Delivery of pitch/thermoplastic/thermoset resins in RTM systems

Resin or pitch is melted in a melt blender apparatus ( 11 ) and then loaded, into a heated jacketed holding tank ( 12 ). A pair of feed lines ( 14, 16 ) receives resin from the holding tank ( 12 ) and feeds an upper gear pump ( 15 ) and a lower gear pump ( 17 ). A mixing enhancement such as a static mixer ( 18, 19 ) is located in each of the feed lines ( 14, 16 ) between the gear pumps ( 15, 17 ) and the resin delivery ends ( 25, 26 ) of the feed lines. The resin-melt feed lines may be equipped with pressure indicators ( 27, 28, 32, 34 ) and pressure relief valves ( 23, 24 ). The resin-melt feed lines may also be equipped with pump accumulators ( 31, 33 ). Resin melt pressure created by the gear pumps ( 15, 17 ) forces a piston inside the accumulator back to the desired position. The accumulators ( 31, 33 ) can also be used to maintain constant pressure in the feed stock. Resin can be recycled from the accumulators ( 31, 33 ) into the melt blender ( 11 ).