Screw Extrusion Theory with Application to Double-Base Propellant

1958 ◽  
Vol 50 (10) ◽  
pp. 1569-1576 ◽  
Author(s):  
M. L. Jackson ◽  
F. J. Lavacot ◽  
H. R. Richards
Keyword(s):  
2013 ◽  
Vol 80 (3) ◽  
Author(s):  
Thelma G. Manning ◽  
Joseph Leone ◽  
Martijn Zebregs ◽  
Dinesh R. Ramlal ◽  
Chris A. van Driel

In order to eliminate residual solvents in ammunition and to reduce the emissions of volatile organic compounds to the atmosphere, the U.S. Army ARDEC has teamed with TNO in developing a new process for the production of solventless propellant for tank ammunition. To reduce the costs of solventless propellants production, shear roll mill and continuous extrusion processing was investigated. As described in this paper JA-2 a double base propellant cannot be processed without solvent by the extrusion process. An alternative JA-2 equivalent propellant was defined. The aim of this work is to demonstrate the manufacturing of this propellant by solventless continuous twin screw extrusion processing while maintaining gun performance characteristics of conventional JA-2 propellant. This is elucidated by explicitly researching the relationship between interior ballistic properties of the gun propellant and utilizing a continuous manufacturing process. Processing conditions were established, and the propellant was manufactured accordingly. The extruded propellant has the desired properties, which resulted in a comparable gun performance as the conventional JA-2 propellant.


1984 ◽  
Vol 18 (2) ◽  
pp. 249-251
Author(s):  
Rudolf Slavicek ◽  
Heinz Mack
Keyword(s):  

Author(s):  
Parinya CHALERMSOOK ◽  
Hiroshi IMAI ◽  
Vorapong SUPPAKITPAISARN

Author(s):  
Volker Weiser ◽  
Stefan Kelzenberg ◽  
Sebastian Knapp ◽  
A. Koleczko ◽  
E. Roth
Keyword(s):  

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Chao-Hua Fang ◽  
Ming Li ◽  
Yun-Feng Zhang ◽  
Hua Liu

Abstract Background The interference screw is the most popular device that fixes the graft for anterior cruciate ligament reconstruction, reducing the incidence of windshield effect and bungee effect. For the screw, either metallic, “bioresorbable,” or polyetheretherketone (PEEK) material is available. PEEK is popular and extensively used due to its stability, biocompatibility, radiolucency, and elastic modulus. Rare relevant complications were reported, but here, we report two cases of extra-articular migrations of PEEK interference screw from the tibial tunnel after anterior cruciate reconstruction. Case report An 18-year-old boy and a 56-year-old woman underwent anterior cruciate ligament reconstruction using a PEEK interference screw to fix the graft in the tibial tunnel. They suffered from screw extrusion from the tibial tunnel after 40 days and six months, respectively, with an incision rupture or palpable subcutaneous mass. They underwent a second operation and recovered well. Conclusions The exact incidence of extra-articular migrations of PEEK interference screws is unknown, but it seems to be quite low; despite this and its uncertain cause, the negative effects caused by the PEEK material need to be considered.


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