A Window in Grease Technology 10º Lubgrax Meeting August 14 – 15 2019

São Paulo – Brasil by

Carl F Kernizan

Topics

•  What is a grease •  Function, Chemical Composition & Formulation •  Grease Manufacture & Testing •  Grease Market & Trends •  Grease Applications •  Conclusions •  Acknowledgment

What is a Grease?

• The National Lubricating Grease Institute (NLGI) Definition: “A solid to semi-solid product of dispersion of a thickening agent in a liquid lubricant. Additives imparting special properties may be included.”

l  Tribology Definition – ASTM D288 Solid or semi-solid product of a dispersion of a thickening agent in a liquid lubricant. Additives with special properties can be added.

l  Grease is: •  Thickener component •  Base fluid •  Additive components

thickened oil not a thick oil!

Function and Chemical Composition

Typical Grease Composition

Oil + Thickener + Additives = Performance requirements of lubricating grease

Performance Targets: •  Consistency •  Oxidative and thermal stability •  Dropping point •  Corrosion resistance •  Structure stability •  Keep moving parts apart •  Load carrying capability •  Friction and Wear protection •  Water resistancy •  Viscometrics •  Low temperature behavior •  Elastomer compatibility

Base Stock50-95%

Performance Additives

1-15%

Thickener3-40%

Function and Chemical Composition

Base Oils – API Classification

•  Mineral oils – 90% of market –  Naphthenic –  Paraffinic –  Aromatic (almost eliminated) –  Re-refined –  White Oil

•  Synthetics –  Synthetic hydrocarbons –  Esters and ethers –  Other synthetics

•  Vegetable or bio-based oils

Function and Chemical Composition Base Oils - Property Comparison

Property Naphthenic Group I Group II/III PAO/Syn

Appearance Translucent Opaque Opaque Light-white

Soap Formation Excellent Moderate to good Moderate to fair Fair

Soap Solubility (Yield)

Excellent Moderate to good Moderate Difficult

Oxidative Stability Low Moderate Good Excellent

Low Temperature Good Moderate to poor Good Excellent

Advantage High yield Low temp.

Oxidation High temp. stability

Oxidation High temp. stability Low temp.

Oxidation High temp. stability Low temp

Disadvantage Oxidation High temp stability Seal issues

Lower yield Low temp.

Lower yield Borderline seals

Lower yield Seal issues

Function and Chemical Composition What Makes Grease Different from Oil? It Contains a Thickener What are Thickeners

• Soaps or Salts of Fatty Acid(s) + Metal Oxide Base -Simplesoaps–1metalhydroxide+fa6yacidClarenceE.Earle,U.S.PatentNo.2,274,675,March3,1942-LithiumEP2 -Complexsoaps–1metalhydroxide+2ormorefa6yacids -Mixedsimple&complexsoaps–combinaJonofmetalhydroxides&fa6yacids -FuncJonalizedsoaps

• Non-soaps -InsituchemicalreacJonofPolyOrganicmaterials(Polyurea)inabaseoil -DispersionsofPolymers,silicaorclaysdispersedinabaseoil

Three-dimensional network of fibers or surface-active particles •  Fibergreaseslookandcanactlikeasponge •  ParJcledispersionscanlooklikericepudding •  Amorphouspolymerdispersionsinoil •  Blood-likeplateletsdispersedinoil Characteristics •  ShearStability

• Abilitytoresistchangeinconsistencyduringservicelife •  ThermalStability

• DroppingPoint• HightemperatureoperaJnglimits

Simple Lithium Complex Lithium

Ca Sulphonate Polyurea Clay

Chemically Active Typically organic, react at the surface of lubricated contact, react within the matrix of the grease •  Anti-wear

• Phosphate Ester • Zinc Dithiophosphate

Chemically Inert Affect a physical property such as structure, rheology, or water tolerance •  Polymers

• Tackifiers - PIB • Viscosity Improvers – OCP • Pour Point Depressants

•  Solid Additives • Graphite • Molybdenum Disulfide (MoS2, or Moly) • PTFE Teflon®

•  Color • Dye

Function and Chemical Composition Performance Additives

•  Extreme Pressure • Sulfurized Olefins • Antimony Ditihiocarbamates • Thiadiazoles/triazoles

•  Corrosion Inhibitors • Metal sulfonates • Metal phosphates

•  Oxidation Inhibitors • Amines • Phenols

Additive Component %

Extreme pressure 2.00 – 4.0

Antiwear agent 0.75 – 2.0

Rust inhibitor 0.2 – 0.6

Oxidation inhibitor 0.50 – 1.0

Metal deactivator 0.15 - 0.30

Total 4.00 – 8.0

Grease Formulation For the Formulator •  Grease Type •  NLGI Grade •  Viscometric Targets •  Performance Parameters •  Color

