US Patent 7147895 Resin transfer molding process

A wind tunnel blade (30) connected to a base (32) and held in position by a two-piece cuff (34). The wind tunnel blade (30) is formed in a resin transfer molding process in which central, fore, and aft foam core sections (70, 72, 74) are placed together to form the wind tunnel blade (30). Radius fillers (120) are used to fill the gaps between the outer edge of the foam core sections. The radius fillers (120) used in the wind tunnel blade (30) are formed by a braided sleeve (122) surrounding a number of unidirectional tows (124). A tip (68) is formed separately from the rest of the wind tunnel blade (30) and is glued to the top thereof. Stacked layers of braided fibers (100) are used to reinforce the central core section (70).