There are a wide variety of grease additives, similar to those used in fluid lubricants, that effectively boost the performance of a specific grease. Most grease networks are three-dimensional, which makes it possible for the additive molecules to become physically trapped.
Bulk vs. Surface Grease Additives
The main grease additives can be divided into two different categories, those that work in the bulk of the grease and those that work on the surface of the metal
Additives that work in the bulk of the grease include antioxidants and scavengers. Antioxidants effectively extend the life of lubricants by preventing oxidation. This minimizes deposits, sludging, and the thickening of the base oil. Scavengers react with undesirable contaminants, such as sulfur or acids to reduce risk.
Additives that work on the surface include anti-wear agents, corrosion inhibitors, extreme pressure agents, friction modifiers, metal deactivators, and seal swell agents. Anti-wear agents prevent wear under low-load, high-speed operating conditions.
Corrosion inhibitors prevent the corrosion of metals that come in contact with the lubricants. This protects equipment and extends the life of the lubricant.
Extreme pressure agents, often referred to as EP agents, prevent seizure under high temperatures and high loads. Friction modifiers lessen the friction between moving parts through surface adsorption. Metal deactivators prevent the metal from catalyzing the oxidation of the lubricant. Seal swell agents help elastomer seals and gaskets do their job.
Grease additives play a major role in the regular use of grease. They enhance existing desirable properties, suppress existing undesirable properties, and impart new properties.
