Abstract: A fiber-reinforced thermoplastic resin filament is obtained by impregnating a continuous reinforcing fiber with a thermoplastic resin, and satisfies all of conditions (a) to (c). (a) The volume ratio of a reinforcing fiber in a fiber-reinforced thermoplastic resin filament is 30 to 80%; and the volume ratio of a thermoplastic resin in a fiber-reinforced thermoplastic resin filament is 70 to 20%. (b) The thickness of a fiber-reinforced thermoplastic resin filament is 0.01 to 3 mm. (c) The length of a filament contained in a fiber-reinforced thermoplastic resin filament is 1 m or more.

Abstract: A fiber-reinforced thermoplastic resin filament for a 3D printer is formed by impregnating a thermoplastic resin into a plurality of continuous reinforcing fibers, wherein: an average value S of a roundness parameter s of a cross section is 60% to 100%, the average value S being evaluated by (i) taking a photograph of the cross section perpendicular to the axial direction of the filament, (ii) drawing an inscribed circle and a circumscribed circle of the filament in a cross-sectional image and determining the diameter length of each, (iii) calculating the roundness parameter s defined by equation (1), and (iv) repeating (i)-(iii) at a plurality of locations on the filament and calculating the average value S of the roundness parameter s; and the coefficient of variation of the diameter length of the circumscribed circle is 0% to 10%.

Abstract: A fiber-reinforced thermoplastic resin includes a continuous fiber base material made from continuous reinforcing fibers, and a thermoplastic resin applied to the surface thereof. The thermoplastic resin coats the entire surface of the continuous fiber base material in a solidified state, and impregnates the continuous fiber base material while leaving voids therein, with these voids being formed intermittently in the direction in which the fibers are arranged. A laminate uses the fiber-reinforced thermoplastic resin base material.

Abstract: A method produces thermoplastic resin-impregnated sheet-shaped reinforcing fiber bundle obtained by impregnating reinforcing fibers made from continuous fibers with a thermoplastic resin, said method including: an application step in which a sheet-shaped reinforcing fiber bundle obtained by arranging reinforcing fibers made from continuous fibers in one direction is passed through an application section which retains thermoplastic resin, and the thermoplastic resin is applied to the sheet-shaped reinforcing fiber bundle to constitute a thermoplastic resin-impregnated sheet-shaped reinforcing fiber bundle; a further impregnation step in which the applied thermoplastic resin is further impregnated into the inside of the thermoplastic resin-impregnated sheet-shaped reinforcing fiber bundle; and a shaping step in which the thermoplastic resin-impregnated sheet-shaped reinforcing fiber bundle is shaped and solidified by cooling.

Abstract: A fiber-reinforced thermoplastic resin filament is obtained by impregnating a continuous reinforcing fiber with a thermoplastic resin, and satisfies all of conditions (a) to (c). (a) The volume ratio of a reinforcing fiber in a fiber-reinforced thermoplastic resin filament is 30 to 80%; and the volume ratio of a thermoplastic resin in a fiber-reinforced thermoplastic resin filament is 70 to 20%. (b) The thickness of a fiber-reinforced thermoplastic resin filament is 0.01 to 3 mm. (c) The length of a filament contained in a fiber-reinforced thermoplastic resin filament is 1 m or more.

Abstract: A fiber-reinforced thermoplastic-resin base includes continuous reinforcing fibers aligned in parallel to each other and a thermoplastic resin is impregnated thereinto, wherein the base has a fiber volume content of 40-65 vol % and a dispersion parameter D of the fibers, determined by (i)-(iv), of 90% or more: (i) a cross-section of the fiber-reinforced thermoplastic-resin base that is perpendicular to the alignment direction of the reinforcing fibers is divided into a plurality of sections, and one of the sections is photographed, (ii) the photograph image of the section is divided into a plurality of square units each having a one-side length t, (iii) a dispersion parameter d is calculated, (iv) with respect to other sections, (i) to (iii) are repeatedly performed, and an average value of dispersion parameters d of the plurality of sections is dispersion parameter D.

Abstract: A fiber-reinforced thermoplastic-resin base includes continuous reinforcing fibers aligned in parallel to each other and a thermoplastic resin is impregnated thereinto, wherein the base has a fiber volume content of 40-65 vol % and a dispersion parameter D of the fibers, determined by (i)-(iv), of 90% or more: (i) a cross-section of the fiber-reinforced thermoplastic-resin base that is perpendicular to the alignment direction of the reinforcing fibers is divided into a plurality of sections, and one of the sections is photographed, (ii) the photograph image of the section is divided into a plurality of square units each having a one-side length t, (iii) a dispersion parameter d is calculated, (iv) with respect to other sections, (i) to (iii) are repeatedly performed, and an average value of dispersion parameters d of the plurality of sections is dispersion parameter D.