![]() Large quantities of casein are used by the tanning industry in making leather finishes. Calf leather may be either chrome or vegetable tanned, chrome leather being the most common.Ī protein substance prepared by precipitation of skim milk. It is lighter weight than cowhide leathers and more supple also lighter and finer grained than side, kip or split leathers, which are used in place of calf leather for many purposes. It is soft, fine-grained and supple and possesses considerable strength in relation to its weight and substance. Leather made from the skins of young cattle from a few days to a few weeks old. The part of the hide left after the bellies and shoulders have been removed. Leather from which the top surface of the grain has been removed by an abrasive cylinder of sandpaper.Ī solution of a weak acid or alkali and the corresponding salt used to minimize changes in pH values. Leather buyers often flex shoe upper leather in order to get an indication of the way in which the appearance of the leather will be preserved in a shoe during wear.Ī saturated solution of common salt and water used for preserving raw stock to be later used for making leather. ![]() The break of leather refers to the pattern of parallel folds or tiny wrinkles formed on the grain side when it is bent inwards. Cattle are branded with markings that identify ownership but also damages the hide. Marking or printing with a hot iron, freeze process, or punch. If the wet blue curls or shrinks, it is considered not fully tanned or properly basified. A 10cm x 10cm piece of wet blue is placed in boiling water for 2 – 3 minutes. For untanned hides, the term croupon is used.Ī test applied to chrome-tanned leather during the tannage to ascertain whether or not it is fully tanned. The term bend is only used inrefeering to tanned leather. The bend is usually the best part of the hide and is used for making soles of boots and shoes, saddles etc. The portion of a cattle hide remaining after the hide has been cut in half and the shoulder and belly portions have been trimmed off. The underside of a hide between the fore and the hind legs. The hide was spread over a broad oval wooden beam, and hence the name. The name “beamhouse” was originally applied to the building where skilled artisans fleshed hides and scraped away all hair and epidermis prior to tanning. The beamhouse operations include soaking, fleshing, liming, unhairing, deliming and bating. The area of a tannery where non-leather forming substances are removed from the skin prior to tanning. ![]() The enzymes remove unwanted skin components (unwanted nitrogenous constituents) making the final leather soft.Ī convex wooden slab sloping downwards from about waist height, over which a hide or skin is placed for trimming off excess flesh or for unhairing by hand. The softening of skins by treating them with pancreatic enzymes. ![]() This is achieved by raising the pH slowly in the tanning liquor. The chemical binding of the tanning chemicals to the skin protein. Usually the first finish coat that is applied to the leather surface. The main portion of a raw hide, obtained by first cutting the hide longitudinally along the backbone, then trimming off head and belly, leaving a “bend” and shoulder.ĭeteriorative effects on hides, skins or leather caused by bacteria.Ī special hydrometer used in tanneries to test the strength of tanning liquids by specific density. No opaque finishing chemicals are used in the finishing formulation. Leather that has been through-dyed and then finished with transparent finishing chemicals so as to retain the natural beauty of the leather. Hides cured by exposure of the flesh side to mild rays of the sun until they are dry: usually the hides are tensioned by lacing into a square wooden frame. In the preparation of the skin for tanning, the adipose tissue is thoroughly removed by the fleshing operation in the beamhouse. The underlying layer of a hide or skin, known as the “flesh”. ![]()
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