Polyurea Grease

Long life high temperature low/zero ash grease that is popular in pre-lubricated bearings.  Newer di-urea greases better than tetra-urea predecessors

The key advantages include:

  • Does not melt until over 260°C
  • Di-urea version is shear-stable over a long period of time making it ideal for lubricated-for-life applications
  • As there are no metals or minerals involved, it is almost completely ashless, making it a good choice in total-loss high temperature applications
  • Low specific gravity in combination with good metal adhesion means it does not readily fling off high speed rotating parts

Limitations:

  • Tetra-urea version incompatible with many other types of grease, often setting solid
  • Manufacturing from basic raw materials involves the production of toxic levels of isocyanide gas, so unless there is a special reason to do so, it is better to manufacture from polyurea powder

Manufacturing Principle (Polyurea powder version):

Heat powder and oil together to just over 200°C, then cool and mill or homogenise.  Milling/Homogenising is very important with this grease type.

Recommended Process Vessel (Polyurea powder version):

  • Heated and cooled grease kettle, no pressure needed