Introduction To The Different Types of Greases
Greases are mostly used as a lubricant for moving objects to reduce friction, or to repel unwanted fluids to avoid rust. In this article, we will go through the basic fundamentals of most greases.
What is grease made of?
Both industrial and household greases usually consist of three main substances; Base oil, which make up at least 70% of the grease, a thickener that will make the grease more solid and into a semi-fluid, and lastly, an additive for specific properties such as low oxidation or even anti-rust.
Types of greases
Silicone grease – The most common type of industrial grease is usually silicone based, this means the base oil is a type of silicone fluid mixed with thickeners and additives. A big advantage of using silicone grease is the fact that it’s not oil-based, and therefore be used together with more sensitive materials such as rubber and plastics. Furthermore, silicone in general can handle very high temperatures and often considered a more cost-effective option when it comes to greases.
PFPE Grease – This is the most high-end grease there is on the market, with a fluoroether-based chemical formula, it is 100% inert and often used in aerospace and aviation applications. The grease is usually thickened with PTFE, and that is why many PFPE greases can be named a PTFE grease. It is also extremely durable and will last in extreme humidity as well as high/low temperatures, making it an easy choice for industrial professionals, as well as home-fixers.
Laboratory Grease – For more advanced and specialized applications such as high vacuum and laboratory glass joints, scientists use different types of laboratory grease to properly seal the systems. These greases are usually more expensive, and can just like all other greases; have different base oils. Silicone based laboratory grease are very common due to the non-reactive properties and also its relatively low price tag. However nowadays, laboratories tend to move away from silicone or even hydrocarbon based greases which is used in vacuum systems, because it has a higher chance of contamination as well as lower efficiency, compared to PFPE based greases.
Food-Grade Grease – These greases are commonly made of low-sulfur petrochemicals, and is in direct or indirect contact with foods, often used in food processing facilities, food storages, and food technology facilities. The United States Department of Agriculture (USDA) has three classes of food-grade greases; H1, H2, and H3. H1 greases are the safest and can even come in contact with food, however H2 and H3 are solely used for equipments with zero risk of being in contact with the food.
Water-soluble grease – The different greases previously mentioned, are mostly water-resistant to some degree, however there are greases that are specifically designed to be water-soluble. These greases are often a mixture and can contain silicone, non-reactive chemicals, and even vegetable oil, and used in areas such as hospitals, personal use, and highly sensitive research and experiments.