Grease12-Hydorxystearic Acid 9.49 9.49 20.44

Azelaic Acid 1.81 1.81 3.90

Lithium Hydroxide Monohydrate 2.3 2.30 4.96

Naphthenic - 750 SUS 38.16 16.41 35.35

Paraffinic 150 BS 38.16 16.41 35.35

Tackyfier 3.53

Molybdenum Disulfide 3

EP Additive 2

AW additive 0.75

Corrosion Inhibitor 0.6

Metal Deactivator - Cu 0.1

AO 0.1

Total 100 46.42 100.00Soap Alkalinity (Calc) 0.15Acid:Base Ratio 4.19Viscosity

40C 253.48 100C 18.01VI 73

LiX EP 2 3%Moly - ISO 220 Soap NormalizationGrease

Hydrogenated Castor Oil 10.01 10.01 20.76Lithium Hydroxide Monohydrate 1.47 1.47 3.05NAPHTHENIC 750 SUS 85.46 36.75 76.20EP Additive 1.5 Polymer - Water Resistance 1AO 0.25 Metal Deactivator - Cu 0.2Corrosion Inhibitor 0.1DYE 0.01

Total 100 48.23 100Soap Alaklainity (Calc) 0.09Acid:Base Ratio 6.81Viscosity 40C 143.3 100C 11.25VI 45

Soap NormalizationLi EP2 - ISO 150

Grease Manufacture

Modern Process

Source: Contactor™ is a registered trade market of Stratco, Inc, Scottsdale, AZ

•  1-4 – batch to semi-continuous manufacture and transfer to storage •  5 – complete manufacture and transfer to storage

•  All can make essentially the same grease •  But due to different processing controls the same recipe will turn out differently

1.  Open Kettle 2.  Autoclave 3.  Contactor™ 4.  Microwave 5.  Continuous Grease Unit (CGU)

Followed by cooling, mixing and homogenization

Source: Microwave – Dr. Lou Honary form Environment Lubricants Manufacturing Inc. & University of Northern Iowa

Grease Manufacture

Modern Process

Cooling, Additives, Milling,Storage,Packaging

Top Temperature Fully melted soap (Li)

Constant Temp for saponification

Dehydration followed by Heating to Top Temperature

Cooling with oil/Quench - structure formation

Initial charge of components

Temperature Time Curve – TT Curves

Temp

Time

Grease Manufacture

Modern Process

•  Grease making is a path dependent controlled chemical reaction process •  The output depends on the following

–  Control of raw materials –  Temperature & pressure –  Rate of heating and cooling –  Mixing –  Homogenization –  Deaeration

Process Parameters Property

Maximum heating temperature Complete reaction

Cooling rate Fiber formation

Alkalinity Stability

Stirring time and rate Texture/appearance

Milling Homogeneity

Temperature of additive addition Appearance/odor

Process Control

Grease Manufacturing

Modern Process

4MT Cooking

Kettle

15MT Finishing

Kettle

Pump 1 Pump 2

Packaging

Homogenizer (Mill)

Basket Filter

Deaerator

Grease Testing

Global Standards D4950 Properties/Characteristics ASTM D ISO DIN IP NF-T 60 FTM 791 b GOST

(Russian)1 Determination of Dropping Point 566/2265 2176 51801 132 102 1421 6793

Determination of Cone Penetration2 1/1 -1/2 -1/4 Cones 217 2137 51804/1-2 50 132 311 5346

Roll Stability 1831Determination of Flow Pressure 51805

3 Corrosion Preventing Properties 1743 51802 220 135 40001.2 5757Corrosive Effects on Copper 1261 2160 51811 112 5309.4Determination of Ash of Greases 128 51803 5 M 07-037 1461(Including Sulfate) 6474Neutralization Number 128 51809/1-2 37/137 133

974 139 112Content of Solid Foreign Matters 1404 51813 134 3005.3 6370Effects of Water

4 Water Washout Test 1264 51807/2 215Static Test 51807/1Spray off 4049

Salt Fog Test B117 9227EMCOR 6138 11007 51802 220

Water Content 95 3733 74 113 1044Oxidation Stability 942 51808 142 3453 5734

5 Oil Separation 1742 51817 121 1631 321/2 7142Contents of Base oil & Soap 128 51814Contents of LI/Na/Ca By AAS 51815 M 07-38Determination of Li/Na by Flame 3340 199PhotometryDetermination of Solids 51831 3720/22(Graphite/MoS2)Determination of Particle Size 51832 9270of Solid LubricantsDensity 59Evaporation Loss 972 51581 183 9566Pumpability Properties

