Composition and function of grease

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Greases are a class of lubricants with non-Newtonian fluid characteristics between semi-fluid and solid obtained by dispersing one or more thickeners in one or more liquid lubricants. Grease has a certain type, easy to adhere, liquidity is lower than the corresponding base oil.

The basic composition of grease includes:

Thickener. The thickener accounts for about 2% to 35% in the grease, and is generally dispersed in the liquid lubricant in a colloidal state to form a spatial network structure, or only dispersed in the base oil in the form of a dispersed phase, which plays a role in adsorbing and limiting the flow of the base oil. The choice of thickener directly affects the mechanical stability, high temperature resistance, colloidal stability, water resistance and other properties of the grease.

Base oil. Base oil accounts for about 65% ~ 98% in grease and is the dispersion medium of thickener. The choice of base oil directly affects the lubricity, evaporation, low temperature properties of the grease and the compatibility with the sealing material.

Additives. Additives account for about 0 to 10% of the grease, which can improve some of the performance of the grease. According to the performance requirements of grease, structure improvement agent, antioxidant, metal passivator, rust inhibitor, extreme pressure agent, oiliness agent, anti-wear agent, wire drawing agent, etc. can be added.

The two basic functions of grease are lubrication and protection:

Lubrication: Grease has the effect of reducing the surface wear of the two friction pairs in relative motion.

Protective effect: Grease can isolate or reduce the contact between the surface of the friction pair or the surface of the object and corrosive substances, and play a role in reducing or slowing down the erosion and damage of the surface of the material by chemical effects, including rust prevention, corrosion prevention and water resistance.