Abstract: A fiber-reinforced resin molding material molded product includes a fiber-reinforced resin molding material prepared by impregnating chopped fiber bundles obtained by cutting a reinforcing fiber bundle with a matrix resin, wherein in a region excluding 30 mm from an edge of the molded product, when an arbitrary rectangular region having an area of 40 mm2 or more and defined by a thickness of the molded product and a width in a direction perpendicular to a thickness direction of the molded product is set in a cross section in an arbitrary thickness direction of the molded product, with respect to a bundle thickness of the chopped fiber bundles present in the set rectangular region.

Abstract: A fiber-reinforced resin molding material is obtained by impregnating a chopped fiber bundle with a matrix resin, has a layered structure including three or more layers in a thickness direction thereof, and satisfies the relationships Lao>Lam and Wao>Wam, where Lao and Wao represent the number average fiber length and the number average fiber bundle width, respectively, of the chopped fiber bundle in the outermost layer thereof, and Lam and Wam represent the number average fiber length and the number average fiber bundle width, respectively, of the chopped fiber bundle in a middle layer thereof.

Abstract: A method of producing a partially separated fiber bundle wherein, while a fiber bundle includes a plurality of single fibers travels along a lengthwise direction of the fiber bundle, a separator provided with a plurality of projected parts is penetrated into the fiber bundle to create a separation-processed part, and entangled parts, where the single fibers are interlaced, are formed at contact parts with the projected parts in at least one separation-processed part, thereafter the separator is removed from the fiber bundle, and after passing through an entanglement accumulation part including the entangled parts, the separator is penetrated again into the fiber bundle, characterized in that a separation processing time t1 during being penetrated with the separator and a time t2 from being removed with the separator to being penetrated again into the fiber bundle satisfy Equation (1): 0.03?t2/(t1+t2)?0.5.

Abstract: A production method for a separated fiber bundle includes at least: [A] a partial separation step for obtaining a partially separated fiber bundle in which separation-processed parts, each separated into a plurality of bundles, and not-separation-processed parts are alternately formed along the lengthwise direction of a fiber bundle comprising a plurality of single fibers; and [B] a cutting step for cutting the not-separation-processed parts of the partially separated fiber bundle formed in the step [A] along the lengthwise direction of the fiber bundle. A separated fiber bundle produced by the method, a fiber-reinforced resin molding material that uses the separated fiber bundle, and a production method for the fiber-reinforced resin molding material.

Abstract: A fiber-reinforced resin molding material molded product includes a fiber-reinforced resin molding material prepared by impregnating chopped fiber bundles obtained by cutting a reinforcing fiber bundle with a matrix resin, wherein in a region excluding 30 mm from an edge of the molded product, when an arbitrary rectangular region having an area of 40 mm2 or more and defined by a thickness of the molded product and a width in a direction perpendicular to a thickness direction of the molded product is set in a cross section in an arbitrary thickness direction of the molded product, with respect to a bundle thickness of the chopped fiber bundles present in the set rectangular region.

Abstract: A fiber-reinforced resin molding material is obtained by impregnating a chopped fiber bundle with a matrix resin, has a layered structure including three or more layers in a thickness direction thereof, and satisfies the relationships Lao>Lam and Wao>Wam, where Lao and Wao represent the number average fiber length and the number average fiber bundle width, respectively, of the chopped fiber bundle in the outermost layer thereof, and Lam and Wam represent the number average fiber length and the number average fiber bundle width, respectively, of the chopped fiber bundle in a middle layer thereof.

Abstract: A partially separated fiber bundle having a surface of a reinforcing fiber coated with a sizing agent containing a water-soluble polyamide-based resin, in which a separated fiber section consisting of a plurality of separated fiber bundles and an unseparated fiber section are provided alternately along a longitudinal direction of the reinforcing fiber bundle consisting of a plurality of single yarns, wherein the reinforcing fiber bundle contains 600 fibers/mm or more and less than 1,600 fibers/mm of fibers per unit width while the reinforcing fiber has a drape level of 120 mm or more and 240 mm or less.

