A brief history of Polyurea Greases and their application in Continuous Casters

Polyurea greases have been a significant component in the lubrication industry due to their superior performance characteristics under high temperatures and loads. Here is a brief overview of the history and development of polyurea greases:

1. Initial Development:

Polyurea greases were developed around the 1950s. They were formulated as an alternative to the then commonly used soap-thickened greases, like lithium, calcium, and sodium-based greases, which had limitations regarding stability, temperature resistance, and water resistance.

2. Structural Innovation:

The unique diurea thickener structure in polyurea greases is formed by the reaction between a diamine and a diisocyanate. This distinctive structure contributes to the grease's excellent mechanical and thermal stability, high dropping points, and good oxidative stability, setting polyurea greases apart from traditional soap-thickened greases.

3. Enhancement and Specialization:

Over the years, advancements in technology and a better understanding of polyurea chemistry have led to the development of more specialized and enhanced polyurea greases, catering to specific industrial needs. Modifications in base oils, additives, and thickener structures have enabled the formulation of polyurea greases with improved performance under extreme conditions and challenging environments.

4. Current Applications:

Today, polyurea greases are ubiquitous and are utilized in diverse applications including, but not limited to, electric motors, fans, pumps, automotive components, and various industrial machinery, where they continue to provide reliable lubrication, protection against wear, and extended service life of components.

Polyurea greases are widely used in continuous casters within the steel industry due to their distinctive properties that make them suitable for the extreme conditions and specific requirements of continuous casting processes. Here’s why polyurea greases are preferred in continuous casters:

1. High-Temperature Stability:

Continuous casters operate at high temperatures, and polyurea greases maintain their structural integrity and lubrication efficiency under such conditions, preventing premature breakdown and ensuring consistent lubrication.

2. Excellent Mechanical Stability:

Polyurea greases exhibit excellent shear stability, maintaining their consistency and staying in place under high shear conditions, which is crucial for the reliability of components such as bearings in continuous casters.

3. Good Water Resistance:

The presence of water and steam is common in continuous casters, and polyurea greases resist water washout effectively, maintaining a protective lubrication film on the components and preventing corrosion.

4. Long Service Life:

Polyurea greases offer extended service life due to their exceptional stability, reducing the frequency of re-lubrication intervals and minimizing maintenance requirements and downtime.

5. Resistance to Contaminants:

They resist contamination from mill scale and other debris, maintaining their lubricating properties and protecting equipment surfaces from wear and corrosion.

6. Oxidative Stability:

Polyurea greases exhibit resistance to oxidation, preventing the formation of harmful by-products and deposits, which is particularly important for maintaining component integrity and preventing premature failures.

7. Enhanced Load-Carrying Capacity:

The excellent load-carrying capacity of polyurea greases ensures protection against wear and damage under the heavy loads typical of continuous casting operations.

8. Broad Operating Temperature Range:

Polyurea greases can operate effectively over a wide temperature range, making them suitable for various sections of continuous casters, from high-temperature zones to cooler areas.

9. Compatibility with Various Base Oils:

The ability to formulate polyurea greases with various base oils allows for tailoring the lubricant’s properties to meet specific requirements and conditions of continuous casting processes.

Polyurea greases are chosen for continuous casters in the steel industry predominantly due to their ability to perform reliably under the extreme conditions of high temperatures, heavy loads, and contamination. Their superior properties such as high-temperature stability, mechanical stability, water resistance, and long service life make them invaluable for ensuring the smooth and efficient operation of continuous casters, reducing maintenance needs, and prolonging the life of components.