Leather Manufacturing Process?

In China, people are accustomed to producing PVC resin as raw material. Artificial leather Known as PVC artificial leather (artificial leather); artificial leather made from PU resin is called PU artificial leather (PU leather): synthetic leather made from PU resin and non-woven fabric is called synthetic leather PU. synthetic leather )

The development of China's synthetic leather and synthetic leather industry has become a new rising trend. development potential The industry is characterized by the following characteristics:

　 (1) synthetic leather and synthetic leather are developing rapidly and the market is widening day by day.

Nowadays, there are many kinds of leather products in daily life, such as interior decoration, sofa fabrics, automobile interior decorations, clothing, footwear and bags. People often think that these products are made of natural leather. Otherwise, a large proportion of these leather products are occupied by synthetic leather and synthetic leather.

In China, it is customary to use PVC resin as raw material to produce artificial leather known as PVC artificial leather (artificial leather); artificial leather made from PU resin is called PU artificial leather (referred to as PU leather); synthetic leather made from PU resin and non-woven fabric is called PU synthetic leather (synthetic leather). For the PU synthetic leather and PU synthetic leather, the industry has not been accurately named at present, but some people used to call these three kinds of leather synthetic leather. How to name it? We need to be unified and standardized so as to give it a more appropriate name.

Synthetic leather and synthetic leather are an important part of the plastics industry, and are widely used in various sectors of the national economy. The production of synthetic leather and synthetic leather has been developing for more than 60 years in the world. Since 1958, China has developed and manufactured artificial leather, which is an early industry in China's plastics industry. In recent years, the development of China's synthetic leather and synthetic leather industry is not only the growth of the equipment production line of production enterprises, the continuous increase of product output and the annual increase of varieties and colors, but also has its own industry organization and considerable cohesion in the process of development, so that China's artificial leather and synthetic leather enterprises, including related industries, can be organized together to develop into a fairly strong industry.

After PVC artificial leather, PU synthetic leather has been studied and developed by scientists for more than 30 years. As an ideal substitute for natural leather, it has made breakthrough technological progress.

PU first appeared on the fabric surface on the market in 1950s. By 1964, the DuPont Co of the United States developed a PU synthetic leather for upper. After the Japanese company established an annual production line of 600 thousand square meters, after more than 20 years of continuous research and development, PU synthetic leather has been growing rapidly in terms of product quality, variety and output. Its performance is more and more close to natural leather, and some properties even exceed natural leather. It reaches the level that is hard to distinguish between natural and genuine leather, and occupies a very important position in human daily life.

Today, Japan is the largest producer of synthetic leather, and the products of coke, Li Di, Dongli, Chung Fang and others are basically representing the international level of development in 1990s. Its fiber and non-woven fabrics are developing towards the direction of ultra-fine, high density and high nonwovens. Its PU manufacturing is developing towards PU dispersion and PU water emulsion, and the product application areas are constantly widening, from the beginning of shoes and bags to other aspects of clothing, ball games, decoration and other special application fields, which extend to all aspects of people's daily life. {page_break}

　 (2) the challenge of artificial leather and synthetic leather to natural leather.

Natural leather is widely used in the production of daily necessities and industrial products due to its excellent natural properties. But with the growth of world population, the demand for leather has doubled, and the limited number of natural leather has long been unable to meet people's needs. To solve this problem, scientists began to study artificial leather and synthetic leather decades ago to make up for the shortage of natural leather. Over the past 50 years, the process of research and history is the challenge of artificial leather and synthetic leather to natural leather.

Starting from the research and analysis of the chemical composition and structure of natural leather, scientists began to enter the PVC artificial leather from nitrocellulose varnished cloth, the first generation of artificial leather. Scientists have made many improvements and explorations on this basis, first of all, the improvement of the substrate, followed by the modification and improvement of the coating resin. By 1970s, the process of needling and netting of non-woven fabrics made of synthetic fibers made the base material have lotus shaped section and hollow fiber like structure, and achieved the porous structure, which accords with the requirements of the mesh structure of natural leather. At that time, the surface of synthetic leather has been able to achieve micro pore structure polyurethane layer, which is equivalent to the surface of natural leather, so that the appearance and inner structure of PU synthetic leather are approaching to natural leather. Other physical properties are close to the index of natural leather, and the color is more vivid than natural leather. Its temperature resistance is more than 1 million times, and its natural temperature can also reach the level of natural leather at low temperature.

The emergence of microfiber PU synthetic leather is the third generation of artificial leather. The non-woven fabric of its three-dimensional structure network is synthetic leather, which creates the conditions for catching up with natural leather in the substrate. The product combines the newly developed PU slurry with open hole structure and the processing technology of composite surface layer, which has played a role in the super surface area and strong water absorption of superfine fiber. The ultra-fine PU synthetic leather has the inherent hygroscopic characteristics of the natural leather of the bundle like ultrafine collagen fiber, so it can match the high-grade natural leather in terms of the internal microstructure, the appearance and texture and the physical comfort of people. In addition, the superfine fiber synthetic leather has exceeded the natural leather in chemical resistance, uniformity of quality, adaptability in production and processing, and waterproof, mildewing and denaturation.

Practice has proved that the excellent properties of synthetic leather can not be replaced by natural leather. From the market analysis at home and abroad, synthetic leather has also replaced natural leather with insufficient resources. The use of synthetic leather and synthetic leather for bags, garments, shoes, vehicles and furniture decoration has been increasingly recognized by the market. Its wide application range, large quantity and variety are the traditional natural leather which can not be satisfied.