Knowledge Of Leather Industry

　　 Leatherwear Differentiation is the basic knowledge that the leather care industry and consumers need to master. Modern leather processing technology is more and more advanced and leather varieties are more and more. It is far from enough to distinguish the authenticity from the thickness and density of leather surface. Mastering the knowledge of leather distinction and understanding the performance characteristics and expansion strength of leather will help greatly in leather design and manufacture, renovation and cleaning of leather industry, repair of damaged products, and purchase and use of leather products by leather products.

The leather industry includes leather, regenerated leather and leather. Artificial leather 。

Leather is made from cattle, sheep, pigs, horses, deer or some other animals. After tanning, the leather is made of leather materials with various properties, strength, touch, color and pattern. It is a necessary material for modern leather products. Among them, cowhide, sheepskin and pigskin are three kinds of leather materials used for leather making. The dermis is divided into two types: head skin and two skin.

(1) the skin of the first layer is a cattle, sheep and pig skin with grain. There are natural scar and blood tendon marks on the surface. Occasionally, there are knife injuries in the processing process and very low belly parts. The whole grain of the skin can be distinguished from the animal skins from the size and density of the pores. There are more kinds of cattle skin, such as cow skin, meat, cattle hide, cattle hide, cow hide, Bull Hide, Uncastrated Bull Hide and castrated bull skin. There are also cattle hide, buffalo skin, yak skin and calf skin in China. Among them, the pores of the buffalo hide are thicker and thinner, while the yellow cattle hide is smaller and thicker than that of the buffalo hide. The pores of sheep skin are thinner, denser and slightly skewness, mainly consisting of two main categories: sheep skin and goat skin. Pigskin's rule of long hair is a small number of 3~5 roots, so it is easy to distinguish. It is easy to distinguish between pigskin and pig skin. The famous wild boar is known as wild boar. The boar skin has obvious porcine skin pores and grain characteristics. Because of its special collagen fiber structure, it can be made into very soft. clothing Leather or glove leather is of high value. In addition, ostrich skin, crocodile skin, short nosed crocodile skin, lizard skin, snake skin, bullfrog skin, sea fish skin (shark skin, cod skin, fish skin, eel skin, pearl fish skin, etc.), freshwater fish skin (with grass carp, carp skin and other scaly skin), fur fur fox fur (Yin Hu skin, blue fox skin, etc.), wolf skin, dog skin, rabbit skin and so on are easy to identify, and can not be made of two layers of skin.

The skin of the first layer is made directly from the raw skins of various animals, or the skins of cattle, pigs, horses and other animal skins with thicker cortex are sliced and cut into two layers.

(2) the two layer skin is the two layer of loosely woven fibrous tissue. It is processed by chemical material spraying or covered with PVC and PU film.

Therefore, the effective way to distinguish the skin of the head and the 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 fibrous layer and a slightly loose overlayer which is closely connected with it. It has good strength, elasticity and process plasticity. The two layer of leather is only a loose fibrous tissue layer. It can only be used for making leather products only after spraying chemical raw materials or polishing. It maintains certain natural elasticity and process plasticity, but its strength is poor, and its thickness is the same as that of the head skin.

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

The following is a detailed description of leather processed by leather.

1. Water stained leather It refers to all kinds of soft skin, which are bleached and colored with various colors, such as cattle, sheep, pigs, horses and deer.

2, open edge beads: also known as film leather, is thrown into two sides along the backbone, and to repair the wrinkled belly and some parts of the skin or two layers of open skin, on the surface of all kinds of pure color, metal color, pearl, color, or two colored or multicolored PVC film processing.

3, lacquer: leather made of two layers of leather, coated with various chemical raw materials, pressed or matted.

4, repair surface: it is a poor top layer of leather, polishing the surface, grinding the surface of the scar and blood tendon marks, with a variety of popular color paste spray, pressed into grain or smooth effect of the skin.

