Application status of the hottest polyurethane in

2022-09-21
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Application status of polyurethane in synthetic leather industry

I. application overview of polyurethane in synthetic leather industry

the application of polyurethane in synthetic leather has shown a rapid growth trend in recent years

1. Polyurethane products industry has formed a complete professional system

China's polyurethane has formed a huge industrial system from basic petrochemical raw materials to polyurethane application products. Polyurethane is an important branch of petrochemical products, which is formed by the reaction of polyisocyanate and polyol. Polyurethane products are divided into two categories: foam products and non foam products. It is a very important product category in the plastic industry. Polyurethane foam products include soft, hard and semi-hard foam; Non foam products include coatings, adhesives, synthetic leather, elastomers and elastic fibers (spandex). Because polyurethane products have the characteristics of adjustable hardness, wear resistance, solvent resistance, low temperature resistance and adhesion with most materials, with the increasing progress of science and technology, the polyurethane industry has developed rapidly. Polyurethane and composite materials are widely used in aviation, automobile, construction, light industry, textile, environmental protection and other industrial fields, and as new materials, they gradually replace traditional steel, wood and other application materials in some fields, New products related to the production and use of polyurethane, such as equipment, processes, materials, spare parts and decorative parts, are constantly launched in the market, leading each other and developing together. We know that the global demand for polyurethane is tens of millions of tons, of which foamed polyurethane accounts for 40%, non foamed polyurethane accounts for 60%, and Asia is expected to reach 3million tons next year. The global polyurethane industry has gradually accelerated in the past two years, largely thanks to the progress of high technology, the recovery of economic environment and the development of processing industry

the development of domestic polyurethane industry in recent years is in a high growth stage. The output of polyurethane in China is more than 1million tons, especially after entering the 21st century. Due to the rapid development of the national economy, the demand for polyurethane has increased rapidly, with an annual growth of more than 7%. First of all, polyurethane foam mainly includes hard, soft, semi-rigid, high resilience, etc., and the output has reached 550000 tons, accounting for more than 60% of the total output of polyurethane. It is mainly used in furniture, transportation tools, household appliances, petrochemical pipelines, construction and other industries, as well as civil products. The annual growth rate of per capita consumption of polyurethane foam in developed countries is about 3% - 4%. The growth rate of soft foam in China is about 13% higher than that in other countries, while that of hard foam is as high as 17%. Secondly, polyurethane used in synthetic leather can replace natural leather, which is a major scientific and technological progress in the last century. Now it is developed in clothing, shoes and hats, bags, sofas and other products. Its hand feel, color, elasticity and air permeability are better than PVC artificial leather. In 2002, polyurethane synthetic leather has been produced 320000 tons, reaching the highest level in the history of polyurethane synthetic leather last year. Through analysis, the proportion of polyurethane used in artificial leather and synthetic leather accounts for 20% of polyurethane in China. Polyurethane is used in sole materials, which has the advantages of light weight, anti-skid, good elasticity, high strength, wear resistance, oil resistance and so on. It is replacing rubber as the best choice of sole materials. Now there are 100 large-scale sole production lines in China. According to the statistics of 2002, the annual application of polyurethane raw materials in the global shoe industry has reached more than 800000 tons. Polyurethane has both plastic and rubber elastic properties, and is an excellent material with excellent bearing capacity

at present, the production capacity of polyurethane elastomer in China is about 100000 tons, accounting for about 10% of polyurethane. The consumption will maintain an average annual growth rate of more than 6%, which is widely used in the manufacturing of industrial supplies, sporting goods, automotive parts, etc. Polyurethane coating is a kind of high-grade and durable synthetic resin coating, with an output of more than 200000 tons. The two-component alkyd polyurethane coating is the mainstream. The application technology of polyurethane finishing agent for synthetic leather is also developing in recent years. Polyurethane adhesive has become an industry with a wide variety and wide application, with an output of about 40000 tons. Polyurethane material as the bonding layer is an important auxiliary material of artificial leather and synthetic leather, which has been widely used. Polyurethane fiber is a kind of high elastic fiber, which is used in sports clothing and general clothing. There are dozens of polyurethane fiber production enterprises in China, with a total production capacity of more than 100000 tons

2. The healthy development of polyurethane industry enterprises

the development of polyurethane industry depends on the technical practice and innovation of polyurethane industry. Polyurethane industry and synthetic leather industry develop interactively

China's polyurethane industry is one of the fastest growing regions in the world. Well known enterprises such as Yantai Wanhua, Wenzhou Huafeng, Shandong Yutian, Shanghai Gaohua, etc. Yantai Wanhua has embarked on a path of independent innovation, becoming the sixth enterprise with independent intellectual property rights of MDI in the world and the largest MDI supplier in Asia, laying the foundation of China's polyurethane industry. Only Wanhua in China has its own MDI raw material production technology with measurement accuracy. Wanhua MDI market share is one of the leading enterprises in the PU industry in the Asia Pacific region, and MDI production and marketing has always maintained a leading position. Similar to Yantai Wanhua, which has both Polyurethane manufacturing and synthetic leather products, it has formed a characteristic of mutual drive and development under the market economic system

first, what materials are used in the oil cylinder of Jinan test hydraulic universal experimental machine by large international companies? The investment in polyurethane industry is rising

