Tanning is the procedure of preparing or processing skins/ hides into leather using tannic acidity. The raw bovine collagen fibres from the pelt are changed into a reliable material that won’t rot. The main distinction between raw hides and tanned hides is the fact that raw hides dry up to create a hard, inflexible material that whenever re-wetted (or wetted back) putrefies, while tanned material gets dry to some flexible form that doesn’t become putrid when wetted back. The tanning process considerably increases the natural characteristics from the leather for example its dimensional stability, abrasion resistance, chemical as well as heat resistance, its potential to deal with repeated cycles of wetting and drying.
Need for Tanning
1. It protects the leather from being dehydrated- The tanning processes always be sure that the leather maintains its inner moisture.
2. It protects the leather from decaying when exposed to water- Chemical management of leather which belongs to the tanning process prevents the leather from going bad because of rotting.
3. It can make the leather porous- Focusing on the leather with the tanning processes reveals the leather in order that it becomes airy and absorbent.
4. It greatly increases the tensile strength from the leather- Tanning accumulates resilience within the leather. This will make the leather resist all sorts of climate conditions.
5. It improves the versatility from the leather- Tanning helps make the leather supple and soft improving its workability and moulding characteristics. This will make it easy to be employed in producing leather articles.
Types of Tanning Processes
1. Vegetable-tanning: This tanning process involves using tannins along with other ingredients present in vegetable matter produced from wood and plants. These include chestnut, oak, redoul, tanoak, hemlock, quebracho, mangrove, wattle (acacia), and myrobalan. It’s supple and brown in colour, using the exact shade with respect to the combination of chemicals and also the colour of your skin. It’s the only type of leather appropriate to be used in leather carving or rubber stamping.
Vegetable-tanned leather isn’t stable in water it has a tendency to discolour, and when left to soak after which dried will make it shrink, render it less supple, and harder. In serious trouble, it’ll shrink drastically and partially gelatinize, becoming rigid and finally brittle.
2. Chrome-tanning: This tanning process was invented in 1858. It’s the most broadly used tanning process today. It calls for using chromium sulfate along with other salts ofchromium. It’s smoother and pliable than vegetable-tanned leather and doesn’t discolour or lose shape as drastically in water as vegetable-tanned. It’s also referred to as wet-blue because of its colour produced from the chromium. More esoteric shirt is possible using chrome tanning.
3. Mineral Tanning: In mineral tanning, the pelts are drenched in mineral substances normally the salts of chromium, aluminum and zinconium.
4. Oil Tanning: Within this tanning process, the pelts are drenched in a few fish oils which tend to make a very supple, pliable and soft leather like chamois.
5. Combination tanning: This can be a tanning technique that mixes several of the aforementioned tanning techniques discussed. Mostly, it’s a mixture of vegetable and chemical tanning. The pelts are first tanned while using chrome tanning technique and it is later re-tanned while using vegetable tanning process. A mix of two tanning techniques is deliberately completed to acquire a very supple leather. Also, leather that’s to get a machine technique due to its final use sometimes experiences the mixture tanning process.