Bating is a further step in the purification of the hide prior to tanning. The unwanted components consist of some of the protein degradation products,epidermis,hair root,and the“scud” on the surface of the skin and in the hair follicle and pores. Some of...[繼續(xù)閱讀]

    Sheepskins and some of other small skins contain large amounts of natural fat. As already mentioned,sheepskins contain up to 30% fat which has to be removed. Excessive amounts of fatty substances in the skin may interfere with uniform penetration of tanni...[繼續(xù)閱讀]

    8.1 Conventional Pickling Method Pickling refers to the treatment of the hide with salt and acid to bring the skin to the desired pH for either preservation or tanning. At the end of the pickling operation the skin is theoretically a purified network of h...[繼續(xù)閱讀]

    In chrome tannage,pickled pelt is treated with basic chrome sulphate. Each chrome complex molecule reacts with several carboxyl groups of collagen to produce crosslinking between different molecule chains of the collagen. This will strengthen the fiber ne...[繼續(xù)閱讀]

    After chrome tanning it is common to allow excess chrome liquor to drain off the wet-blue,and to stand them in a damp condition for a day or more. Further fixation of chrome and setting of the wet-blue fibers occur. Where a flat leather is required,the we...[繼續(xù)閱讀]

    Wet-blue is acid and develops acidity on standing. Under acid conditions the leather protein is cationic and this is further accentuated by the mineral retannage. Consequently negatively charged colloids,such as vegetable tans,amino-resins,dystuffs,fatliq...[繼續(xù)閱讀]

    Chrome leathers are dyed either discontinuously in drums or continuously on the machines(through-feed dyeing,spray dyeing or dyeing by roller coating). When they are dyed in drums,it is usually carried out during the processes of retanning and fatliquroin...[繼續(xù)閱讀]

    After retanning,dyeing and fatliquoring,the leathers are horsed up overnight to allow excess liquor to drain off. Then the leathers are sammed and set out to reduce the water content further. At this stage,the leather still contains about 50%-60% water. T...[繼續(xù)閱讀]

    The term “finishing” refers to the further processing of the leather after drying. The aim is to adapt the leather to the fashion demands of the consumer with regard to color,surface effect,etc. by coating it with mixture of pigment,film forming material,...[繼續(xù)閱讀]

    Vegetable substances have been used for tanning since ancient times. The properties of vegetable-tanned leather include low extensibility,good strength,shape retention,storage of moisture,embossing properties,and polishing properties of the grain and of t...[繼續(xù)閱讀]