olyurea Grease Definition
Polyurea greases are becoming an interesting alternative to more conventional soap-based products as demand. increase to be able to tailor different physical and chemical properties towards specific applications. Polyurea greases are almost always chosen because of their high temperature properties. The invention and development of polyurea thickened greases is one the most important advances in grease technology since the end of the Second World War. The technology was developed in Japan where it is still an impressive 21% of their grease market. These ashless non-soap greases are generated by the step-growth polymerisation reaction of different isocyanates and amines in various mineral or synthetic base oils. These polyurea thickened greases tend to have high temperature performance, inherent anti oxidative properties and can exhibit either high shear stability or thixotropic behaviours. These properties have recently made them the preferred choice for filled-for-life applications in both bearings and constant velocity joints and have increased their importance in steel plants and electric motors. However, their positioning as multipurpose greases has been limited by the high safety required with the storage and handling of their toxic raw materials and difficulty in their manufacture and packaging.
Polyurea Grease Applications
- Used in agricultural equipment.
- Used in steel plants and electric motors.
- Electric motor bearings especially high output (horsepower), high load electric motors.
- Unsealed electric motor bearings operating under moist conditions.
- Fin fan bearings.
- High-temperature pump bearings.
- Sealed-for-life bearings.
- Antifriction bearings operating at high speeds (10,000 rpm and greater).
- Automotive wheel bearings, chassis parts and underhood applications such as alternators, air conditioner compressor clutch bearings, water pumps and idler pulleys.
- Ball or roller bearings operating at high temperatures where low oil separation is required.
- Constant velocity joints.
- Agitator bearings in washing machines.
- Bearing applications requiring a high-temperature, extreme pressure, long life grease.
- Applications where low noise operations are beneficial or required.
- high operating temperatures.
- inherent antioxidative.
- high thermal stability.
- low bleed.
- dropping point approximately 270 C.
- extremely robust.
- very good water resistance.
- good mechanical stability.
- high-shear stability.