What is pure polyester yarn? Pure polyester yarns are made of relatively sophisticated imported and domestic production equipment, and polyester staple fibers are made by direct spinning of polyester melts or indirect spinning of polyester chips. Because the raw materials used for "big chemical fiber" products are basically qualified grades, the quality indexes of their regular products are all excellent. "Big chemical fiber" polyester staple fiber is the main raw material of cotton textile industry. "Big chemical fiber" production equipment is to eat "fine grain" equipment.