Aerospace reinforced structural polymers at automotive fabrication speed

Fiber reinforced composites are the material of choice for aerospace applications due to their high strength and stiffness-to-weight ratio, and fatigue tolerance. However, traditional continuous fiber composites suffer from several drawbacks including slow processing time, and high touch labor. As a result, the automotive industry has focused on increasing fabrication speed by eliminating touch labor and forming primarily thermoplastic composites that do not undergo the long cure cycles of aerospace grade thermosets. To achieve this, the fiber length is often severely degraded to a few millimeters, resulting in reduced mechanical properties. In the proposed work, defect free nonwoven reinforcement fabrics with fiber length greater than 25mm will be produced using a novel wet laid dispersing system. The nonwoven fabric may consist of a mixture of thermoplastic and reinforcing fibers, of which the thermoplastic can be melted to consolidate the composites. The resulting materials have been shown to exhibit quasi-isotropic mechanical properties that exceed common automotive materials at similar manufacturing time and in some cases at lower costs. Touch labor is reduced by eliminating the need for complex quasi-isotropic laminate sequences that must be carefully followed in the case of continuous fiber reinforcement.