The difference between the first skin and the second skin - leather knowledge

Leather classification is the basic knowledge that the leather care industry and consumers need to master. The modern leather processing technology is more and more advanced, and the leather varieties are also more and more. It is far from enough to distinguish the authenticity and the type from the thickness and density of the pores on the leather surface. Mastering leather to distinguish knowledge, understand the leather's performance characteristics and expansion strength, for leather design and production, leather care industry renovation cleaning and damage repair, leather products, consumer purchase and use of leather goods have a great help.

Looking at the world's tanning industry, leather includes leather, recycled leather and artificial leather.

The leather is raw hides peeled off by cows, sheep, pigs, horses, deer, or some other animals. After being tanning and processing in a leather factory, the leather is made of leather material with various characteristics, strengths, feels, colors, patterns, and is a modern leather product. The necessary materials. Among them, cowhide, sheepskin and pigskin are the three major skin types used as raw materials for leather making. The dermis is divided into the first layer of skin and the second layer of skin.

(1) The top layer of the skin is cattle, sheep, pigskin, etc. with a grain surface. There are natural scars and blood marks on the surface of the skin. Occasionally, there are knife wounds in the processing process and the intestines where the utilization rate is extremely low. Imported skins and cows are also numbered. Full grain hides can be distinguished from animal skins by the size and density of the pores. There are many types of leather, such as cowskin, beef cattle, grazing cows, cowskins, bullskins, uncut bulls, and castrated bulls. In China, there are yellow leather, buffalo leather, yak skin and yak skin. Among them, buffalo hides have coarser and more sparse pores; yellow leather has finer and denser pores than buffalo hides. The pores of sheepskin are finer, denser, and slightly slanted. There are mainly two types of sheep skin and goat skin. The rule of long-haired pigskin is the distribution of 3 to 5 roots and a small beak, so it is easy to distinguish, generally using artificially raised pig skins, as well as wild pigskin. The famous is the South American wild boar. This wild boar skin has obvious Pork skin pores and grain features, due to its special collagen fiber structure, can be processed into a very soft garment leather or gloves leather, a high value. In addition, ostrich skin, crocodile skin, short-nose crocodile skin, lizard skin, snakeskin, bullfrog skin, saltwater fish skin (having shark skin, eel skin, eel skin, eel skin, pearl skin, etc.), freshwater skin ( There are scales such as grass carp and squid skin, hairy foxes (silver foxes, blue foxes, etc.), wolf skins, dog skins, and rabbit skins, etc., which are easily recognizable and cannot be made into second skin.

The first layer of skin is directly processed from the raw skin of various animals, or the skin of cattle, pigs, horses, etc. in the thicker skin is cross-sectioned into upper and lower layers. The upper part of the tightly fibrous tissue is processed into various heads. Leather

(2) The second layer of skin is a relatively loose two-layer part of fibrous tissue that has been chemically sprayed or covered with PVC or PU film.

Therefore, an effective method for differentiating between the scalp skin and the bilayer skin is to observe the longitudinal section fiber density of the skin. The first layer of skin is composed of a dense and thin layer of fibers and a slightly loose overlayer that is closely associated with it, and has good strength, elasticity, and process plasticity. The second layer of skin has only a loose fibrous tissue layer, and can only be used to make leather products after spraying chemical raw materials or polishing. It maintains a certain natural elasticity and process plasticity characteristics, but its strength is poor, and its thickness requires the same layer. Like skin.

There are also various kinds of leather used in the current popular production, and the leather processing process is somewhat different, but the method of differentiation is the same.

The following details the various leathers that have been processed :

