Effect on fixed-length tensile on retraction property and morphology of core-spun yarn.

Three kinds of lycra/wool core-spun yarn were tested in different elongation. Yarn was retracted dramatically after test. Retraction property and morphology of core-spun yarn were analyzed. The results showed that, with the tensile fixed-length increased, retraction rate of yarn increased. When tensile fixed length was less than 10%, level of yarn retraction was lower and structure change little. When tensile fixed length was lager than 10%, evel of yarn retraction was higher. The yarn structure was destroyed after stretching. Morphology of core-spun yarn become loose and tightness decreased. Strands were retracted dramatically. The degree of twist of the two single yarn declined and pore appeared between two single yarn. [ABSTRACT FROM AUTHOR]