Cloth-lined interceptor motor insulation for strong insulation-to-propellant interlock

A method of providing a very strong mechanical interlock between the insulator in a composite interceptor rocket motor and the solid composite interceptor propellant composition to thereby obviate the need for a liner, said method comprising:

• (i) providing a mandrel shell with a boss, said mandrel shell with a boss provided with a clean, release liner on the outer surface thereof, said release liner including a perforated bleeder to permit excess resin to be removed from insulator during curing process and to permit easy release of mandrel shell with a boss from lay-up materials placed on said release liner with perforated bleeder;
• (ii) placing a cloth mat of a first lay-up material over said release liner with bleeder;
• (iii) applying a second lay-up material comprising an uncured rubber insulator composition over said cloth mat, said uncured rubber insulator composition curable by a predetermined vulcanization cycle at high temperature and pressure;
• (iv) subjecting said first and second lay-up materials, said mandrel shell with boss, and said release liner including perforated bleeder to a vacuum bag and autoclave curing environment to complete a vulcanization cycle at a predetermined temperature of about 300.degree. F., predetermined pressure from about 100-150 psi, and for a predetermined curing time period from about 20 to about 30 minutes, said predetermined temperature, pressure, and curing time sufficient to achieve vulcanization to consolidate said first and said second lay-up materials to form vulcanized insulator cloth mat cured to a state of cure which enables said second lay-up material to be ground to fit contour and shape of said composite interceptor rocket motor into which said vulcanized insulator/cloth mat is to be inserted;
• (v) removing from said vacuum bag and autoclave curing environment, said mandrel shell with a boss with said vulcanized insulator/cloth mat which is supported by said mandrel shell with a boss;
• (vi) grinding said outer surface of said vulcanized insulator/cloth mat to said contour and shape of said composite interceptor rocket motor;
• (vii) removing said ground vulcanized insulator/cloth mat from said release liner or said mandrel shell with a boss;
• (viii) inserting said ground vulcanized insulator/cloth mat into an interceptor rocket motor case and adhesively securing the outer surface of said ground vulcanized insulator/cloth mat to the inside of said interceptor rocket motor case;
• (ix) casting an uncured solid composite interceptor propellant composition onto the cloth mat side of said vulcanized insulator/cloth mat;
• and,
• (x) curing said solid composite interceptor propellant composition to said vulcanized/cloth mat to form a very strong mechanical interlock between said insulator in said composite interceptor rocket motor and said cured solid composite interceptor propellant composition.