US3883279A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for making polymeric film
Assignee: EIDP Inc
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Filing: 1973-08-02
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Granted: 1975-05-13
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Expires: 1993-08-02
Abstract
Abstract An apparatus is provided for making polymeric film wherein flowable polymeric material is extruded in molten form through an extrusion die orifice and onto a moving quenching surface in the form of a web of material. Such apparatus includes means for selectively controlling (by heating or cooling) the temperature of isolated parts of die lips defining the die orifice combined with means for pinning the web across its full width to such quenching surface whereby to improve thickness uniformity of the film formed thereby. A method also is provided of making this polymeric film of improved thickness uniformity.
Inventors
- 👤 David Edward Heyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 10:12
CPC Classifications
G; G05; G05D; G05D5/00; G05D5/02; G05D5/03; B; B29; B29C; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/25; B29C48/30; B29C48/305; B29C48/31; B29C48/313; B29C48/78; B29C48/86; B29C48/865; B29C48/87; B29C48/88; B29C48/91; B29C48/911; B29C48/9135; B29C48/914; B29C48/915; B29C48/9165; B29C48/92; B29C2948/00; B29C2948/92; B29C2948/92009; B29C2948/92114; B29C2948/92152; B29C2948/92504; B29C2948/92609; B29C2948/92647; B29C2948/92704; B29C2948/92819; B29C2948/92857; B29C2948/92904
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
132 words
An apparatus for improving the gauge profile of a web of polymeric film including: an extrusion die for extruding a web of material onto a moving quenching surface; means for selectively heating thermally isolated parts of die lips of the extrusion die; means for pinning the web of material fully across its width to the quenching surface; means for removing the web of material from the quenching surface in the form of a web of film; means for measuring the thickness of the web of film across the width thereof and transmitting a signal based thereon; and means for actuating the means for selectively heating the thermally isolated die lip parts of the extrusion die; based on such signal in a manner to improve the gauge profile of the web of film.
Claim 2
Independent Claim
132 words
An apparatus for improving the gauge profile of a web of polymeric film including: an extrusion die for extruding a web of material onto a moving quenching surface; means for selectively heating thermally isolated parts of die lips of the extrusion die; means for pinning the web of material fully across its width to the quenching surface; means for removing the web of material from the quenching surface in the form of a web of film; means for measuring the thickness of the web of film across the width thereof and transmitting a signal based thereon; and means for actuating the means for selectively heating the thermally isolated die lip parts of the extrusion die; based on such signal in a manner to improve the gauge profile of the web of film.
Claim 3
Dependent Claim
20 words
The apparatus of claim 1 wherein the web of material is pinned to the quenching surface by full wire pinning.
Claim 4
Dependent Claim
19 words
In the apparatus of claim 1 wherein such thermally isolated parts of the die lips are defined by slots.
Claim 5
Dependent Claim
130 words
In the apparatus of claim 1 such die lips each having a continuous surface in opposed relationship to each other defining an extrusion orifice therebetween and such apparatus having means defining a plurality of slots in such die lips, each of such slots having an inner and outer portion with the inner portion positioned adjacent to and spaced from the surfaces of the die lips defining the extrusion orifice, and wherein the slots adjacent to each other define a thermally isolated die lip part therebetween which parts are substantially thermally isolated from the other die lip parts and from the body of the extrusion die and wherein a heater element is positioned between each of the slots and inwardly from the surfaces of the die lips defining the extrusion orifice.
Claim 6
Dependent Claim
22 words
The apparatus of claim 4 wherein the outer portion of each slot has a greater width than the rest of the slot.
References Cited (Backward Citations)
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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) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |