Emissions from Resin Transfer Molding (RTM) and Infusion

When considering styrene emissions from an RTM or infusion process, there are four potential sources of process emissions: 1. The transfer of resin from the original container (drum, tank, etc) to the working tank. 2. The air that is displaced by resin injected in the mold (or discharged via vacuum pump in vacuum infustion). 3. Incidental resin leakage at the injection port. 4. Mold perimeter leaks.

Assuming that resin handling does not produce any spills, that the containers are kept covered except during the actual transfer, and that the mold does not leak around the parting line, then the only source of emissions is air escaping from the mold cavity and some minor dripping at the injection point (and for infusion, emission in the vacuum pump exhaust).

Emissions from this process have generally been reported at 1% of the styrene weight. The RTM emissions factor continues to be the best available data and therefore is acceptable for reporting emissions from RTM and infussion processes.

The emissions calculation would be:

Weight of Resin Consumed X % Styrene Monomer X 1% Emissions Factor = Emissions by Weight

Example: 100 lb. Resin used; Styrene content = 40% 100 lb. X 40% monomer X 1% Emiss. Factor = 0.4 lb Emissions