Patent US4812267A successfully refreshed from Google Patents.
US4812267A
Expired / Lapsed
US
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Process for extruding a thermoplastic melt
Assignee: Hoechst AG
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Filing: 1987-10-02
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Granted: 1989-03-14
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Expires: 2007-10-02
Abstract
Abstract On extrusion of thermoplastic melts, flow anomalies occurring in the extrusion dies can be decisively reduced when dies are used whose surfaces coming into contact with the melts are provided with a thermally applied spray coating.
Inventors
- 👤 Karl-Ludwig Hoffmann
- 👤 Gunter Eiden
- 👤 Eugen Morach
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:22
CPC Classifications
B; B29; B29C; B29C48/00; B29C48/03; B29C48/09; B29C48/10
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
107 words
A process for extruding a thermoplastic melt, in which process a thermoplastic is molten in an extruder at elevated temperature under shear and transported as a homogeneous melt through an extrusion die whose surface coming into contact with the melt is coated, wherein the melt is transported through a die whose surface coming into contact with the melt has been coated by means of a thermal spray process with a powder, having a grain size of 1 to 250 μm, of a metal, a metal alloy, a metal carbide, a metal oxide or a cermet to provide a spray coating roughness of up to about 70 μm.
Claim 2
Dependent Claim
107 words
A process for extruding a thermoplastic melt, in which process a thermoplastic is molten in an extruder at elevated temperature under shear and transported as a homogeneous melt through an extrusion die whose surface coming into contact with the melt is coated, wherein the melt is transported through a die whose surface coming into contact with the melt has been coated by means of a thermal spray process with a powder, having a grain size of 1 to 250 μm, of a metal, a metal alloy, a metal carbide, a metal oxide or a cermet to provide a spray coating roughness of up to about 70 μm.
Claim 3
Dependent Claim
32 words
The process as claimed in claim 1, wherein the melt is transported through die whose surface coming into contact with the melt has been coated with an aluminum oxide/titanium dioxide powder mixture.
Claim 4
Dependent Claim
63 words
An extrusion forming metal die, wherein a surface coming into contact with the thermoplastic melt has been provided with a coating having a roughness up to about 70 μm by means of a thermal spray process with a powder, having a grain size of 1 to 250 μm, of a metal, a metal alloy, a metal carbide, a metal oxide or a cermet.
Claim 5
Dependent Claim
63 words
An extrusion forming metal die, wherein a surface coming into contact with the thermoplastic melt has been provided with a coating having a roughness up to about 70 μm by means of a thermal spray process with a powder, having a grain size of 1 to 250 μm, of a metal, a metal alloy, a metal carbide, a metal oxide or a cermet.
Claim 6
Dependent Claim
51 words
An extrusion forming apparatus having a metal surface thereof provided with a coating having a roughness up to about 70 μm comprising the product of applying to the metal surface by thermal spraying a powder mixture of aluminum oxide/titanium oxide, said coated surface being adapted for contact with a thermoplastic melt.
Claim 7
Dependent Claim
51 words
An extrusion forming apparatus having a metal surface thereof provided with a coating having a roughness up to about 70 μm comprising the product of applying to the metal surface by thermal spraying a powder mixture of aluminum oxide/titanium oxide, said coated surface being adapted for contact with a thermoplastic melt.
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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) | 1992-03-13 | 1992-09-12 | 1993-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-03-13 | 1996-09-12 | 1997-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-03-13 | 2000-09-12 | 2001-03-14 | $7700.00 | Window Closed / Lapsed |