The difference between calcium based grease and lithium based grease

1.Specification 6 Calcium based grease is a medium viscosity mineral lubricating oil thickened with calcium soap made from animal and vegetable oils (synthetic fatty acids are used for synthesizing calcium based grease) and lime, and made with water as the solvent. According to their working cone penetration, they are divided into four grades: 1, 2, 3, and 4. The larger the grade, the harder the grease and the higher the drip point. Calcium based grease is a product that tends to be phased out internationally, but its usage is still significant in China.

2.purpose

Calcium based grease is mainly used for lubricating rolling bearings and parts that are prone to contact with water or moisture in various industrial and agricultural machinery such as automobiles, tractors, water pumps, and small and medium-sized electric motors. Because calcium based lipids are mainly used in compression cups, they are also known as "cup lipids". Rolling bearings with a temperature range of 10 ℃~60°C and a speed below 3000r/min can generally be used. No.1 is suitable for centralized grease feeding systems and automotive chassis friction grooves, with a maximum operating temperature of 55°C. No.2 is suitable for rolling bearings of general medium speed, light load, small and medium-sized machinery (such as electric motors, water pumps, blowers), lubrication parts of wheel hub bearings and clutch bearings of automobiles and tractors, and corresponding lubrication parts of various agricultural machinery, with a maximum operating temperature of 60°C. No.3 is suitable for bearings on various medium-sized machinery with medium load and medium speed, with a maximum operating temperature of 65°C. No.4 is suitable for heavy-duty and low-speed heavy machinery equipment, with a maximum operating temperature of 70°C. Product performance.

Good water resistance, not easily emulsified or deteriorated when in contact with water, and can be used in humid environments or in contact with water. Has good shear stability and thixotropy. Stability and low oil separation during storage.

Has good pumpability. The performance of synthetic calcium based lipids is similar to that of natural calcium based lipids, but attention should be paid to the instability of the quality of synthetic fatty acids. If lipids are made from materials containing low carbon dioxide, skin hardening often occurs. matters needing attention.

Lithium based grease is made from natural fatty acid (stearic acid or 12 hydroxystearic acid) lithium soap, thickened medium viscosity mineral lubricating oil or synthetic lubricating oil, while synthetic lithium based grease is made from synthetic fatty acid lithium soap, thickened medium viscosity mineral lubricating oil.

3. The characteristics of lithium based grease are as follows:

Lithium based grease, especially 12 lithium stearate thickened grease, has only two intersection temperatures. The first intersection temperature (that is, from the pseudo gelled state to the gelled state) is generally above 170 ℃, and the second phase change temperature (that is, from the gelled state to the dissolved state) is generally above 200 ℃. Therefore, when selecting suitable mineral oil, lithium based grease can be used at 120 ℃ for a long time or 150 ℃ for a short time. In particular, 1 lithium stearate thickened grease, whose soap fibers form twisted ribbons with double strands and tangles through the electronic microscope, has good mechanical stability.

Through the adsorption heat of alkyl hydrocarbons by lithium stearate and lithium stearate, it was found that the binding strength of carboxyl capped fatty acid lithium and lithium stearate to the liquid phase on the surface of soap fibers and to the liquid phase inside the crystal lattice were relatively high, as determined by gas chromatography. Therefore, lithium based lubricants have good colloidal stability. The solubility of alkali metals to water is relatively low, therefore, lithium based grease has good water resistance and can be used for mechanical parts that are damp and in contact with water.