Grease smoothens our
life and kills those scary creaks.
It has happened to all of us at some time or the other – we
unwittingly get grease stains on our hands, legs or, unfortunately,
on our favorite dresses. Hands and legs can be washed albeit with
some effort but it is when we struggle to get it off our clothes
that we wish we had been more careful.
We generally get these stains from places like garage doors,
shutters, vehicles and the like. Why is grease used in all these
places? Grease is used because its application aids smooth movement,
reducing friction. Ever wondered what goes into the making of
grease, without which the hinges of our doors and windows would
Types of grease
Grease, as we know, is thick and oily.
It is made so with the help of inedible lard. This lard could be fat
extracted from waste animal parts or could be synthetic. Synthetic
grease is made from a derivative of petroleum.
There are many kinds of grease, for different purposes. The common
types are yellow grease and white grease. Fat for white grease is
sourced from inedible hog fat, while fat for yellow grease is also
sourced from hog fat and may contain parts used to make white
Brown grease is another variety of grease that contains beef and
mutton fats in addition to hog fats. The other types of grease are
bone grease, which has bone as its source of fat; hide grease with
its source being hide of animals; and, garbage grease with its
source being the otherwise unusable parts of animals.
Grease that is made from a mineral or synthetic source consists of a
thickening agent mixed well in a liquid lubricant. The liquid
lubricant generally used is synthetic oil or any other synthetic
fluid. The thickening agent used is generally chosen from soap, an
inorganic gel or any other organic substance.
Synthetic greases are made in two forms – water soluble and water
resistant. Their composition is such that they can be used over wide
temperature ranges. The purpose for which the grease is intended
determines the other additives that go into it. Additives are chosen
to obtain the correct level of viscosity, thickness and any other
specifically desired characteristic.
A popular synthetic grease is silicone. In silicone, both the oil
and the base are synthetic. The composition of silicones is
partially organic. Silicone is also called polysiloxane. Silicone
fluids are used as components in hydraulic fluids. It is also used
where water repellence is needed, for example, while working with
textiles, paper and other such substances. Silicone rubbers are also
widely used mainly for electric insulation, chemical stability, and
resistance to temperature changes.
Grease and the Sepoy Mutiny
History tells us that grease was the
bone of contention and finally led to the Sepoy Mutiny in India. Rifles that
the sepoys or soldiers used were greased with the fat of cows or
pigs. Cows are sacred to Hindus and Muslims consider pigs unclean.
The soldiers were required to bite off the end of the cartridge
before loading the rifle. Neither the Hindu soldiers nor the Muslim
soldiers were comfortable with this. They revolted and this mutiny
sparked off a series of events that played an important part in
India’s Freedom Struggle.