Abstract: Bevel Gear Grease Case study continued – Mechanisms revealed
The most important difference between a lubricating grease and a liquid lubricant is the thickener. This gives the grease its structure and properties. The thickener is responsible for the non-Newtonian behavior and characteristics of the lubricating grease. Since Clarence E. Earle first filed for a US patent in 1940 for the use of lithium soaps as lubricating grease thickeners, lithium thickeners still dominate the market, with 69.1 wt% of the market. 2013 was the peak production for lithium greases, with 76.6 wt% of the market and a global production volume of 905,300 MT.
In 2016, the price of lithium hydroxide soared from its 2015 cost. At the 2016 NLGI Annual Meeting, coffee break chatter was mostly doom and gloom. In the 2017 to 2020 timeframe, the supply pressure eased, with an increase in supply and easing in demand caused by Covid-19. As the economies of the world got back on their feet, demand for electric vehicles soared exponentially as did the price of lithium. As reported earlier this year, the price of lithium went through the roof with prices hitting more than US$90 per kg ($40 per pound) in December 2022, with significant shortages and supply issues.
This paper will review the proposals from 2017 in how to reduce the dependency on lithium thickeners for both commodity and premium grease markets and offer some revised thoughts on how to move forward.