The gel time represents the maximum period for which mixed reactants could be dispensed by the RIM machine into the mold without risk of producing a defective molding due to failure of reactants to maintain fluid flow in the mold. (Note: it has been reported, see for example, U.S. Pat. No. 4,218,543 at column 5, lines 8-22 that the shot time, i.e. the time for which material can be injected into a