A UNIDIRECTIONAL REINFORCEMENT AND A METHOD OF PRODUCING A UNIDIRECTIONAL REINFORCEMENT

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.