2.3. Fused Filament Fabrication Procedure

Both LCPs were processed via FFF using an E3D Toolchanger motion system from E3D-Online, Chalgrove, United Kingdom, possessing several component adaptions. The utilized high-temperature hot-end for FFF was from Slice Engineering, Gainesville, FL, USA, and allowed printing temperatures of up to 500 °C with a 0.4 mm diameter titanium nozzle. The layer height varied between 0.10 and 0.20 mm, the printing speed varied between 25 and 45 mm/s and the nozzle temperature varied between 300 and 440 °C. The utilized LCP filaments exhibited a diameter of around 1.75 mm. The LCP-H exhibited a certain diameter irregularity due to mass fluctuations that appeared during the filament production with a single-crew extruder from Collin Lab & Pilot Solutions GmbH, Maitenbeth, Germany. The mass fluctuations were primarily caused by a poor trickling behavior of the powdery LCP-H from the hopper and could be avoided in future work using a melt pump, for instance. On the contrary, the LCP-L filament had a very uniform diameter. G-codes for the path planning at FFF were created with the slicer software ideaMaker 4.1.1 from Raise 3D Technologies, Inc., Irvine, CA, USA. The tensile test samples were printed with two different path planning strategies, namely 0° and 90°. Here, 0° means that the printing lines were deposited parallel to the tensile direction and 90° means that the printing lines are perpendicular to the tensile direction. The 90° direction was chosen to quantify the adhesion between different layers, whereas the 0° direction should result in the highest mechanical properties since the orientation of LCP molecules is expected to be parallel to the tensile direction in this case. The build platform temperature was set to 120 °C and a bonding agent was used to improve the adhesion of the printed samples on the build platform.