5, embossed leather: generally used to repair leather or open side beads to suppress all kinds of patterns or patterns. For example, the crocodile pattern, the lizard pattern, the ostrich skin pattern, the python skin pattern, the water ripple, the beautiful bark pattern, the litchi pattern, the imitation deer pattern, and so on, and all kinds of stripes, flower patterns, stereoscopic patterns or creative patterns reflecting various brand images.

6, printed or burnt leather: the material is the same as the embossed leather, but the processing technology is different. It is printed or ironed into a variety of patterns or patterns of the first layer or two layers of leather.

7, frosted skin: the leather surface is polished, and the grain scar or rough fiber is worn out to reveal the smooth and smooth leather fabric and then dyed into various popular colors.

8, anti velvet skin: also called "Pi Pi", is the surface of the skin is ground into velvet, and then stained with a variety of popular colors into the first layer of skin.

9, laser skin: also known as laser skin, using laser technology to etch various leather patterns on leather surface.

Two, regenerated skin: after crushing all kinds of animal skins and leather waste, chemical raw materials are processed and made. 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.

Three. Artificial leather Also known as imitation leather or rubber, it is a general term for man-made materials such as PVC and PU. It is in Spin Based on cloth or non-woven fabrics, it is made of foam or laminating films of various formulations, such as PVC and PU, and can be made according to the requirements of different strength, wearability, cold resistance, color, luster, pattern and pattern. It has many features, such as a wide variety of colors, good waterproof performance, neat edges, high utilization rate and relatively low price, but most of them can not reach the real leather effect. 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 has been produced, and its surface technology is almost the same as that of domestic leather.

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　 How do we distinguish the skin of the buffalo hide? \ "two layers of skin \"?

The skin of the first layer is the surface of the dermis. The skin is relatively thin and the price is high. The furniture made is comfortable and soft. Generally, the first layer of skin should be more than 10 yuan or a square foot.

The two layer of skin is the lower layer of the dermis. Two layers of leather are cheaper and harder. They are also common in the market, usually two yuan skin 4-6 yuan per square foot. .

The distinction between the first layer skin and the two layer skin is to observe the longitudinal fiber density of the skin. The skin of the first layer is composed of a dense thin fiber layer and a slightly loose overlayer which is closely connected with it. The two layer of leather is only loose fiber tissue layer, spraying chemical raw materials or polishing. When the leather is folded and relaxed, wrinkles disappear immediately, and wrinkles do not disappear.

Dermis identification

1: identification of dermis

Hand touch: that is to say, the leather surface is touched by hand. If it feels smooth, soft, plump and elastic, it is genuine leather. Generally, synthetic leather surface is harsh, rigid and soft.

It is seen that the leather has a clearer coat and pattern, and the yellow cattle skin has more symmetrical pores. The yak skin has coarse and sparse pores, and the goats have scaly pores.

Smell: all leather has the smell of leather, and artificial leather has strong odor of plastic.

Ignite: a little fiber is torn off from the back of genuine leather and artificial leather. After burning, pungent smell is formed, and artificial leather is formed.

2, identify artificial leather and synthetic leather

With the above four basic recognition methods, it is obvious to compare artificial leather and synthetic leather. In addition, artificial leather and synthetic leather have the following characteristics:

1. Press the leather surface with your fingers. There is no obvious pore wrinkle. If there is wrinkle after pressing, it will not disappear obviously.

2, leather surface has no pores, which is an important feature of distinguishing genuine and fake leather.

3, cut corners burning, smell, but not the smell of hair.

3, how to distinguish cattle leather, pig leather, horse leather and sheep leather.

Different types of leather have different characteristics and uses. For example, cattle leather is thin, high strength, and most suitable for making leather. shoes Leather goods; sheepskin leather is light, thin and soft, which is the ideal fabric for leather garments; pig leather has good permeability and permeability.

