US3926706A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Film blowing method
Assignee: Reifenhauser KG
•
Filing: 1972-12-11
•
Granted: 1975-12-16
•
Expires: 1992-12-11
Abstract
Abstract A method of for the blowing of thermoplastic film wherein a pair of closed envelopes of thermoplastic material are extruded from concentric and coaxial dies and are independently blown and orientated prior to being passed together between a pair of calendering and compression rolls. A parting compound to enable separation of the laminated foils emerging from the rolls or an adhesion means may be applied to the interface of the two blown bodies.
Inventors
- 👤 Fritz Reifenhauser
- 👤 Herbert Rahlfs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:20
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/06; B32B27/08; B29; B29C; B29C48/00; B29C48/001; B29C48/0013; B29C48/0015; B29C48/0016; B29C48/03; B29C48/09; B29C48/16; B29C48/18; B29C48/21; B32B1/00; B32B1/08; B29C48/10; B32B2398/00; B32B2398/20; B32B2597/00
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
84 words
A METHOD OF PRODUCING A MULTILAYER FOIL, COMPRISING THE STEPS OF: COAXIALLY EXTRUDING AN INNER THERMOPLASTIC TUBE WITHIN AN OUTER THERMOPLASTIC TUBE FROM OUTLETS LYING IN A COMMON PLANE; BLOWING EACH TUBE INDEPENDENTLY OF AND OUT OF CONTACT WITH THE OTHER FROM DIFFERENT BLOWING SOURCES TO STRETCH THE OUTER TUBE INDEPENDENTLY OF THE INNER TUBE AND IMPART DIFFERENT DEGREES OF ORIENTATION IN THE DIRECTION OF EXTRUSION AND TRANSVERSELY THERETO; AND COLLECTIVELY PINCHING SAID TUBES DOWNSTREAM OF SAID BLOWING STEP WITH THEIR SURFACES BONDING TOGETHER.
Claim 2
Independent Claim
84 words
A METHOD OF PRODUCING A MULTILAYER FOIL, COMPRISING THE STEPS OF: COAXIALLY EXTRUDING AN INNER THERMOPLASTIC TUBE WITHIN AN OUTER THERMOPLASTIC TUBE FROM OUTLETS LYING IN A COMMON PLANE; BLOWING EACH TUBE INDEPENDENTLY OF AND OUT OF CONTACT WITH THE OTHER FROM DIFFERENT BLOWING SOURCES TO STRETCH THE OUTER TUBE INDEPENDENTLY OF THE INNER TUBE AND IMPART DIFFERENT DEGREES OF ORIENTATION IN THE DIRECTION OF EXTRUSION AND TRANSVERSELY THERETO; AND COLLECTIVELY PINCHING SAID TUBES DOWNSTREAM OF SAID BLOWING STEP WITH THEIR SURFACES BONDING TOGETHER.
Claim 3
Dependent Claim
51 words
The method defined in claim 1 wherein said tubes are blown to an inflated diameter approximately d3 and contact one another in the blown state, an inner one of said tubes having a diameter d2 and an outer one of said tubes having a diameter d1, (d3/d2) being greater than (d3/d1).
Claim 4
Dependent Claim
27 words
The method defined in claim 1 wherein the outer one of said tubes is extruded at a lower linear velocity than the inner one of said tubes.
References Cited (Backward Citations)
US2848747A
Cited
US2957201A
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US3023461A
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US3184358A
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US3486196A
Cited
US3322870A
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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) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |