A NEW PROCESS FOR FABRICATING NONWOVEN FIBROUS-REINFORCED ELASTOMER COMPOSITES

A new type of mold was developed and tested for structural reaction injection molding (SRIM) of elastomer composites having polymer matrices made from a mixture of two components. These mixtures had short pot lives and relatively high viscosity. Channel systems for polymer feeding and vacuum application were investigated. The mold cavity was provided with up to 24 polymer feeding holes and 38 vacuuming holes. The cavity and channels were made from transparent materials that allowed easy observation and video recording of the polymer matrix flow. In addition, some design parameters were studied such as channel layout. Investigations were carried out on the mechanism of polymer matrix flow and fiber breakage during the formation of fiber-reinforced composites made of non-woven fiber reinforcement structures with considerably longer fiber lengths than reported earlier. Other studies included determination of the effects of fiber type, fiber dimensions, and fiber/matrix v/v ratio on the matrix flow during impregnation.