Patent ID: 8025754

Claim:
A method of preparing a reinforcing structure for use in manufacture of a pultruded part where the reinforcing structure is pulled through a pultrusion die along a continuous longitudinal pull direction, the method of making the reinforcing structure comprising the steps of: forming a first reinforcing structure comprising the steps of arranging at least a plurality of first reinforcing fibers in a generally planar, non-overlapping configuration so that the first reinforcing fibers do not extend over or cover one another, and bonding a permeable transport web of staple fibers to the first reinforcing fibers to provide shear strength and anti-skew properties sufficient to substantially maintain the relative orientations of the first reinforcing fibers when subjected to the pulling forces encountered during pultrusion, so that the first reinforcing structure has a thickness of about 0.004 inches to about 0.020 inches; forming a second reinforcing structure comprising the steps of arranging at least a plurality of second reinforcing fibers in a generally planar, non-overlapping configuration so that the second reinforcing fibers do not extend over or cover one another, and bonding a permeable transport web of staple fibers to the second reinforcing fibers to provide shear strength and anti-skew properties sufficient to substantially maintain the relative orientations of the second reinforcing fibers when subjected to the pulling forces encountered during pultrusion, so that the second reinforcing structure has a thickness of about 0.004 inches to about 0.020 inches; and positioning a plurality of longitudinal rovings between the first and second reinforcing structures.