EXTRUSION OF HIGH-PERFORMANCE POLYETHERIMIDE PIPE SYSTEMS FOR AIRCRAFTS

摘要

In the aviation industry high-performance thermoplastics are challenging metals in many fields. Inrnthis paper a pipe-extrusion process for high-temperature polyetherimide (PEI) andrnpolyetheretherketone (PEEK) is presented. Both the weight advantage over stainless steel pipesrnand the price advantage over titanium confirm the huge potential of thermoplastic pipe systems inrnthe aviation sector. In these studies extensive material tests were conducted on different types ofrnPEI to fulfil the high standards of aircraft. The media resistance and especially the reactions withrnhydraulic fluids turn out to be the most challenging requirements.rnVarious parameter studies were carried out and led to considerable improvements in processing atrnhigh temperatures in the extrusion process. It transpired that small changes in the processrnparameters and environmental influences are the greatest obstacles to error-free production.rnAdjustments to the thermal management of the calibration system significantly improved thernrobustness of the process to the extent that PEI-pipes of different wall thickness were ultimatelyrnproduced in reproducible quality. Therefore the nozzle-area was analysed using thermal imagingrnto generate input parameters for complex analytical calculations of the temperature-zones duringrncalibration.