The role of grease is mainly to lubricate, protect and seal.
The vast majority of greases are used for lubrication and are called anti-friction greases. Anti-friction grease mainly plays the role of reducing mechanical friction and preventing mechanical wear. At the same time, it also plays the role of protection against metal corrosion, and the role of sealing and dustproof. There are some greases that are mainly used to prevent metal from rusting or corroding, called protective greases. For example, there are a few greases such as industrial vaseline that are specially used for sealing, which are called sealing greases, such as thread grease. Greases are mostly semi-solid substances with unique fluidity.
Grease works on the principle that the thickener keeps the oil where it needs to be lubricated, and when there is a load, the thickener releases the oil to lubricate.
At room temperature and at rest, it is like a solid, can hold its shape without flowing, and stick to metal without slipping. At high temperature or when subjected to external force exceeding a certain limit, it can flow like a liquid. When grease is sheared by moving parts in machinery, it can flow and lubricate, reducing friction and wear between moving surfaces. When the shearing action stops, it can restore a certain consistency. The special fluidity of the grease determines that it can be lubricated in parts that are not suitable for lubricating oil. In addition, because it is a semi-solid substance, its sealing effect and protection effect are better than that of lubricating oil.
