Rotational moulding of PEEK polymer liners with carbon fibre/PEEK over tape-placement for space cryogenic fuel tanks

PEEK polymers are investigated as replacement materials for metallic liners in composite overwrapped pressure vessels (COPVs) for fuel tank applications in space. A novel, integrally heated, rotational moulding tool has been developed to produce PEEK polymer liners, samples of which have then been overwrapped using CF/PEEK in a laser assisted tape-placement (LATP) process to produce demonstrator samples of a polymer lined COPV. Helium permeability testing has shown that the designs are capable of resisting leakage to acceptable levels for fuel storage, while X-ray CT scanning and cryogenic cycling have shown that the current design is capable of resisting crack growth over multiple cycles. Nano-indentation testing has shown that the LATP process has created a region of reduced modulus in the PEEK polymer at the surface of the liner where the CF/PEEK has been tape-laid. This laser-affected zone of reduced polymer modulus in the composite interface region has enabled an enhanced resistance to crack growth formations from thermal residual stresses in comparison to hot plate moulded test samples. (C) 2017 Elsevier Ltd. All rights reserved.The authors would like to thank the Irish Research Council (IRC) (EPSPG/2011/66) and the European Space Agency (ESA) (B00015002) for joint funding of this research under the Network Partnering Initiative (NPI) and Innovation Triangle Initiative (ITI). They would also like to acknowledge the specific help and technical support provided by Michael Flanagan of NUI Galway, Derrick Doyle and Fintan Doyle of ÉireComposites Teo, and Dr. Terry McGrail and David Jones of the Irish Centre for Composites Research (ICOMP). A final thanks to Prof. Peter McHugh and Dr. Reyhaneh Neghabat Shirazi of NUI Galway for use and training with the nano-indentation testing equipment

Rotational moulding of PEEK polymer liners with carbon fibre/PEEK over tape-placement for space cryogenic fuel tanks

PEEK polymers are investigated as replacement materials for metallic liners in composite overwrapped pressure vessels (COPVs) for fuel tank applications in space. A novel, integrally heated, rotational moulding tool has been developed to produce PEEK polymer liners, samples of which have then been overwrapped using CF/PEEK in a laser assisted tape-placement (LATP) process to produce demonstrator samples of a polymer lined COPV. Helium permeability testing has shown that the designs are capable of resisting leakage to acceptable levels for fuel storage, while X-ray CT scanning and cryogenic cycling have shown that the current design is capable of resisting crack growth over multiple cycles. Nano-indentation testing has shown that the LATP process has created a region of reduced modulus in the PEEK polymer at the surface of the liner where the CF/PEEK has been tape-laid. This laser-affected zone of reduced polymer modulus in the composite interface region has enabled an enhanced resistance to crack growth formations from thermal residual stresses in comparison to hot plate moulded test samples. (C) 2017 Elsevier Ltd. All rights reserved.The authors would like to thank the Irish Research Council (IRC) (EPSPG/2011/66) and the European Space Agency (ESA) (B00015002) for joint funding of this research under the Network Partnering Initiative (NPI) and Innovation Triangle Initiative (ITI). They would also like to acknowledge the specific help and technical support provided by Michael Flanagan of NUI Galway, Derrick Doyle and Fintan Doyle of ÉireComposites Teo, and Dr. Terry McGrail and David Jones of the Irish Centre for Composites Research (ICOMP). A final thanks to Prof. Peter McHugh and Dr. Reyhaneh Neghabat Shirazi of NUI Galway for use and training with the nano-indentation testing equipment.peer-reviewe