Tribological behavior of polyacetal composite lubricated in sodium hypochlorite solution

Sodium hypochlorite (NaClO) solution is the most widely used disinfectant in the food industry. If NaClO solution can be used as a lubricant, the maintenance cost is reduced and the food safety is warrantied. Hypothetically, the concentration of the available chlorine in the solution affects the tribological behaviors. In this study, we investigated the tribological behavior of a composite of polyacetal (POM) resin and rice bran ceramics (RBC) in a lubricating solution of NaClO with two concentrations. The mean friction coefficient was higher in NaClO solution with 25 mg/L available chlorine than in purified water and in NaClO with 2500 mg/L available chlorine. The wear resistance of the composite was also degraded in the presence of 25 mg/L available chlorine. From the investigations of the tribological behavior of an RBC disk, the wear in the lower available chlorine was considered to be affected by degradation of the carbon parts. Although we should improve the tribological properties in the presence of 25 mg/L available chlorine, the POM/RBC composite had a sufficient potential to use in NaClO solution as a tribomaterial.