Evaluation of tribological performances of palm oil-blended food grade lubrication / Wan Zulhilmi Wan Suhaidi ... [et al.]

Conventional industrial lubricants from mineral oil are recognized for their harmful effects on both humans and the environment. It has driven a worldwide shift to embrace food-grade lubricant due to their biodegradability, favourable viscosity, cost-effectiveness, and wide availability. This study evaluates the tribological performances of blended palm oil, assessing its suitability as an eco-friendly and efficient alternative in the industry. Although there have been numerous studies exploring the tribological performances of vegetable oils, research on the foodgrade lubrication using a blend of palm oil and industrial gear oil still has potential for further improvement and advancement. Therefore, this investigation intends to measure the wear rate and coefficient of friction using the Pin-on-Disc tribometer according ASTM G-99 standard. Using industrial gear oil as the base, 15 different samples with concentrations of 0%, 15%, and 30% palm oil were tested under varying applied loads, ranging from 30N - 60N, and speeds ranging from 600 rpm - 900 rpm. Utilizing the Surftest machine SV600, both samples of S7L3P15 and S7L4P15 indicated the lowest surface roughness (Ra), which is 0.04 µm. Furthermore, the FTIR spectrometer demonstrated the presence of aliphatic hydrocarbons, olefins, and esters in the functional groups of both G70P30 and G85P15 sample oils. Beyond this point, out of 15 samples tested, 12 samples had wear rates under 50 (10-6) mm³/Nm and coefficients of friction below 0.1 in the Pin on Disc test. G70P30 is the optimum biolubricant concentration because it reduces wear rate and friction more than G100P0 and G85P15. In conclusion, the blended palm oil can increase the development of biodegradable and environment-friendly lubricant oil without concerns about downgrading the tribological performances.