Patent US3765808A successfully refreshed from Google Patents.
US3765808A
Expired / Lapsed
US
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Apparatus for extruding thermoplastic tubing
Assignee: EIDP Inc
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Filing: 1970-11-18
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Granted: 1973-10-16
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Expires: 1990-11-18
Abstract
Abstract Tubular film casting and orientation by extruding a molten thermoplastic polymer (e.g., polyethylene or polypropylene) through an annular die and melt-drawing the tubular film over an undercut internal quench mandrel while directing helium along the undercut portion of the mandrel, preferably at a pressure sufficient to resist film neck-in.
Inventors
- 👤 J Lyon
- 👤 H Yang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:12
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/25; B29C48/88; B29C48/90; B29C48/901; B29C48/902; B29C48/03; B29C48/09; B29C48/10; B29C48/001; B29C48/0018; B29C48/0019
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
75 words
In a tubular film casting and orientation apparatus comprising an annular die for extruding a molten thermoplastic polymer and an undercut internal quench mandrel over which the tubular film is melt-drawn, the improvement of means for introducing a flow of helium along the undercut portion of said mandrel and adjacent the tubular film in the zone between said die and the plane of initial quenching, and an absorbent packing between said mandrel and said die.
Claim 2
Dependent Claim
75 words
In a tubular film casting and orientation apparatus comprising an annular die for extruding a molten thermoplastic polymer and an undercut internal quench mandrel over which the tubular film is melt-drawn, the improvement of means for introducing a flow of helium along the undercut portion of said mandrel and adjacent the tubular film in the zone between said die and the plane of initial quenching, and an absorbent packing between said mandrel and said die.
Claim 3
Dependent Claim
27 words
An apparatus as defined in claim 1 wherein the undercut portion of said quench mandrel is provided with ports for the flow of helium through said zone.
Claim 4
Dependent Claim
24 words
An apparatus as defined in claim 1 wherein means are provided for the flow of helium through said packing and out of said zone.
References Cited (Backward Citations)
US2987765A
Cited
US3142092A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-15 | 1977-04-16 | 1977-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-15 | 1981-04-16 | 1981-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-15 | 1985-04-16 | 1985-10-16 | $7700.00 | Window Closed / Lapsed |