FIELD: polymer fiber production. SUBSTANCE: invention relates to endless threat covered by a special mixture sensible to UV radiation. Invention includes forming a multitude of continuous single fibers by way of their mechanical stretching from multiple small jets of molten thermoplastic material(s) flowing out of holes of at least one corresponding device. Surface of at least a part of single fibers is covered by above-mentioned liquid mixture reacting upon UV irradiation before single fibers combine into at least one thread. This thread is then wound onto rotating spool under UV irradiation. EFFECT: enhanced process efficiency. 12 cl, 1 dwg
