Non-Destructive Porosity Measurements of 3D Printed Polymer by Terahertz Time-Domain Spectroscopy

Featured Application Non-destructive porosity measurements of 3D printed materials by terahertz time-domain spectroscopy. The porosity and inhomogeneity of 3D printed polymer samples were examined using terahertz time-domain spectroscopy, and the effects of 3D printer settings were analysed. A set of PETG samples were 3D printed by systematically varying the printer parameters, including layer thickness, nozzle diameter, filament (line) thickness, extrusion, and printing pattern. Their effective refractive indices and loss coefficients were measured and compared with those of solid PETG. Porosity was calculated from the refractive index. A diffraction feature was observed in the loss spectrum of all 3D printed samples and was used as an indication of inhomogeneity. A sweet spot of printer settings was found, where porosity and inhomogeneity were minimised.

Automated summary

This study examines the porosity and inhomogeneity of 3D printed materials using terahertz time-domain spectroscopy and analyzes the effects of 3D printer settings. By systematically varying printer parameters, a sweet spot of printer settings is found where porosity and inhomogeneity are minimized.