Provided is a method of recycling carbon fibers that allows obtaining continuous carbon fibers. The present embodiment is a method of recycling carbon fibers that includes preparing a carbon fiber reinforced plastic molded product including carbon fiber reinforced plastic containing carbon fibers and a resin and drawing the carbon fiber reinforced plastic while performing a heating treatment on the carbon fiber reinforced plastic molded product. A temperature of the heating treatment is equal to or above a glass-transition temperature of the resin and below a thermal decomposition start temperature, and the temperature is below a thermal degradation temperature of the carbon fibers.

A carbon fiber recycling method utilizes a carbon fiber recycling device for recycling carbon fiber from a carbon fiber polymer composite by using a microwave. The carbon fiber recycling device has a cavity and at least one microwave supplying unit. The carbon fiber recycling method adjusts the microwave supplying unit to change the angle between the long axis direction of the cavity and the electric field direction, and to make the long axis direction of the carbon fiber parallel to the electric field direction. By radiating the microwave on the carbon fiber polymer composite, energy of the microwave is quickly absorbed by the carbon fiber to quickly increase a temperature of the carbon fiber, and the carbon fiber polymer composite is effectively and quickly decomposed to remove most polymer matrix of the carbon fiber polymer composite, so as to achieve the objective of recycling the carbon fiber indeed.

The present technology provides a carbon fiber reinforced plastic that includes carbon fibers covalently bonded to an energetic polymer and a polymer matrix. Also described is a method for recycling carbon fibers from the carbon fiber reinforced plastic material using microwave energy to separate the carbon fibers from the polymer matrix.

The present invention is based upon the discovery that the level of adhesion between steel reinforcing elements and rubber products, such as conveyor belts, in which they are embedded can be significantly reduced by heating the steel reinforcing elements by induction heating to break down the level of bonding between the steel reinforcing elements and the rubber in the article. The present invention more specifically discloses a method for recovering steel reinforcements from a conveyor belt carcass having steel reinforcements which are bonded to the carcass of the conveyor belt, said method comprising (1) heating the steel reinforcements in the conveyor belt by induction heating to a temperature which is sufficient to substantially breakdown bonding between the steel reinforcements and the carcass of the conveyor belt and (2) applying a mechanical force to the steel reinforcements which is sufficient to separate the steel reinforcements from the conveyor belt carcass.

Methods for the recycling of carpet are disclosed that produce clean face fiber suitable for industrial use. The methods allow the recovery of face fiber material, for example a polyester or a polyamide, from carpets that includes a face fiber material and a backing material, and include the steps of heating the carpet to a temperature lower than the melting point of the face fiber material, but higher than the initial thermal decomposition temperature of the backing material, for a time and at a temperature sufficient to thermally decompose, pyrolyze, or oxidize at least a portion of the backing material, rendering the backing material friable, that is more friable than the untreated backing; and applying mechanical force to the carpet so as to liberate the friable backing material from the face fiber material.

A method for manufacturing a carbon fiber is provided which involves: (1) immersing a carbon fiber composite material (CFC) in an acidic aqueous solution to elute at least a part of a resin component of the CFC, to thereby obtain a substantially fibrous product; and (2) immersing the substantially fibrous product obtained in step (1) in an alkaline aqueous solution to elute at least a part of a resin component of the substantially fibrous product, to thereby obtain a fibrous product. A method for manufacturing a carbon fiber reinforced resin composition is provided which involves manufacturing a carbon fiber by the above method and manufacturing a carbon fiber reinforced resin composition using the resulting carbon fiber. Using these methods, it is possible to recover and recycle a carbon fiber from a carbon fiber composite material (CFC) at a low cost without deteriorating the carbon fiber.

A carbon fiber recycling method utilizes a carbon fiber recycling device for recycling carbon fiber from a carbon fiber polymer composite by using a microwave. The carbon fiber recycling device has a cavity and at least one microwave supplying unit. The carbon fiber recycling method adjusts the microwave supplying unit to change the angle between the long axis direction of the cavity and the electric field direction, and to make the long axis direction of the carbon fiber parallel to the electric field direction. By radiating the microwave on the carbon fiber polymer composite, energy of the microwave is quickly absorbed by the carbon fiber to quickly increase a temperature of the carbon fiber, and the carbon fiber polymer composite is effectively and quickly decomposed to remove most polymer matrix of the carbon fiber polymer composite, so as to achieve the objective of recycling the carbon fiber indeed.

A method and apparatus for recovering fibres from fibre reinforced polymer (FRP) materials uses a thermomechanical process to produce high quality recovered fibres and powdered polymer resin. The thermo- (cryo-) mechanical process uses a combination of a selected range of temperatures and mechanical force, and is chemical and solvent-free, and produces zero waste. Fibre length remains unchanged after processing and mechanical properties of the recovered fibres are comparable to or better than those of virgin fibres. The recovered fibres and powdered polymer resin may be used to make new FRP products.

A method for manufacturing a carbon fiber is provided which involves: (1) immersing a carbon fiber composite material (CFC) in an acidic aqueous solution to elute at least a part of a resin component of the CFC, to thereby obtain a substantially fibrous product; and (2) immersing the substantially fibrous product obtained in step (1) in an alkaline aqueous solution to elute at least a part of a resin component of the substantially fibrous product, to thereby obtain a fibrous product. A method for manufacturing a carbon fiber reinforced resin composition is provided which involves manufacturing a carbon fiber by the above method and manufacturing a carbon fiber reinforced resin composition using the resulting carbon fiber. Using these methods, it is possible to recover and recycle a carbon fiber from a carbon fiber composite material (CFC) at a low cost without deteriorating the carbon fiber.

Methods for the recycling of carpet are disclosed that produce clean face fiber suitable for industrial use. The methods allow the recovery of face fiber material, for example a polyester or a polyamide, from carpets that includes a face fiber material and a backing material, and include the steps of heating the carpet to a temperature lower than the melting point of the face fiber material, but higher than the initial thermal decomposition temperature of the backing material, for a time and at a temperature sufficient to thermally decompose, pyrolyze, or oxidize at least a portion of the backing material, rendering the backing material friable, that is more friable than the untreated backing; and applying mechanical force to the carpet so as to liberate the friable backing material from the face fiber material.