Patent US6240356B1 successfully refreshed from Google Patents.
US4525313A
Expired / Lapsed
US
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Process and apparatus for producing single- or multi-base propellants
Assignee: Fraunhofer-Gesellschaft zur Förderung der Angewandten Forschung eV
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Filing: 1983-11-03
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Granted: 1985-06-25
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Expires: 2003-11-03
Abstract
Abstract Single- or multi-base propellants are produced in a solvent process from their starting components, of which at least one is moistened with alcohol, using a twin-shaft screw extruder, that has an inlet zone run at a raised temperature, then nextly a mixing and kneading zone and lastly an outlet zone. The temperature in the kneading and mixing zone and in the outlet zones is kept at a value that is higher than in the inlet zone. Furthermore there is a temperature drop towards the outlet zone.
Inventors
- 👤 Dietmar Muller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 09:09
CPC Classifications
C; C06; C06B; C06B21/00; C06B21/0033; C06B21/0075; B; B30; B30B; B30B11/00; B30B11/22; B30B11/24; B30B11/243
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
141 words
A process for producing an at least single-base propellant in rod form using a twin shaft screw extruder with an intake zone for starting components of said propellant, at least one of said components being moistened with alcohol, with a mixing and kneading zone downstream from and next to said intake zone in which solvent is run into said components for plastifying same and with an outlet zone downstream from said kneading and mixing zone, said outlet zone being next to screw means of said extruder and having a molding head for forming said components as processed in said extruder into at least one rod, said intake zone being kept at a raised temperature, and said kneading and mixing zone and said outlet zone being kept at a generally constant temperature that is greater than the temperature of the inlet zone.
Claim 2
Dependent Claim
141 words
A process for producing an at least single-base propellant in rod form using a twin shaft screw extruder with an intake zone for starting components of said propellant, at least one of said components being moistened with alcohol, with a mixing and kneading zone downstream from and next to said intake zone in which solvent is run into said components for plastifying same and with an outlet zone downstream from said kneading and mixing zone, said outlet zone being next to screw means of said extruder and having a molding head for forming said components as processed in said extruder into at least one rod, said intake zone being kept at a raised temperature, and said kneading and mixing zone and said outlet zone being kept at a generally constant temperature that is greater than the temperature of the inlet zone.
Claim 3
Dependent Claim
62 words
The process as claimed in claim 1 for producing at least double-base propellant, wherein in said kneading and mixing zone at least two sections are each kept at a temperature that is constant within said section, the temperature of the product going down from one such section to the next thereof in the direction of motion of said product through said extruder.
Claim 4
Dependent Claim
69 words
The process as claimed in claim 1 for producing single-base propellant wherein at said intake zone the temperature of a housing part near a screw thereof is kept at a value of 40±3° C., in the kneading a mixing zone it is kept at 56±3° C. and in the outlet zone it is kept at such a value that the temperature of the components is equal to 64±3° C.
Claim 5
Dependent Claim
64 words
The process as claimed in claim 2 for producing at least single base propellant wherein at said intake zone the temperature of a housing part near a screw thereof is kept at a value of 35±5° C., in the kneading a mixing zone it is kept at between 50±3° C. and 45±3° C. and in the outlet zone it is equal to 40±3° C.
Claim 6
Dependent Claim
29 words
The process as claimed in claim 4 wherein there is a temperature drop in the mixing and kneading zone in the downstream direction from 50±3° C. to 45±3° C.
Claim 7
Dependent Claim
15 words
The process as claimed in claim 4 wherein said propellant produced is a three-base propellant.
Claim 8
Independent Claim
152 words
An apparatus for producing an at least single-base propellant in rod form comprising a twin shaft screw extruder having a housing, screw means in said housing in which components for making said propellant may be pumped by said screw means, said housing walling in an intake zone for starting components of said propellant, a mixing and kneading zone downstream from and next to said intake zone, said mixing zone being adapted for the addition of solvent into said components for plastifying same, and an outlet zone downstream from said kneading and mixing zone, said outlet zone having a molding head for forming said components as processed in said extruder into at least one rod, means for keeping said intake zone at a raised temperature, and means for keeping said kneading and mixing zone and said outlet zone at a generally constant temperature that is greater than the temperature of the inlet zone.
