How To Knead Cowhide Belt Leather?

HongDing is the leading genuine leather belt manufacturer in China, the following is called the kneading processing method of cowhide belt leather.

Leather tanning is the chemical and physical processing of the protein in the skin with tannins. Through a series of processes and the use of some chemicals, it causes a series of changes in the protein in the hides of cows, pigs, sheep and other animals and denatures collagen. The tanned leather is soft, firm, and wear-resistant, not easy to decay and deteriorate. Therefore, the tanned leather can be used to make various leather daily necessities. According to the conditions of middle school, this experiment only introduces the easier tanning process.

【operating】

(1) Soak 500g of dried animal skins in a bucket until soft (about 3 to 5 days).

(2) Take out the softened skin, spread it on a flat plate, with the wool side facing down, and use a spatula to remove the meat and oil attached to the skin. Then take 300 g of saturated lime water, add 50 g of sodium sulfide, and stir evenly to make a depilatory solution. Dip the hair removal liquid with a brush and apply it to the roots of the fur on the skin board. Then fold the skin in half. After about 3 to 4 hours, the hair on the skin is easy to fall off. Then use a shovel to completely remove the hair.

(3) After depilation, immediately rinse the skin in running water to remove most of the lime and sodium sulfide, and then soak in water for 1 to 2 days.

(4) Prepare an iron pot, add about 2L of saturated Glauber's salt solution, and heat slightly to keep the temperature of the solution at about 40°C. Remove the skins from the water, wring them dry, and put them in the pot. Knead the skin continuously with your hands, take out the thenardite after it is basically "full", and dry it. After about half an hour, perform the second and third "eating nitrate". The method is the same as the first time. 500g dry skin can "eat" about 250g nitrate. Dry the skin after eating nitrate to remove the floating nitrate on the skin.

(5) Prepare another iron pan, add 500g of clear oil (not all used up), and heat to keep the oil temperature at about 40°C. Put the skin after "eat nitrate" into warm oil, push and pull with your hands, so that the oil is in constant contact with the skin and penetrates evenly into the skin. After "eaten enough" oil, let the skin dry on a wooden stick to dry it naturally.