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Cowhide rugs and cowhides are increasingly popular materials in both the fashion and home entertainment sectors and are renowned for their rugged natural appearance and sleek contemporary style. These natural products have been used by man since time immemorial since the time when humans first killed an animal for food and removed its skin to make clothing and shelter materials.

Over the centuries, numerous ways were discovered to make hide more useful and durable than raw hide, most notably by tanning the hide, which ensures that the hide will not decompose by permanently altering the proteinaceous nature of the hide. This process requires the acidification of the skin and it is interesting to note that the Romans used human urine in the process and archaeological evidence has been found in Pompeii of urine collected from public baths for this purpose only.

There are mainly two forms of tanning processes, vegetable tanning and the more modern chrome tanning, which was first used commercially in 1856. The chrome tanning process produces a softer, higher quality cowhide. Being tanned with chrome salts, animal skins have a resulting smoother and more uniform texture.

This tanning method consists of the following steps:

1) Soak the skin

Raw cowhides are thoroughly washed before tanning, where dirt, manure, blood, and some preservatives such as sodium chloride and bactericides are initially applied and removed from the hide.

2) Skin pickling

Pickling dramatically increases the acidity of the hide to pH 3, allowing the chrome tanning salts to penetrate deep into the skin of the hide. Salts are also added to the pickling solution to prevent the skin from swelling excessively. This ensures that the skin lasts a long time and to help it can be preserved by adding up to 2% by weight of fungicides and bactericides.

3) Tan: Chrome tan

After pickling, which can take several days, the pH of the solution will gradually decrease in acidity, which is when the chrome salts are added to the mix. To fix the chromium in the skin, the pH is slowly increased by adding a chemical base that allows the cross-linking of the chromium ions with the free carboxyl groups in the collagen protein of the skin. This fixing process ensures that the leather is resistant to bacteria and high temperatures. Once finished, chrome-tanned leather will contain approximately 2-3% dry weight Cr3+.

4) Basification

Chromium salts are fixed with magnesium oxide and an antifungal to ensure that the leather does not rot or mildew.

5) This penultimate step is done mechanically to ensure that the finished cowhide is of the required thickness; this includes squeezing, splitting, and finally reducing.

6) Lastly, the leather is soaked with formate-baking soda and synthetic oils that make the final product smooth, subtle and soft to the touch.

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