Method of making a reinforcing mat for a pultruded part

A method of preparing a reinforcing structure for use in the manufacture of a pultruded part where the reinforcing structure is pulled through a pultrusion die along a continuous longitudinal pull direction, the method comprising the steps of:

• arranging a plurality of first reinforcing fibers generally parallel to the longitudinal pull direction in a generally planar, non-overlapping configuration so that the first reinforcing fibers do not extend over or cover one another;
• arranging a plurality of second reinforcing fibers at an angle with respect to the first reinforcing fibers and in a generally planar, non-overlapping configuration so that the second reinforcing fibers do not extend over or cover one another;
• positioning a permeable transport web of staple fibers having a weight of about 10 grams per square meter to about 1200 grams per square meter adjacent at least one of the first and second reinforcing fibers;
• and
• bonding the permeable transport web of staple fibers to the first and second reinforcing fibers to provide longitudinal strength, shear strength and anti-skew properties sufficient to substantially maintain the relative orientations of the first and second reinforcing fibers when subjected to the pulling forces encountered during pultrusion, so that the reinforcing structure has a thickness of about 0.004 inches to about 0.020 inches.