Lubricant

Preface
 It gives me immense pleasure in Presenting the
Presentation of Lubricants.
 The Subject matter contained in the Presentation is written
in a comprehensive, easy to understand language and lucid
style. The matter has been systematically developed in the
conceptual manner with suitable diagram from the basic
principle of Lubricants.
 I hope that the present Presentation will fulfill the needs of
student and teacher and Prove helpful in achieving their
goal.
presented by:- Abhishek Raj

Acknowledgement
 Achieving a milestone alone for any person is extremely
difficult. However, there are some motivators who come across
the curvaceous path like twinkling stars in the sky and make
the task much easier. It becomes our humble and foremost
duty to acknowledge all of them.


I sincerely express my gratitude to my chemistry faculty Dr.
Monika Sogani.



I would also like to acknowledge our other friends and our
family members for their moral and financial support without
which it would have been impossible to complete this project.

Contents:
Introduction
Function of Lubricants
Classification of Lubricants
Properties of Lubricants
Emulsification Number
Precipitation Number
Neutralization Number

Saponification Value
Flash and Fire Point
Cloud and Pour Point


Introduction
Lubricants are those substances, which
are Used to reduce the force of Friction
between two sliding surfaces. Or,
Any substance introduced between two
moving sliding surfaces with a view to
reduce the friction (or frictional resistance)
between them, is known as a lubricants.


The process of reducing
friction between moving sliding
surfaces by the introduction of lubricants in
between them, is called lubrication.

lubrication

Grease(lubricant)

Some Examples
Almost every moving component requires LUBRICANT

Standard lock

Pendulum Clock

window lifting
mechanism


Function of Lubricants
1. As a Coolant: The frictional heat generated
at the a point of contact between the rubbing
parts is localized at the surface peaks. The
lubricating oil absorbs the heat and hence
act as coolant.


2. Reduce the Frictional Resistance: To
reduce the frictional resistance, is one of the
main function of lubricants.

Resistance free rotatory wheel

3.Provides Protection against Corrosion: The
lubricants cover the metal surface and hence the
attack of atmospheric corrosive
environment on metal surface is
prevented.
Corroded metal
4. Improve the efficiency of the machine: Since the use
of lubrication minimizes the
liberation of frictional heat,
it reduces expansion of metal.
Working machine

Classification of Lubricants
Semi-solid
Lubricant
Solid
Lubricant

Liquid
Lubricant
Lubricant


1. Solid Lubricants: The Lubricants
existing in solid form are known as solid
lubricants. E.g. graphite, soap, wax, mica,
chalk, etc


2. Semi-Solid Lubricants: These are neither solid
nor liquid. A Semisolid lubricant is obtained by
combining lubricating oil with thickening agent.
E.g.:-Silica gel, Grease, Vaseline, etc.

Grease


3. Liquid Lubricants: These exist in liquid
form and are used to reduce friction by
providing a uniform film between them.
These are also very important and are widely
used in several machines and tools because
They act as:a) Sealing agent
b) Corrosion inhibitors and
c) Cooling medium.

Example of liquid lubricants: custard oil, Synthetic oil, mineral
oil, petroleum oil,etc…
Condition for using liquid lubricants:1. Where solid and semisolid lubricants are not
suitable.
2. In light machines like watches, clocks, sewing
Machines etc..
3. In such type machines where less amount of
Heat is produced during motion so that the
produced heat is insufficient to ignite or burn
the lubricants.

Types of Liquid Lubricating Oil:1.Animal oil and Vegetable oils: Animal and
vegetable oil are very important and are extracted
from the animal and Vegetable.
 These have good oiliness and viscosity properties.
For example:
Animal Oils:- Whale oil, seal oil, etc..
Vegetable Oil:- mustard oil, cotton seed oil, etc..

Types of Liquid Lubricating Oil:-

Animal Oil

Vegetable Oil

Types of Liquid Lubricating Oil:2.Mineral oil or Petroleum oil:- These are basically lower
molecular weight hydrocarbon with 12-50 carbon atom.
 These oils are obtained by the fractional distillation of
petroleum.

(Petroleum oils)

3.Emulsions:- are the products of two immiscible liquids in
which one liquid acts as dispersion medium and the other the
dispersed phase.
e.g. mixture of oil and water
 Emulsions are used in several machines (mix. of oil and water)
like boring machine, milling machines, etc..

