the grease monkey life
Grease is king, at least to us. We sell all sorts of lubricants, from super-high-tech and specialized to super-basic low-tech lubes, and everything in between. Grease is still our jam.
Grease is a solid or semisolid lubricant. Most greases are oils mixed with thickeners (like soaps). Other thickeners include clays, tar, graphite, mica, lithium stearate, fatty acid derivatives.
Soaps help with temperature resistance, water resistance, and stability of the grease itself. There's simple soaps (most common worldwide), mixed soaps (not very common), and complex soaps (very common in North America due to high-temperature properties).
Base oils of greases consist of mineral oils (paraffinic and naphthenic), synthetics (PAO, ester, PAG, and alkylbenzenes), naturals (vegetable oils), and high performance (silicones and fluorinated fluids).
Grease has a viscosity. This viscosity changes during shearing. As the shearing occurs the viscosity can drop almost to the viscosity of the base oils used to make the grease. Thixotropics come into play with shearing, where the grease thins during shearing and becomes more viscous when the shearing stops - of course depending on the grease and the application this is more or less evident.
Most greases are consistency-rated via the NLGI system (National Lubricating Grease Institute). For instance, from NLGI 000 with a fluid appearance (consistency of cooking oil) all the way to NLGI 6 with a very hard appearance (consistency of cheddar cheese).
Other grease types include calcium complex, lithium complex, aluminum complex, polyurea, clay/bentonitefluoroether based, laboratory grease, silicone grease, and food grade grease.
Greases have additives as well:
· Antioxidants to retard oxidation for longer life.
· Rust inhibitors to prevent rusting/corrosion of ferrous materials.
· Antiwear additives for wear protection.
· Extreme pressure additives for high load and shock load.
· Tackifiers and polymers for water resistance and metal adhesiveness.
· Molybdenum disulfide/graphite for protection and friction reduction under high loads/sliding conditions at low speeds.