? What is artificial leather?

what is called leather
The average consumer is used to linking "leather" together and calling it indiscriminately. Leather shoes shopping guide staff to "leather" have a comprehensive understanding. In fact, "skin" and "leather" are different, they are closely related, but also have strict differences. "Skin" refers to the skins of various animals (ie, rawhide), which are transformed into a fixed and durable substance called "leather" after a series of physical and chemical processing tanning ". Raw hides that have not been physically and chemically tanned are particularly hard when dried, but are soft and perishable when soaked in water. After chemical tanning, because the tanning agent and the protein fiber in the hide are firmly combined and fixed, the animal skin becomes a soft, tough, water should not be deformed, dry should not shrink, heat resistance, resistance to chemical agents and other properties, and has the advantages of air permeability, water permeability and anti-aging leather. Another significant difference between "skin" and "leather" is that most animal skins will start to shrink when soaked in warm water at 40 degrees Celsius, while leather tanned by chrome salt will not change even when placed in boiling water at 100 degrees Celsius. Leather has such properties, in addition to daily leather products, especially leather shoes, but also widely used in industrial production, become a common and indispensable raw materials. In addition, it is also an indispensable material for military equipment and facilities. For example, military boots, aviation hats, holsters, ammunition boxes, armed belts, and saddles are all made of leather.
artificial leather
Synthetic leather is developed on the basis of artificial leather. As early as the 1920 s, foreign countries began to produce nitrocellulose lacquer cloth, which was called "proposed leather". In the late 1940 s, there was a product of scraping polyvinyl chloride (PVC) on the cloth, which was commonly used as artificial leather. With the development of the plastics industry, it broke through the technical difficulties of plastic film foaming, and foam artificial leather came out in 1960. The base of artificial leather has also been developed into knitted fabrics, single-sided and double-sided fleece or non-woven fabrics. With the production of non-woven fabrics, synthetic leather was born. In 1963, the United States DuPont company first made synthetic leather, named "Koffen". In 1978, Shanghai also made synthetic leather. After that, countries around the world competed for development. As many as nearly a hundred species, for the leather shoes industry and products to provide a wealth of raw materials.
A. artificial leather:
We are not unfamiliar with artificial leather, but what is it? How is it made? Artificial leather is actually plastic products, the main raw materials used are PVC paste resin, polyamide, polyurethane, etc. with a variety of additives, such as plasticizers, stabilizers and so on. Common cloth and cotton-based artificial leather two categories. Bucket-based artificial leather is a natural fiber fabric or synthetic fiber fabric coated with a layer of plastic (such as polyvinyl chloride), after a certain temperature of plasticized foam molding, polishing or rolling pattern to form a smooth or embossed artificial leather. Such as in the PVC paste resin cloth on the coating after scraping, sprinkle with hair agent (such as grinding salt), after plasticization, washing, drying, then become suede artificial leather (commonly known as suede). The production process of cotton-based artificial leather is the same as that of cloth-based artificial leather, but the base is different. The performance of artificial leather mainly depends on the characteristics of plastics. It has excellent properties such as low relative density, large mechanical strength, acid resistance, alkali resistance, oil resistance, folding resistance, and water impermeability. In appearance, the color of artificial leather, pattern variety, extremely beautiful. It is a good raw material for making all kinds of women's leather shoes. But artificial leather permeability and moisture absorption is poor, the average person wearing artificial leather shoes feel "stuffy feet".
B. Synthetic leather
Synthetic leather is different from artificial leather. It is a synthetic fiber layer impregnated with a polymer material and has a fiber structure similar to natural leather, so it has the characteristics of general natural leather, such as air permeability and water absorption. All aspects of performance are better than artificial leather. The manufacture of synthetic leather goes through three steps: base forming, impregnation liquid preparation, processing and finishing. Generally, nylon or polyester fiber is needled and pressed to form, and is impregnated and shrunk; reheat is characterized as the base; and then polyurethane, dimethylformamide, toluene and other raw materials are prepared into paste, coated and scraped on the base, and then impregnated and rolled into synthetic leather. Synthetic leather is completely made of fiber and polymer resin as raw materials, which belongs to the secondary processing products of synthetic fiber. So it also has the following advantages:
A. finished product quality uniform, consistent rules, suitable for large-scale mechanized, automated production, is conducive to the footwear industry to improve labor productivity.
B. can be made into a variety of brightly colored shoes, almost all natural leather products synthetic leather can be replaced.
c. Synthetic leather is relatively small in density and consumes less raw materials, which is conducive to reducing production costs and reducing sales prices.
Synthetic leather because of the above advantages, coupled with the continuous emergence of new varieties in recent years, such as the emergence of soft, hard, smooth, flower, suede and other different new varieties, it is not only used for all kinds of leather shoes, sneaker, travel shoes and other footwear, but also widely used in a variety of leather products. However, synthetic leather still has the problem of poor air permeability. Synthetic leather produced at home and abroad, according to general standards, can reach a milligram or more than 0.7 milligrams per square centimeter per hour. High-quality synthetic leather with a breathability of 2.7 mg. However, compared with the air permeability of natural leather, it is still about twice as poor. Others such as tortuousness, adhesive strength, formability, side processing, feel, etc. are similar to natural leather.