Classification And Identification Of Raw Leather

　　皮革分為天然皮革(真皮)、再生皮革、人造革(PU/PVC)。真皮是牛、羊、豬、馬、鹿或某些其它動物身上剝下的原皮，經皮革廠加工后，制成各種特性、強度、手感、色彩、花紋的皮具材料，是現代真皮制品的必需材料。

Dermis is usually composed of epidermis (dermis), dermis, reticular layer, and subcutaneous layer (removed).

Among them, cowhide, sheepskin and pigskin are three kinds of leather materials used for leather making.

1. The skin of the first layer refers to the cattle, sheep and pig skin with grain (dermis), and the skin has natural and special texture effect.

Imported leather may also have branding.

The whole grain of the skin can be distinguished from the animal skins from the size and density of the pores.

There are many kinds of cattle skin, such as yellow cattle hide (cattle hide, cattle hide, Bull Hide, bull skin, uncastrated bull skin and castrated bull skin), buffalo skin, cow skin, yak skin and calf skin, etc. the best part of the cattle cortex is two provinces of Shandong and Henan, and the middle part of our country. But our country's skin resources are short of (the United States, Brazil and other beef exporting countries are the most abundant).

Yellow cattle skin is smaller and thicker than that of buffalo skin, and its grain is fine and smooth.

The coarse and sparse pores of buffalo skins are single, and the grain is concave and convex. The buffalo skin is better in some parts of Sichuan and Jiangxi, but the resources are relatively scarce (India and Egypt).

Sheepskin mainly includes sheepskin, goat skin and mixed sheep.

The pores of the sheepskin are thinner and denser, and the texture is particularly like copper coins.

Goats are mostly used for shoemaking, and sheep for clothing.

Sheepskin is best in Sichuan, Hubei and other places.

Pigskin is a very * * * e, which is easy to distinguish from the 3 "pints" of the long hair. It is easy to distinguish. Pigskin and pig skins are commonly used.

In addition, ostrich, crocodile, short nosed crocodile, lizard, snake, bullfrog, sea fish (shark, COD, fish, eel, pearl fish, etc.), freshwater fish (such as grass carp, carp and scaly fish) are also raw materials for making skin.

It is also used as fur for high-grade clothing. It is called fur or fur such as fox fur (Yin Hupi, blue fox fur, etc.), wolf skin, dog skin, rabbit skin, and expensive mink skin and so on.

Collection

2. Two layers of skin without dermis, fibrous tissue (reticular layer), processed by chemical material or coated with PVC and PU film. Therefore, the effective way to distinguish the first layer skin and two layer skin is to observe the fiber density of the longitudinal section of the skin.

The skin of the first layer is composed of a dense, thin dermis and a slightly reticular layer closely connected with it. It has good strength, elasticity and process plasticity.

The two layer of leather is only a loose fibrous tissue layer (net layer). Only after spraying chemical raw materials or grinding surfaces can it be used to make leather products. It maintains certain natural elasticity and process plasticity, but its strength is slightly worse. Its practice requires similar skin to the head.

The difference is that it has a fluffy effect and can produce a series of effects different from the top layer.

There are more commonly used nap and suede, and there are other deer fleece for special process.

There are also various kinds of leather used for fashion production today, but there are some differences in the processing technology.

After crushing all kinds of animal skins and leather waste, the chemical materials are processed and manufactured.

Its surface processing technology is the same as leather surface and embossed leather. It is characterized by its neat edge, high utilization rate and low price. However, the skin is generally thicker and its strength is poor. It is only suitable for making the products of price, such as price document box, pull rod bag, club sleeve and so on. The structure of its longitudinal section is uniform and uniform, and the solidification effect of liquid mixed fiber can be identified.

It is made on the basis of textile fabric or non-woven fabric, and is made by foaming or laminating of various formulations such as PVC and PU. It can be made according to the requirements of different strength, wearability, cold resistance, color, luster, pattern and pattern. It has many characteristics, such as a wide variety of colors, good waterproof performance, neat edges, high utilization rate and relatively low price, but most of the artificial leather can not reach the dermis effect with its elasticity and elasticity. Its longitudinal section can see thin bubbles, holes, cloth or surface film and dry dry synthetic fiber.

It is a very popular material from the early stage until now. It is widely used to produce various leather products or some of the genuine leather materials.

Its increasingly advanced manufacturing process is being widely used in the manufacture of two layers of leather.

Nowadays, the leather like leather with the characteristics of leather is produced, and its surface technology is very basic, and its fiber structure almost achieves the effect of real leather, and its price is also quite.

But leather and imitation leather (recycled leather and artificial leather) can not be compared: Unique hygiene (natural pores and fibers) and durability.

From the grades of leather:

Full grain flour >

Half grain noodles >

Light mending skin

Refacing

From leather hardness and hardness:

Chrome tanning >

Semi tanned leather >

Whole vegetable tanning (baking)

From the style of leather:

Oil wax, water dyed skin, tattoo, napapi, wax, embossed leather, leather repair, varnish, frosted skin, film skin, printed leather, crack skin, anti velvet leather, etc.

Very great, because you are exposed to many benzene, phenol, alkane, alkene chemicals, harmful to the human body, if the factory does not have good protective measures, the possibility of aplastic anemia and cancer is very great.

Regenerated leather (bran paper) is a kind of product that is produced from the leather waste and leather products. It is a supplementary material commonly used in leather related products such as leather goods, leather shoes and furniture.

As an intermediate sandwich, regenerated leather (Pi Kangzhi) is replaced by cardboard with its unparalleled texture, elasticity, tenacity, moisture resistance and processing adaptability. As a fabric, regenerated leather can show various performance effects through embossing, printing and PU composite processes, and is widely used in leather making, furniture, book cover and other production.

According to incomplete statistics, our country now needs to import more than 8400 tons of regenerated leather from abroad every year. The successful cooperation of this project fills the gap of China's regenerated leather production.