Abstract: To measure a thickness or a coverage of a resin present at a surface layer of a prepreg in a non-contact manner using a simple technique, a measurement method for a resin state which is a method for measuring a state of a resin present at a surface layer of a prepreg impregnated with the resin in an unidirectional reinforced fiber base material includes: irradiating the surface layer of the prepreg with light from an irradiation source; receiving reflected light from the surface layer of the prepreg by a sensor; and calculating at least one of a thickness or a coated state of the resin present at the surface layer of the prepreg from intensity of the reflected light.

Abstract: A reinforcing fiber prepreg has a thermosetting resin as a matrix, wherein a part of the reinforcing fiber prepreg is a low-adhesion region that has been treated to reduce adhesiveness, and the resin reaction rate of the low-adhesion region is preferably 0.1%-20%; a tape and a wound body is obtained from the reinforcing fiber prepreg; and methods produce the reinforcing fiber prepreg and reinforcing fiber prepreg tape. This makes it possible to provide a reinforcing fiber prepreg tape of which the adhesiveness is appropriately reduced to enable suitable application to conveyance for AFP while using a simple technology.

Abstract: A prepreg is formed by impregnating reinforcing fibers with a heat-curable resin with a cure extent greater than or equal to 3% and less than 50%, chopped prepreg obtained by cutting the prepreg is dispersed in a flat shape, and the chopped prepreg is thermally bonded together to form a fiber reinforced resin sheet. The fiber reinforced resin sheet can be used in press forming, has excellent uniformity of basis weight as a forming material allowing dense filling into a mold, and enables obtaining a shaped product that has excellent mechanical characteristics because of increased volume content of the reinforcing fibers.

Abstract: A production method for a fiber-reinforced plastic, in which a preform made of a reinforcing fiber substrate and having a three-dimensional shape and an inner mold operatable in a lateral direction different from an up-down direction are disposed in a mold cavity formed by an upper mold and a lower mold, and a state in which a plate thickness of the preform has been made greater than the thickness of a molded article to be obtained is brought about, and a matrix resin is injected and impregnated into the preform, and, after that, at least one of the upper mold and the lower mold is operated toward the other and the inner mold is operated in the lateral direction to pressurize the preform, whereby the thickness of the preform is controlled so as to be equal to a predetermined product's thickness, and subsequently the matrix resin is hardened by heating to obtain the molded article, and a production apparatus for a fiber-reinforced plastic for use in the production method.

Abstract: A simple technique measures a width of a gap present in a surface layer of a reinforced fiber laminate and is applicable to a fiber placement process. In the method in which at least one of a fiber reinforced substrate of the surface layer and a fiber reinforced substrate having an exposed part due to the presence of a gap is a unidirectional reinforced fiber substrate, the reinforced fiber laminate is irradiated with light in a direction vertical to an orientation direction of a continuous fiber present in a unidirectional reinforced fiber substrate of the reinforced substrate and at an acute angle with respect to a surface of the fiber reinforced substrate of the surface layer, and a sensor receives reflected light from the irradiation light, thereby calculating the width of the gap.

Abstract: A water feeding system provided with: a first feed water line through which first feed water flows; a second feed water line through which second feed water having a lower pressure than the first feed water flows; a first heater that heats the first feed water; a first feed water introducing line that guides first heated feed water, which is the first feed water that has been heated by the first heater, to the second feed water line; a medium heat exchanger that causes the first heated feed water to exchange heat with a medium, thereby cooling the first heated feed water and heating the medium; and a cooling water injecting line that injects cooling water having a lower temperature than the first heated feed water into the first feed water introducing line, at a position located further to the second feed water line side than the medium heat exchanger.

Abstract: A water feeding system provided with: a first feed water line through which first feed water flows; a second feed water line through which second feed water having a lower pressure than the first feed water flows; a first heater that heats the first feed water; a first feed water introducing line that guides first heated feed water, which is the first feed water that has been heated by the first heater, to the second feed water line; a medium heat exchanger that causes the first heated feed water to exchange heat with a medium, thereby cooling the first heated feed water and heating the medium; and a cooling water injecting line that injects cooling water having a lower temperature than the first heated feed water into the first feed water introducing line, at a position located further to the second feed water line side than the medium heat exchanger.

Abstract: A method of producing a reinforcing fiber preform includes: holding at least one substrate laminate by a shaping mold composed of at least two molds that face each other, wherein the at least one substrate laminate is selected from a substrate laminate produced by laminating multiple reinforcing fiber substrates each having a fixing material applied to at least one surface thereof and a substrate laminate produced by laminating multiple reinforcing fiber substrates with the fixing material interposed therebetween; and subsequently applying an electric current to the substrate laminate in a direction of lamination to heat the reinforcing fiber substrates and thereby apply heat to the fixing material to fix substrate layers in the substrate laminate to each other; wherein a means of making electric resistance in a fixing area is relatively lower compared to that in a non-fixing area in the substrate laminate.

Abstract: A production method for a fiber-reinforced plastic, in which a preform made of a reinforcing fiber substrate and having a three-dimensional shape and an inner mold operatable in a lateral direction different from an up-down direction are disposed in a mold cavity formed by an upper mold and a lower mold, and a state in which a plate thickness of the preform has been made greater than the thickness of a molded article to be obtained is brought about, and a matrix resin is injected and impregnated into the preform, and, after that, at least one of the upper mold and the lower mold is operated toward the other and the inner mold is operated in the lateral direction to pressurize the preform, whereby the thickness of the preform is controlled so as to be equal to a predetermined product's thickness, and subsequently the matrix resin is hardened by heating to obtain the molded article, and a production apparatus for a fiber-reinforced plastic for use in the production method.

