Tanning is the process of preparing or processing skins/ hides into leather using tannic acid. The uncooked collagen fibres of the pelt are remodeled into a stable materials that will not rot. The principal distinction between uncooked hides and tanned hides is that uncooked hides dry out to form a hard, rigid materials that when re-wetted (or wetted back) putrefies, while tanned material dries out to a flexible kind that doesn’t grow to be putrid when wetted back. The tanning process significantly improves the pure qualities of the leather reminiscent of its dimensional stability, abrasion resistance, chemical and warmth resistance, its resistance to repeated cycles of wetting and drying.
Importance of Tanning
1. It protects the leather from being dehydrated- The tanning processes always make sure that the leather maintains its internal moisture.
2. It protects the leather from decaying when subjected to water- Chemical therapy of leather which is a part of the tanning process prevents the leather from going bad as a result of rotting.
3. It makes the leather porous- Working on the leather through the tanning processes opens up the leather in order that it turns into airy and absorbent.
4. It enormously improves the tensile strength of the leather- Tanning builds up resilience in the leather. This makes the leather resist all kinds of weather conditions.
5. It enhances the pliability of the leather- Tanning makes the leather supple and soft bettering its workability and moulding qualities. This makes it straightforward to be utilized within the manufacturing of leather articles.
Kinds of Tanning Processes
1. Vegetable-tanning: This tanning process entails the use of tannins and other ingredients found in vegetable matter derived from wood and plants. Examples embrace chestnut, oak, redoul, tanoak, hemlock, quebracho, mangrove, wattle (acacia), and myrobalan. It’s supple and brown in color, with the exact shade relying on the mixture of chemicals and the colour of the skin. It is the solely type of leather suitable for use in leather carving or stamping.
Vegetable-tanned leather shouldn’t be stable in water; it tends to discolour, and if left to soak and then dried will cause it to shrink, render it less supple, and harder. In hot water, it is going to shrink drastically and partly gelatinize, becoming rigid and finally brittle.
2. Chrome-tanning: This tanning process was invented in 1858. It’s the most widely used tanning process today. It involves the use of chromium sulfate and other salts ofchromium. It’s more supple and pliable than vegetable-tanned leather and does not discolour or lose shape as drastically in water as vegetable-tanned. It’s also referred to as wet-blue for its colour derived from the chromium. More esoteric colors are doable utilizing chrome tanning.
3. Mineral Tanning: In mineral tanning, the pelts are soaked in mineral substances normally the salts of chromium, aluminum and zinconium.
4. Oil Tanning: In this tanning process, the pelts are soaked in certain fish oils which have a tendency to supply a really supple, soft and pliable leather like chamois.
5. Combination tanning: This is a tanning method that combines or more of the above tanning strategies discussed. Largely, it’s a mixture of vegetable and chemical tanning. The pelts are first tanned using the chrome tanning method and is later re-tanned using the vegetable tanned leather tanning process. A blend of tanning strategies is deliberately carried out to achieve a really supple leather. Additionally, leather that’s to obtain a finishing approach because of its ultimate use sometimes goes via the combination tanning process.