Abstract: A random mat includes a chopped fiber bundle [A] obtained by obliquely cutting a partially separated fiber bundle [B] prepared by alternately forming separation-processed sections, each of which is separated into a plurality of bundles, and not-separation-processed sections, along the lengthwise direction of a fiber bundle, wherein the total cross-sectional area of reinforcing fibers exhibits a specific change amount between both tips of the chopped fiber bundle [A]; a production method produces the random mat; and a fiber-reinforced resin molding material uses the random mat.

Abstract: A partially separated fiber bundle includes separation-processed sections and not-separation-processed sections that are alternately formed along the lengthwise direction of a fiber bundle that includes a plurality of single fibers, wherein the separation-processed sections include a plurality of divided fiber bundles that have been divided by separation processing. The partially separated fiber bundle is characterized in that the numbers of single fibers of the divided fiber bundles in the separation-processed section are nonuniform.

Abstract: A fiber-reinforced resin molding material [C] includes a chopped fiber bundle [A] and a matrix resin [B], the material being characterized in that, when divided into n layers along the thickness direction of the fiber-reinforced resin molding material [C], the number-average fiber length [Lk] of the chopped fiber bundle [Ak] constituting each layer Fk (1?k?n) gradually increases from one outermost layer F1 of the fiber-reinforced resin molding material [C] toward the other outermost layer Fn. Also provided is a molded article obtained by molding the fiber-reinforced resin molding material. This fiber-reinforced resin molding material exhibits excellent flowability, and can exhibit excellent mechanical properties when made into a molded article.

Abstract: A fiber-reinforced resin molding material containing at least bundled aggregates [A] of discontinuous reinforcing fibers and a matrix resin [M], wherein each of the bundled aggregates [A] is obtained by cutting a partially-separated fiber bundle, prepared by forming separation treatment sections separated into a plurality of bundles and non-separation treatment sections alternately along a lengthwise direction of a fiber bundle including a plurality of single fibers, at an angle ? (0°<?<90°) with respect to the lengthwise direction of the fiber bundle.

Abstract: A discontinuous fiber-reinforced composite material including a discontinuous reinforcing fiber aggregate of a discontinuous reinforcing fiber having a number average fiber length of 3 to 100 mm and a matrix resin, the discontinuous reinforcing fiber aggregate including a plurality of discontinuous reinforcing fiber bundles having a predetermined number of unidirectionally-bundled single yarns of the discontinuous reinforcing fiber, wherein the discontinuous reinforcing fiber bundle has a cut surface inclined at a predetermined angle with respect to an orientation direction of the single yarn of the discontinuous reinforcing fiber bundle and has different fiber bundle lengths defined as a distance between both ends along the orientation direction of the single yarn of the discontinuous reinforcing fiber bundle, and the longer the fiber bundle length of the discontinuous reinforcing fiber bundle is, the smaller a tip angle defined as an acute angle at an end of a two-dimensional plane projection of the discont

Abstract: A molded article of a fiber-reinforced resin contains at least a bundled aggregate [A] of discontinuous reinforcing fibers and a matrix resin [M], wherein the average layer thickness h in the molded article of the fiber-reinforced resin is 100 ?m or less and the CV value of the average layer thickness h is 40% or less; and a compression molding method therefor. It is possible to reliably and greatly reduce the occurrence of stress concentration in the molded article and to thereby achieve higher mechanical properties and further reduce variation in the mechanical properties.

Abstract: A method of producing a partially separated fiber bundle wherein, while a fiber bundle includes a plurality of single fibers travels along a lengthwise direction of the fiber bundle, a separator provided with a plurality of projected parts is penetrated into the fiber bundle to create a separation-processed part, and entangled parts, where the single fibers are interlaced, are formed at contact parts with the projected parts in at least one separation-processed part, thereafter the separator is removed from the fiber bundle, and after passing through an entanglement accumulation part including the entangled parts, the separator is penetrated again into the fiber bundle, characterized in that a separation processing time t1 during being penetrated with the separator and a time t2 from being removed with the separator to being penetrated again into the fiber bundle satisfy Equation (1): 0.03?t2/(t1+t2)?0.5.

