Influence of 3D Printed Surface Texturing on the Tribocharging Process of Polymer Slabs in Conformal Contact

Polymers are frequently used as contact materials in industrial applications that exploit the triboelectric effect. The aim of this paper is to investigate, with the help of 3D printing manufacturing technologies, how tribocharging of polymers is affected by their surface morphology. The experiments were performed using a linear tribometer to create the electric charge through friction between two samples. To highlight the correlation of surface texture with the level of triboelectric charge, the Polylactic acid (PLA) samples were manufactured with three different surface geometries, referred to as “lines”, “zigzag” and “waves”. The first series of experiments consisted in charging the surface of the PLA samples with the tribocharging bench for 20 and 40 cycles, with an Aluminum bar. The cartography of the electric potential at the surface was then performed, using a 2D mapping system to entrain the capacitive probe of an electrostatic voltmeter. In the second series of experiments, after tribocharging, the PLA samples were placed under the probe of the electrostatic voltmeter for 10 min to determine the surface potential decay (SPD) curve. The range of surface potential values was smaller for the “lines”-textured samples than for the other two, pointing out that the geometry of the texture significantly influences the outcome of the triboelectric charging. When comparing the SPD curves of the three textures for 20 cycles, it can be noted that ones for PLA with “lines” and “zigzags” are almost the same, but different from those of “waves”-type samples.