Grease is o fine dispersion of on oil-insoluble thickening agent- usually soap in o fluid lubricant which is generally mineral lubricating oil. The soap is mode up of fatty acid, tallow or vegetable oil saponified with alkali which can be hydrated lime, caustic soda, lithium hydroxide or aluminum hydroxide. The lubricating oil component is refined base oil•naphthenic, of medium viscosity index, or cylinder oil stock. Structurally grease is a "water-in-oil" emulsion. Its appearance is smooth, mostly translucent, soft or hord.
Grease manufacturing procedure
Grease manufacturing can be described as an art as well as science. It is akin to cooking food In spite of detailed recipes the cooks personal attention and supervision at critical stoges only can give best results
Manufacturing of Greases
The manufacture of Greases therefore involves the following steps, some of which may be accomplished simultaneously.
- Cut bock
The operations ore carried out in vessel known os Grease Kettle, which is equipped with some form of agitation and with heating facility. The rate of cooling is very important in the development of the proper structure for many types of Grease, hence, close temperature control is required to manufacture a grease of desired properties. The structure of the greose can be modified by milling which can be carried out in the kettle itself during the cooling period or may be done outside the kettle. For out side milling, a high shear Homogenizer or Colloid mill is normally used. Depending upon the types of grease, the total time required for manufacture of a grease batch in a kettle varies from 1 0 / 20 hours.