Scientists Look to Soy for Metal-Cutting Lubrication

Lubricants in industrial metal cutting typically start with water and petroleum. But there’s a new ingredient in town––soybean oil.

Right now, the job takes buckets of the petroleum-water mix. Two researchers from Missouri University of Science and Technology, Monday Okoronkwo and Anthony Okafor, think they can replace buckets with just a few drops of soybean oil, according to results published in the International Journal of Advanced Manufacturing Technology.

Okoronkwo, professor of chemical engineering, and Okafor, mechanical engineering professor, are leaning on soybean oil’s qualities to improve lubrication. Soybean oil is biodegradable and requires less cleanup than petroleum. A peer-reviewed lifecycle assessment also showed that using soybean oil as a raw material can help lower CO₂ emissions and energy costs during product production. Okafor also projects it will be cheaper and safer for workers.

Okoronkwo and Okafor are testing their new mixture on machines used in automotive, aerospace and medical manufacturing. Once they demonstrate the mixture’s performance, soybean oil lubricants can move directly to industrial applications.

Soy Oil: BioPreferred with Equal Performance

Soybean oil has also demonstrated itself as a noteworthy lubricant ingredient in Fareway Stores, Inc.’s fleet of 81 tractor-trailers and equipment. The soy-based lubricant meets sustainability goals without sacrificing performance or cost.

Fleet management reports grease based in soybean oil is easy to apply and stays on, keeping equipment and grounds cleaner. Its pleasant odor is a plus for workers, too.

Many other companies have also utilized soybean oil in lubricants. Iowa-based Natural Soy Products  manufactures a fifth-wheel grease containing 67% soy oil, displacing the petroleum found in traditional fifth-wheel grease.

According to the company, the average over-the-road semitractor-trailer uses about 20 pounds of fifth-wheel grease per year. The approximately 2 million semis rolling across America’s highways utilize an estimated 40 million pounds of fifth-wheel grease each year. The U.S. Department of Agriculture also recognized this soy-based grease as a qualified product in its BioPreferred program.

Molecular Performance Benefits

It’s not just these organizations that have found soybean oil useful for their products. Countless other products have seen its performance firsthand, and a study funded by the United Soybean Board showed soybean oil’s performance is measurable on a molecular level.

The study showed the triglyceride structure of soybean oil provided many benefits sought out by the industrial sector looks for.

• The high molecular weight of the triglyceride structure of soybean oil showed low volatility of soybean oil base stocks, decreased exhaust emissions and reduced engine sludge.
• A high viscosity index provided high-shear stability and reduced the need for polymeric viscosity index improver additives.
• Ester linkages caused inherent lubricity and the ability to adsorb onto metal surfaces, as well as more engine power and better fuel economy.
• A more soluble product lowered contaminants and polar deposits and required fewer detergent additives.

Outside of the Missouri S&T applied research and molecular structure performance, soybean oil is abundant in supply and provides companies increased sustainability compared with petroleum products. Read more about U.S. soybean oil in lubricants here.