What is the pu resin like

The pu resin is a kind of various product forms of the multi-purpose synthetic resin, its product forms include foam plastic, elastomer, coatings, adhesives, fiber, synthetic leather, waterproof materials and paving materials, etc., is a more and more widely used synthetic resin insulation material. Its excellent performance is widely used in many fields of the national economy. Product application fields involve light industry, chemical industry, electronics, textile, medical treatment, construction, building materials, automobile, national defense, aerospace, aviation, etc.

The Development History of PU Leather

In China, it is customary to call PU resin PU synthetic leather (Jane PU leather); the artificial leather made from PU resin and non-woven fabric is called PU synthetic leather (or synthetic leather). For PU synthetic leather, PU synthetic leather, the industry has not been accurately named, but there are People used to the above three kinds of leather collectively known as synthetic leather. How to name it? We need to be unified and regulated Fan, in order to give it a more appropriate name.Artificial leather and synthetic leather are an important part of the plastics industry and are widely used in various industries of the national economy.

Artificial leather, synthetic leather production in the international has more than 60 years of development history, China began to develop and produce artificial leather in 1958, it is an earlier development of the industry in China's plastics industry.In recent years, the development of the Chinese leather and synthetic leather industry is not only the growth of the equipment production line of production enterprises, the growth of product output year after year, the increase of varieties and colors year by year, but also the development of the industry has its own industry organization, there is considerable cohesion, so that the Chinese leather, synthetic leather enterprises, including related industries organized together, developed into an industry with considerable strength. Following PVC synthetic leather, PU synthetic leather has undergone breakthrough technological progress as an ideal alternative to natural leather after more than 30 years of intensive research and development by scientific and technological experts.PU coating on fabric surfaces first appeared on the market in the 1950s, and by 1964, DuPont in the United States had developed a PU synthetic leather for use as a shoe upper. After the Japanese company established a production line with an annual output of 600,000 square meters, after more than 20 years of continuous research and development, PU synthetic leather has been rapidly increasing in terms of product quality, variety and output. Its performance is getting closer and closer to natural leather, and some properties even exceed natural leather, reaching a degree that is inseparable from the true and false nature leather, and occupies a very important position in human daily life. Today, Japan is the largest producer of synthetic leather, and the products of several companies such as Kurerashi, Teijin, Toray, and Zhongfang basically represent the international level of development in the 1990s. Its fiber and non-woven fabric manufacturing towards ultra-fine, high-density and high non-woven effect development: its PU manufacturing towards PU dispersion, PU water emulsion in the direction of development, product application areas continue to broaden, from the beginning of the footwear, luggage field development to clothing, balls, decoration and other special application areas, throughout all aspects of people's daily lives.

PU leather is different from artificial leather

Artificial leather is the earliest invention of a substitute for leather fabrics, it is made of PVC plus plasticizer and its

His additive calendering compound is made on cloth, the advantage is cheap, rich in color, a variety of patterns.The disadvantage is that it is easy to harden and become brittle.

PU synthetic leather is used to replace PVC artificial leather, which is priced more than PVC Artificial leather should be high. In terms of chemical structure, it is closer to the leather fabric, which it does not use plasticizers to achieve Soft nature, so he will not become hard, brittle, at the same time has a rich color, a variety of patterns of excellence Point, the price is cheaper than leather fabrics, so it is welcomed by consumers.

Leather fabrics and PVC artificial leather, PU synthetic leather use two methods to distinguish: one is the use of fabrics Backside difference, the method is PVC artificial leather, PU synthetic leather generally back is cloth base (or knitted cloth base) You can see it with your eyes; The second is to distinguish by burning and melting, which is to take a small piece of fabric Put on the fire, the leather fabric will not melt, while PVC artificial leather, PU synthetic leather will melt.

The difference between PVC artificial leather and PU synthetic leather can be distinguished by the method of gasoline soaking, and the method is used a small piece of fabric, placed in gasoline for half an hour, then removed, if it is PVC artificial leather, it will hardening, brittle, if it is PU synthetic leather, it will not become hard, brittle.

PU leather products maintenance method

Cleaning method:

1. Wash it with water and detergent, and avoid gasoline scrubbing

2. Don't dry wash

3. Only water can be washed, and the washing temperature should not exceed 40 degrees

4. Do exposure use sunlight

5. Do not touch some organic solvents

6. The PU leather coat needs to be hung in bags for collection, which can not be folded

PU synthetic leather

Production methods

The production methods of PU synthesis can be divided into dry, wet and condensed method.

Dry method (also known as coating method): it is to combine PU resin into a sol with a certain solid content and a certain viscosity, coated on the release paper as a carrier, through the oven, control a certain temperature, speed and other process conditions, so that the solvent volatilizes to form a film. Then coated with a bonding layer on it and composite with the bottom cloth, after drying, curing, cooling and then peeling off with the release paper, and finally through the printing process and other processes, that is, dry PU synthetic leather, release paper experience paper machine rewinding, can be reused.

Wet method: the base cloth is directly impregnated in the pu resin that has been prepared, and then washed and cured by 25% of the aqueous dimethylformamide solution, and then washed by hot water, and finally dried and post-treated, that is, wet PU synthetic leather.

Cohesion coating method: it is to impregnate the base cloth in PU resin after washing and curing, and then coat and post-treat with resin, that is, to obtain the condensation coating method PU synthetic leather.

Influencing factors

There are mainly: resin, solvent, from the paper, cloth base, coloring agent selection, in addition to the process conditions such as: solid content, viscosity, coating amount, temperature, oven, air volume, production speed, cloth smell gap, environmental temperature, humidity, dust content all affect the quality of PU leather.

Extensive application of TPU in shoe materials

TPU is synthesized from isocyanates and polyols. Isoocyanates confer the strength of the TPU material, and polyols confer the flexibility of the TPU material. With the different raw material formula, the hardness of TPU can be adjusted, and TPU has excellent wear resistance, which is very suitable for making shoes.

Outsole: The outermost layer of soles that touch the ground is called the outsole. The most important requirements of the outsole are anti-slip and wear-resistant. The traditional shoe sole uses rubber or EVA material, and due to the wear resistance of TPU, it has gradually occupied a place in the shoe sole.

In addition to the whole shoe outsole using TPU material, some wedges use TPU heel part, paste a layer of TPU in the outer layer of the heel, called the sky skin. Because the heel part is the strongest and frequent friction, sky skin can protect the main part of the heel.