Properties of Lubricants
Oiliness
o It is an important properties of a lubricant, it shows
the capacity of a lubricants to stick on the surface of
machine parts under high pressure and load.

Volatility
o It shows the evaporation behavior of lubricant at high
temperature.
o A good lubricant should have low volatility

Emulsification
o It is the property of a lubricant due to which the
lubricating oil mixed with water to form an emulsion.
o A good lubricant should have low emulsion number.

Properties of Lubricants
 Corrosion Stability
• It is properties of lubricant which represents its
resistance toward the metals.
• A good lubricant should not take part in
corrosion.
 Thermal Stability
• A good lubricant must be stable towards heat.
• It should not decompose during operation at high
temperature.

EMULSIFICATION NUMBER
 Emulsification is the property of a lubricant due to which the
lubricating oil get mixed with water to form an emulsion.
• Generally emulsion are the product of two immiscible liquids.
• For example, a mixture of water and oil.

 Process to calculate emulsification number
• First of all 20 ml of oil is taken in test tube. Then Steam of 100oC is passed
through it so that temperature rises to 90oC and volume become 40 ml.
• Then tube is placed in a bath to maintained its temp. at 900C. and then
time in second is noted, when layer of water and oil are distinctly
separated.
• then the Time Taken in second is known as
steam emulsion number.

(Emulsion)

Neutralization Number
 The neutralization number is an indication of
acidic and basic impurities in the lubricating oil.
 As we know Determination of acidity is more
common and is expressed in term of acid value or
acid number.
 In Fact, the acid number greater than 0.1 is
usually taken as an indication of oxidation of the
oil.
 The source of acidity in oil may be:a) Products of oxidation of oil.
b) Contamination of oil by so2 from combustion of
the fuel.

Saponification Value
 It is helpful in the determination of adulteration
in oil.
 It is determined by refluxing a known weight of
oil sample with a known amount of standard
alcoholic KOH solution.
 Saponification Value=Volume of
KOH*Normality*Eq.Wt.of KOH/weight of the oil
sample

Flash and Fire Point
 Flash point is the minimum temperature at which
a lubricant gives sufficient vapor and burn for a
moment, when a flame is brought near it.
 Fire Point is the lowest temperature at which the
lubricant gives sufficient vapor and burn
continuously for at least five seconds, when a
flame is brought near to it.

 The flash and fire point is determined by PenskyMarten’s apparatus .

Cloud and Pour Points
• Cloud Point is defined as the temperature
at which an oil becomes cloudy or hazy in
apparatus, while the temperature at which
the oil ceases to flow is called pour Point.
• Cloud point and pour point indicates the
suitability of lubricants in cold condition.
• These are determined with the help of cloud
and pour point apparatus.

Cloud and pour point apparatus


What we have
learnt yet ?????


 Definition
 Lubricants are those substances,
which are used to reduce the force of Friction between two sliding surfaces.

 Function of Lubricant





It acts as coolant.
It reduces the frictional resistant.
It provides protection against corrosion
It also improve the efficiency of the machine.

 Classification of Lubricants
 Solid Lubricants. (ex: wax, chalk)
 Semi-solid Lubricants. (ex: Grease, Vaseline)
 Liquid Lubricants
Further liquid lubricant is divided into:o Vegetable oil. (ex: mustard oil and cotton oil)
o Petroleum oil. (ex: diesel and petrol)
o Emulsions. (ex: mixture of oil and water)

 Properties of Lubricants
1.
2.
3.
4.

Oiliness: It shows the capacity of lubricants to stick on the surface of machine
parts.
Volatility: It shows the evaporation behavior.
Corrosive stability: A good lubricant should not take part in corrosion.
Thermal stability: A good lubricant must be stable toward heat.



Emulsification Number: It is the property of a lubricant due to which
lubricating oil gets mixed with water to form emulsion.



Neutralization Number: It is the indication of acidic and basic impurities in
lubricating oil.





Saponification Value: It is helpful in the determination of adulteration in oil.
Flash and Fire Point
Cloud Point: is defined as the temperature at which oil becomes cloudy or hazy in
apparatus.



Pour Point: the temperature at which the oil ceases to flow is called pour point.

To Make Silence and To Listen Us

References:
For Text: - Chemistry Book ( JHUNJHUNUWALA)
For Images and diagram: - Google

Lubricant

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