Leather can be seen everywhere around us, such as leather shoes and beautiful leather bags that we usually wear. When we buy them, we will ask if they are right. So let's take a look at the process and classification of leather today
1. By use
Living leather, national defense leather, industrial and agricultural leather, cultural and sports goods leather;
2. According to tanning method
Chrome tanned leather, vegetable tanned leather, oil tanned leather, aldehyde tanned leather and combination tanned leather. In addition, it can be divided into light leather and heavy leather. Leather generally used for shoes, clothing, gloves, etc., called light leather, measured by area; The leather that is tanned with thick animal skin by vegetable tanning agent or combination and used for the inner and outer soles of leather shoes and industrial accessories is called heavy leather, which is measured by weight.
3. By animal type
It mainly includes pig leather, cattle leather, sheep leather, horse leather, donkey leather and kangaroo leather, and a small amount of fish leather, reptile leather, amphibian leather, ostrich leather, etc. Cattle leather is divided into cattle leather, buffalo leather, yak leather and yak leather; Sheepskin leather is divided into sheep leather and goat leather. Among the main types of leather, cattle leather and sheep leather have fine surface, small hair eye, fine and compact internal structure, good fullness and elasticity, and good physical properties. Therefore, superior cattle leather and sheep leather are generally used as leather materials for products, and their prices are higher among the bulk leather.
4. By Hierarchy
There are first layer leather and second layer leather, and the first layer leather includes full grain leather and corrected leather; Second layer leather includes pig second layer leather and cow second layer leather.
5. By manufacturing method
It is a common term in the leather product market and is a customary name for natural leather to distinguish synthetic leather. In the concept of consumers, "" also has the meaning of non fake. Animal leather is a kind of natural leather, which we often say. It is a kind of leather material with various characteristics, strength, feel, color and pattern made of animal (raw hide) after tanning and processing in a leather factory. It is a necessary material for modern products.
The processing process of animal leather is very complex, and the finished leather needs to go through dozens of processes: raw leather - soaking - meat removal - degreasing - unhairing - alkali soaking - swelling - lime removal - softening - pickling - tanning - layering - shaving - retanning - neutralization - dyeing - oiling - filling - drying - finishing - finishing - finished leather. There are also many kinds of leather, such as sheep leather, cattle leather, horse leather, snake leather, pig leather, crocodile leather, etc.
Among them, cow hide, sheep hide and pig hide are the three major raw materials used in leather making.
1) Regenerated skin
It is made by crushing the waste skins and leftovers of various animals and blending them with chemical raw materials. Its surface processing technology is the same as that of the trimmed leather and embossed leather. Its characteristics are that the edges of the leather sheet are neat, the utilization rate is high, and the price is cheap; However, the leather body is generally thick and has poor strength, so it is only suitable for making affordable briefcases, pull rod bags, golf club sleeves and other finalized products and affordable belts. The fiber structure in the longitudinal section is uniform and consistent, which can identify the solidification effect of mixed fibers of liquid substances.
2) Artificial leather
Artificial leather is also called imitation leather or rubber, which is the general name of PVC, PU and other artificial materials. It is made of PVC and PU foamed or coated with different formulas on the basis of textile cloth or non-woven cloth. It can be processed according to different strength, wear resistance, cold resistance, color, luster, pattern and other requirements. It has the characteristics of a wide variety of colors, good water resistance, neat edges, high utilization rate and relatively cheap price.
Artificial leather is a very popular kind of material, which is widely used to make various leather products or replace some materials. Its increasingly advanced manufacturing technology is being widely used in the processing and manufacturing of two-layer leather. Nowadays, the artificial leather with very similar characteristics has been produced and put on the market. Its surface technology and the fiber structure of the base material have almost achieved the effect, and its price is about the same as that of the domestic top layer leather.
3) Synthetic leather
Synthetic leather is a kind of plastic product which simulates the composition and structure of natural leather and can be used as its substitute material. The surface is mainly polyurethane, and the base material is non-woven fabric made of polyester, cotton, polypropylene and other synthetic fibers. Its front and back are very similar to leather, and have certain air permeability. Characterized by beautiful luster, it is not easy to get mildewed and moth eaten, and is closer to natural leather than ordinary artificial leather.
There are many varieties of synthetic leather. In addition to the common characteristics of synthetic fiber non-woven fabric substrate and polyurethane microporous surface, the varieties of non-woven fibers and processing technology are different. Synthetic leather has smooth surface, thick and thin opening, uniform color and strength, and is superior to natural leather in terms of water resistance, acid and alkali resistance and microorganism.
Seeing this, I believe you have a new understanding of leather. The manufacturing process is very complex. If you want to know more, Zhongda Machinery welcomes your advice!