#LEATHER HIDES SERIES#

The hides may also be softened by milling which is dry tumbling with atomized moisture injected into the tumbler.įinishing consists of placing a series of coatings on the surface of the leather. Upholstery leather is normally toggle dried (spreading the leather over expanding frames held by toggles or clips) Staking is the mechanical softening of the leather after drying. There are several methods of drying depending on the type of leather being produced. The next process is setting, which is the removal of excess water and spreading the hide out prior to drying. They are then lubricated with natural fat or synthetic fatty type chemicals, or a combination of both to obtain the softness required by the final product. After shaving, chrome tanned hides are again placed in rotating drums with hot water, dyes and synthetic tanning materials to obtain the desired colour. Depending on the end use of the leather product, the hides are split into sheets of required thickness and processed further through a shaving machine for added quality. Splitting and shaving are the next steps following tanning. This process is normally performed in drums taking two to four days. The process is slower than chrome tanning and involves the chemical substance tannin, or tannic acid, which is extracted from the barks of trees. Vegetable tanning is used for such various products as shoe soles, luggage, saddlery, belt leathers and some upholstery. After this treatment the hide is considered tanned. Once this has been achieved the chrome is fixed by adding an alkaline chemical such as sodium carbonate or bicarbonate. It usually takes eight hours for the chrome to penetrate all the way into the hide. The process begins in rotating drums with a bath in a chemical containing trivalent chrome. Most upholstery, shoe uppers, garments and bag leathers are chrome tanned. There are several methods of tanning but the most common are Chrome and Vegetable Tanning. Tanning is the final process in turning hides and skins into leather. which involves soaking the hides in a solution of water, salt and acid. After the hair has been removed the hides are neutralized with acids and treated with enzymes to remove any deposits and to increase softness.

The hair is removed by chemical digestion using a solution of lime and sodium sulphide with occasional rotation. Freshly fleshed hides are shipped in refrigerated trucks to a tannery for immediate processing into leather. The leather process can be summarized in 5 basic steps.Īfter the hide has been removed, it is fleshed, removing any remaining meat tissue or fat.

Because of the by product nature of leather, it puts far less demand on the earth than synthetic leathers, which are produced from plastics and petroleum based chemicals. The leather process converts these hides into a viable and useful material. Therefore no cow loses its life for its skin. Leather is a by-product of the meat industry. The hides of cattle are the main source of leather. As civilization advanced, preserving hides and tanning them into leather became an important industry. This was the beginning of leather processing. The fact that the skins turned stiff and rotted was a problem, but ways of softening and preserving the hides were discovered. In prehistoric times, people used to wrap themselves in dried animal pelts. The story of leather goes as far back as humanity itself.

Leather hides