Unidirectional reinforcement, a method of producing a unidirectional reinforcement and the use thereof

A unidirectional reinforcement for the manufacture of fiber reinforced composites by a Closed Mold Method, the unidirectional reinforcement comprising:

• continuous unidirectional rovings arranged in a longitudinal direction of the reinforcement and bonded to each other by a thermoplastic and/or thermoset binder,
• the reinforcement having two longitudinal edges, a top surface and a bottom surface and continuous members arranged on at least one of the top surface and the bottom surface of the reinforcement,
• the continuous members running in a direction transverse to the direction of the unidirectional rovings, wherein the continuous members include thin discrete flow passage forming means, for forming flow passages for resin, arranged transverse to the unidirectional rovings on at least one of the top surface and the bottom surface of the reinforcement,
• the thin discrete flow passage forming means forming to the sides thereof transverse flow passages extending from one longitudinal edge of the unidirectional reinforcement to the opposite longitudinal edge thereof, wherein the flow passages are configured to facilitate, when wetting-out a stack of reinforcements, impregnation of the reinforcement with resin, and
• the thin discrete flow passage forming means are secured on the unidirectional rovings by additional yarns running on and transverse to the thin discrete flow passage forming means, each additional yarn remaining continuously on the surface of the reinforcement having the thin discrete flow passage forming means laid thereon, the additional yarns being adhesively bonded to at least the unidirectional rovings.