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

Abstract

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.

Effect of Post-Printing Cooling Conditions on the Properties of ULTEM Printed Parts

“…The test samples were printed using a Stratasys F900 machine (Eden Prairie, MN, USA) in directions X, Y, and Z, as reported in ref. [ 2 ] and shown in Figure 1 .…”

“…AM offers unprecedented levels of freedom for the design and application of 3D-printed polymer materials, e.g., in automotive, aerospace, biomedical, and dentistry fields [ 1 ]. Currently, fused deposition modeling (FDM) is one of the AM technologies that has been extensively applied in the manufacture of 3D-printed polymer parts [ 2 , 3 ]. During this process, a polymer is extruded through a heated nozzle and deposited in a semi-molten state to create the required shape via sequential build-up of layered depositions [ 4 ].…”

“…One of the main disadvantages of FDM-processed polymeric parts is their highly anisotropic nature due to the intrinsic properties of the extruded filament, oriented build process, and limited degree of fusion between the layers [ 5 , 6 ]. These issues lead to anisotropy in the mechanical and thermophysical properties of 3D-printed polymer parts, especially in the direction perpendicular to the construction layer (XZ) [ 2 , 4 , 5 , 6 , 7 ]. Furthermore, due to voids and porosity that are inherent to the FDM printing process, polymer samples manufactured by FDM typically have lower mechanical strength and possess lower apparent mechanical properties compared to parts manufactured using traditional processing techniques, such as compression and injection moldings [ 8 ].…”

“…Furthermore, it is well known that the properties of 3D-printed parts processed by FDM strongly depend on the building process parameters (e.g., infill percentage, build and raster orientation, layer thickness and width, feed rate, printing speed, nozzle diameter, etc.). The effect of the building process parameters on the mechanical (tensile, flexural, impact) [ 9 , 10 , 11 , 12 , 13 , 14 , 15 ], flame-retardant [ 2 , 12 ], and thermal properties [ 16 , 17 ] of 3D-printed parts has been thoroughly discussed in the literature.…”

The Tensile, Thermal and Flame-Retardant Properties of Polyetherimide and Polyetherketoneketone Processed via Fused Filament Fabrication

“…This is primarily attributed to the inherent properties of the extruded filaments (traxels), the layer-oriented construction method, and the limited degree of fusion between individual layers [4,19]. These issues result in anisotropy in the flame-retardant [12,20], mechanical (including fatigue) [4,10,13,[21][22][23] and thermophysical [4,11,21,24,25] characteristics of 3Dprinted polymer parts, particularly in the direction perpendicular to the layering process (XZ). Moreover, because of voids and porosity inherent to the FFF printing process, polymer samples fabricated using FFF typically exhibit reduced mechanical strength and possess inferior overall mechanical properties when compared to components produced using conventional manufacturing methods like compression and injection moulding.…”