Abstract: The relative entropy value of yarn kept changing during the course of filaments texturing, due to the direct relationship between the relative entropy and the disordering degree, the textured yarns’ luster influenced badly by the disordering degree of the surface filaments was affected by its relative entropy remarkably. To show the inner reaction between relative entropy and the luster of the textured yarns among which ATY was chosen for its typical disordering structure and high surface disordering degree, here sizes of filaments were spun, tested and analyzed in a single factor plan. The results showed that, the air-jet texturing could introduce significant rise in the disordering degree (1.28 to 4.25) and the relative entropy (0.3 to 1.45), while the multi-differential shrinking rise these two factors in a softer manner; along with the kept rising of relative entropy and disordering degree, the yarns’ peak reflection ratio and reflection ratio kept going down, while the peak width was broadened, the luster was softened, the shinning effect was diminishing.

Key words: air textured yarnr, relative entropy value, luster, disordered degree