Provided is an intermediate base material (incised prepreg) which has exceptional surface quality and mechanical properties when solidified and with which it is possible to obtain a fiber-reinforced plastic having excellent three-dimensional shape conformance properties. This incised prepreg has, in a prepreg that includes a resin and reinforcing fibers oriented in one direction, incisions substantially parallel to the orientation direction of the reinforcing fibers (the incisions substantially parallel to the orientation direction of the reinforcing fibers are referred to as parallel incisions) and incisions that cut across the reinforcing fibers (the incisions that cut across the reinforcing fibers are referred to as intersecting incisions).

A method of manufacturing stiffened structural panel for an aircraft including a main sheet made of composite material with unidirectional fibers, and a stiffening structure secured to the main sheet and made of a composite material comprising a resin and chopped fibers, the stiffening structure including on the one hand a base adhering to one of the two lateral faces of the main sheet, and a network of stiffeners in the form of a grid projecting from the base. The method includes a step of compression molding the stiffening structure from a block formed of a prepolymer reinforced with chopped fibers.

A method of manufacturing stiffened structural panel for an aircraft including a main sheet made of composite material with unidirectional fibers, and a stiffening structure secured to the main sheet and made of a composite material comprising a resin and chopped fibers, the stiffening structure including on the one hand a base adhering to one of the two lateral faces of the main sheet, and a network of stiffeners in the form of a grid projecting from the base. The method includes a step of compression molding the stiffening structure from a block formed of a prepolymer reinforced with chopped fibers.

A resin member is formed from a resin material containing filler and an insulating base polymer as a main component. The resin member includes an alignment layer close to a surface of the resin member. The alignment layer includes the filler aligned in the surface direction and the base polymer filling the space between pieces of the filler. The alignment layer includes a carbonized portion that is carbonized matter of the base polymer, contains graphite, and provides electrical conductivity and thermal conductivity.

A resin member is formed from a resin material containing filler and an insulating base polymer as a main component. The resin member includes an alignment layer close to a surface of the resin member. The alignment layer includes the filler aligned in the surface direction and the base polymer filling the space between pieces of the filler. The alignment layer includes a carbonized portion that is carbonized matter of the base polymer, contains graphite, and provides electrical conductivity and thermal conductivity.

A substantially flat-plate-shaped laminated base material has at least a layer-shaped body α and a layer-shaped body β are layered or disposed side by side, the layer-shaped body α having one or more cut prepregs A in which reinforcing fibers oriented in one direction are impregnated with a resin composition, the volume fraction of fiber is 45-65%, and at least a portion of the reinforcing fibers are segmented into a fiber length of 10-300 mm by a plurality of cuts, and the layer-shaped body β having one or more base materials B in which reinforcing fibers having a fiber length in the range of 10-300 mm are impregnated with a resin composition.

A substantially flat-plate-shaped laminated base material has at least a layer-shaped body α and a layer-shaped body β are layered or disposed side by side, the layer-shaped body α having one or more cut prepregs A in which reinforcing fibers oriented in one direction are impregnated with a resin composition, the volume fraction of fiber is 45-65%, and at least a portion of the reinforcing fibers are segmented into a fiber length of 10-300 mm by a plurality of cuts, and the layer-shaped body β having one or more base materials B in which reinforcing fibers having a fiber length in the range of 10-300 mm are impregnated with a resin composition.

A device for producing a pultruded article is provided with: a mold in which an intermediate molded article comprising reinforcing fibers impregnated with a thermosetting resin is heated and hardened; and a pultrusion device that causes a pultruded article generated by heating and hardening the intermediate molded article in the mold to be pultruded from the mold. The mold comprises a pressing member that is elastically deformable and that presses the intermediate molded article.

A device for producing a pultruded article is provided with: a mold in which an intermediate molded article comprising reinforcing fibers impregnated with a thermosetting resin is heated and hardened; and a pultrusion device that causes a pultruded article generated by heating and hardening the intermediate molded article in the mold to be pultruded from the mold. The mold comprises a pressing member that is elastically deformable and that presses the intermediate molded article.

A resin member is formed from a resin material containing filler and an insulating base polymer as a main component. The resin member includes an alignment layer close to a surface of the resin member. The alignment layer includes the filler aligned in the surface direction and the base polymer filling the space between pieces of the filler. The alignment layer includes a carbonized portion that is carbonized matter of the base polymer, contains graphite, and provides electrical conductivity and thermal conductivity.