Abstract: A method of producing a partially separated fiber bundle includes a partial separation processing step for alternately forming separation-processed sections, each divided into a plurality of bundles, and not-separation-processed sections along the lengthwise direction of a fiber bundle, wherein a separation means provided with a plurality of projected parts is penetrated into the fiber bundle to create separation-processed parts, the separation means is removed from the fiber bundle, and the separation means is penetrated into the fiber bundle again, characterized in that a sizing agent is applied at an arbitrary timing during the production process of the partially separated fiber bundle. A partially separated fiber bundle is obtained by the production method, a fiber-reinforced resin molding material uses the partially separated fiber bundle, and a production method makes the fiber-reinforced resin molding material.

Abstract: A fiber-reinforced material includes a discontinuous reinforcing fiber aggregate of a discontinuous reinforcing fiber having a number average fiber length of 3 to 100 mm and a matrix resin, the discontinuous reinforcing fiber aggregate including a plurality of discontinuous reinforcing fiber bundles having a predetermined number of unidirectionally-bundled single yarns of the discontinuous reinforcing fiber, wherein the discontinuous reinforcing fiber bundle has a cut surface inclined at a predetermined angle with respect to an orientation direction of the single yarn of the discontinuous reinforcing fiber bundle and has different fiber bundle lengths defined as a distance between both ends along the orientation direction of the single yarn of the discontinuous reinforcing fiber bundle, the shorter the fiber bundle length of the discontinuous reinforcing fiber bundle, the smaller a tip angle defined as an acute angle at an end of a two-dimensional plane projection of the discontinuous reinforcing fiber bundle

Abstract: A partially separated fiber bundle includes separation-processed sections, each divided into a plurality of bundles of at least three bundles, and not-separation-processed sections, that are alternately formed along the lengthwise direction of a fiber bundle that comprises a plurality of single fibers. The partially separated fiber bundle is characterized in that, at any width-direction cross-section taken along the lengthwise direction thereof, a rate of single fibers contained in a region at which adjacent divided fiber bundles are joined by a not-separation-processed part is 67% or less relative to the total single fibers in the width-direction cross-section.

Abstract: A partially separated fiber bundle having a surface of a reinforcing fiber coated with a sizing agent containing a water-soluble polyamide-based resin, in which a separated fiber section consisting of a plurality of separated fiber bundles and an unseparated fiber section are provided alternately along a longitudinal direction of the reinforcing fiber bundle consisting of a plurality of single yarns, wherein the reinforcing fiber bundle contains 600 fibers/mm or more and less than 1,600 fibers/mm of fibers per unit width while the reinforcing fiber has a drape level of 120 mm or more and 240 mm or less.

Abstract: A partially separated fiber bundle includes separation-processed sections, each divided into a plurality of bundles of at least three bundles, and not-separation-processed sections, that are alternately formed along the lengthwise direction of a fiber bundle that comprises a plurality of single fibers. The partially separated fiber bundle is characterized in that, at any width-direction cross-section taken along the lengthwise direction thereof, a rate of single fibers contained in a region at which adjacent divided fiber bundles are joined by a not-separation-processed part is 67% or less relative to the total single fibers in the width-direction cross-section.

Abstract: A fiber-reinforced resin molding material includes at least bundled discontinuous reinforcing fiber aggregates and matrix resin, wherein said bundled reinforcing fiber aggregates include both reinforcing fiber aggregates (A) which are formed by cutting continuous reinforcing fiber strands after fiber splitting, in which said strands are completely split into multiple bundles, and reinforcing fiber aggregates (B) having at least unsplit strand sections in which fiber splitting is incomplete, an incision substantially originating from fiber splitting is present at least at one of both end portions of said reinforcing fiber aggregates (B), and a ratio of the weight of said reinforcing fiber aggregates (B) to the total weight of reinforcing fibers in said material is 5-50%.