US4399094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process and apparatus for forming a plastic film
Assignee: NUC Corp
•
Filing: 1981-05-26
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Granted: 1983-08-16
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Expires: 2001-05-26
Abstract
Abstract A plastic film is formed by annealing a molten tubular film in a first enclosed space and immediately thereafter directing cold air perpendicular to the axis thereof and expanding and solidifying the film in a second enclosed space while in contact with cold air flowing parallel to film travel.
Inventors
- 👤 Shigeo Fujitani
- 👤 Youichi Matsuda
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:43
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/885; B29C48/03; B29C48/09; B29C48/10; B29C48/911; B29C48/9115; B29C48/912; B29C48/001; B29C48/0018; B29C48/0019
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
91 words
In a process for forming a plastic film from a thermoplastic resin by blow-film extrusion, the improvement which comprises subjecting the molten tubular film extruded from a die to annealing in a first enclosed space, immediately thereafter blowing cold air for rapid cooling to the outer surface of said tubular film in the direction perpendicular to the axis thereof, and permitting said tubular film to expand and solidify in a second enclosed space, while it is in contact with cold air flowing in the same direction as said tubular film travel.
Claim 2
Dependent Claim
91 words
In a process for forming a plastic film from a thermoplastic resin by blow-film extrusion, the improvement which comprises subjecting the molten tubular film extruded from a die to annealing in a first enclosed space, immediately thereafter blowing cold air for rapid cooling to the outer surface of said tubular film in the direction perpendicular to the axis thereof, and permitting said tubular film to expand and solidify in a second enclosed space, while it is in contact with cold air flowing in the same direction as said tubular film travel.
Claim 3
Dependent Claim
24 words
The process for forming a plastic film as set forth in claim 1, wherein the thermoplastic resin is a polyolefin or an olefin copolymer.
Claim 4
Dependent Claim
35 words
The process for forming a plastic film as set forth in claim 1, wherein the thermoplastic resin is one consisting mainly of low density polyethylene or an ethylene copolymer having a density lower than 0.94.
Claim 5
Dependent Claim
25 words
The process for forming a plastic film as set forth in claim 1, wherein the blow-up ratio of said tubular film is 1 to 5.
Claim 6
Independent Claim
95 words
An apparatus for forming a plastic film which comprises a molten resin extrusion die having a circular die lip and an air port, an annealing chamber of cylindrical body installed concentrically outside said die lip, an air ring which is installed in contact with said annealing chamber and is provided with a blow-off slit which opens horizontally at the end of a circular air passage and with apertures of slits and/or holes formed on the upper plate ring thereof, and an air flow rectifying cylindrical body installed outside said apertures on said upper plate ring.
Claim 7
Independent Claim
95 words
An apparatus for forming a plastic film which comprises a molten resin extrusion die having a circular die lip and an air port, an annealing chamber of cylindrical body installed concentrically outside said die lip, an air ring which is installed in contact with said annealing chamber and is provided with a blow-off slit which opens horizontally at the end of a circular air passage and with apertures of slits and/or holes formed on the upper plate ring thereof, and an air flow rectifying cylindrical body installed outside said apertures on said upper plate ring.
Claim 8
Dependent Claim
26 words
The apparatus as set forth in claim 5, wherein said apertures formed on the upper plate ring of the air ring are adjustable for their opening.
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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) | 1986-08-15 | 1987-02-14 | 1987-08-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-15 | 1991-02-14 | 1991-08-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-15 | 1995-02-14 | 1995-08-16 | $7700.00 | Window Closed / Lapsed |