Leather manufacturing process

Leather shoes and all kinds of leather products can only be made by chemical treatment to make them soft, tough, wear-resistant, breathable, waterproof, heat-resistant and elastic. This process of processing "raw skin" into "ripe skin" (that is, leather) is called "tanning" or "tanning leather".

Tanning technology production must go through three processes: preparation, tanning and finishing.

A. The production procedure includes cleaning, soaking, meat removal, liming, hair removal and liming. After the skins or dry boards are cleaned and soaked, the silt and dirt attached to the skins can be removed and the original soft state can be restored. Then scrape off the oil and carrion attached to the skin, soak in lime water to make the raw rubber fibers on the skin swell properly, and then remove the epidermis and bristles to make the skin white and elastic. The final ash removal is to neutralize the alkaline limewater infiltrated into the skin with acid.

B. Tanning is the main process of making leather from hides. Tanning agent and rawhide are put into a regular, symmetrical and slowly rotating wooden barrel, so that the rawhide is constantly turned over, and the tanning agent is promoted to penetrate into the rawhide, which is combined with the protein fiber of the rawhide and fixed to become a water-insoluble substance-leather. The leather made in this way will not stick and rot after drying. Leather tanning methods can be divided into vegetable tanning, chrome tanning, oil tanning and chrome-vegetable tanning. Tanning materials include mineral tanning materials (such as chrome alum and red alum) and vegetable tanning materials (such as tannic acid). Different tanning materials have different uses to make leather. The upper leather for leather shoes is required to be resistant to twists and turns, soft and elastic, and mostly made of mineral tanning materials; Leather shoes bottom leather requires not only resistance to twists and turns, but also strength, firmness and elasticity, so vegetable tanning materials are generally used.

C. leather finishing means modification and decoration. Its purpose is to improve product quality; The second is to beautify the goods and make the leather products rich and colorful, which is deeply loved by consumers. Many defects of leather can be made up by careful finishing. Finishing generally includes cleaning, dyeing, elongation, drying, leveling, ironing, oiling, kneading, color spraying and polishing. Through the continuous processing of these processes, leather can have elasticity, fullness, softness, elongation, water resistance, air permeability, hygroscopicity and other properties. At the same time, the leather surface can achieve fine, smooth and clear grain surface, uniform tone and luster, and beautiful appearance.

Types of leather

Shoe shopping guide must fully understand and master the characteristics of leather, so as to get twice the result with half the effort.

There are many kinds of leather. The raw material used in leather making is rawhide (the same below), which mainly comes from ungulates in mammals, mostly from domestic animals, such as pigs, cows, sheep, horses, mules, donkeys, camels and domestic dogs. Followed by wild animals, such as deer, muntjac, wild boar, antelope, antelope and so on. These wild animal skins are excellent raw skins in leather industry, and most of them can be made into high-grade leather shoes (or leather products); Thirdly, seals, hippos, finless porpoises, sharks, whales, snakes, pythons, lizards, crocodiles, ostriches and other animals. Can be made into various high-quality leather shoes or other high-grade leather products with special properties.