FIELD: textile industry. SUBSTANCE: fully aromatic synthetic filaments are spun from liquid crystal polymeric solutions, have crystal size (plane110) no in the excess 0f 50 Angstrom and content of ionic substance not in the excess of 1.0 wt%. Said filaments have low content of ionic substance, high heat-resistance and high longitudinal elasticity. Method involves forming and neutralizing sulfuric acid or phosphoric acid polyparaphenylene terephtalamide; regulating moisture content of obtained filaments to 15-300 wt% and providing deionizing treatment combined with thermal treatment of without it. Filaments are used for manufacture of insulation and low-dielectric materials, cords, fabric, sheet-like structures for printed circuit boards. EFFECT: simplified method, improved insulating and other operating characteristics of filaments and wider range of products obtained from such filaments. 14 cl, 2 tbl, 2 ex
