System and method for resin transfer moulding

A system for vacuum-assisted resin transfer moulding of composite articles, the system comprising:

• a manifold comprising a body and a plurality of valves, wherein the body of the manifold defines a resin inlet, a plurality of resin outlets and an internal resin chamber therebetween, and wherein each of the plurality of valves is arranged to control flow between the internal resin chamber and a corresponding one of the resin outlets;
• a plurality of valve control mechanisms, each of the plurality of valve control mechanisms being arranged to receive a respective valve control signal and in response operate a corresponding one of the valves of the manifold;
• a controller configured to transmit valve control signals to each of the plurality of valve control mechanisms, the controller configured:
• prior to the start of a first period of a resin transfer process, to close each of the plurality of valves to prevent resin egress via the resin outlets;
• at the start of the first period of the resin transfer process, to open a first of the valves corresponding to a first resin outlet to permit egress of resin via the first resin outlet;
• and
• after the end of the first period of the resin transfer process, open at least another of the valves to permit resin egress via at least another of the resin outlets, subsequent to the first resin outlet;
• and
• at least one capacitive sensor, positioned adjacent to the internal resin chamber along the resin flow path at a predetermined location relative to at least one of the resin outlets for detecting spread of resin within the internal resin chamber, the at least one capacitive sensors being configured to communicate resin spread data to the controller, the resin spread data indicating the detected position of resin relative to the position of the at least one of the resin outlets,
• wherein:
• the controller is configured to delay ingress of resin via the at least another of the resin outlet until the controller determines that a resin front originating from the first resin outlet has at least substantially reached a predetermined position corresponding to the at least another of the resin outlets subsequent to the first resin outlet, and
• the controller is further configured to use the resin spread data to make a determination whether a resin front has at least substantially reached the position of at least one of the resin outlets.

A system for vacuum-assisted resin transfer moulding of composite articles, the system comprising:

• a mould enclosure enclosing a fibre pack;
• an evacuation port located at a periphery of the fibre pack, the evacuation port being coupled to a vacuum pump operable during a resin transfer process to evacuate air from the mould enclosure to establish a negative pressure therein relative to an external pressure external to the mould enclosure;
• a plurality of resin ports distributed across the mould enclosure, the plurality of resin ports being spaced from one another and positioned in a sequence along a resin flow path within the fibre pack;
• a plurality of valves, each of the plurality of valves being arranged configured to control resin ingress into the fibre pack through a respective one of the plurality of resin ports;
• a plurality of valve control mechanisms, each of the plurality of valve control mechanism being configured to receive a respective valve control signal and in response operate a corresponding one of the plurality of valves;
• a controller configured to transmit the valve control signals to each of the plurality of valve control mechanisms, wherein the controller is configured:
• prior to the start of a first period of the resin transfer process, to close each of the plurality of valves to prevent ingress of resin into the fibre pack via the resin ports, and to establish the negative pressure within the mould enclosure;
• at the start of the first period of the resin transfer process, to open a first of the plurality of valves corresponding to a first resin port located at the start of the resin flow path to permit ingress of resin into the fibre pack via the first resin port;
• and
• after the end of the first period of the resin transfer process, to open at least another of the plurality of valves to permit resin ingress into the fibre pack via at least another of the resin ports positioned subsequent to the first resin port in the sequence, resin ingress via the at least another of the subsequent resin ports being in order of the position in the sequence of the at least another of the subsequent resin ports along the resin flow path;
• and
• at least one resin spread detector for detecting spread of resin within the fibre pack, the at least one resin spread detector being configured to communicate resin spread data to the controller, the resin spread data indicating the detected position of resin relative to the position of the at least another of the subsequent resin ports,
• wherein:
• the controller is further configured to delay ingress of resin via the at least another of the subsequent resin ports until the controller determines that a resin front originating from the first resin port in the sequence, and progressing along the resin flow path through the fibre pack during the resin transfer process, has at least substantially reached the position of the at least another of the subsequent resin ports in the sequence,
• the controller is further configured to use the resin spread data to make a determination whether a resin front has at least substantially reached the position of a respective subsequent resin port, and
• the controller is further configured to determine a position of the resin front relative to the at least another of the subsequent resin ports by determining at least one resin spread parameter, the at least one resin spread parameter including at least one of:
• time elapsed relative to the start of the first period of the resin transfer process, resin flow rate, fibre volume between adjacent resin ports, and fibre density.