NCC and Surface Generation partner to demonstrate thermoplastic overmolding capabilities

The National Composites Centre (NCC, Bristol, UK) is currently supporting Surface Generation Ltd. (Rutland, UK) in the application of their PtFS technology with a thermoplastic composites injection overmolding process. The two companies have worked together to produce a number of carbon fiber reinforced / PA6 automotive demonstrators which are due to be assessed by an automotive OEM. Each manufactured component weighs 1.2 kg and comprises four continuous carbon fiber reinforced / PA6 composite inserts overmolded with short carbon fiber PA6. 

“PtFS technology provides a variety of benefits for injection molding,” says Sean Cooper, principal research engineer for High Volume Manufacturing at the NCC. 

Cooper explains:

“The ability to keep the average tool temperature higher than usual during the injection phase of the process can reduce the clamping force and injection pressures required for mold filling. The zonal temperature control is exploited to ensure an optimum joint is achieved between the inserts and the overmolding material. Enhanced thermal control also facilitates manufacturing for variable thickness injection moldings. I am very pleased that the first commercial research activity in composites overmolding performed here at the NCC, has been supporting Surface Generation in demonstrating the value of their tooling technology. Our work with Surface Generation is exactly what the NCC was set-up to achieve – providing the technology, the technical skills and the innovation environment companies need to accelerate their composites R&D.” 

Alasdair Ryder, special projects engineer at Surface Generation adds, “The NCC’s equipment capability and the proactive support from the High Volume Manufacturing (HVM) team have contributed towards a successful manufacturing campaign. We look forward to returning in 2019 for the manufacture of opposite handed parts as we demonstrate further improvements to our process capability and stability.”

The NCC’s overmolding equipment and the related facility cost was funded by the Aerospace Technology Institute (ATI,Cranfield, Bedfordshire, UK) and West of England Combined Authority (WECA, Bristol, UK). The NCC overmolding cell supplied by Engel (Schwertberg, Austria) features a horizontal 1700T press, injection barrel temperatures/pressures up to 420°C and 2000 bar with a shot volume up to 6400 cm³. In addition to the acquisition of the overmolding cell, the NCC have also invested £690k of its High Value Manufacturing Catapult (HVM Catapult) funding into a capability development project to further apply fundamental research across design, simulation, structural-analysis, manufacturing and physical/mechanical testing of high performance overmolded structures.