Abstract: Taking the model TNY-12 single seamless underwear machine manufactured by Jintiansuo company as an example, this paper introduced the mechanical elements and principle of seamless knitting machine. Combined with knitting principle, the paper described the procedure of commonly used underwear stitchs and theirs structure characteristics, such as plain plating, and float plating. The author also briefly explained the design methods in each key part of the seamless suit. Finally, the major technical points in the knitting process are discussed, such as direction of yam twist, yam tension and the position of the yarn carrier.

Key words: weft knitting; seamless underwear; process design; stitch structure; product development