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What are top leather, genuine leather, water dyed leather, open bead leather, patent leather, trimmed leather, embossed leather, printed or burnt leather, sanded leather, suede leather, laser leather, recycled leather and artificial leather?
Leather differentiation is the basic knowledge that leather care industry and consumers need to master. Modern leather processing technology is more and more advanced, and there are more and more kinds of leather. It is not enough to distinguish authenticity and types only from the thickness and density of pores on the leather surface. Mastering the knowledge of leather differentiation and understanding the performance characteristics and expansion strength of leather are of great help to the design and manufacture of leather products, the renovation and cleaning of leather care industry and the repair of damage, and the purchase and use of leather products by leather products consumers.
Throughout the world leather industry, leather includes genuine leather, reclaimed leather and artificial leather.
1. Leather is the original skin peeled from cattle, sheep, pigs, horses, deer or other animals. After tanning in leather factory, leather materials with various characteristics, strength, feel, color and pattern are made, which are essential materials for modern leather products. Among them, cowhide, sheepskin and pigskin are the three raw materials for tanning. There are two kinds of dermis: the first layer and the second layer.
(1) The first layer of skin is cattle, sheep and pig skin, with grain surface, natural scars and traces of blood tendons on the skin surface, occasional knife wounds during processing and extremely low utilization rate of belly. The first layer of imported leather also has the number plate of the ox. Full grain leather can be distinguished by pore thickness and density. There are many kinds of cowhide, including cowhide, beef cowhide, grazing cowhide, bull cowhide, castrated bull cowhide, castrated bull cowhide and so on. In China, there are cowhide, buffalo hide, yak skin and yak skin. Among them, the pores of buffalo hide are thicker and thinner; The pores of cowhide are thinner and denser than buffalo hide. The pores of sheepskin are fine, dense and a little inclined, mainly sheepskin and goatskin. Pigskin is easy to distinguish because the rule of long hair is 3~5 small pieces. Generally, artificially raised pig skins and wild boar skins are the famous South American wild boar. This kind of wild boar skin has obvious characteristics of pig skin pores and grain surface. Because of its special collagen fiber structure, it can be processed into very soft garment leather or glove leather with high value. In addition, ostrich skin, crocodile skin, crocodile skin, lizard skin, snake skin, bullfrog skin, marine fish skin (including shark skin, cod skin, sole skin, eel skin, pearl fish skin, etc. ), freshwater fish skin (including scaly fish skin such as grass carp skin and carp skin) and hairy fox skin (silver fox skin and blue fox skin, etc. ).
The top skin is directly processed from the original skins of various animals, or the skins of cattle, pigs, horses and other animals with thick skins are cut into upper and lower layers, and the upper layer with tight fiber structure is processed into various top skins.
(2) The second skin consists of two layers with loose fiber structure, and is processed by spraying chemical materials or covering PVC and PU films.
Therefore, an effective way to distinguish the first skin from the second skin is to observe the fiber density on the longitudinal section of the skin. The top layer is composed of a dense and thin fiber layer and a slightly loose transition layer closely connected with it, which has good strength, elasticity and process plasticity. The second layer of leather has only a loose fibrous tissue layer, which can only be used to make leather products after spraying chemical raw materials or polishing. It maintains certain characteristics of natural elasticity and process plasticity, but its strength is poor, and the thickness requirement is the same as that of the first layer of leather.
There are also all kinds of leather that are popular now. Leather processing technology is somewhat different, but the method of distinguishing is the same.
The following details the surface treatment of various leathers:
1. Water dyed leather: refers to all kinds of soft leather made by bleaching and dyeing the top skins of cattle, sheep, pigs, horses, deer and other animals. Various colors, swelling and polishing.
2. Open-edged beaded leather: also known as coated leather, it is made by throwing it in half along the spine, trimming the first layer of leather or the second layer of open-edged cowhide on the loose belly and limbs, and sticking various PVC films of solid color, metallic color, bright pearl color and magic color on its surface.
3. Patent leather: leather made of two layers of leather blanks sprayed with various chemical raw materials by calendering or extinction.
4. Leather trimming: it is a poor top leather blank. The surface is polished to remove the scars and traces of blood tendons. After spraying various popular colors of leather paste, it is pressed into leather with grain or smooth effect.
