Major advances have been made in a RIM process which permits low viscosity reactives to be injected onto preshaped fiber reinforcement in a mold.
Interest from a large number of end-users and in a wide variety of automotive parts has spawned a rapid increase in process technology and composite performance. Comparison of fiber types, fiber orientation, processing aids and techniques with resulting effects on physical properties will be discussed. Processing technology required to RIM large parts for structural applications has been defined. Strength to thickness ratios allow an overall weight savings in a tire cover application. Excellent wet-out without fiber movement in the mold has led to nearly isotropic properties; therefore over design to account for fiber orientation by other molding techniques has not been needed.