Unit - Chemistry of Garments: Leather
Heartsunleather Custom Leather Labels Wholesale Supplier can provide you the best leather products. While an animal is alive, its skin is soft, flexible, very tough and hard wearing and essentially semipermeable: meaning that although water vapour can travel out, it is not able to penetrate and come in. This changes when the animal dies. If the skin is then kept moist it deteriorates by rotting, and if it is dried it goes hard and brittle.
The purpose of the tanning process is stabilise its structure so that the skin (from animals including goats and kangaroos, but more often cattle hide) can retain it's natural properties. After chemically processing the skin, it will no longer be subject to putrefecation.
Tanning is essentially the reaction of collagen fibers in the hide with tannins, chromium, alum, or other chemical agents. The most common tanning agents used in the U.S. are trivalent chromium and vegetable tannins extracted from specific tree barks. Alum, syntans (man-made chemicals), formaldehyde, glutaraldehyde, and heavy oils are other tanning agents.
There are approximately 111 leather tanning facilities in the United States. However, not every facility may perform the entire tanning or finishing process. Leather tanning and finishing facilities are most prevalent in the northeast and midwest states; Pennsylvania, Massachusetts, New York, and Wisconsin account for almost half of the facilities. The number of tanneries in the United States has significantly decreased in the last 40 years due to the development of synthetic substitutes for leather, increased leather imports, and environmental regulations.
Traditionally, tanning used tannins, bitter plant polyphenolic compounds that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.
The term tannin (from tanna, an Old High German word for oak or fir tree, as in Tannenbaum) refers to the use of wood tannins from oak in tanning animal hides into leather; hence the words "tan" and "tanning" for the treatment of leather. However, the term "tannin" by extension is widely applied to any large polyphenolic compound containing sufficient hydroxyls and other suitable groups (such as carboxyls) to form strong complexes with proteins and other macromolecules.
Leather is a durable and flexible material and can be produced through manufacturing processes that range from cottage to heavy industries.