High Performance Greases

The most common and predominant grease in industrial application is lithium soap based with EP additive depending upon the application the NLGI consistency requirement. Of late newer grease technology has been developed and complex soap type, stearates , sulfonates and other environment friendly and special application types greases produced and accepted.


Some of them are explained below




To get away from the temperature and high speed limitations of calcium greases, anhydrous greases were developed – aluminum and sodium base.


They are generally formed by reacting a common base with two dissimilar organic acid compounds, such as a normal soap base and complexing agents, generally of short chain metallic or organic materials and made “in situ” (in place) in the grease kettle. This makes greases to meet more demanding requirements.


In the 1930s and 1940s, researchers started to find new thickeners for “multipurpose” greases. Calcium complex greases were the first, followed shortly after by the lithium and barium greases. The barium greases never achieved the popularity of the lithium greases. They are heat and water resistant, but have some inherent low temperature problems and toxicological reservations.


Calcium complex greases became commercially available in the late 1940s. In recent years, this grease’s share of the market has been failing. While they offer both water and heat resistance, they can be sensitive to water-becoming firmer or softer under different conditions-and, if overheated, they tend to harden. They do, however, carry high loads in operating bearings without the addition of extreme pres-sure (EP) additives.


Complex soap-based greases were developed to improve the heat resistance of previous simple soap based greases. Combinations of additives and oils are carefully selected to maximize the performance of the greases. They generally have good mechanical stability, low temperature pumpability-some will even have good reversibility characteristics and will operate at temperatures which are moderately high. Their dropping point may be 100°F. to 200°F. (38°C. to 93°C.) higher than the dropping point of corresponding soap greases.




Only two of the non-soap thickened greases are significant-clay and ureas.


Clay-A form of bentonite (clay-like) materials consisting of hydrous aluminum silicate, which is of very fine grain size and capable of absorbing large amounts of fluid, and has excellent plasticity. The clay is treated, making it very resistant to heat and adequately resistant to water. These are the nonmelt base materials.


Ureas -Also known as polyureas, they are made with ashless organic thickeners. These greases have a natural resistance to oxidation. Most polyurea greases are developed for a single specific application. Because of peculiar shear and rust preventive characteristics, they historically were not considered general application, multipurpose greases. However, recently new products are on the market with these claims.


Other Metal Grease


Aluminum-These greases, which are also known as aluminum stearates, are very water resistant and fairly rust resistant. However, their heat resistance (i.e. low dropping point) is no better than the calcium. They also possess a low shear stability and have gel-forming tendencies. Little of this type of grease~ has been produced and marketed for the past 30 years.