From gearboxes and gear wheels to bearings and chain systems, grease has many different applications. Like oil lubricants, it can seal parts, protecting them from water and corrosion while reducing unwanted friction. However, unlike oils that flow freely, lubricating grease is far more viscous, meaning it can stay in place.
Composition of grease
Grease lubricants are typically around 80 to 90 percent base oil, with the oil selected for the product impacting its performance. While some greases use a mineral base oil, others are manufactured with synthetic oils instead to infuse the lubricant with exceptional abilities, which a natural oil can’t supply. Synthetic oils can help grease deliver enhanced electrical properties, improved chemical resistance or allow it to operate effectively at a wide range of temperatures.
A key ingredient of any grease is a thickening agent, which is designed to hold the included oil in place. This thickener gives the grease increased water resistance, stability, sealing ability and a more robust melting point.
Finally, the third inclusion of any grease is the dedicated additive package. This specially formulated selection of additives will enhance the overall performance of the grease, can increase its resistance against oxidation, enable it to reduce friction more efficiently and help it provide protection against rust and other forms of corrosion.
Staying in place
For grease to be efficient, it must provide adequate levels of lubrication so that abrasion and friction are reduced, and, just like oil, to defend against potential corrosives. Grease can offer unique benefits over oils, however. Grease can create a protective seal that ensures water, dirt and unwanted contaminants stay out of lubrication points. Much thicker than oil, grease will stay where it has been applied, making it ideal for roller, slide and ball bearings, open gear wheels and gear boxes.
Selecting between grease and oil
Due to its consistency, grease will stay in place within a given lubrication point, has the ability to seal, provides excellent protection against corrosion and can handle heavy loads. Despite these qualities, grease does have its own limitations.
In comparison to oils, greases are not able to conduct heat, taking it away from parts of machinery that need to cool, like engines. Additionally, grease cannot be filtered, while oil can be refined to increase its purity. While oil and water can be easily separated, this can be an exceptionally difficult process with grease.
Choosing the right type of grease
Finally, every different application will place specific demands on the grease used. Sector-specific applications may require particular considerations – for example, greases used in mechanical processes in the food industry must always be food safe, in case they come into contact with products being manufactured.
When selecting the right grease for an application, it’s crucial to consider all factors involved, from the dirt, water and chemicals it will need to cope with to the temperatures it will be subjected to. Viscosity of the grease’s base oil is also key, with a low-viscosity option working best at low temperatures, and a high-viscosity base oil suiting a higher temperature.