Pigskin leather: the pores on the surface of the leather are round and thick, and are inclined into the leather. The pores are arranged in three groups, with many small triangular patterns on the leather surface.

Cattle leather: yellow cattle leather and buffalo leather are called cow leather, but there are some differences between the two. The pores on the surface of the yellow cattle leather are round, straight into the leather, and the pores are dense and uniform, arranged irregularly, as if they are full of stars. The surface of buffalo leather is larger than that of yellow cattle leather, and its pores are less than that of yellow cattle leather.

Leather: the surface of the leather is also oval, slightly larger than that of yellow cattle leather, and arranged in a more regular pattern.

Sheep leather: the pores of the grain surface are oblate and the pores are clear.

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　　 Quality identification of leather

The skin can be divided into 8 layers (the most can be divided into two layers). The outermost layer is the top layer skin, with the best quality, followed by two layers of leather. Its strength, elasticity and air permeability are not as good as the first layer skin. Car seats must be made of first coat. Now, a compound skin on the market is made of two layers of leather, which is covered with a layer of glue film. The surface is exquisite. It looks like the skin of the first layer. Some businesses deceive the user by masquerading as the first layer of leather, so we should pay attention to the identification.

From a professional point of view, the identification of leather should be judged from the smell, specific gravity, light fastness, migration resistance, atomization, hot yellowing and friction resistance of the automobile skin. Since most owners do not have professional knowledge in this area, it is difficult to judge. We should use the following simple methods to identify them.

1. Volume label method

The leather on the back of the factory will be marked with the date of manufacture, the name and area of the leather factory, etc. Of course, the manufacturing date should not be too long. Over 3 years of leather should pay attention to mould.

2. Olfaction method

Good leather should not be pungent after treatment, so too much solvent and paint smell is not good.

3. Heat resistance method

It is best to ask for a small piece of leather with the manufacturer, and touch the sample with a cigarette head for about 2~3s, so as to avoid the purchase of artificial leather products.

4. Viewing method

Under the magnification of 30 times, leather can be seen as the surface of the earth, pit and hole, and its permeability is good. Leather for automobile needs special treatment such as wear resistance, light resistance and so on, and part of the pores will be covered.

5. Cutting method

Cross cutting leather with razor blades, leather from outer layer to inner layer of color must be consistent (black appearance, deep gray inside, is a normal phenomenon). Pay attention to whether there is a color difference below the surface layer, so that you can avoid buying two times of second-hand leather that is dyed or changed.

6. wipe method

Wipe the leather surface with stains oil, and notice whether there is fading and falling off. It can avoid two times of leather changing.

7. Origin law

All countries in the world produce leather, but only Europe (Scandinavian, Italy, Austria and Germany) has a long history of leather industry, and naturally its leather processing level is much higher than that of low-grade Southeast Asian leather.

8. Document law

The leather of the factory has clear information on origin, origin, trademark, leather measurement and leather authorization.

9. Guarantee Law

This is the easiest way. When choosing leather chairs, don't forget to ask the store if there is a guarantee card, so as to avoid buying inferior leather, second, to develop regular maintenance habits, and then to provide permanent after-sales service.

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　 Identification methods of genuine leather and fake leather

1. Finger method; press the skin with your fingers, and the surface will have tiny wrinkles. When the fingers are lifted, the wrinkles disappear immediately. Artificial leather and synthetic leather have no wrinkles.

2, use the water method; dripping a little water on the leather, then dry the water stains, and touch the feeling of sticky wet hands, it is the real leather.

3. Feel the law; look at the front of the leather, carefully observe with the eyes, and the real leather has pores. Artificial leather There is no pore. Look at the reverse side of the leather. Look for the part that is not broken. If it is a base cloth, it must be synthetic leather or synthetic leather.

Identification of skin, two skin and regenerated skin

When the leather is folded and relaxed, wrinkles disappear immediately, and wrinkles do not disappear.