Lubricants and Adhesives

8/10/2019 Lubricants and Adhesives

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Welcome

to the

Monsoon Session 2014 @NIT Calicut

Enjoy the Pleasantness of Monsoon in the Campus!!!


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S7B. Tech. Monsoon 2014

CY 3011 LUBRICANTS AND ADHESIVES


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What is a lubricant ?

A substance introduced to reduce frictionbetween moving surfaces


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Lubricus= Slippery (Latin)

Early concept of lubrication was slipperiness

and a lubricant was considered as one

promoting sliding.


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Why is it needed?

Reduces friction

Helps to reduce tear and wear

Acts as a coolant Prevents corrosion

Keeps out dirt

Acts as a seal
http://www.google.co.in/imgres?q=lubrication+systems+in+cars&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=v3Z28ueNKgoFAM:&imgrefurl=http://www.english-online.at/travel/cars/cars-and-how-they-work.htm&docid=mXPx1KFQXuWWEM&imgurl=http://www.english-online.at/travel/cars/lubrication-system.gif&w=236&h=191&ei=2W_lUJ_-MILKrAeApoHoCg&zoom=1&iact=hc&vpx=837&vpy=175&dur=1076&hovh=152&hovw=188&tx=126&ty=90&sig=111074418618254241189&page=2&tbnh=144&tbnw=178&start=10&ndsp=15&ved=1t:429,r:14,s:0,i:130