Claim 9
Independent Claim
152 words
An apparatus for producing an at least single-base propellant in rod form comprising a twin shaft screw extruder having a housing, screw means in said housing in which components for making said propellant may be pumped by said screw means, said housing walling in an intake zone for starting components of said propellant, a mixing and kneading zone downstream from and next to said intake zone, said mixing zone being adapted for the addition of solvent into said components for plastifying same, and an outlet zone downstream from said kneading and mixing zone, said outlet zone having a molding head for forming said components as processed in said extruder into at least one rod, means for keeping said intake zone at a raised temperature, and means for keeping said kneading and mixing zone and said outlet zone at a generally constant temperature that is greater than the temperature of the inlet zone.
Claim 10
Dependent Claim
28 words
The apparatus as claimed in claim 7 wherein said screw means is in the form of two screws and of means for turning the same in opposite directions.
Claim 11
Dependent Claim
27 words
The apparatus as claimed in claim 7 wherein said screw means is in the form of two screws and means for turning them in the same direction.
Claim 12
Dependent Claim
90 words
The apparatus as claimed in claim 7 wherein said heating means is designed for so heating the housing that while producing single-base propellant at said intake zone the temperature of a housing part near said screw means of said extruder is kept at a value of 40±3° C., in the kneading and mixing zone it is kept at 56±3° C. and in the outlet zone it is kept at such a value that the temperature of the components is equal to 64±3° C., said screw means having oppositely turning screws.
Claim 13
Dependent Claim
85 words
The apparatus as claimed in claim 8 for producing single-base propellant wherein the screw means is in the form of two screws turning in the same direction and the connection between the overall length of less the length of the outlet zone (herein named L) and the inner diameter (herein named D) is: ______________________________________
Screw direction the same, length overall
.sup. L = 23D
Intake zone (40 ± 3° C.)
L.sub.1 = 9D
Mixing and kneadlng zone (56 ± 3° C.)
L.sub.2 = 14
______________________________________
Claim 14
Dependent Claim
82 words
The apparatus as claimed in claim 8 for producing single-base propellant wherein wherein the screw means is in the form of two screws turning in opposite directions and the connections between the overall length less the length of the outlet zone (herein named L) and the inner diameter (herein named D) is: ______________________________________
Screw direction opposite, length overall
L = 26D
Intake zone (40 ± 3° C.)
L.sub.1 = 11D
Mixing and kneading zone (56 ± 3° C.)
L.sub.2 = 15D
______________________________________
Claim 15
Dependent Claim
102 words
The extruder as claimed in claim 8 for producing three-base propellant wherein in the case of an overall length of the screw means made up of screws turning in the same direction of 23 times the inner diameter of the housing, with the addition of the length of the outlet zone the connections between the lengths of the separate zones and the temperatures thereof are: ______________________________________
Intake zone (35 ± 5° C.)
L.sub.1 = 5D
First kneading and mixing zone (50 ± 3° C.)
L.sub.2 ' = 9D
Second kneading and mixing zone (45 ± 3° C.)
L.sub.2 ' = 9D
______________________________________
Claim 16
Dependent Claim
17 words
The extruder as claimed in claim 7 wherein said housing has at least one gas letoff opening.
Claim 17
Dependent Claim
23 words
The extruder as claimed in claim 10 wherein the at least one gas letoff opening is placed in the mixing and kneading zone.
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) | 1988-06-24 | 1988-12-24 | 1989-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-24 | 1992-12-24 | 1993-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-24 | 1996-12-24 | 1997-06-25 | $7700.00 | Window Closed / Lapsed |