Abstract: A composite material includes: carbon fibers having an average fiber length of more than about 10 mm and about 100 mm or less; and a thermoplastic resin. The carbon fibers are substantially two-dimensionally-randomly oriented. The composite material includes a carbon fiber bundle (A) in a ratio of more than 0 volume % and less than about 30 volume % to a total volume of the carbon fibers, the carbon fiber bundle (A) including the carbon fibers of a critical single fiber number defined by formula (1) or more. An average number (N) of the carbon fibers in the carbon fiber bundle (A) satisfies formula (2). Critical single fiber number=600/D??(1) 1.0×104/D2<N<2.5×104/D2??(2) D is an average fiber diameter (?m) of the carbon fibers.

Abstract: A composite material includes: carbon fibers having an average fiber length of more than about 10 mm and about 100 mm or less; and a thermoplastic resin. The carbon fibers are substantially two-dimensionally-randomly oriented. The composite material includes a carbon fiber bundle (A) in a ratio of about 30 volume % or more and less than about 90 volume % to a total volume of the carbon fibers, the carbon fiber bundle (A) including the carbon fibers of a critical single fiber number defined by formula (1) or more. An average number (N) of the carbon fibers in the carbon fiber bundle (A) satisfies formula (2). Critical single fiber number=600/D??(1) 6×104/D2<N<2×105/D2??(2) D is an average fiber diameter (?m) of the carbon fibers.

Abstract: A composite material includes: carbon fibers having an average fiber length of more than about 10 mm and about 100 mm or less; and a thermoplastic resin. The carbon fibers are substantially two-dimensionally-randomly oriented. The composite material includes a carbon fiber bundle (A) in a ratio of more than 0 volume % and less than about 30 volume % to a total volume of the carbon fibers, the carbon fiber bundle (A) including the carbon fibers of a critical single fiber number defined by formula (1) or more. An average number (N) of the carbon fibers in the carbon fiber bundle (A) satisfies formula (2). Critical single fiber number=600/D??(1) 1.0×104/D2<N<2.5×104/D2??(2) D is an average fiber diameter (?m) of the carbon fibers.

Abstract: There is provided a fiber-reinforced composite material is constituted by reinforcing fibers with an average fiber length of 5 mm to 100 mm and a thermoplastic resin, in which in a viscoelastic characteristic that is defined by following formulas (1) and (2), an average value in a range of ?25° C. of the melting point of a matrix resin to +25° C. of the melting point of a matrix resin satisfies following formula (3): tan ?=G?/G???(1) tan ??=Vf×tan ?/(100?Vf)??(2) 0.01?tan ???0.2??(3) wherein G? represents a storage modulus (Pa) of the fiber-reinforced composite material, G? represents a loss modulus (Pa) of the fiber-reinforced composite material, and Vf represents a volume fraction (%) of the reinforcing fibers in the fiber-reinforced composite material.

Abstract: The present invention relates to a shaped product being excellent in isotropy constituted by a fiber-reinforced composite material in which discontinuous reinforcing fibers are isotropic in a plane and are two-dimensionally oriented in the thermoplastic resin, the reinforcing fibers contained in the shaped product includes a reinforcing fiber bundle (A) constituted by the reinforcing fibers of the critical single fiber number defined by formula (1) or more, a ratio of the reinforcing fiber bundle (A) to the total amount of the reinforcing fibers in the shaped product is 20 vol % or more and less than 90 vol %, and the average number (N) of the reinforcing fibers in the reinforcing fiber bundle (A) satisfies formula (2): Critical single fiber number=600/D??(1) 0.7×104/D2<N<1×105/D2??(2) wherein D is an average fiber diameter (?m) of the reinforcing fibers.

Abstract: There is provided a random mat of the present invention including: reinforcing fibers having an average fiber length of 5 to 100 mm; and a thermoplastic resin, wherein a fiber areal weight of the reinforcing fibers is from 25 to 3,000 g/m2, for a reinforcing fiber bundle (A) including the reinforcing fibers equivalent to or more than a critical single fiber number defined by formula (1), a ratio of the reinforcing fiber bundle (A) to a total amount of the reinforcing fibers in the mat is from 30 vol % to less than 90 vol %, and an average number (N) of the reinforcing fibers in the reinforcing fiber bundle (A) satisfies formula (2): Critical single fiber number=600/D ??(1) 0.7×104/D2<N<1×105/D2 ??(2) wherein D is an average fiber diameter (?m) of single reinforcing fibers.