Analysis of thermoplastic polyurethanes properties in the 3D printing process.
Additive manufacturing (AM) has evolved a lot with technological advances. One of the main methods of processing polymers using additive manufacturing is extrusion deposition, also known as 3D printing via fused filament manufacturing (FFF), one of the most widely used commercial 3D printing methods. This master's project aims to analyze the influence of the properties of different thermoplastic polyurethanes (TPU's) in the 3D printing process via extrusion deposition and to analyze how the modification of process parameters can influence the quality of the printed parts manufactured with these different materials. The comparison will be made between two commercial TPU's called TPU 575 and TPU 690, using a commercial 3D TPU as a reference for printing. The materials were characterized using Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA) and also in rheological analyzes such as Melt flow Index (MFI) and Capillary Rheometry. Subsequently the TPU 575 and TPU 690 were processed in a single screw extruder to obtain the filament needed for 3D printing. The results obtained so far allow us to infer that there will may be a great influence of the temperature and also of the shear rate in the printing process and consequently in the quality of the printed parts. In this way, 3 printing parameters, that can change the shear and temperature conditions during 3D printing, were chosen: the printing temperature, the diameter of the extrusion nozzle and also the height of the printed layer. The analysis of the mechanical properties and the surface aspect of the parts will be done through the tensile tests and confocal or optical microscopy.