Contact electrification between polymers and steel

• Contact electrification charge increases with contact load and nominal area.
• Contact stress is the key factor that determines the charge density.
• A linear relationship between charge density and contact stress is proposed.

Electrification occurs when metals are put into contact with polymers, and the mechanism is still not fully understood. In this paper, experimental study of contact electrification between a metal and polymers was conducted. Effects of contact cycle, load, and nominal area on electrification were investigated. Results showed that electrification charge increased with real contact area. However, experimental results showed that charge density increased with nominal area and decreased with load. The key factor that determined the charge density was contact stress. Charge density decreased with contact stress linearly. A quantitative relationship between charge density and contact stress was proposed.