Patent ID: 8057887

Claim:
A multi-layer composite structure comprising: a plurality of melt extruded multi-filament semi-crystalline polypropylene fibers having a modulus greater than about 8 GPa, a maximum cross sectional dimension less than about 100 microns, and at least one of the following characteristics: a) greater than 80% crystallinity according to WAXS measuring techniques, and b) a ratio of equatorial intensity to meridonal intensity of greater than 1.0 as measured by SAXS techniques; a first layer comprising the polypropylene fibers, wherein said first layer includes, on its surface, one or more of the following treatments: i) at least one thermoset resin-reactive group, ii) size, or iii) fibrillations; a polymeric bonding agent, wherein said surface treatments of said first layer impart increased bonding strength with said polymeric binding agent; and a second layer; wherein the polymeric binding agent secures the first layer to the second layer.