Hides and skins: Physical change and effects within chemical processing

摘要

The forces applied to skins in wet chemical processing relate to the type of processing vessel and its internal configuration. These forces can be viewed as constant when processing at uniform loadings, float levels, speed of rotation and time. However, the way that these forces act will vary as the skin physically changes. For example: 1. As skins rehydrate in soaking they soften, so the mechanical action is reduced. 2. Alkaline swelling causes the hides to become less flexible, and the mechanical action increases. 3. The inflexibility of a limed skin decreases in deliming, and the skins become more flaccid. 4. As fully-penetrated tanning agents throughout a pickled skin begin to fix and create leather, the skin becomes more rigid. Even if the forces applied remain constant, the mechanics involved alter in line with changes in skin characteristics and behaviour.