Shell-DeLimon Rheometer 51816/1Decompression Characteristics 51816/2Apparent Viscosity 1092 139

Grease Testing

Global Standards D4950 Properties/Characteristics ASTM D ISO DIN IP NF-T 60 FTM 791 b GOST

(Russian)Extreme Pressure Properties

6 4-ball Wear 2266 51350-4 239 6503.27 4-ball Load 2596

Load Wear Index 2596Timken Test 2509 326

High Temperature Life 2596Mechanical Dynamic Testing

8 Life Performance of Automotive Wheel Bearing Grease -High Temp

3527

Rolling Bearing Performance Test 1689 Fretting Wear 4170

SKF R2F Method 51806 331.2/331.1Churning Test 266

FAG FE 8 (EP Grease) 51821/2FAG FE 9 51821/1

Wheel Bearing Leakage Test 1263 791-345410 Wheel Bearing Leakage Test 4290

AcceleratedFAG KSM Test

11 Low Temperature Torque 4693 1861478

Elastomer Compatibility12 Change of Hardness (Shore A) 4289 R 868 53505

Change of Volume 4289 1817 53521 3603.3Base Oil Test

Viscosity 445 3104 51562 71Viscosity Index (VI) 2270 2909 2909

Pour Point 97 3016 51597 15Flash Point 92 2592 51376 36

Aniline Point 611 297751775/ 51787

2

FTIR 51820 EColor Code 2049 51411

Grease Testing NLGI/ASTM D 4950 Classifications •  Defined NLGI marks and classes

•  Grease tested and certified against a variety of ASTM test methods –  Chassis greases – 2 classes

1.  LA - basic grease 2.  LB - highly formulated, wide temperature range

–  Wheel bearing Greases – 3 classes 1.  GA - basic grease 2.  GB - intermediate grease 3.  GC - high performance grease

NATIONAL LUBRICATING GREASE INSTITUTE

GC

NLGI AUTOMOTIVE

WHEEL BEARING LUBRICANT

NATIONAL LUBRICATING GREASE INSTITUTE

LB

NLGI AUTOMOTIVE

CHASSIS LUBRICANT

NATIONAL LUBRICATING GREASE INSTITUTE

GC-LB

NLGI AUTOMOTIVE

WHEEL BEARING & CHASSIS LUBRICANT

Grease Market & Trends

Volumes by Region & Thickener Types Total 2017 Worldwide Sales: 2.57 Billion Pounds (1.12 Million MT)

Source: NLGI 2017 Annual Production Survey

Lithium52%

LithiumComplex20%

Calcium11%

CalciumComplex

1%CalciumSulfonate

3%Aluminum

3%

Polyurea6%

Sodium0%

Non-soap3%

Othersoap1%

PRC; 35.20821889

Pacific and Southeast Asia; 6.140780931

Japan; 7.176422023

India; 7.03890432

Africa and Middle east; 4.94797566

Carribean , Central and South America;

3.156577594

Europe ; 18.8

North America ; 18.32

0 200,000 400,000 600,000 800,000 1,000,000 1,200,000 1,400,000

0

500,000,000

1,000,000,000

1,500,000,000

2,000,000,000

2,500,000,000

3,000,000,000

2012 2013 2014 2015 2016 2017

Global NLGI Grease Survey

Blbs Mmt

Grease Applications

55% of the Worldwide Market – Industrial

Railroad

Marine

Aviation

Power

Paper

Food

Textiles

Auto

Machinery

Open Gear Chains Conveyors

Source: Kline

Steel 30.0%

Off-Highway Transportation

12.0%

Mining 16.0%

Manufacturing 17.0%

Other 25.0%

Furnaces Rolling Mills

Grease Applications

45% of the Worldwide Market – Automotive

HD Trucks

Light Trucks

Source: Kline

Cars

Buses

Agriculture

Construction

Commercial77.8%

Consumer22.2%

Conclusions

When to Lubricate with a Grease •  Choice depends on:

–  Expected operating conditions –  Lubrication system to be used

Ø  Greases are primarily used in rolling element bearings –  In machine parts that are difficult to reach during operation

Ø  To reduce lubricant leakage, dripping and spattering Ø  To seal out contaminants Ø  For intermittently run or stored equipment Ø  For extreme operating conditions (high temperatures, pressures, shock

loads, low speeds) Ø  For noise reduction (grease acts as a "cushion“ in badly worn equipment) Ø  To suspend solid additives (act as a reservoir)

Acknowledgments

l Co-workers at KV Tech for all their support l Lubgrax l Conepro and Braxel