Effects of friction type and humidity on triboelectrification and triboluminescence among eight kinds of polymers

Triboelectrification and triboluminescence were measured from the sliding or rolling frictional contacts between polymers of PA66, POM, ABS, PET, PP, PVC, PE, and PTFE in various humidity conditions. As compared to the rolling friction, triboluminescence intensity was higher in sliding friction. However, the saturation values of triboelectrification were almost the same in both friction types. The saturation charges of all the sliding couples showed their maxima at the humidity from 10 to 30%. It is attributed to the humidity effect; it enhanced charge transfer which resulted in the increase or decrease of electrification. ► Triboelectrification and triboluminescence were simultaneously measured. ► Effects of friction type and humidity were compared for polymer combinations. ► Saturation charge was the same in rolling and sliding contacts. ► Photon emission was larger from sliding than from rolling. ► Humidity effects were explained by ions from water.