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Major companies

.
http://www.google.co.in/imgres?q=lubricant+companies+in+india&start=335&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=Vohckiviq02LtM:&imgrefurl=http://topnews.in/companies/shell&docid=UoK6P4f98POesM&imgurl=http://topnews.in/files/Shell-Grand-prix-2010.jpg&w=400&h=400&ei=CXTlUP-4EY6Prgeb9IHYBw&zoom=1&iact=rc&dur=327&sig=111074418618254241189&page=19&tbnh=152&tbnw=170&ndsp=19&ved=1t:429,r:42,s:300,i:130&tx=125&ty=85http://www.google.co.in/imgres?q=lubricant+companies+in+india&start=375&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=1y9tU4_lvHGI6M:&imgrefurl=http://www.top10best.in/indian-companies-by-highest-revenue/&docid=L_X-Erb_g23ldM&imgurl=http://www.top10best.in/wp-content/uploads/2012/09/Hindustan-Petroleum.jpg&w=203&h=250&ei=CXTlUP-4EY6Prgeb9IHYBw&zoom=1&iact=rc&dur=499&sig=111074418618254241189&page=21&tbnh=148&tbnw=120&ndsp=19&ved=1t:429,r:81,s:300,i:247&tx=42&ty=77http://www.google.co.in/imgres?q=lubricant+companies+in+india&start=335&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=Vohckiviq02LtM:&imgrefurl=http://topnews.in/companies/shell&docid=UoK6P4f98POesM&imgurl=http://topnews.in/files/Shell-Grand-prix-2010.jpg&w=400&h=400&ei=CXTlUP-4EY6Prgeb9IHYBw&zoom=1&iact=rc&dur=327&sig=111074418618254241189&page=19&tbnh=152&tbnw=170&ndsp=19&ved=1t:429,r:42,s:300,i:130&tx=125&ty=85http://www.google.co.in/imgres?q=lubricant+companies+in+india&start=261&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=kB7TtEoaDEwE_M:&imgrefurl=http://www.exportersindia.com/indian-suppliers/industrial-lubricant.htm&docid=Ngo7wU2cn-7euM&imgurl=http://74.84.129.4/dynamic/company_logo/1179349.jpg&w=100&h=100&ei=o3PlUMDXAY6GrAeExoCgDg&zoom=1&iact=rc&sig=111074418618254241189&page=15&tbnh=80&tbnw=80&ndsp=18&ved=1t:429,r:73,s:200,i:223&tx=39&ty=37http://www.google.co.in/imgres?q=lubricant+companies+in+india&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=Wyep8xzmsoJdsM:&imgrefurl=http://www.bp.com/sectiongenericarticle.do?categoryId=9047472&contentId=7081136&docid=XSE9SAbzMgRVnM&imgurl=http://www.bp.com/liveassets/bp_internet/globalbp/STAGING/global_assets/images/locations/india/india_castrol_375x220.jpg&w=375&h=220&ei=I3HlUPi4CM3HrQfG5YDQCQ&zoom=1&iact=rc&sig=111074418618254241189&page=4&tbnh=139&tbnw=226&start=55&ndsp=18&ved=1t:429,r:58,s:0,i:268&tx=79&ty=71http://www.google.co.in/imgres?q=lubricant+companies+in+india&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=RkFhD2kme6s0wM:&imgrefurl=http://trade.indiamart.com/details.mp?offer=3489213912&docid=WOBK9wBSDr0d-M&imgurl=http://2.imimg.com/data2/XK/XB/MY-2222234/mak-lubricants-suppliers-in-chennai-250x250.jpg&w=250&h=250&ei=I3HlUPi4CM3HrQfG5YDQCQ&zoom=1&iact=rc&dur=234&sig=111074418618254241189&page=2&tbnh=145&tbnw=150&start=12&ndsp=19&ved=1t:429,r:17,s:0,i:139&tx=82&ty=114http://www.google.co.in/imgres?q=lubricant+companies+in+india&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=WzkqZGyXOpomUM:&imgrefurl=http://www.indiamart.com/ludhianaoil/profile.html&docid=zoCOhWAA6MbJwM&imgurl=http://2.imimg.com/data2/JL/WF/MY-/logo-250x250.gif&w=199&h=88&ei=I3HlUPi4CM3HrQfG5YDQCQ&zoom=1&iact=hc&vpx=144&vpy=307&dur=125&hovh=70&hovw=159&tx=86&ty=69&sig=111074418618254241189&page=2&tbnh=70&tbnw=159&start=12&ndsp=19&ved=1t:429,r:13,s:0,i:127http://www.google.co.in/imgres?q=lubricant+companies+in+india&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=kUQiebgkqF-iRM:&imgrefurl=http://www.indian-commodity.com/top-news/ioc-to-market-bio-lubricant-next-year.aspx&docid=4xKdw2lpsdGnaM&imgurl=http://www.indian-commodity.com/top-news/images/IOC-To-Market-Bio-Lubricant-Next-Year.gif&w=429&h=502&ei=I3HlUPi4CM3HrQfG5YDQCQ&zoom=1&iact=rc&dur=468&sig=111074418618254241189&page=2&tbnh=145&tbnw=125&start=12&ndsp=19&ved=1t:429,r:12,s:0,i:124&tx=42&ty=65http://www.google.co.in/imgres?q=importance+of+lubrication&num=10&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=sBkGuZuHsyGfBM:&imgrefurl=http://anikcorinstallations.com/the-importance-of-lubrication&docid=sn9GaL3u-tqyIM&itg=1&imgurl=http://anikcorinstallations.com/wp-content/uploads/2012/04/lubrication-service.jpg&w=224&h=224&ei=4CzlUJ2nFJHrrQeZh4Fg&zoom=1&iact=hc&vpx=846&vpy=95&dur=1342&hovh=179&hovw=179&tx=105&ty=79&sig=111074418618254241189&page=3&tbnh=133&tbnw=140&start=29&ndsp=19&ved=1t:429,r:34,s:0,i:196


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Adhesive

An adhesive is any substance that, when

applied to the surfaces of materials, binds the

surfaces together and resists separation.

The term "adhesive" may be used

interchangeably with glue, cement, mucilage

or paste.


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Why is it needed?

The use of adhesives offers many advantages over other binding

techniques such as sewing, welding, bolting etc.

These advantages include :

The ability to bind different materials together

The ability to distribute stress more efficiently acrossthe joint

Cost effectiveness of an easily mechanized process

Improvement in aesthetic(std) design

Increased design flexibility


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Major companies

United Gilsonite

Laboratories

(German)

MAPEI
http://www.logo-tape.de/en/index.htmhttp://www.uhu.com/de/produkte/korrektur-produkte.htmlhttp://www.ugl.com/http://www.brandsoftheworld.com/logo/fevicol?original=1


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Surfaces

We need to know the features of surfaces

onto which the lubricant/ adhesive is to be

tried.

