrode and the extruded sheet so as to product a discharge in a streamer corona state onto the extruded sheet, whereby the extruded sheet is brought into tight and close contact with the surface of the moving chill body electrically grounded so as to be chilled quickly.
Inventors
- 👤 Yasutomi Yoshino
- 👤 Fumio Nishimura
- 👤 Haruhiko Watanabe
- 👤 Masahiro Kobayashi
- 👤 Kunio Takeuchi
- 👤 Haruo Okudaira
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:54
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/915; B29C48/9165; B29C48/03; B29C48/07; B29C48/08; B29C48/914
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
117 words
A process for production of a sheet of a polyamide material which comprises extruding the polyamide material in a melt state in the form of sheet and bringing the extruded sheet in a melt state into contact with the surface of a moving chill body for quenching to give an undrawn film, characterized in that a direct current of high voltage is applied between an electrode having discharge points arranged discontinuously and the extruded sheet so as to produce a discharge in a steamer corona state onto the extruded sheet, whereby the extruded sheet is brought into tight and close contact with the surface of the moving chill body electrically grounded so as to be chilled quickly.
Claim 2
Dependent Claim
117 words
A process for production of a sheet of a polyamide material which comprises extruding the polyamide material in a melt state in the form of sheet and bringing the extruded sheet in a melt state into contact with the surface of a moving chill body for quenching to give an undrawn film, characterized in that a direct current of high voltage is applied between an electrode having discharge points arranged discontinuously and the extruded sheet so as to produce a discharge in a steamer corona state onto the extruded sheet, whereby the extruded sheet is brought into tight and close contact with the surface of the moving chill body electrically grounded so as to be chilled quickly.
Claim 3
Dependent Claim
18 words
The process according to claim 1, wherein the polyamide material comprises an aliphatic polyamide as the major component.
Claim 4
Dependent Claim
16 words
The process according to claim 2, wherein the aliphatic polyamide is nylon 6 or nylon 66.
Claim 5
Dependent Claim
32 words
The process according to claim 1, wherein the quantity of the current discharged in a streamer corona state is 10 mA to 5 A per 1 m wide of the extruded sheet.
Claim 6
Dependent Claim
32 words
The process according to claim 4, wherein the quantity of the current discharged in a streamer corona state is 20 mA to 500 mA per 1 m wide of the extruded sheet.
Claim 7
Dependent Claim
15 words
The process according to claim 1, wherein the electrode is connected to a negative terminal.
Claim 8
Dependent Claim
32 words
The process according to claim 1, wherein the extruded sheet is chilled at a temperature between 0° C. and the temperature which is 20° C. lower than the maximum temperature for crystallization.
Claim 9
Dependent Claim
23 words
The process according to claim 7, wherein the extruded sheet is chilled at a temperature of 0° C. to the glass transition temperature.
Claim 10
Dependent Claim
24 words
The process according to claim 1, wherein the undrawn sheet after chilling is drawn at least in one direction to give a drawn sheet.
Claim 11
Dependent Claim
22 words
The process according to claim 9, wherein the drawing is effected at a draw ratio of 1.1 to 8 in one direction.
Claim 12
Dependent Claim
25 words
The process according to claim 9, wherein the drawing is effected biaxially at a draw ratio of 1.1 to 6 in each of two directions.
Claim 13
Dependent Claim
14 words
The process according to claim 11, wherein the drawing is effected sequentially and biaxially.
References Cited (Backward Citations)
US3223757A
Cited
US3361728A
Cited
US3427686A
Cited
US3655307A
Cited
US4111625A
Cited
JPS5141762A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-05-18 | 1984-11-17 | 1985-05-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-05-18 | 1988-11-17 | 1989-05-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-05-18 | 1992-11-17 | 1993-05-19 | $7700.00 | Window Closed / Lapsed |