Effect of Temperature on Conductivity of PLA-Carbon 3D Printed Components.

There is continued growth in 3D print technology utilising thermoplastic materials that include polylactic acid (PLA) to print components of systems. The electrical properties of 3D printed thermoplastic components are critical because the product’s conductivity is temperature dependent owing to the kinetics of breakage and reformation of their aggregated structure. This knowledge drives research to make 3D printed components more functional in terms of their electrical properties in addition to their mechanical properties. This research studies the effect of temperature on the conductivity of 3D printed components. The range of temperature T considered is 22 ˚C≤T≤55˚C . A conductive 3D print filament made of PLA and filled with 4% carbon black is printed using Fused Deposition Modelling (FDM). The layer height and infill ratio are varied while the material resistivity ρ is measured as a function of temperature change. The measured magnitudes of resistivity lies in the range of 29.38 Ω≤ρ≤6750 Ω. The ρ is found to be a parabolic function of T – depicting an increase to a maximum and subsequent decrease. The parabolic nature of the ρ function is most visible in sample 1 which demonstrates an absolute change in ρ of 26%. The sample consisting of 50% infill ratio and 0.2 mm layer thickness (STDev 0.446) demonstrates least response to variations in temperature with the range investigated. This investigation reports on the significance of processing variables of FDM on the thermal sensitivity of conductive 3D printed Components.