Abstract: A method of producing a reinforcing fiber preform includes: holding at least one substrate laminate by a shaping mold composed of at least two molds that face each other, wherein the at least one substrate laminate is selected from a substrate laminate produced by laminating multiple reinforcing fiber substrates each having a fixing material applied to at least one surface thereof and a substrate laminate produced by laminating multiple reinforcing fiber substrates with the fixing material interposed therebetween; and subsequently applying an electric current to the substrate laminate in a direction of lamination to heat the reinforcing fiber substrates and thereby apply heat to the fixing material to fix substrate layers in the substrate laminate to each other; wherein a means of making electric resistance in a fixing area is relatively lower compared to that in a non-fixing area in the substrate laminate.

Abstract: A method for laser-cutting a carbon fiber substrate such as a preform is configured from fabric material comprising at least carbon fibers, characterized by cutting the carbon fiber substrate at initial conditions which have been set so that the state of the substrate that is being cut with a laser can be suppressed with or prevented from deviating from a target state. By the method, it is possible to effectively solve various problems such as dissipation of heat, positional shifting from the focal length range of the laser, and soot, and the carbon fiber substrate can be stably cut at the target desired state.

Abstract: A method of manufacturing a preform includes forming a sheet-shaped structure made of a reinforcing-fiber base material with reinforcing fibers arranged in a predetermined direction into a shape along a lower mold having a three-dimensional shape with a recessed section by using the lower mold and a plurality of upper molds each having a pressing mechanism, wherein the sheet-shaped structure is placed on the lower mold while at least one spot in the sheet-shaped structure is temporarily pressed with at least one of the upper molds, and at least one spot other than the temporarily pressed spot in the sheet-shaped structure is pressed with another upper mold and, then, a spot which is neither the temporarily pressed spot nor the pressed spot is pressed with yet another upper mold, and the spot which has been temporarily pressed with the upper mold is pressed by a predetermined pressing force.

Abstract: A manufacturing apparatus of a preform to be used for an RTM forming, wherein a layered body consisting of a plurality of layered reinforcing-fiber base materials to which a fixing agent consisting primarily of a thermoplastic resin is attached is formed by heating into a predetermined shape, comprising a forming mold consisting of a first mold and a second mold facing each other, wherein, only the first mold is provided with a heating mechanism and a contact face of the second mold contacting the reinforcing-fiber base material is made of a material which is less thermally conductive than the first mold.

Abstract: Provided is a RTM method wherein a molding die composed of a temperature control mechanism, which is arranged on at least one of a plurality of dies that form a molding die and adjusts the temperature of the die, and a valve mechanism, which starts and stops supply of a resin in a state of having fluidity to the cavity of the molding die, is used. In the method, a plurality of the valve mechanisms are arranged on the molding die, each of the valve mechanisms is provided with one or a plurality of temperature control systems which adjust the temperature of the valve mechanism, the resin in the state of having fluidity is supplied to the cavity from the valve mechanisms, and a reinforcing fiber base material contained in the cavity is impregnated with the resin.

Abstract: A method of producing a carbon fiber aggregate cutting an edge material of a carbon fiber base material composed of carbon fibers to obtain a cut piece, and forming the cut piece into a web and/or into a nonwoven fabric to obtain a carbon fiber aggregate.

Abstract: A process for producing a molded fiber-reinforced resin by an RTM method includes disposing a molding precursor in a molding cavity of a mold; closing the mold in which the molding precursor is disposed; injecting a heated and pressurized resin into the molding cavity of the mold closed; solidifying the resin injected into the molding cavity; opening the mold after the resin has been solidified; and taking out the molded fiber-reinforced resin from the mold opened.

Abstract: A method for laser-cutting a carbon fiber substrate such as a preform is configured from fabric material comprising at least carbon fibers, characterized by cutting the carbon fiber substrate at initial conditions which have been set so that the state of the substrate that is being cut with a laser can be suppressed with or prevented from deviating from a target state. By the method, it is possible to effectively solve various problems such as dissipation of heat, positional shifting from the focal length range of the laser, and soot, and the carbon fiber substrate can be stably cut at the target desired state.

Abstract: A method for manufacturing a preform and a preform manufactured by the method includes a plurality of substrates to which a binder has been affixed laminated to form a laminate and a forming die is used to form the laminate, thereby manufacturing a preform which is a precursor in resin transfer molding (RTM) of fiber reinforced plastic (FRP). During the manufacturing the laminate is pressed into a predetermined shape by the forming die, the binder is melted by directly heating the binder of the substrates in the laminate being pressed or both and is cooled thereafter to solidify the binder, and the substrates are adhered between layers thereof to retain the formed shape of the preform.

Abstract: A process for producing a molded fiber-reinforced resin by an RTM method includes disposing a molding precursor in a molding cavity of a mold; closing the mold in which the molding precursor is disposed; injecting a heated and pressurized resin into the molding cavity of the mold closed; solidifying the resin injected into the molding cavity; opening the mold after the resin has been solidified; and taking out the molded fiber-reinforced resin from the mold opened.

Abstract: A layered carbon-fiber product obtained by layering one or more sheets of carbon-fiber fabrics each prepared using one or more carbon-fiber bundles each including a plurality of carbon fibers arranged in a single direction, wherein at least a part of a surfaces and/or an edge face of the layered carbon-fiber product includes a graphitized part and the graphitized part exhibits a Raman spectrum in which an intensity ratio of a D band to a G band (D-band intensity/G-band intensity) is 0.3 or less.