Basic knowledge of leather:
1. The meaning of genuine leather
"Leather" is a common word in the leather product market, and it is a customary name for natural leather to distinguish synthetic leather. In consumers' minds, "dermis" also has a non-fake meaning. It is mainly processed from animal skins. There are a wide variety of leathers, varieties, structures, qualities, and prices. Therefore, genuine leather is not only a collective term for all natural leathers, but also a vague mark on the commodity market.
From a physiological point of view, any animal skin has hair, epidermis and dermis. Since the dermis contains net-like small fiber bundles, they have considerable strength and air permeability.
The epidermis is located under the hair, close to the top of the dermis, and is composed of different shapes of epidermal cells. The thickness of the skin varies from animal to animal. For example, the skin thickness of cowhide is 0.5 to 1.5% of the total thickness; sheep skin and goat skin are 2 to 3%; and pig skin is 2 to 5%. The dermis is located under the epidermis, between the epidermis and the subcutaneous tissue, and is the main part of the hide. Its weight or thickness accounts for more than 90% of the hide.
2. Raw materials for tanning
The raw material for tanning is animal skins. Although pigskin, cowhide and sheepskin are the most common in our lives, in fact most animal skins can be used for tanning. But cowhide, pigskin and sheepskin are of good quality and large in output, and they are the main raw materials for tanning.
Although there are many types of raw leather for tanning, according to a series of laws and regulations such as animal protection regulations issued internationally, the raw materials used for production are restricted to a certain extent. Commonly used leathers are: cow leather, sheep leather, pig leather and horse leather. leather.
3. The characteristics and differences of leather
First layer leather and second layer leather: According to the level of leather, there are first layer and second layer leather. The first layer leather includes grain leather, trimmed leather, embossed leather, special effect leather, and embossed leather; second layer leather It is divided into two layers of pig leather and second layer of cattle leather.
Grain leather: Among many leather varieties, full-grain leather tops the list because it is processed from the finest raw materials with less disability. The natural pattern beauty of animal skins. It is not only wear-resistant, but also has good air permeability. Tianhu series leather products use this kind of leather as raw materials to produce high-quality leather products.
Shaved leather: It is made by using a leather grinding machine to lightly polish the surface and then press the corresponding pattern. In fact, the natural leather surface with disability or roughness has been "facelifted". This kind of leather has almost lost its original surface condition,
Full-grain leather characteristics: divided into soft leather, wrinkle leather, front leather, etc. The characteristic is to keep the grain intact, the pores are clear, small, tight, irregularly arranged, the surface is plump and meticulous, full of elasticity and good air permeability. It is a high-grade leather. Leather products made from this cowhide are comfortable, durable and beautiful in use.
Half-grain leather characteristics: it is processed and ground into only half of the grain during the production process, so it is called half-grain cowhide. Part of the style of natural leather is maintained, the pores are flat and oval, the arrangement is irregular, and the hand feels hard. Generally, poorer grade raw materials are used. So it is a mid-range leather. Due to the particularity of the process, its surface is free of disability and scars and its utilization rate is high, and its finished products are not easy to deform, so it is generally used for large briefcase products with a larger area.
Shaved cowhide characteristics: also known as "smooth cowhide", also known as matte cowhide and shiny cowhide in the market. The characteristic is that the surface is flat and smooth without pores and grains. The grain surface of the middle and surface layer is slightly polished. A layer of colored resin is sprayed on the leather to cover the leather surface texture, and then sprayed with water-based light-transmitting resin, so it is a high-grade leather . Especially the shiny cowhide, with its bright and dazzling, noble and gorgeous style, is the popular leather for fashion leather goods.
Special-effect cowhide characteristics: its production process requires the same as modified cowhide, except that beads, metallic aluminum or metallic copper are added to the colored resin for comprehensive spraying on the leather, and then a layer of water-based light transparent resin is rolled. The finished product has a variety of Luster, bright colors, graceful and luxurious, it is currently popular leather, belonging to mid-range leather.
Characteristics of embossed cowhide: Use patterned flower plates (aluminum, copper) to heat and press various patterns on the leather surface to form a style of leather. At present, "Litchi pattern cowhide" is popular in the market, which uses a pattern of lychee pattern, and the name is also called "Litchi pattern cowhide".
Two-layer leather: It is obtained by splitting thick leather with a plying machine. The first layer is used to make full-grain leather or trimmed leather. The two layers are made into two-layer leather through a series of processes such as painting or filming. It has poor abrasiveness and is the cheapest kind of leather of its kind.
Two-layer cowhide characteristics: the reverse side is the second layer of cowhide leather, coated with a layer of PU resin on the surface, so it is also called film cowhide. The price is relatively cheap and the utilization rate is high. With the change of craftsmanship, it is also made into various grades, such as imported two-layer cowhide. Because of its unique craftsmanship, stable quality, and novel varieties, it is the current high-end leather, and the price and grade are no less than the first-layer leather.