5. Embossed leather: generally, various patterns or patterns are pressed with trimmed leather or open-edged beaded leather. Such as crocodile pattern, lizard pattern, ostrich pattern, python pattern, water ripple pattern, beauty pattern, litchi pattern, deer pattern, and various stripes, plaids, three-dimensional patterns or creative patterns that reflect various brand images.
6. Printed or burnt leather: The material is the same as embossed leather, but the processing technology is different. It is printed or burned into the first or second skin with various patterns or patterns.
7. Scrubbing the leather: polish the leather surface, remove the grain surface scars or rough fibers, expose the neat and uniform leather fiber tissue, and then dye it into various popular colors to form the first layer or the first layer.
8. Suede leather: also known as suede leather, it is the first layer of leather that polishes the surface of leather blank into suede and then dyes it into various popular colors.
9. Laser leather: Also called laser leather, it refers to the latest leather variety that uses laser technology to etch various patterns on the leather surface.
Second, reclaimed leather: it is made by grinding waste skins and leather scraps of various animals and mixing them with chemical raw materials. Its surface processing technology is the same as leather trimming and embossed leather, which is characterized by neat edges, high utilization rate and low price. However, the leather body is generally thick and the strength is poor, so it is only suitable for making cheap briefcase, trolley bag, club cover and other shaped products and cheap belts. The fiber structure in the longitudinal section is uniform, and the solidification effect of fluid mixed fiber can be recognized.
Third, artificial leather: also known as imitation leather or rubber compound, is the floorboard of artificial materials such as PVC and PU. It is formed by foaming or laminating PVC and PU with different formulations on textile fabric or non-woven fabric. It can be made according to different requirements of strength, wear resistance, cold resistance, color, luster and pattern. It has the characteristics of various colors, good waterproof performance, neat edge width, high utilization rate and lower price than real leather, but most artificial leather can not reach the effect of real leather in hand feel and elasticity. In its longitudinal section, fine bubble holes, cloth base or surface film and dry man-made fibers can be seen. It is a very popular material in the early days and is widely used to make various leather products or some genuine leather materials. Its increasingly advanced production technology is being widely used in the processing and production of double skin. At present, the artificial leather with genuine leather characteristics on the market has almost reached the effect of genuine leather in surface technology and fiber structure of base material, and its price is equivalent to that of top leather in China.
What's the difference between the first skin, the second skin and the regenerated skin of buffalo hide?
The first layer of leather is the surface layer of genuine leather. The first floor is relatively thin and expensive, and the furniture made is comfortable and soft. Generally, the price of the top layer of leather per square foot is above 10 yuan.
The second layer is the lower layer of dermis. Two-layer leather is cheaper and harder, and it is also common in the market. Generally, two layers of skin are 4- 1 square 6 yuan. .
The difference between the first skin and the second skin is to observe the fiber density in the longitudinal section of the skin. The top layer consists of a dense and thin fiber layer and a slightly loose transition layer closely connected with it. The second skin has only a loose fibrous tissue layer, which is treated by spraying chemical raw materials or polishing. When the leather is folded in half and relaxed, the wrinkles disappear from the cowhide immediately, but the wrinkles will not disappear from the recycled leather.
Skin recognition knowledge
1: Identification of dermis
Touch by hand: that is, touch the leather surface by hand. If it feels smooth, soft, plump and elastic, it is genuine leather. But the general synthetic leather is hard, hard and soft.
At first glance, the hair and pattern of the dermis are clear, the pores of cowhide are well-proportioned and fine, the pores of yak skin are thick and sparse, and the pores of goatskin are fish-scale-shaped.
Smell: All dermis has the smell of leather; Moreover, artificial leather has a strong plastic pungent smell.
Ignition: tear off a little fiber from the back of genuine leather and artificial leather. After ignition, it is artificial leather that emits a pungent smell and forms a knot. It's genuine leather that smells like hair without induration.
2. Distinguish artificial leather from synthetic leather
With the above four basic identification methods, it is obvious to compare and identify artificial leather and synthetic leather. In addition, artificial leather and synthetic leather have the following characteristics:
1. When leather is pressed with fingers, there are no obvious pores and wrinkles. If there are wrinkles after pressing, they will not disappear naturally.
2. There are no pores on the leather surface, which is an important feature to identify the authenticity of leather.
3, cut off the corners and burn, there is a taste, but it is not the smell of burning hair.
