Added: 10/19/2005 |
Essential phases of skin preparation: preservation, soaking, liming, fleshing, batingPeople began to make leather many thousand years ago. In fact, leather manufacture is one of the oldest manufacturing industries. Before that animals had been hunted only for food but at some point, primitive men began to remove the skin from the animals before actually eating them.
There is evidence that at that period of time men used keen flints to peel the animal skin away from the skeleton. But then people realized that to avoid rapid decomposition and decay of skin, some skin preparation procedures should have been done. Men noticed that drying the animal skin would certainly protect them, but resulting material was rather uncomfortable, inflexible, and rough.
Soon men realized that the skin should have been softened and this could have been done by rubbing the skin with fats, which also prevents the skin from getting wet. A long time ago the process of tanning skin was discovered. This process quickly spread and was improved numerous times by different nations and generations. As you can see the basic processes of skin preparation has fairly deep roots.
Today, leather production is a fairly complex process. There are many different types of leather. But, in addition to that, various leather manufacturers use their own techniques of skin preparation. Often the same kinds of leather are prepared by different producers in different ways.
As it was said above, the flayed animal skin without the special skin preparation will quickly get rot due to the exposure to microorganisms that produce enzymes. In order to prevent or diminish this harmful exposure, the skin should be preserved. Nowadays, it is mainly done by drying and salting. These procedures of skin preparation dehydrate the skins; thereby considerably decrease the chances of survival for microorganisms. But these procedures alone are not sufficient to ensure the maximum preservation of the material. The skin also requires tanning.
Tanning makes the skin impervious to bacteria exposure and also makes it possible to preserve softness, suppleness, and mechanical resistance. Any leather regardless of type and origin consists of the network of fibres. Fibres, in turn, are made up of proteins, most important of which is collagen. The animal skin consists of such layers as the dermis, the epidermis, and subcutaneous tissue. The dermis is the only important of them for the leather manufacture.
Skin preparation involves several phases: preservation, soaking, unhairing, liming, deliming, fleshing, scudding, and finally bating. Preservation is used to prevent the fresh skin from decomposition. There are several ways to preserve skin: it may be salted, dried, dry-salted, or pre-tanned. Soaking is used to restore skin`s original water content after preservation. Liming is aimed to split up the fibres and remove the elements of the interfibrillar skin material. During the next phase, deliming, most of the alkaline substances are neutralized.
Fleshing refers to the removal of a skin`s subcutaneous layer. The last stage of skin preparation is bating. Bating can be administered to the bookbinding leather or other light leather whenever fine, silky, and elastic grain is required. The goals of bating are breaking of the lime-soap emerged during liming; the action on the protein fibres in order to increase leather`s quality and to attain a fine silky grain.
Article comments:
No comments for this article yet. Post your comment now!