1, water stained leather: refers to the use of cattle, sheep, pigs, horses, deer and other layers of skin bleaching and dyeing all kinds of colors, drums fell, and glazing processed from a variety of soft skin.
2. Beaded skin: Also known as the film leather, it is thrown in two along the back of the spine, and trimmed to loosely wrinkle the intestines and the extremities of the first layer of skin or the second layer of open leather, on its surface A variety of net color, metal color, fluorescent pearl color, Symphony two-color or multi-color PVC film processing.
3, patent leather: leather with two layers of leather blanks after spraying chemical raw materials after pressure or matte processing.
4. Shave the skin: it is the poor skin of the first layer. The surface is polished to remove the scars and blood marks on the surface. After being sprayed with a variety of popular color skins, the skin is pressed into grain or smooth surface.
5, embossed leather: generally used to repair the skin or open edge bead to suppress a variety of patterns or patterns. For example, crocodile pattern, lizard pattern, ostrich grain pattern, python pattern, water ripple, beautiful bark pattern, litchi pattern, imitation deer pattern, etc., as well as various stripes, lattices, three-dimensional patterns or reflect various brands. The image of creative patterns and so on.
6, printed or branded leather: The same choice of materials as embossed leather, but the processing process is different, is the printing or ironing into a variety of patterns or patterns of the first layer or second skin.
7. Matte leather: The surface of the leather is polished and the grain scars or rough fibers are abraded to expose the neat and smooth leather fiber tissue and then dyed into various popular colors.
8, suede: also known as suede, is the skin surface polished into velvet, and then dyed a variety of popular colors made of the first layer of skin.
9, laser skin: also known as laser skin, cited laser technology in the leather surface etching a variety of patterns of the latest leather varieties.
10. Reconstituted leather: After crushing various animal skins and leather waste materials, it is prepared by processing chemical raw materials. The surface processing technology is the same as the leather trimming and embossing leather. Its characteristic is that the edge of the skin is more neat, the utilization rate is high, and the price is cheap; however, the skin is generally thicker and the strength is poor, and it is only suitable for making an affordable document case and a drawbar bag. The styling process products, such as the club cover and the flat-price belt, are uniform in the longitudinal section fibrous structure, and can recognize the coagulation effect of the liquid substance mixed fiber.
11, artificial leather: also known as imitation leather or rubber, is a generic term for PVC and PU and other man-made materials. It is made on the basis of textile or non-woven fabrics, and is made of various formulas such as PVC and PU, which can be foamed or coated. It can be based on different strength, wear resistance, cold resistance, color, luster, and pattern. Patterns and other requirements for processing, with a variety of colors, waterproof performance, neat trim, high utilization and cheaper than the price of leather, but most of the artificial leather, its feel and flexibility can not achieve the effect of leather; its vertical Cut surface, you can see the fine bubble hole, cloth or surface film and dry dry man-made fibers. It is a type of material that has been very popular since the early days and is widely used to make leather products, or parts of leather materials. Its increasingly advanced production technology is being widely used in the processing of two-layer leather. Today, artificial leather, which resembles the characteristics of genuine leather, is available for market production. Its surface texture is extremely fibrous. It almost reaches the effect of genuine leather. Its price is comparable to that of the domestic first layer leather.

Identification of artificial leather and natural leather

With the development of social science and technology, artificial leather technology is also maturing, product quality is greatly improved, especially in the simulation of leather, can be real, in breathability, flexibility, feel and appearance and many other aspects are similar to natural leather, but the price But it is far lower than natural leather. Therefore, in order to improve our ability to identify, we now introduce some simple and direct methods for reference.

1, visual identification method: First of all, should be identified from the leather pattern, pores and other aspects, in the surface of natural leather can see patterns, pores do exist, and the distribution is uneven, the opposite side of the animal fibers, side section, the level is clearly visible There are animal fibers on the lower layer. When the fingernails are used for scratching, the leather fibers will rise up and there will be a nappy feeling. A small amount of fibers can also fall down. The synthetic leather can see the fabric on the reverse side and there is no animal fiber on the side. Generally, the skin is not pored. However, some have artificial leather pores, there will be no obvious pores, some patterns are not obvious, or there are more regular artificial patterns, the pores are quite consistent.
2. Hand-feeling identification method: Secondly, the leather feel is elastic. When the leather is bent down about 90 degrees, there will be natural wrinkles. The different parts are bent, the thickness of the folds produced, and the amount of unevenness are obvious. It is believed that this is a genuine leather because natural leather has a natural non-uniform fibrous structure, and thus the formation of wrinkle lines is also markedly uneven. The synthetic leather feels like a plastic, the recovery is poor, and the folds are similar in size.
3, odor identification method: natural leather has a very strong taste of the skin, even after treatment, the taste is more obvious, and artificial leather products, there is a share of plastic taste, no fur taste.
4, burning identification method: mainly smell the smell of coke and see the state of ash, natural leather burning will emit a burning smell of hair, fired ash is generally easy to break into a powder, and artificial leather, flame after burning Prosperous, it shrinks rapidly, and it has an unpleasant taste of plastic. It sticks when burned, and it hardens into a block after cooling.

In imitation leather garments, machine wash is the most prominent selling point. Leather pants are easy to clean like jeans. This imitation leather is specially processed and finished, such as stone grinding, baking and laser engraving, and its features are as light as nothing. , feel very comfortable.

Advantages of imitation leather materials: In addition to comfort, the imitation leather garments are more expensive than the leather, and the imitation leather garments whose style closely follows the fashion trend are especially welcomed by the younger generation. Plus leather garments with designs, prints, embossing and embroidery are popular in spring and summer.