17 Synthetic plastic as semi-finished products in form of sheets, foils, plates, pultruded profiles and tubes; semi-finished goods made from ceramics and fiber fabrics, namely, fiber for insulation, fabrics and knits in the form of foils, panels and molded parts for isolation at temperatures between 1000°F and 2200°F; plastic fibers, other than for textile use; insulators for electrical, thermal, and both electrical and thermal insulation; electrical ceramic insulators; electrotechnical ceramic insulators being electrical, thermal, and acoustic ceramic insulators; ceramic thermal insulators for heat shielding at temperatures between 1000°F and 2200°F, namely, for use in exhaust systems, booster stages, tubing, friction heat shields, radar nose cones; ceramic and fiber electrical insulators; electrotechnical insulators being electrical, thermal, and acoustic insulators made of ceramics and fibers; ceramic and fiber thermal insulators for heat shielding at temperatures between 1000°F and 2200°F, namely, for use in exhaust systems, booster stages, tubing, friction heat shields, radar nose cones