A method for improving the translation efficiency of fiber strength into composite strength is provided. A single unidirectional tape, single unidirectional fiber web or a stack of unidirectional web/unidirectional tape plies formed from partially oriented fibers/tapes is primed under mild conditions followed by subjecting the primed plies to an axial extension stress in the axial fiber direction of each fiber ply by passage through a compression apparatus. The axial extension stress extends the fibers, strengthening them, while also compacting the plies together and thereby forming a composite having improved strength. Production yield is improved by avoiding maximal fiber stretching and thereby avoiding typical manufacturing loss, and low weight composite armor having increased strength is achieved.

A carbon fiber tape material is favorable in followability to molds and impregnation with matrix resins, and capable of enhancing the productivity in producing a reinforcing fiber laminate by a method of fiber placement and capable of providing a molded body with high mechanical strength when the material is impregnated with a resin and molded. The carbon fiber tape material has a carbon fiber bundle group including a plurality of carbon fiber bundles arranged in parallel with the fiber orientation direction and a fabric are integrated, and satisfies (a) to (c): (a) the fabric includes one or more thermoplastic resins; (b) the carbon fiber tape material excluding the fabric is between 120 g/m.sup.2 and 400 g/m.sup.2 in basis weight; and (c) the fabric elongation rate with a load of 80 mN/50 mm applied to the fabric is 5% to 100% in at least one direction of the fabric.

Provided is a tube body intermediate including: a carbon fiber disposed with respect to an outer circumferential surface of a mandrel so as to extend in an axial direction of the mandrel; and a fixing member having a tubular shape and disposed with respect to the outer circumferential surface of the mandrel so as to cover the carbon fiber. Also provided is a tube body production method including: disposing a fiber body with respect to an outer circumferential surface of a mandrel so that the fiber body extends in an axial direction of the mandrel; disposing a fixing member with a tubular shape with respect to the outer circumferential surface of the mandrel so that the fixing member covers the fiber body; and impregnating the fiber body with a resin on the outer circumferential surface of the mandrel and then heating the resin to mold the resin.

A tube body production method includes: a disposing step of disposing carbon fibers with respect to an outer circumferential surface of a mandrel so that the carbon fibers extend in the axial direction of the mandrel; and a molding step of impregnating the fiber body with a resin on the outer circumferential surface of the mandrel and then heating the resin to mold the resin, wherein the disposing step and the molding step are performed in a state where the axial direction of the mandrel coincides with an up-down direction.

The purpose of the present invention is to further enhance the strength of a manufactured composite structure by further suppressing the occurrence of wrinkling. A method for manufacturing a composite structure, the method comprising: a lamination step for layering a plurality of fiber sheets and molding a plate-form laminate; a forming step for forming a recess formed by a curved surface in a prescribed portion of the laminate; a short-direction deformation step for deforming the laminate in the short direction thereof after the forming step to configure a long-direction cross-section of the laminate in a prescribed shape; and a long-direction deformation step for deforming the laminate in the long direction after the forming step, so that the recess formed in the forming step deforms, to configure a short-direction cross section in a prescribed shape.

Various embodiments related to three dimensional printers, and reinforced filaments, and their methods of use are described. In one embodiment, a void free reinforced filament is fed into an conduit nozzle. The reinforced filament includes a core, which may be continuous or semi-continuous, and a matrix material surrounding the core. The reinforced filament is heated to a temperature greater than a melting temperature of the matrix material and less than a melting temperature of the core prior to drag the filament from the conduit nozzle.

Various embodiments related to three dimensional printers, and reinforced filaments, and their methods of use are described. In one embodiment, a void free reinforced filament is fed into an conduit nozzle. The reinforced filament includes a core, which may be continuous or semi-continuous, and a matrix material surrounding the core. The reinforced filament is heated to a temperature greater than a melting temperature of the matrix material and less than a melting temperature of the core prior to drag the filament from the conduit nozzle.

A composite hat stringer for stiffening a panel includes a plurality of composite fabric plies arranged to form a cap, a pair of flanges and a pair of webs respectively connecting the cap with the pair of flanges. The cap includes at least one 0° composite tape ply interleafed in the composite fabric plies within the cap.

To provide a novel material that maintains suppleness which is the advantage of a material using fibers and has a low thermal shrinkage ratio, and a method for producing the material, a partially welded material using the material, a composite material, and a method for producing a molded product. A material including: a first region, a fiber region, and a second region continuously in a thickness direction; the first region and the second region being each independently a resin layer including from 20 to 100 mass % of a thermoplastic resin component and from 80 to 0 mass % of reinforcing fibers; the fiber region including from 20 to 100 mass % of thermoplastic resin fibers and from 80 to 0 mass % of reinforcing fibers; the thermoplastic resin component included in the first region and the thermoplastic resin component included in the second region each independently having a crystallization energy during temperature increase of 2 J/g or greater, measured by differential scanning calorimetry; and the thermoplastic resin fibers included in the fiber region having a crystallization energy during temperature increase of less than 1 J/g, measured by differential scanning calorimetry; wherein the crystallization energy during temperature increase is a value measured by using a differential scanning calorimeter (DSC) in a nitrogen stream while heating is performed from 25° C. to a temperature that is 20° C. higher than a melting point of the thermoplastic resin component or the thermoplastic resin fibers at a temperature increase rate of 10° C./min.

To provide a novel material that maintains suppleness which is the advantage of a material using fibers and has a low thermal shrinkage ratio, and a method for producing the material, a partially welded material using the material, a composite material, and a method for producing a molded product. A material including: a first region, a fiber region, and a second region continuously in a thickness direction; the first region and the second region being each independently a resin layer including from 20 to 100 mass % of a thermoplastic resin component and from 80 to 0 mass % of reinforcing fibers; the fiber region including from 20 to 100 mass % of thermoplastic resin fibers and from 80 to 0 mass % of reinforcing fibers; the thermoplastic resin component included in the first region and the thermoplastic resin component included in the second region each independently having a crystallization energy during temperature increase of 2 J/g or greater, measured by differential scanning calorimetry; and the thermoplastic resin fibers included in the fiber region having a crystallization energy during temperature increase of less than 1 J/g, measured by differential scanning calorimetry; wherein the crystallization energy during temperature increase is a value measured by using a differential scanning calorimeter (DSC) in a nitrogen stream while heating is performed from 25° C. to a temperature that is 20° C. higher than a melting point of the thermoplastic resin component or the thermoplastic resin fibers at a temperature increase rate of 10° C./min.