Introduction of carbon fiber as material in eyeframes
Carbon fiber is a kind of new materials of eyeframes, It has not only the inherent characteristics of carbon, but also has the soft and machinable of textile fibers. The carbon fiber is as the material for producing eyeframes and sunglasses, and these eyeframes has the soft and machinable of textile fiber. And carbon fiber is very resisting corrosion. After tested the carbon fiber eyeframes, they could keep its original shape perfectly in the kinds of badly environments, the feature is not available in metal also titanium eyeframes.
Carbon fiber is a new material with excellent performance, and its weight is less than 1/4 of steel, its tensile strength is generally above 3500Mpa, and it is 7-9 times of steel.Therefore, the ratio of its strength and density can be up to 2000Mpa/(g/cm3), and the ratio of A3 steel is only about 59Mpa/(g/cm3). Many people expect that the application of materials will be from the steel age to the composite materials age which will be extensive used.
Carbon fiber is inorganic polymer fiber with carbon above 90%. One of them called graphite fiber with more than 99% carbon. The fatigue durability of carbon fiber is very good, its conductivity is between non-metal and metal, the hot dilation coefficient is small, the corrosion resistance is good, the density is low. Carbon fiber can be carbonized by polyacrylonitrile fiber, bitumen fiber, viscose silk or phenolic fiber.Carbon fiber can be processed into fabrics, belts, boards, paper and other materials.In addition to as the adiabatic insulation materials, carbon fiber is generally not used alone. Most of the time it is used as reinforcing material to be added to resin, metal, ceramics, beton and other materials to form composite materials. The reinforced composite material can be used for aircraft structure materials, electromagnetic shielding materials, artificial ligament and substitute material, also used in rocket shell ,powerboat, industrial robots, automobile springs and the drive shaft, etc.
Carbon fiber is a new material for military and civilian, it is key material for technology-intensive and political sensitivities. The Coordinating Committee headed by the United States (COCOM), some countries were implemented an embargo policy at that time. In March 1994, although COCOM had disbanded, but the shadow of embargo blockade still covered over the sky, the advanced technology of carbon fiber is still not come in, especially the high performance PAN strand technology, even we joined into the WTO, the situation could not happen big changes.Therefore, there is no choice but we can continue to develop the carbon fiber industry by ourselves. Especially Japan、Germany and USA as carbon fiber production technology leading, they remained fairly cautious attitude to Chinese carbon fiber materials, only few Chinese company can establish cooperative relations with them, with their products import channels.
At present carbon fiber production reached more than 60000 tons/year all over the world. The mainly factories are in Japan, the United States and Germany, also few companies of South Korea and China mastered the core technology of carbon fiber production, and they already had mass production. Our research on carbon fiber began in the 1960s and began to study high-strength carbon fiber in the 1980s. We had achieved some success over these years. The carbon fiber industry developed very fast in the 21st century,and Chinese carbon fiber industry had entered into industrialization. Then, some factories began to produce the carbon fiber production. According to incomplete statistics, there are 12 big scale of manufacturers for carbon fiber production in China at present,.The total production capacity is over 2000 tons/year, and the product specifications are 1K, 3K, 6K and 12K. Currently, the domestic T300 and T700 carbon fiber products developed by autonomous technology have reached the international level.With the growing demand for carbon fiber in China in recent years, carbon fiber has been listed as a new product of national chemical fiber industry and as a hot spot of new materials industry. According to incomplete statistics, there are 11 carbon fiber manufacturers are planed to built and some are under construction, the total production capacity is more than 6,000 tons/year.
Though our carbon fiber production development is late in China, but the consumption is increasing and keep demand. The main use include sports equipment, general industry and aerospace and so on. The sports leisure products is the largest demander, it occupy consumption about 80% ~ 90%. The demanding for carbon fiber has exceeded 7000 tons/year in China. Main application field is as below: the mature markets have the aerospace and defence(aircraft, rockets, missiles, satellites, radar, etc.) ,and sports leisure products (golf clubs, fishing gear, tennis rackets, badminton racket, shaft, bicycle, rowing, etc.). Emerging markets have reinforced plastic, pressure vessels, construction reinforcement, wind power and friction materials, drilling platform, etc., and has been as the material of eyeframes in these years, for manufacture produce kinds of carbon fiber eyeframes and carbon fiber sunglasses.
The characteristics of carbon fiber is high hardness, good toughness and corrosion resistance and is very light. It is very nice material for eyeframes. But the disadvantage is that it is very difficult to process. So until now, only a few eyeframes manufacturer can produce high quality and complex structure of the carbon fiber eyeframes. Most factories can only do simple eyeframes, the parts of the eyeframes must be connected with screws or rivets, also the colors are unitary. After our research for many years, we now can use a special way to connect the parts of the eyeframes,they are the same as the metal eyeframes, titanium eyeframes and the acetate eyeframes. Also we can combine different colors of carbon fiber to offer more choices for our customers.