Typical Fracture Appearance of Broken Wool Fibers After Simulated Sunlight Irradiation

摘要

After determining the wet bundle strength of sunlight irradiated wool, the broken fiber ends are evaluated optically by electron microscope. Three different modes of fiber fracture are identified. Due to the breakage morphology, we assume that the histological wool components are damaged to a different extent as a function of irradiation time. Thus, the frequency of the breakage modes may serve to indicate the stage of fiber damage. We suppose that the initial step of photodamage is the pho-tooxidation of the internal lipids, because they are obviously modified after a very short time of irradiation, while the keratin components are visibly intact. After long irradiation periods, the fibrous structure of the keratin fibrils is no longer recognizable.