Het powders, Propellants with Controlled Temperature Dependence

After a general survey of conventional propellants, there will follow a description of the HET propellants. HET powders are propellants of heterogeneous structure. They are characterized by the powder granules worked into powder basic masses. The powder granules may be grains of single‐base, double‐base or triple‐base propellants. Single‐base powder basic masses are suited to take up a maximum of 70% granules. Granule percentages of about 50% have found to be most efficient. In the case of HET propellants with single‐base matrix, their temperature dependence can be present at discretion, i.e. with neutral of negative temperature exponent, by the type, grain size and percentage of the granules worked in. HET propellants with single‐base powders as basic masses can be produced with explosion heat values of up to 4300 Joule/g. Their manufacture does not present any problems and it is easy from the technical point of view. As full‐strip propellants, the HET types with single‐base powders as basic masses have progressive burning characteristic. HET propellant types are suited also for the manufacture of maccaroni and strip powder. The free‐flowing powder types can be surface coated as usual.