DANA POINT, Calif. — Lubricating grease manufacturing is an energy-intensive, multi-phase effort, beginning with a tricky saponification step in a heated reactor, or “kettle,” then blending base oil and additives into the resultant hot soap, and finally moving to homogenizers or mills to temper the grease into a glossy dispersion. Attendees of the NLGI International’s Annual Meeting here in early November got a glimpse into a new grease technology which has the potential, its creator hopes, to make grease manufacturing as easy as other lubricant blending. If so, one of the major barriers to competing in the grease market — the need to invest heavily in specialized equipment — could begin to tumble.
The “overbased metals technology,” James Reddy of OM Group told Lube Report, eliminates the difficult “cooking step” that must be done in reactor vessels to make traditional soap-based lubricating greases. The components merely need to be stirred and heated in a normal blending tank for about a half-hour, then are ready for the addition of base oil and a few additives. No milling is needed afterward, either.
The most widely used greases worldwide are based on metal soaps, especially lithium soaps, but the OMG technology is a non-soap grease with the translucent appearance of a gel, Reddy explained. “It means you can make grease without the mess, with no cooking,” he said. Small batch sizes are also feasible in a blending tank, versus reactor kettles that lose efficiency unless fully charged.
OMG’s patented process reacts lime, oil and acid to create an overbased calcium oleate/carbonate liquid base that is mixed with water and acid, then heated and stirred for about 30 minutes, forming a crystalline gel (actually an inverse emulsion). This non-soap base can then be blended with antioxidants, base oils and tackifiers to boost its performance. Depending on the base oil and other components, the overbased calcium oleate grease could even be biodegradable or synthetic. And if made with an FDA white oil and other approved additives, the grease can receive H1 food-grade registration from NSF.
Reddy, global product manager with OM Group in Westlake, Ohio, said his company will not itself make the grease; he was at the NLGI meeting to seek downstream partners to evaluate the technology, then help them to create products and commercialize them.
Dr. Antonio De Vera is OMG’s product development scientist and led the grease development project for the past year. In a company statement, he noted that the OMG chemistry forms a microemulsion that holds the oil in a micelle matrix.” This matrix, the grease’s “backbone,” is “exceedingly efficient in holding and delivering oil when and where needed in critical applications and under challenging conditions.
Tests with pilot batches show the emulsion grease can deliver excellent performance, stressed Reddy, with good antiwear, extreme pressure and low-temperature pumpability, and, with the addition of tackifiers, resistance to water wash-out.
Reddy said OMG expects that, given the lower projected manufacturing costs, the price for the finished grease would be lower than that of lithium complex greases. The trick, he acknowledged, would be to ensure the product can hold on to grease’s premium pricing — one reason the company wants to focus on niche specialties such as food-grade, synthetic and biodegradable applications.
OMG, which supplies the lubricant and fuels industry with tackifiers, EP and antiwear additives, and other metal carboxylate additives, is undertaking to develop other spin-offs of the technology as well. Having created a liquid version of the grease base material, it is undertaking to make a powder version for ease of transport and handling; it could be blended directly into base oil to form the grease emulsion. Reddy also suggested the overbased calcium oleate chemistry has potential as a lube additive, to give lubricity, detergency and higher TBN to engine oils.