![]() ![]() Residual water from wet skins is pressed out by forcing it through metal rolls. ![]() Leftover acids from the tanning are neutralised. By tanning the skin is irreversibly chemically preserved and converted to the material leather. In the tanning process tannins are absorbed by the hides and skins and turn them into leather. The Pickling process makes the fibres of the hides and skins more receptive to tanning. The bottom is used for suede or split leather for other uses. The top layer, or grain side will produce a fine, smooth grain leather. To get a uniform thickness, the hide/skin is cut into two or more horizontal layers. Any debris that is left over is referred to as ‘glue stock’. However, this process is now done by machine. Traditionally, using a sharp but curved blade, any excess flesh was removed by placing them on a beam. The net result is hairless hides which are very greasy, mainly because they still have a high fat content.īy this stage, the hides are still in a soaked yet softened condition. The main purpose of this process is to separate the hair from the hides. The hides are soaked in liming drums which contain a solution made of lime and sulphur compounds. One of the most important steps in beamhouse operations is ‘ liming’. Salted bovine hides need several hours and dried hides need several days. The hides can be treated for several days, depending on the amount of salt and the dryness of the skins. Curing (salt conservation treatment) also removes water from the hides and soaking them makes the hides swell and return to their original softness. The hides are soaked in clean water to get rid of any dirt and mainly to remove the salt applied in the earlier stage. One common by-product derived from rawhide is dog chews. This involves all stages mentioned below between preservation and tanning.Īll skins and hides which are completed as finished products, without undergoing any tanning, retain the characteristics of untanned skin including parchment. The process of preparing the hides for tanning is known as beamhouse operations (wet production). Preservation by drying, salting or freezing.These rawhides are checked for quality and also sorted by weight before arriving at the tannery.Īdditional information to this processing step In some cases, they can be stored for a while. Rawhides have to be conserved after the animals have been slaughtered and before they reach the tannery. Preservation by drying, salting or freezing 16 Finish - Surface colouration and surface processing. ![]()
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