Abstract: Entropy was a state function, the relative entropy value of the yarns varied directly to the logarithm of its disorderness degree, hence the entropy changing during texturing influenced the inner structure and properties concerning badly. The ordinary filaments were flat and smooth, this order was ruined by texturing which was growing the relative entropy of the system, thus bigger loss of strength and elongation at break was to be tested. To indicate the relationship between texturing entropy change and the stretching properties, 10 textured sample yarns were designed and spun, then tested. The results showed that along with the increasing both of the entropy change and disorderness degree, both the loss of strength and the loss of elongation at break grew quickly, to 50% or so. When multi-differential shrinking was added, the ATY’s loss of strength curve was flatten, as well as its loss of elongation at break curve was laid down though at the same time of the growing both of the entropy change and disorderness degree.

Key words: entropy, textured yarn, texturing entropy change, strength