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New Method Of Carbon Fiber Recovery Developed By University Of Nottingham

2011/9/6 14:09:00 63

Recovery Of Carbon Fiber From University Of Nottingham

Carbon fiber reinforced plastics (CFRP) composites were originally used in aerospace, automobile racing and high-end sports products. At present, this material is gradually being applied to many new manufacturing fields. For these new fields, products with good performance, high strength and light weight are very important.

In recent decades, with the fall of prices and

Technology maturity

Carbon fiber has been widely used in commercial aircraft and civil aircraft, entertainment, industry and other fields.

Carbon fiber precursor production line

It is understood that the aerospace industry is the largest consumer market of carbon fiber, and carbon fiber consumption accounts for 21% of the total consumption.

According to a report by Lucintel, the global carbon fiber market has increased by two digits in the past 5 years.

It is very difficult to deal with a composite material structure at the end of service life.

Although landfill is still the cheapest option, most EU Member States promulgated laws in 2004 to prohibit landfill disposal of composite materials.

Landfill treatment is not a good choice because carbon thermosetting materials are

Non degradation

And they will cause health and safety risks.

Carbon fiber recycling is driven by government research incentives and driven by the desire of manufacturers to have green manufacturing processes and products.

Some commercial feasible methods of recovering carbon fibers, such as high temperature decomposition, microwave radiation (for enhanced decomposition of high temperature) and fluidized bed method, can be used for carbon fiber recovery. However, these methods will lead to shorter fiber length and fiber degradation, resulting in lower fiber properties.

carbon fibre

According to experts, a team from University of Nottingham has developed a method to recycle carbon fibers, which will retain almost 100% fiber properties.

An economical solvent system has been developed to dissolve epoxy resin in composite materials, thus separating a single form of carbon fiber without destroying their length.

The team used supercritical fluids.

Dissolving ability

These supercritical fluids have been proved to be effective in a number of other industries.

Scientists studied supercritical water, carbon dioxide and some organic solvents, including ethanol, methanol and acetone, and finally used propanol, a low price short chain alcohol, which is suitable for dissolving resin in normal condition.

Alcohol is very good because they only need moderate pressure (2~7 MPa) to enter the supercritical state, even though the temperature is relatively high, which is 200 ~450 C.

Compared with water, this alcohol is more convenient for them to use. Water needs a pressure of 22.1 MPa and a high temperature of 374 centigrade to reach the critical point.

In addition, ethanol and methanol are effective in dissolving polyester resins in glass fiber composites, but they can not dissolve epoxy resin very well. Propanol (propanol) can decompose epoxy resin successfully.

The test results show that the recycled carbon fiber has high strength and stiffness, which is 99% of the original strength and rigidity.

So far, these experiments are only carried out in the laboratory, and more research is needed to commercialize the process.

According to experts, carbon fiber recycling has three environmental benefits: it prevents the waste of carbon fiber from being buried once and at the same time, the components made from recycled carbon fiber are also recyclable, because carbon can retain an important part of the original performance, even after two times of utilization. In addition, the recycling process itself has greatly reduced energy consumption.