Patent US4871493A successfully refreshed from Google Patents.
US4871493A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for extrusion of thermoplastic resin films
Assignee: Resonac Holdings Corp
•
Filing: 1987-07-10
•
Granted: 1989-10-03
•
Expires: 2007-07-10
Abstract
Abstract In preparing a film by extruding a molten thermoplastic resin, a heater in which a temperature profile varying in the width direction can be set is arranged in the width direction in the vicinity of a die lip, and a temperature sensor for detecting a resin temperature profile in the vicinity of the outlet of the die lip and a sensor capable of detecting a thickness profile of a film or the like in the width direction are disposed. The output of the heater is controlled according to signals from the temperature sensor and thickness sensor to automatically adjust the thickness of the film or the like in the width direction, whereby a homogeneous film with a reduced thickness unevenness can be stably prepared with a high precession of control of the thickness unevenness. .
Inventors
- 👤 Sumio Goto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:38
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/911; B29C48/9135; B29C48/914; B29C48/03; B29C48/07; B29C48/08; B29C48/78; B29C48/86; B29C48/865; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92114; B29C2948/92152; B29C2948/92209; B29C2948/92323; B29C2948/92428; B29C2948/92504; B29C2948/92609; B29C2948/92647; B29C2948/92704; B29C2948/92819; B29C2948/92857; B29C2948/92904
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
145 words
A process for preparing a film of a thermoplastic resin by extruding a molten thermoplastic resin onto the surface of a cooling roll from a die, wherein a heater in which a temperature profile varying in the width direction can be set is arranged in the width direction on the die in the vicinity of a die lip of the die, a temperature sensor for directly detecting a resin temperature profile in the vicinity of the outlet of the die lip is disposed in the vicinity of the die lip and apart from the die, and a thickness sensor capable of detecting a thickness profile in the width direction of a film is disposed, and the output of said heater is controlled according to signals from the temperature sensor and thickness sensor, whereby the thickness of the film in the width direction is automatically adjusted.
Claim 2
Dependent Claim
145 words
A process for preparing a film of a thermoplastic resin by extruding a molten thermoplastic resin onto the surface of a cooling roll from a die, wherein a heater in which a temperature profile varying in the width direction can be set is arranged in the width direction on the die in the vicinity of a die lip of the die, a temperature sensor for directly detecting a resin temperature profile in the vicinity of the outlet of the die lip is disposed in the vicinity of the die lip and apart from the die, and a thickness sensor capable of detecting a thickness profile in the width direction of a film is disposed, and the output of said heater is controlled according to signals from the temperature sensor and thickness sensor, whereby the thickness of the film in the width direction is automatically adjusted.
Claim 3
Dependent Claim
44 words
A preparation process according to claim 1, wherein a heater, a part or the entirety of which is divided into a plurality of blocks having a length not larger than 50 mm along the width direction of the die, is used as the heater.
Claim 4
Dependent Claim
34 words
A preparation process according to claim 1 or claim 2, wherein the heater is disposed so that the distance between the heater and the outlet of the die is not larger than 200 mm.
Claim 5
Dependent Claim
21 words
A preparation process according to claim 1 or claim 2, wherein aluminum is used as a heat conductor of the heater.
Claim 6
Independent Claim
171 words
An apparatus for the preparation of thermoplastic resin films, which comprises a die for extruding a molten thermoplastic resin and at least one cooling roll for cooling a resin film extruded in the molten state from said die, said apparatus further comprising (a) a heater which is disposed on said die in the vicinity of a die lip of said die and in which a temperature profile varying in the width direction of the film can be set, (b) a temperature sensor for directly detecting a resin temperature profile in the vicinity of the outlet of said die lip, said temperature sensor being disposed in the vicinity of the outlet of the die lip and apart from the die, (c) a thickness sensor capable of detecting a thickness profile in the width direction of the film and (d) a controller for controlling the output of said heater while receiving signals from said thickness sensor and temperature sensor, wherein the thickness in the width direction of the film can be automatically adjusted.
Claim 7
Independent Claim
171 words
An apparatus for the preparation of thermoplastic resin films, which comprises a die for extruding a molten thermoplastic resin and at least one cooling roll for cooling a resin film extruded in the molten state from said die, said apparatus further comprising (a) a heater which is disposed on said die in the vicinity of a die lip of said die and in which a temperature profile varying in the width direction of the film can be set, (b) a temperature sensor for directly detecting a resin temperature profile in the vicinity of the outlet of said die lip, said temperature sensor being disposed in the vicinity of the outlet of the die lip and apart from the die, (c) a thickness sensor capable of detecting a thickness profile in the width direction of the film and (d) a controller for controlling the output of said heater while receiving signals from said thickness sensor and temperature sensor, wherein the thickness in the width direction of the film can be automatically adjusted.
Claim 8
Dependent Claim
38 words
A preparation apparatus according to claim 5, wherein a part or the entirety of the heater is divided into a plurality of blocks having a length not larger than 50 mm along the width direction of the die.
Claim 9
Dependent Claim
34 words
A preparation apparatus according to claim 5 or claim 6, wherein the heater is disposed so that the distance between the heater and the outlet of the die is not larger than 200 mm.
Claim 10
Dependent Claim
19 words
A preparation apparatus according to claim 5 or claim 6, wherein the heater comprises aluminum as a heat conductor.
References Cited (Backward Citations)
US3341388A
Cited
US3761553A
Cited
US3883279A
Cited
US4426239A
Cited
US4409160A
Cited
US4454084A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-02 | 1993-04-03 | 1993-10-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-02 | 1997-04-03 | 1997-10-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-02 | 2001-04-03 | 2001-10-03 | $7700.00 | Window Closed / Lapsed |