Effect of Thermocycling on the Properties of Goat Skin Leather

The pickled goat skins were crosslinked by chromium, aluminum, wattle extract and chestnut extract, respectively. The samples were thermal treated in a container held at different temperature for 5 h for different cycles. The xerothermic stability, water vapor permeability and dimensional stability of the samples were characterized before and after thermal treatment. The effect of thermocycling on the properties of tanned samples was discussed. It was found that the thermocycling at moderate temperature (50 °C) exerted little influence on the xerothermic shrinkage temperature (Txs) of the tanned collagen fibers. The treatment at higher upper limit temperature (100 °C and 150 °C) decreases the Txs and results in an impaired thermal stability. The water vapor transmission rate was decreased after the thermal treatment, likely due to the reduction of the amount of hydrophilic groups of collagen macromolecules as well as the decrease of the pore ratio of leather. Treatment at high temperature damaged the dimensional stability of the specimens.