Lubricant

presented by:- Abhishek Raj

Interaction With Lubricants

Presented by: Abhishek RajGuided By: Dr. Monika Sogani


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.


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:IntroductionFunction of LubricantsClassification of LubricantsProperties of LubricantsEmulsification NumberPrecipitation NumberNeutralization Number


Saponification ValueFlash and Fire PointCloud 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)


window lifting mechanism

Pendulum Clock

Almost every moving component requires LUBRICANT

Standard lock

Some Examples


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.

Figure shows how lubricant as coolant uses



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.

4. Improve the efficiency of the machine: Since the use of lubrication minimizes the

liberation of frictional heat,

it reduces expansion of metal.


Corroded metal

Working machine


Classification of Lubricants

Lubricant

Solid LubricantSemi-solid LubricantLiquid Lubricant



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

graphite

wax



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.

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

like boring machine, milling machines, etc..

(Petroleum oils)

(mix. of oil and water)

Properties of LubricantsOilinesso 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 volatilityEmulsificationo 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 NumberThe 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 PointFlash 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 Pensky-Marten’s apparatus .


Fire Point Determination


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 Lubricants1. Oiliness: It shows the capacity of lubricants to stick on the surface of machine

parts.

2. Volatility: It shows the evaporation behavior.

3. Corrosive stability: A good lubricant should not take part in corrosion.

4. 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.



Thank You All

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

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Transcript of Lubricant