Explanation

Also known as cladding layer, it is bonded on the surface of solid propellant to control the combustion area of the grain, reduce or eliminate various stresses that may be generated during the manufacturing, storage and application of the grain. When some propellants contain migratory components (such as nitrate plasticizer), the liner should also have anti migration function. The general liner is composed of macromolecule materials with good mechanical properties, fillers with good heat resistance [such as SiO2, TiO2, Al (OH) 2, etc.] and other functional additive. The selection of materials is determined by the basic composition of the thermal insulation layer and propellant. For the engine charge cast against the wall, spray coating or rotary roller coating process is generally adopted; For freely filled particles, extrusion, wrapping, or wrapping processes can be used. Good adhesion, excellent mechanical and anti migration properties and low characteristic signals are the basic requirements for liner materials.

Classification