Abstract: A 28 tex mulberry/cotton (55/45) knitting yarn was spun with air-jet vortex spinning technology. By using multiple objective grey situation decision model the key spinning elements including air-jet nozzle and spindle were selected and decided that the optimal ones are five-hole nozzle and spindle with 1.3 mm inner diameter. Three key parameters of air-jet vortex spinning process including spinning speed, nozzle pressure and the distance between nozzle and front drafting roller were also optimized by orthogonal test and the test results show that the optimal spinning speed is 300 m/min, the nozzle pressure is 0.6 MPa and the distance between nozzle and front drafting roller is 18 mm.

Key words: mulberry fiber; air-jet vortex spinning; multiple objective grey situation decision; orthogonal test; process optimization