Published 1/5/2022

NCC sensor technology unlocks digital potential for liquid resin processes

Research and testing of dielectric sensors performed by the NCC, Meggitt and Cranfield University accurately captures resin infusion data, shows promise for composites manufacturing.

Edited by: Grace Nehls

Senior Managing Editor, CompositesWorld

Initial research into dielectric sensors, which originated at Cranfield University led by Dr. Alex Skordos, Reader in Composites Process Science at the School of Aerospace, Transport and Manufacturing, was further developed at the composites research center through the NCC’s Technology Pull-Through (TPT) program — which partners with universities to evaluate and mature their low-TRL research ready for industry adoption —and then applied in industry by Meggitt.

The sensor system, a step toward the digitalization of resin transfer molding (RTM), provides accurate data capture of resin infusion. The NCC says this can be used to validate computer simulations of the process, enabling industry to reduce the number of initial experimental trials and facilitate a “right first time” approach, crucially reducing the time and cost spent manufacturing components.

Sensor trials, conducted at typical aerospace material processing conditions of 7 Bar and 180°C, showed the sensors could precisely detect resin as it flowed inside the preform, as well as its cure progression — both of which are invisible as the process occurs. Furthermore, the sensors provided no adverse effects on either the process or part quality.

Hearing of the trials’ success, Meggitt approached the NCC for use of the sensor technology in an ATI-funded project the company was conducting with the NCC’s fellow High Value Manufacturing Catapult center, the University of Sheffield Advanced Manufacturing Research Centre (AMRC, Rotherham, U.K.), producing industrial-scale aircraft components.

“We were interested in applying this sensor technology as a way of building in a smart function to the RTM process for monitoring part production,” notes Dr. Peter Karapapas, principal engineer at Meggitt. “This is with the aim of minimizing the time and effort required in post-production NDT [non-destructive testing] and inspection on future components as we move towards digital manufacturing. The sensors were robust and effective during the demonstration on the large-scale composite housing part designed for a civil aviation jet engine air-oil heat exchanger.”

The NCC team worked alongside the AMRC and Meggitt to successfully integrate the sensors into a closed RTM tool, with no modifications to the tool being required. In trials, the sensors successfully captured data on the resin flow progression and degree of cure, agreeing with results from previous reports and theoretical models.

“A large part of the NCC’s role within the composites industry is to enable the transition of technologies from academic research to being ready for industry to use and benefit from. This project is an excellent example of this, with it being developed in our Technology Pull-Through program, and now being used by Meggitt,” concludes Dr. Enrique Garcia, CTO at the NCC.