3. How to distinguish cowhide, pigskin, horse skin and sheepskin?
Different types of leather have different characteristics and uses. For example, cowhide has fine surface and high strength, which is most suitable for leather shoes and leather goods; Sheep leather is light and soft, which is an ideal fabric for making leather clothes. Pigskin has good air permeability and moisture permeability.
Pig skin: The pores on the skin surface are round and thick, and extend obliquely into the skin. The pores are arranged in groups of three, and the leather presents many small triangular patterns.
Cowhide: Cowhide and buffalo hide are both called cowhide, but there are some differences between them. The pores on the surface of cowhide are round and extend straight into the leather. Pores are compact and even, and arranged irregularly, like stars all over the sky. The pores on the surface of buffalo hide are thicker than those in cattle hide, the number of pores is less than that in cattle hide, and the leather is slack, which is not as detailed and plump as that in cattle hide.
Horse skin: the hair on the leather surface is also oval, slightly larger than the pores of cowhide, and arranged regularly.
Sheepskin: The pores on the grain surface of leather are flat and round, and the pores are clear. They form a group of several, arranged in fish scales.
Leather quality appraisal
Cowhide can be divided into multiple layers (up to 8 layers). The outermost layer is the first layer with the best quality, followed by the second layer, which is not as good as the first layer in strength, elasticity and air permeability. Car seats must use the first layer of leather. A kind of synthetic leather sold in the market now is to stick a layer of adhesive film on the surface of the second layer of leather, which looks like the first layer of leather and has a delicate surface. Some merchants pretend to be the first layer of skin to deceive users, so we should pay attention to identification.
From a professional point of view, the identification of leather should be judged from the smell, specific gravity, light resistance, migration resistance, atomization, thermal yellowing and friction resistance of automobile leather. Because most car owners have no professional knowledge in this field, it is difficult to judge. You might as well use the following simple methods to identify.
1, labeling method
The back of the leather in the factory will be marked with the date of production, the name and area of the leather factory, etc. Of course, the production date should not be too long, and the leather over 3 years should pay attention to whether there is mildew.
2. Smell method
Good leather should not have pungent smell after treatment, too much solvent smell and paint smell are not good.
3. Heat resistance method
It is best to ask the manufacturer for a small piece of leather and burn the sample with cigarette butts for about 2 ~ 3 seconds to avoid buying artificial leather products; Because of the large contact area, it takes a long time to burn with a lighter.
4. Watching method
Under the magnifying glass of 30 times, we can see that leather is like the surface of the earth, with holes and good air permeability. Automobile leather needs special treatment such as wear resistance and light resistance, and pores will be covered.
5, cutting method
When cutting leather with a blade, the color of leather should be consistent from the outer layer to the inner layer (it is normal that the outer layer is black and the inner layer is dark gray). Pay attention to whether there is abnormal color under the outer layer to avoid buying second-hand leather with secondary dyeing or discoloration.
6. Wipe method
Wipe the leather surface with degreasing oil, and pay attention to whether there is fading or shedding, so as to avoid buying leather with secondary discoloration.
7. Origin method
All countries in the world produce leather, but only Europe (Northern Europe, Italy, Austria and Germany, etc.). ) has a long history, and naturally its leather processing level will be much higher than that of low-grade Southeast Asian leather.
8. Certificate Law
The leather in the factory has a clear source, origin, trademark, leather measurement project and leather use authorization, and so on.
9. Guarantee Law
This is the easiest way. When buying leather chairs, don't forget to ask the store if there is a warranty service card. First, avoid buying inferior leather; Second, develop the habit of regular maintenance; Third, providing permanent after-sales service can kill three birds with one stone.
Identification method of dermis and fake skin
1, finger method; When you press your finger on the skin, there will be fine wrinkles on the surface. When the finger is raised, the wrinkles disappear from the dermis immediately. Artificial leather and synthetic leather do not wrinkle.
2. Water use method; Drop a little water on the leather, and then dry the water stain. It feels sticky and wet. It's genuine leather.
3. Perception method; Take the leather front and observe it carefully with your eyes. Dermal has pores, artificial leather has no pores. Look at the reverse side of the leather and look for the part that is not folded. If it is base cloth, it must be artificial leather or synthetic leather.
Identification of trimmed skin, double skin and regenerated skin
When the leather is folded in half and relaxed, the wrinkles disappear from the cowhide immediately, but the wrinkles will not disappear from the recycled leather.