Evaluation of the Fire-retardancy of ULTEM 9085 Polymer Composites Processed by Fused Deposition Modelling

In the paper, the results obtained for the fire-retardancy of ULTEM 9085 polymer composites manufactured by the fused deposition modelling (FDM) are summarized. The effects of processing parameters of FDM such as the percentage of infill, thickness of the sample, and the number of the solid layers on either side were experimentally evaluated against fire-retardancy parameters (burn length and heat release rate). Based on the results, all test samples of ULTEM 9085 were observed to have passed the test requirements specified in Federal Aviation Regulation (FAR) & EASA Certification Specifications (CS) Part 25 of Airworthiness standards for the aviation sector. The maximal burn length (approx. 80 mm) was registered for 30 % infill samples with zero solid layers on either side. Based on the results obtained it was concluded that the burn length was almost the same in all build directions. Moreover, inconsistent results were obtained for the heat release rate as a function of the thickness of the sample for different build directions. Though, certain clear effects were obtained regarding burn length as a function of infill percentage proving that fire-retardancy is the most effective at higher infill percentages.