Method for producing dry preform for composite material

Abstract

A novel process for producing a dry preform for a composite material takes advantage of the fact that a reinforcing filament assembly, when consisting of a fiber reinforcement layer a, formed by stringing a first set of parallel strands of fiber reinforcement over a part or all of the plane within any desired shape along the straight axis, and a fiber reinforcement layer b, formed by stringing a second set of parallel strands of fiber reinforcement over the plane at an angle θ with respect to the straight axis, such that 0°<θ<180°, the part of the reinforcing filament assembly that consists solely of the fiber reinforcement b can be deformed as desired. According to this process, strands c of fiber reinforcement are strung using a fiber reinforcement string jig as shown in FIGS.(A) and(B). The layers of the strung strands of fiber reinforcement are brought together by a simple means such as stitching. The integrated layer is then shaped into the reinforcing filament assemblies, which are combined to form a dry preformfor making a composite material having any desired alignment of fiber reinforcement.