Abstract: A stitched unidirectional or multi-axial reinforcement and a method of producing a stitched unidirectional or multi-axial reinforcement includes transversely arranging thin discrete flow passage forming means having a diameter of 70-300 ?m in a direction transverse to the direction of the unidirectional rovings at least on the continuous rovings of the at least one layer, and stitching the thin discrete flow passage forming means and the continuous unidirectional rovings to one another to form a reinforcement.

Abstract: A method to produce a unidirectional reinforcement for fiber reinforced composites by a resin transfer or vacuum infusion molding process include: laying continuous rovings unidirectionally side by side in one layer for forming a unidirectional web, applying thermoplastic or thermoset binder on the web, activating the binder for bonding the rovings together to form a unidirectional reinforcement, and forming flow passages for resin in a direction transverse to the direction of the unidirectional rovings by laying thin discrete flow passage having, under compression, an aspect ratio of equal or less than 2 on the continuous unidirectional rovings.

Abstract: A stitched unidirectional or multi-axial reinforcement and a method of producing a stitched unidirectional or multi-axial reinforcement includes transversely arranging thin discrete flow passage forming means having a diameter of 70-300 ?m in a direction transverse to the direction of the unidirectional rovings at least on the continuous rovings of the at least one layer, and stitching the thin discrete flow passage forming means and the continuous unidirectional rovings to one another to form a reinforcement.

Abstract: A substantially laterally pressure-loaded panel has a side aspect ratio of at least 1.5, is formed of at least two reinforcement layers of substantially unidirectional fibers. The predominant orientation of the fibers form an angle of between about ±55°-±75° (preferably about 60°) with the longer side of the panel, with about one-half of the layers having a positive (+) angle and about one-half a negative (?) angle, within the range. The panel preferably has about 60-100% of its thickness formed by the reinforcement layers. The panels can be used can be used in boat and/or shipbuilding structural panels, pressure-loaded tanks, pressure-vessels and other corresponding structures that are subjected to a lateral pressure load.