grease product knowledge

Greases

Product Knowledge

Presented by : RAJIV RANJAN


What is a grease ?

A solid to semi-fluid product

consisting of a fluid lubricant and a

thickener

It usually contains additives to

enhance performance

Typical grease contents

oil 80-87%

thickener 8-15%

additives 5%

Oil

Thickener

Additives


Lubricating greases vs. Oils

Oils

Fluid

Run away

remove heat (cool)

remove debris (clean)

remove particles

(clean)

Classification

Viscosity (SAE)

Greases

Semi-fluid / semi-solid

Stay in place

Seal

no cooling / no

cleaning

Classification

Consistency (NLGI)


When to lubricate with grease ?

• To decrease dripping and splattering of lubricant

• To decrease frequency of lubrication

• To seal out contaminants

• For intermittent operation

• To suspend solid additives

• Under extreme operating conditions • high temperature

• high pressure

• shock loading

• slow speed / high pressure

• Machine badly worn

• When noise reduction is very important


How grease works ?

• Consider Grease as a Sponge

• 3-D network of thickener particles

• Thickener particles adhere to each other due to chemical attractive forces

• Pores filled with oil/additives


GRADE

NUMBER STRUCTURE

PENETRATION

(WORKED) mm/10

CONE SINKING

DEPTH

SEMI FLUID

SEMI FLUID

VERY SOFT

SOFT

MEDIUM SOFT

MEDIUM

STIFF

VERY STIFF

VERY STIFF

445 - 475

400 - 430

355 - 385

310 - 340

265 - 295

220 - 250

175 - 205

130 - 160

85 - 115

000

00

0

1

2

3

4

5

6

NLGI number


Rolling Element Bearings

Ball bearing

General purpose bearings

Cylindrical roller bearing

Wheel bearings on cars

Bearings on gearboxes

Taper Roller Bearing

Wheel bearings on trucks & LCVs


Wheel Bearing Lubrication

Two basic types

Oil Lubricated

Grease Lubricated

Grease-Lubricated Wheel Bearings

HCV Hub-Cut section Taper roller bearings


CHASSIS GREASE

Pumpability

Good water resistance

“Stay put” anti-squeeze property

Anti-rust properties

Cost

Grease nipple


Grease formulation

Grease = Base oils + Thickeners +

Additives

The thickeners most used in grease

production:

Metal soaps (Li, Ca, Na)

Metal complex soaps (Li, Ca, Al)

Inorganic thickeners (bentonites,

silicates)

Others (polymers, polyurea)


Additives in greases

Antiwear

EP additives

Antioxidants

Tackiness agents

Corrosion inhibitors

Compatibility with thickener systems is

of prime importance


Anti-Wear Additives

Zinc based


Extreme Pressure (EP) Additives

Sulfur-Phosphorus Compounds (S-P)


Other Additives

Anti oxidants

Reduce ill effects of oxidation

Tackifiers

Improve adherence

Corrosion inhibitors


How is grease produced ?

Re

ac

tor

(Pre

ss

uri

sed

)

Homogenisation

(milling)

& Deaeration

Base

Oil

(Major portion) Fatty

Acids Alkali

Fin

ish

ing

Ke

ttle

Base

Oil

(Minor portion) Additives

Heating/cooling

jacket

Filling

Hot

Oil


Performance testing

Penetration

Mechanical stability

Oil separation

Drop point

Water resistance

Extreme pressure

performance

Four Ball weld load test


PENETRATION

Penetration is the depth, in tenths of millimeters, to which a standard cone sinks into the grease under prescribed conditions.


Penetration Contd...


Worked Penetration

Worked to X strokes

X – 10,000


Drop Point

• Determines the temperature at which a soap thickened grease passes from solid to a semi-solid state.

• Measured in deg C


Drop Point contd ….


SIGNIFICANCE

Directional change in consistency while in service

Measure of shear stability

50 gm grease in a tube with 5 Kg weight and rotated

2 hrs, 20-35 deg C

Low shear

MEASURED AS

Change in cone penetration value (in %)before & after test

Roll stability


Heat stability -Oil Separation (Conical Sieve) Method)

SIGNIFICANCE

Co-relates with oil separation in storage

100 deg C, 30 hrs

MEASURED AS

Loss of oil mass


Copper Corrosion ASTM

Temperature 100°C

Duration 24 h

Copper strip in a tube with grease ,compare with the

standard


Wheel Bearing grease leakage test

SIGNIFICANCE

Measures leakage tendency of grease

CONDITION

Wheel-hub assembly under rotation

660 rpm, 6 hrs

113 Deg C

MEASURED AS

Mass of grease + oil leaked out in gms


Resistance to water washout Test

SIGNIFICANCE

Resistance of the grease to getting washed out by water

CONDITION

600 rpm

Water impinge at 5 ml/sec

1 hr

MEASURED AS

Grease mass loss (%)


Emcor Rust Test

SEVERE TEST

10gm grease+20ml water

3 days run

108 hrs stop

SIGNIFICANCE

Corrosion prevention in the presence of distilled water

MEASURED AS

Visual rating system for pass / fail

No. of rust spots


Results

No corrosion – 0 Rating

Traces – 1 Rating (<3 Spots)

Light – 2 Rating (< 1%)

Moderate – 3 Rating (1-5%)

Heavy – 4 Rating (5-10%)

Severe – 5 Rating (>10%)

Emcor Rust Test Contd...


Extreme Pressure & Anti-wear Properties

4 ball weld load test

Wear Scar Dia


Key selling points -

• Superior shock load protection and Better anti-wear performance

• Superior corrosion protection

• Better lubricity

• Excellent resistance to water washout

• Superior control on oil bleeding under operation

• Superior heat stability

• Extremely high structural strength

• Lower leakage tendency under storage

• Longer life


STORAGE AND HANDLING

Storage of barrels-Inside storage ideal

Grease surface in barrels to be convex

Contamination

Water

Solids

Other Lubricants

Dust – the largest enemy of grease


Market Practices

• Poor quality hub grease

• Frequent breakdown

• Bearing failure

• Frequent re greasing

• Used grease/’Batata Grease’ for chassis greasing

Thank You !

RAJIV RANJAN [email protected]

mailto:[email protected]

grease product knowledge

Automotive