which one is the greatest for multi-purpose grease?
Greases have been around for hundreds of years and come in many different forms and varieties. The first universal oils, the first generation of fats, were in their primitive form a mixture of lime and vegetable oils. Until the industrial revolution in the human world, this type of grease was very popular for almost all applications requiring lubrication.
However, in the past few decades, the wisdom of human civilization has shown amazing results, various technologies have emerged, and the growth of human resources has made remarkable progress in mechanical design. This affects the operating parameters and grades, and thus changes the requirements for grease. Because operating parameters such as speed, load, temperature, etc. vary from device to device, it is nearly impossible for one grease to handle all different applications.
As a result, a large number of varieties of greases have been developed, leading to thousands of different models of products appearing on the sales market. The concept of one universal lubricant covering all types of applications is no longer correct. In other words, different kinds of oils need to be used in different places and on different machines. In addition, let's put ourselves in the position of consumer selectivity and suitability, the large amount of fats available may confuse consumers, resulting in unnecessary losses.
As I discussed with you in the past, grease is very important for a lot of machines. Because most dynamic machines run on bearings, and bearings need grease to lubricate, sometimes it's really hard to imagine a machine running without grease. From a historical perspective, shortly after the wheel was invented, people began to use grease to help push and grease the wheel and axle. Next we will focus on the comparison of two popular greases.
（Comparing grease application suitability）
Compared with lithium complex greases, calcium sulfonate greases exhibit superior mechanical and shear stability, indicating less leakage and spillage during operation. It also has better drop point and high temperature life, allowing these greases to be used at higher temperatures.
Unlike lithium-complex greases, which need a significant amount of antimony-zinc or other types of additives, calcium-sulfonate thickeners have inherent extreme-pressure and anti-wear properties. In addition, while sulfonates are known to be natural rust inhibitors, lithium-complex greases invariably need rust-inhibiting additives.
Furthermore, calcium sulfonate, by virtue of its thickener property, provides excellent water-resistance properties and does not break down even in the presence of water. To improve their water-resistance properties, lithium-complex greases usually require tackifiers, which are prone to deplete quickly in the presence of water. Calcium-sulfonate greases are also compatible with lithium and lithium-complex greases.
The few disadvantages of calcium sulfonate greases are their low pumpability and high cost.
However, recent technological advances have brought these greases up to the level of lithium composite greases.Calcium sulfonate greases can be applied to more industrial types than lithium complex greases, so it is the preferred high performance multi-purpose greases.
Lubricating greases basically are composed of a thickener (10 to 15 percent), base oil (80 to 90 percent) and performance additives (5 to 10 percent). Although there are some specific product proportions that may change depending on the formula of the lubricant grease manufacturer, such as multi-purpose grease, bearing grease and calcium sulfonate grease. The total size of the global grease market is similar to an astronomical number because a lot of equipment is inseparable from grease, mainly including calcium, sodium, aluminum/aluminum complex, calcium sulfonate, clay based, polyurea, etc. By far the most popular greases worldwide are lithium-based greases with a market share of more than 75 percent. While various kinds of greases may be required in a particular plant, there have always been efforts to rationalize and minimize the number of greases from a purchasing and logistics standpoint. This likely has led to the development of multi-purpose greases.
Briefly, a multifunctional grease can be defined as a grease consisting of a combination of the properties of two or more special greases, which can be used in a variety of applications. Traditionally, calcium-based greases are used in chassis and sodium-based greases are used in wheel bearings. Many products have changed because of advances in technology. For example, lithium grease can be used in chassis and wheel bearing applications of transport vehicles. Calcium-based grease has high water resistance, but poor high temperature resistance. Sodium based greases, on the other hand, are better at covering high temperatures, but are less resistant to water. When lithium greases appeared on the market, they were found to be superior to calcium and sodium greases and soon became the most popular multi-purpose grease in industry. But it also has a disadvantage that the price is slightly higher than the other two.
High-Performance Multi-Purpose Greases
With the progress of human society, and in the design and construction of modern machinery, machines operate under more harsh conditions, with the expectation of increasing productivity and reducing downtime. This makes it difficult to satisfy these requirements satisfactorily. The National Lubricating Grease Institute (NLGI) GC-LB specification, which is the most closely followed in the transport sector, also requires greases beyond just lithium 12-hydroxy greases.
（Comparison of fully formulated greases）
These stringent requirements can be met by more efficient high-performance greases like lithium-complex, calcium-sulfonate, aluminum-complex, polyurea and clay-based greases. However, because of their compatibility with most widely used lithium greases, lithium-complex and calcium-sulfonate greases appear to be the best candidates of these high-performance multi-purpose greases.