Germany BASF, Huntsman, Japan polyurethane and other international companies jointly invest in polyurethane basic materials in China. It is estimated that in recent years, the production capacity will reach nearly 300000 tons/year of MDI investment. Industry experts know that the three mainstream raw materials of polyurethane MDI, TDI and polyether polyol are favored by investors, including the upstream raw materials nitric acid and dinitrotoluene production plants required for the production of TDI. Although the Polyurethane Sizing industry in China is still a new industry, in recent years, a considerable number of enterprises have invested in Polyurethane Sizing and developed rapidly. Our synthetic leather enterprises have several factories preparing to develop new polyurethane sizing. The output of Pu slurry in China is about 400000 tons. Wenzhou has a high enthusiasm for investment in this industry, which now accounts for half of it. There are more than 50 other slurry production enterprises in China, among which the products of Defa group, Zhejiang Huafeng and Qingdao Yutian occupy the top three in market share. At present, 270 domestic polyurethane enterprises have joined the China Polyurethane Industry Association, and a professional committee of resin for leather and footwear has been specially established from artificial leather, synthetic leather, especially footwear, to adapt to the development of technology and market in the footwear industry

second, new opportunities for polyurethane industry in artificial leather and synthetic leather materials

from the overall situation of synthetic leather, it faces many problems. For example, in 2002, due to the toxic problem of PVC, the European Community banned PVC leather, and the polyurethane industry is facing new development opportunities. Water-based polyurethane resin will become a hot spot in the future. The synthetic leather produced from this raw material has the properties of uniform density and excellent strength, and can reduce the energy consumption in the production process, changing the potential energy consumption of ordinary polyurethane synthetic leather. Wenzhou Huanyu company has also developed a kind of water-based polyurethane resin, which has excellent yellowing resistance, water resistance and adhesion, and is suitable for the processing of various fibers. Various water-based resins can be diluted and compatible with it in any proportion. It can be used in the paste for painting and printing, and can be added to the water-based paint to prevent the cracking of the coating, increase the gloss and lubrication, and can be used as the brightener, rainproof cloth Umbrella surface coating, etc

third, the domestic polyurethane slurry market is still in a relatively tight state

most polyurethane slurry manufacturers are basically based on the regional market, and some enterprises are self-sufficient. Several large domestic manufacturers have a long supply route, and most of them are application enterprises in this region. Due to the rising freight, the competition in the industry is becoming increasingly fierce. Some synthetic leather enterprises purchase in limited quantities, mainly relying on local supply. At present, the price of domestic synthetic resin is at a historical high. First, it is due to the trend that the international oil price of synthetic resin remains high and the rise of coal, electricity and transportation prices, which not only causes the increase of single raw material costs, but also the rise of comprehensive costs; Second, isocyanate, the key raw material of polyurethane, is still tight, and MDI is in the state of quota supply. Third, the market consumption is increasing, and the global polyurethane market demand is growing rapidly. For example, China has become the global production center of PU resin for synthetic leather, which will inevitably lead to the increase of polyurethane consumption. The rapid growth of polyurethane market demand is the fundamental reason for the imbalance of the market

second, the development of artificial leather and synthetic leather using new polyurethane technology

1. Polyurethane has been developed in ultra-fine nonwoven synthetic leather

scientists began with the study and analysis of the chemical composition and organizational structure of natural leather, starting with nitrocellulose lacquer cloth, into PVC artificial leather, which is the first generation of artificial leather products. On this basis, scientists have made many improvements and explorations, first of all, the improvement of the substrate, and then the modification and improvement of the coating resin. In the 1970s, synthetic fiber non-woven fabrics were needled and bonded, which made the substrate have lotus shaped cross-section and hollow fiber shape, reaching the porous structure and meeting the requirements of natural leather. At that time, the polyurethane layer with micro pore structure on the surface of synthetic leather can be achieved, which is equivalent to the particle surface of natural leather, so that the appearance and internal structure of polyurethane synthetic leather are gradually close to natural leather, other physical properties are close to the indicators of natural leather, and the color is more bright than natural leather; Its normal temperature folding resistance can reach more than 1million times, and low temperature folding resistance can also reach the level of natural leather

the emergence of superfine fiber polyurethane synthetic leather is the third generation of artificial leather. The non-woven fabric with three-dimensional structure creates conditions for synthetic leather to catch up with and surpass natural leather in terms of substrate. Combined with the newly developed processing technology of polyurethane slurry impregnation and composite coating with open pore structure, this product plays a huge surface area and strong water absorption role of ultra-fine fibers, making ultra-fine polyurethane synthetic leather have the inherent moisture absorption characteristics of natural leather with fascicular ultra-fine collagen fibers. Therefore, no matter from the aspects of internal microstructure, appearance texture, physical properties and people's wearing comfort, Can be compared with high-grade natural leather. In addition, superfine fiber synthetic leather is better than natural leather in chemical resistance, quality uniformity, mass production and processing adaptability, waterproof and mildew resistance. The development of superfine fiber should be taken as the lead in high simulation leather. It is a general trend to expand the quantity and improve the quality of superfine fiber leather base cloth

at present, the production, manufacturing and R & D organization of microfiber synthetic leather in domestic textile system and plastic processing system is led by Yantai Wanhua. Now, 19 enterprises of different sizes have invested in the manufacturing and operation of high-end nonwoven microfiber coated fabrics in China. Shanghai Huafeng, Yantai Wanhua and Wenzhou Huafeng have an annual output of more than 10 million meters. It is expected that the production capacity will reach more than 100 million meters after all of them are put into operation

2. Application and development of functional polyurethane materials in artificial leather and synthetic leather

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