Manufacturing Method of Acrylic Synthetic Fiber with Smooth Surface

The method of making acrylic synthetic fibers with smooth surface includes preparing spinning solution containing 15-30% copolymer and organic spinning solvent and water. The copolymer contains monomer units of acrylonitrile over 86% and monomer and vinyl monomer containing unsaturated sulfonic radical. The copolymer contains 22-75 mEquivalent sulfonic radical with average molecular weight of 50,0. 00-100,000, water content of spinning solution is 0.5%-8%, viscosity is 50-140 poise at 45 C. The spinning solution is spinned in the condensate containing 40%-70% organic spinning solvent at 0 40 C. The traction ratio is 0.1-1.0, the total elongation ratio is not less than 4 times, and it is washed, hot water elongated, oil treated and dried. Acrylic synthetic fibers with smooth surface were obtained by shrinkage treatment.