US5061409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extrusion of impact and friction sensitive highly energetic materials
Assignee: Northrop Grumman Innovation Systems LLC
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Filing: 1989-09-14
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Granted: 1991-10-29
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Expires: 2009-09-14
Abstract
Abstract Substituting non-metallic screw elements for the previously used metal screw elements in twin-screw extruders reduces the hazards inherent in the extrusion of highly energetic materials which exhibit impact and friction sensitivity when processed in twin screw extruders with metal screw elements.
Inventors
- 👤 David R. Dillehay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:20
CPC Classifications
C; C06; C06B; C06B21/00; C06B21/0033; C06B21/0075; B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/50; B29C48/505; B29C48/507; B30; B30B; B30B11/00; B30B11/22; B30B11/24; B30B11/246; B29C48/03
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
120 words
In the processing of highly energetic materials which exhibit a high sensitivity to impact and friction when processed in extruders with metal-to-metal contact between metal screw elements and metal barrels, the improvement which comprises substituting a non-metallic screw element for the metal screw element and extruding the highly energetic material in said extruder, wherein said screw element has a non-metallic exterior for the entire length of said element which comprises a polyphenyl sulfide polymer and said highly energetic material which exhibits a high sensitivity to impact and friction when processed in an extruder with metal-to-metal contact comprises an inorganic nitrate, an elemental fuel selected from the group consisting of Mg, Al and B and mixtures thereof, and a resin binder.
Claim 2
Dependent Claim
120 words
In the processing of highly energetic materials which exhibit a high sensitivity to impact and friction when processed in extruders with metal-to-metal contact between metal screw elements and metal barrels, the improvement which comprises substituting a non-metallic screw element for the metal screw element and extruding the highly energetic material in said extruder, wherein said screw element has a non-metallic exterior for the entire length of said element which comprises a polyphenyl sulfide polymer and said highly energetic material which exhibits a high sensitivity to impact and friction when processed in an extruder with metal-to-metal contact comprises an inorganic nitrate, an elemental fuel selected from the group consisting of Mg, Al and B and mixtures thereof, and a resin binder.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein the extruder is a twin-screw extruder.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-10-28 | 1995-04-29 | 1995-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-10-28 | 1999-04-29 | 1999-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-10-28 | 2003-04-29 | 2003-10-29 | $7700.00 | Window Closed / Lapsed |