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This article is focused on a novel method to color wool fabric via heat treatment under an inert atmosphere. It can not only give new color to the fabric but also minimize pollution, because it is water and dye-free. The effects of temperature, time and different inert atmospheres (nitrogen, argon) used in the heat treatment on wool fabric color were studied. The bending stiffness, the crease recovery angle and tensile testing were used to analyze the mechanical properties of wool fabric before and after heat treatment. The color fastness to soaping and light of wool fabric after inert atmosphere heat treatment were compared with that of traditional basic yellow dyed wool fabric. The results showed that the K / S value of wool fabric treated with a nitrogen and argon atmosphere increased with the increasing temperature and time. Under the same heat treatment conditions, the maximum K / S value of fabric heat treated under nitrogen was higher than that under argon. The bending stiffness and crease recovery angle performance were improved and positively correlated with the heat treatment temperature and time. The samples treated under the same conditions under nitrogen showed higher bending stiffness and a lower crease recovery angle than under argon. The contact angle of the wool fabric after the treatment would decrease first and then increase with the increasing temperature. The tensile strength of the wool fabric would decrease with increasing temperature and time of the heat treatment in both nitrogen and argon, and the tensile strength of the wool fabric after treatment was higher than 80% of the original tensile strength, although the breaking elongation decreased. The color fastness to soaping and light of wool fabric after inert atmosphere heat treatment were better than for the traditional basic yellow dyed wool fabric. Therefore, the use of inert atmosphere heat treatment to endow wool fabric color is a potential research direction. [ABSTRACT FROM AUTHOR]

The main aim of this article is to introduce a bending fatigue testing apparatus and a new fatigue testing method, which can be used to characterize the bending fatigue behavior of flexible materials by setting the following parameters: pre-tension, bending angle, and bending frequency. The Kevlar 49, poly(p-phenylene benzobisoxazole), Nomex, and high-performance polyethylene fibers are chosen to analyze the bending fatigue properties by the new apparatus. The cyclic stress data, number of cycle bending and bending fatigue photos are recorded during the process of the bending fatigue. The curve of the cyclic stress shows that the stress changes in periods during the cyclic bending process. The curve of the cyclic stress is theoretically analyzed. The S–N and the θ−lnN curves indicate that the pre-tension and the bending angle have significant effects on the bending fatigue life. The morphologies obtained from the digital optical apparatus can be used to explain the bending failure mechanisms of high-performance fibers. It is evident that the new bending fatigue testing apparatus is feasible and accurate in measuring and characterizing bending fatigue properties of fibers. The apparatus could effectively describe the bending fatigue lifetime and bending failure mechanisms of high-performance fibers. [ABSTRACT FROM AUTHOR]