Classification of leather commonly used in safety shoes Leather is mainly divided into leather, recycled leather and artificial leather.
First, the leather. The leather is the raw skin peeled off from cattle, sheep, pigs, horses, deer or some other animals. After being processed by the leather factory, it is made into leather materials with various characteristics, strength, feel, color and pattern. It is a modern leather product. Essential materials. Among them, cowhide, sheepskin and pigskin are the three major types of leather used in tanning.
The dermis is divided into two types: the top layer skin and the second layer skin. It is commonly used in safety shoes.
(1) The top layer skin is a cow, sheep, pig skin, etc. with grain surface, natural scars and blood scars on the leather surface, occasionally knife wounds during processing and intestines with extremely low utilization rate. The imported top layer skin also has the numbering of the cattle. Full grain skin can distinguish the animal skin from the pore size and density. There are many types of cowhide, such as cow hides, meat cowhide, grazing cowhide, cow skin, bull hide, uncastrated bull hide and castrated bull hide. In China, there are also yellow cowhide, buffalo leather, yak leather and yak leather. Among them, the pores of buffalo are thicker and sparse; the yellow cowhide is thinner and denser than the pores of buffalo. The pores of the sheepskin are finer and denser and have a slight slope. There are two main types of sheep skin and goat skin. The rule of pigskin due to long hair is the distribution of 3~5 roots, so it is easy to distinguish. Generally, pigskins are artificially raised, and wild pigskins are also known. The famous wild boars are more obvious. Pig skin pores and grain characteristics, due to its special collagen fiber structure, can be processed into very soft garment leather or glove leather, which 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, squid skin, squid skin, squid skin, pearl skin, etc.), freshwater fish skin ( There are grassy fish, squid skin and other scaly skins), hairy fox skin (silver fox skin, blue fox skin, etc.), wolf skin, dog skin, rabbit skin, etc. are easily identifiable, and can not be made into a two-layer skin. The first layer of skin is directly processed from the raw skin of various animals, or the skin of cattle, pigs, horses, etc., which are thicker in the skin layer, is cut into two upper and lower layers, and the upper part of the fiber structure is processed into various heads. Layer skin.
(2) The second layer of skin is a loose layer of fibrous structure, which is processed by chemical spraying or coating with PVC and PU film. It is commonly used in the production of safety shoes. Therefore, an effective method for distinguishing between the top layer and the second layer is to observe the fiber density of the longitudinal section of the skin. The top layer is composed of a dense and thin fibrous layer and a slightly loose excess layer which is closely connected thereto, and has good strength, elasticity and process plasticity. The second layer of leather has only a loose fibrous tissue layer. It can only be used to make leather products after spraying chemical materials or polishing. It maintains certain natural elasticity and process plasticity, but its strength is poor, and its thickness requires the same layer. The same skin. There are also a variety of leathers used in today's popular production. The leather processing techniques are somewhat different, but the method of differentiation is the same.
Second, the reclaimed skin: the regenerated skin will be pulverized with various animal skins and leather scraps, and then prepared with chemical raw materials. The surface processing technology is the same as that of the leather, the embossed skin, which is characterized by the neat edge of the skin, high utilization rate and low price; but the skin is generally thick and the strength is poor, and it is only suitable for making the cheap briefcase and the trolley bag. The ball-shaped sleeve and other shaped craft products and flat-priced belts have uniform fiber structure in the longitudinal section, which can recognize the solidification effect of the mixed fibers of the fluid.
Third, artificial leather: recycled leather is also called imitation leather or rubber, is the general name for artificial materials such as PVC and PU. It is made of PVC or PU foaming or laminating on various fabrics or non-woven fabrics. It can be made according to different strength, wear resistance, cold resistance and color, luster and pattern. The pattern and the like are required to be processed, and have the characteristics of various colors, good waterproof performance, neat edge width, high utilization rate and low price compared with leather. However, most of the artificial leather cannot have the effect of leather and its elasticity; its longitudinal Cut into the surface, you can see tiny bubbles, cloth or skin film and dry and rayon. It is a class of materials that have been extremely popular since the early days and is commonly used to make a variety of leather products, or parts of leather materials. Its increasingly advanced manufacturing process is being widely used in the processing of two-layer leather. Today, it looks like leather.