Abstract: A reinforcing-fiber composite material includes not less than 20 wt % but less than 70 wt % of discontinuous reinforcing fibers, and a matrix resin, wherein at least a portion of the discontinuous reinforcing fibers forms a fiber aggregation, and at least one bundle of the fiber aggregation has a surface that, when projected onto a two-dimensional plane, has at least one region where the number of monofilaments constituting the aggregation is reduced, at opposite ends in a longitudinal direction of a minimum circumscribed rectangle of the projected surface, and at portions other than the opposite ends.

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 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 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 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 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 method of manufacturing and a device for manufacturing a partial split-fiber fiber bundle and a partial split-fiber fiber bundle obtained are characterized by piercing a fiber splitting means provided with a plurality of protruding parts into a fiber bundle formed from a plurality of single fibers while making the fiber bundle travel along the longitudinal direction thereof and creating a split-fiber processed part, forming entangled parts where single fibers are interlaced at contact parts with the protruding parts in at least one split-fiber processed part, thereafter pulling the fiber splitting means out of the fiber bundle, and after passing through an entanglement accumulation part including the entangled parts, once again piercing the fiber splitting means into the fiber bundle.

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%.

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 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 forming material contains at least a matrix resin and bundled aggregates of discontinuous reinforcing fibers, wherein: the bundled aggregates include both reinforcing fiber aggregates A having a shape formed by cutting after having performed a splitting treatment to completely split the strands of continuous reinforcing fibers into a plurality of bundles of strands, and reinforcing fiber aggregates B1 having a shape that includes unsplit parts where splitting treatment was inadequate and/or reinforcing fiber aggregates B2 having a shape not subjected to splitting treatment; and both the ratio of the weight of the reinforcing fiber aggregates B1 with respect to the total weight of reinforcing fibers in the fiber-reinforced resin forming material, and the ratio of the total weight of the reinforcing fiber aggregates B1 and the reinforcing fiber aggregates B2 with respect to the total weight of reinforcing fibers in the fiber-reinforced resin forming material, are 50-95%.

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 separated bundles. The content of the not-separation-processed sections is 3% or more and 50% or less of the partially separated fiber bundle.

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 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 stampable sheet includes a resin and carbon fiber sheet including fiber bundles of discontinuous carbon fibers, wherein the carbon fiber sheet includes fiber bundles having a bundle width of 50 ?m or greater and opened fibers ranging from fiber bundles having a bundle width less than 50 ?m to fibers obtained by opening to the single-fiber level. When the direction along which the opened fibers have been oriented most is a 0° direction and the range of from the 0° to 90° direction is divided into angular zones, the distribution curve showing the proportion of the number of fiber bundles in each angular zone to that in all angular zones and the distribution curve showing the proportion of the number of opened fibers in each angular zone to that in all angular zones are reverse to each other in terms of gradient of the 0° to 90° direction.

Abstract: A fiber-reinforced resin forming material contains at least a matrix resin and bundled aggregates of discontinuous reinforcing fibers, wherein: the bundled aggregates include both reinforcing fiber aggregates A having a shape formed by cutting after having performed a splitting treatment to completely split the strands of continuous reinforcing fibers into a plurality of bundles of strands, and reinforcing fiber aggregates B1 having a shape that includes unsplit parts where splitting treatment was inadequate and/or reinforcing fiber aggregates B2 having a shape not subjected to splitting treatment; and both the ratio of the weight of the reinforcing fiber aggregates B1 with respect to the total weight of reinforcing fibers in the fiber-reinforced resin forming material, and the ratio of the total weight of the reinforcing fiber aggregates B1 and the reinforcing fiber aggregates B2 with respect to the total weight of reinforcing fibers in the fiber-reinforced resin forming material, are 50-95%.

Abstract: A reinforcing fiber composite material includes at least a matrix resin and discontinuous reinforcing fibers which include discontinuous reinforcing fiber aggregates, wherein the discontinuous reinforcing fibers include at least 5 wt % of discontinuous reinforcing fiber aggregates (A) in each of which a most widened section, where the width of the discontinuous reinforcing fiber aggregate in a direction intersecting the alignment direction of the discontinuous reinforcing fibers is made greatest when the discontinuous reinforcing fiber aggregate is two-dimensionally projected, is present at a position excluding both ends of the discontinuous reinforcing fiber aggregate, and the aspect ratio (width of the discontinuous reinforcing fiber aggregate/thickness of the discontinuous reinforcing fiber aggregate) of the most widened section is 1.3 times or more the aspect ratio of at least one of the ends of the discontinuous reinforcing fiber aggregate.