There are many factors to consider in choosing an industrial grease for a certain application. Speed, load and temperature are the commonly considered factors while others are overlooked. Grease compatibility is one of the things that are often overlooked until problems start happening. Problem with grease compatibility usually happens when an operation changes lubricant brand or supplier.
There are three main components to every industrial grease, the base oil, thickener and additive. There are varying types of these components and incompatibility between different types can result to the properties of the grease being altered. The viscosity or thickness is one example of property that can change due to mixing two different types of grease.
Viscosity describes the grease’s resistance to gradual deformation. It is what stops grease from flowing out of the application point. It is very important property of a grease that dictates its suitability for certain applications. Higher viscosity makes a grease suitable for heavy loading as it prevents the grease from flowing out of the application point from getting squeezed out by the weight. However, thicker grease increases the resistance of moving parts which makes it unsuitable to be used for parts that are needed to move fast. That is why with high speed bearings, lower viscosity greases are used.
Mixing of two incompatible grease can either result to thickening or thinning of the lubricant. If a high load application grease thins out, it can get squeezed out of the application point and result to lubricant starvation which can then result to damaging of the parts. On the other hand, a grease for a high speed application can thicken and hinder the movement of the components which can increases the power required for operation and lead to potential to damages of the components.