Propellants grains

Gun Propellents. Although the stresses on individual gun propellant grains are less severe because of the small size, these propellants must withstand much higher weapon pressures and accelerations. Formulation options are usually more limited for gun propellants than for rocket propellants because the products of combustion must not foul or corrode a gun, should have a low flame temperature, and should exhibit minimum flash and smoke characteristics. Gun propellants are examined microscopically for porosity, are tested for mechanical characteristics, and fired in closed bombs to determine the burning characteristics. 

Solventless Extrusion Process. The solvendess process for making double-base propellants has been used ia the United States primarily for the manufacture of rocket propellant grains having web thickness from ca 1.35 to 15 cm and for thin-sheet mortar (M8) propellant. The process offers such advantages as minimal dimensional changes after extmsion, the elimination of the drying process, and better long-term baUistic uniformity because there is no loss of volatile solvent. The composition and properties of typical double-base solvent extmded rocket and mortar propellant are Hsted ia Table... 

K. Adas, A. Method of Computing Web for Gun Propellant Grains from Closed Bomb Burning Rates, memo report 73, Naval Powder Factory, U.S. Navy, Indian Head, Md., 1954. 

A solid propellant is a mechanical (heterogeneous) or a chemical (homogeneous, or colloidal) mixture of solid-state fuel and oxidizer-rich chemicals. Specially-formed charges of solid propellant (grains) arc placed in the combustion chamber of the solid rocket motor (SRM) at a production facility. Once assembled, the engine does not require additional maintenance, making it simple, reliable and easy to use. 

Microscope Study of the Surfaces of Sectioned M-17 Propellant Grains , PATR 2177 (1955) 23) S.M. Kaye, An Electron Microscope Study of the Surfaces of Sectioned M-15 Propeiiant Grains , PATR 2201 (1955) 24)S.M. Kaye,... 

Multi perforated Propellant Grains. See Cannon Propellant or Cannon Powder in Vol 2, C30—31, Grains of Smokeless Proplnts in Vol 6, G123... 

Specifications. For mil use, specs have been published for Ammonium Perchlorate (MIL-A-23442A, 8 Sept 1966) Ammonium Perchlorate, Technical (MIL-A-192B, 2 Sept 1965) Ammonium Perchlorate for Solid Propellant Grains Mark 75 Mark 76 (MIL-A-23946, 19 Aug 1964) and Ammonium Perchlorate, Special, Coarse for Solid Propellant Grains Mark 75 Mark 76 (MIL-A-23948,19 Aug 1964). The requirements of the First two specs are ... 

Sieg et al, Bonding a Rocket Motor Liner to a Solid Rocket Propellant Grain , USP 3904715 (1975). CA 84, 7210 (1976)... 

Rugg, Feasibility Studies Relative to using New Polymers and Plastics as Inhibitors to Replace Composition Presently Being Used With Rocket Propellant Grains of 155mm HE RAP (Rocket Assisted Projectile) , Final Rept — May-Dec 75, Contract DAAA21-75-C-0267, NY Univ, NY (1975) 11) T. Takayama, JapP 7518052... 

Propellant grains were prepared according to the oxidizer grind of Example 1, as follows Sample E... 

Equations (21)-(24) permit the temperature history of the propellant grain during ignition to be calculated. Ignition of any point on the surface is assumed to occur when the propellant autoignition temperature is reached at that point. The propagation rate can then be predicted from the different times at which the different positions on the propellant surface are ignited. The important basic assumption in this approach is the applicability of the... 

One common method of designing propellent grains is to use a long annulus. This can burn on both the interior and exterior surfaces, so that as burning proceeds the outer surface decreases, but the inner suface increases in such a way that the total surface and therefore mass burning speed remains constant. Similar properties are also shown by thin flakes or discs of propellant which are suitable for use for small arms ammunition. 

Whilst the shape of a propellent grain determines the constancy or otherwise of the burning process, the actual time occupied depends on the grain dimensions. The term web thickness is used to denote the shortest distance in a grain through which burning can go to completion it is... 

Web thickness. The distance of travel of a burning surface in a propellent grain to give complete combustion. 

Finding (Blue Grass) EH-5. The cotton threads used to hold sheets of M8 propellant together and the rayon bags used to hold Ml propellant grains are not destroyed by the caustic under the conditions that were used in this study. This may cause clogging or entanglement in pipes, pumps, or valves. 

Slurries of energetic materials from two sources are treated in the SILVER II process the explosive in the rocket and projectile burster tubes (which may be either Composition B or tetrytol) and the ground-up M28 propellant grain in the rocket motors. 

Reduction of propellant size by grinding under water appears to be feasible with the current concept. However, it is noted that this feasibility depends very much on successful propellant grain extraction using the untested RDM concept. 

M28 propellant grains removed from M55 rockets must be ground to a size suitable for subsequent hy-... 

Objective 1. Validate the ability of the grinding equipment to safely reduce M28 propellant grains to V,-. V2-, and V -inch pieces. 

Results The grinding equipment could grind M28 propellant grains to pass the /4-inch screen. 

---