Method for producing carbon fiber composite material

A method for producing a carbon fiber composite material, comprising:

• melting, kneading and continuously discharging a raw material containing a resin and recycled carbon fibers using a twin-screw kneader,
• wherein the raw material contains 50-70 wt % of the recycled carbon fibers,
• a screw main body of the twin-screw kneader is composed of one rotation shaft and a plurality of cylindrical tubes, and the screw main body has a plurality of transport portions for transporting the raw material and a plurality of barrier portions for restricting a flow of the raw material,
• one of the barrier portions and two of the transport portions that sandwich the one of the barrier portions is defined as one unit, a passage is formed in the plurality of tubes below the two of the transport portions across the barrier portions of each unit,
• when the raw material is transported along an outer circumferential surface of the screw main body,
• transport of the raw material is restricted by the barrier portions provided on the outer circumferential surface, a shearing force is applied to the raw material with the screw main body, and a stretching force is applied to the raw material by passing the raw material from an inlet of the passage provided on the outer circumferential surface to an outlet of the passage,
• and wherein a fiber length of the recycled carbon fibers becomes short during kneading by application of the shearing force.