Due to its characteristics of light weight, high strength, convenient processing and forming, excellent elasticity, chemical corrosion resistance and good weather resistance, composite materials have gradually replaced wood and metal alloy and are widely used in aerospace, automobile, electronics and electrical, construction, fitness equipment and other fields. In recent years, composite materials have made rapid development.
With the development of science and technology, resin and glass fiber continue to improve in technology, manufacturers generally improve the manufacturing capacity, so that the price cost of glass fiber reinforced composites has been accepted by many industries, but the strength of glass fiber reinforced composites is not enough to match that of metal. Therefore, carbon fiber, boron fiber and other reinforced composite materials came out one after another, making the polymer composite material family more complete, has become a necessary material for many industries. At present, the world's annual output of composite materials has reached more than 5.5 million tons, with an annual output value of more than 130 billion US dollars. If the high-value products of military aerospace in Europe and the United States are included, the output value will be even more amazing.
Globally speaking, the world's composite material production is mainly concentrated in Europe, America and East Asia. In recent years, the production and demand of Composite materials in Europe and The United States continue to grow, while Japan in Asia develops slowly due to economic recession, but China, especially the mainland market, develops rapidly. According to PPG, the world's leading composite producer, Europe accounted for about 32 percent of the world's composite production in 2000, with annual output of about 2 million tons. At the same time, the average annual growth rate of COMPOSITE materials in the United States in the 1990s was about twice the GDP growth rate of the United States, reaching 4 to 6 percent. In 2000, the annual output of composite materials in the United States was about 1.7 million tons. In particular, the rapid increase in automotive composites has led to the re-emergence of American cars in the global market. In recent years, the development of composite materials in Asia is closely related to the overall changes in politics and economy, and the share of each country varies greatly. Overall, composite material production in Asia will continue to grow, with total production of about 1.45 million tons in 2000 and expected to reach 1.8 million tons in 2005.
In terms of application, composite materials are mainly used in aerospace, automobile and other industries in the United States and Europe. The use of composite materials for automobile parts in the United States reached 148,000 tons in 2000, and the use of composite materials for automobiles in Europe is estimated to reach 105,000 tons by 2003. In Japan, composite materials are mainly used in residential construction, such as sanitary equipment, etc., and the amount of such products reached 75,000 tons in 2000, while the amount of such products in automobile and other fields was only 24,000 tons. However, globally, the automotive industry is the largest user of composite materials, and the potential for future development is still huge, with many new technologies being developed. For example, in order to reduce the engine noise and increase the comfort of the car, the vibration reduction steel plate with adhesion of thermoplastic resin between two cold-rolled plates is being developed. In order to meet the development requirements of high speed, supercharging and high load, the piston, connecting rod and bearing bush of the engine have begun to apply metal matrix composites. In order to meet the requirements of automobile lightweight, more and more new composite materials will be applied in automobile manufacturing industry. At the same time, as people pay more and more attention to environmental protection in recent years, the application of polymer composite material to replace wood has been further promoted. Composites of plant fibres and waste plastics, for example, have been widely used in North America as pallets and packing cases in place of wooden products; Degradable composite materials have also become the focus of research and development at home and abroad.
In addition, nanotechnology has gradually attracted people's attention, and the research and development of nanocomposites has become a new hotspot. By modifying plastics with nanometer, the aggregation state and crystalline form of plastics can be changed, so that the plastics have new properties, which not only overcome the contradiction between rigidity and toughness of traditional materials but also greatly improve the comprehensive properties of materials.
