Skin and Its Components

Abstract

The skin of any animal is a complex organ, the largest of the body. Each component has its function in the live animal and the tanner must be aware of the impact of each component on processing and on the properties and performance of the resulting leather. First and foremost are the main regions of the skin cross-section, the grain or corium minor, the corium (major) and the flesh layer of the corium; the response of these elements of the fibre structure to the series of processing conditions can affect the fibre weave and its angle, with consequences for the area of the piece, upon which the value of the finished leather depends. Some structural components of the skin can have a marked effect on leather quality; in particular, the veinous system can introduce an unwanted feature to the leather. Others can have a marked effect on the properties and performance of the leather: elastin confers springiness to the leather, but its removal makes the leather more cloth-like and increases the area yield. Components within the fibre structure, the proteins and glycosaminoglycans, must be removed, but not completely, because they contribute to filling of the fibre structure of the leather and therefore to the handle. Although not a component of the skin, dung is an associated component of rawstock, which can have a major effect on the options for processing and consequent economics of the operation.