Let us initially go into it!
http://en.wikipedia.org/wiki/File:ND_DN_2006FO.jpghttp://en.wikipedia.org/wiki/File:Federer_Wimbledon_2006.JPG


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Surfaces

Different surfaces

Metals, Ceramics, Polymers etc.

Evaluation of surface features Surface structure and properties

Substrate, work hardened layer, amorphous

layer, oxide layer, adsorbed gases,contaminants
http://www.google.co.in/imgres?q=surface+structure&um=1&hl=en&sa=N&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=HNpyFDyREQhCVM:&imgrefurl=http://icd.uni-stuttgart.de/?p=5655&docid=WiELfIXpRCmRnM&imgurl=http://icd.uni-stuttgart.de/icd-imagedb/Web_ICD_Research_ResponsiveStructure.jpg&w=640&h=480&ei=zyrlUMDWFs37rAf7nYHICw&zoom=1&iact=hc&vpx=766&vpy=118&dur=546&hovh=194&hovw=259&tx=148&ty=123&sig=111074418618254241189&page=1&tbnh=137&tbnw=192&start=0&ndsp=15&ved=1t:429,r:14,s:0,i:130http://en.wikipedia.org/wiki/File:Close_packing_box.svg


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Metals

o Metal (from Greekmtallon) - mine, quarry, metal

o The atoms of metallic substances are closely positioned to neighbouring

atoms in one of two common arrangements.

o The first arrangement is known as body-centered cubic. In this

arrangement, each atom is positioned at the centre of eight others.

o The other is known as face-centered cubic. In this arrangement, each

atom is positioned in the centre of six others.

o The ongoing arrangement of atoms in these structures forms a crystal.
http://en.wikipedia.org/wiki/File:Close_packing_box.svg


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Hume-Rothery rules

Named after William Hume -Rothery

A set of basic rules describing the conditions

under which an element could dissolve in a

metal, forming a solid solution.

There are two sets of rules, one which refers

to substitutional solid solutions, and another

which refers to intertstitial solid solutions.


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Substitutional Solid Solution Rules

For substitutional solid solutions, the Hume-Rothery rules are:

The atomic radii of the solute and solvent atoms must differ by nomore than 15%

The crystal structures of solute and solvent must match

Complete solubility occurs when the solvent and solute have thesame valency

A metal will dissolve into a metal of higher valency to a greaterextent than one of lower valency.

The solute and solvent should have similar electronegativity.

(If the electronegativity difference is too great, the metals will tendto form intermetallic compounds instead of solid solutions.)

Foundations of Materials Science and Engineering, 4th ed., W. Smith and J.

Hashemi, pp.139-140 (2006).
http://www.clker.com/clipart-6994.htmlhttp://www.clker.com/clipart-11677.htmlhttp://www.clker.com/clipart-6994.html


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Interstitial solid solutions

Solute atoms must be smaller than the

interstitial sites in the solvent lattice.

The solute and solvent should have similar

electronegativity

Hume-Rothery Rules". Van Nostrand's Scientific Encyclopedia. John Wiley &

Sons, Inc. 2002.
http://rosswarner.com/Apict0604.html


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Metal Surface Texture

Lay

Shows the direction of the predominantsurface pattern

Flaws

Random irregularities

(cracks, holes, scratches)

WavinessRecurrent deviation from a flat surface , much likewaves on the surface.
http://www.google.co.in/imgres?q=surface+waviness&um=1&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=TCdlBeo7O7D5qM:&imgrefurl=http://procnc.com/resources/newsletter/august_2010_-_surface_roughness/&docid=PltloPXySljlUM&imgurl=http://procnc.com/images/content/texture.jpg&w=430&h=201&ei=0SvlUIbNGIWyrAeO8oCgAQ&zoom=1&iact=rc&dur=234&sig=111074418618254241189&page=2&tbnh=93&tbnw=200&start=15&ndsp=16&ved=1t:429,r:29,s:0,i:177&tx=116&ty=65http://www.google.co.in/imgres?q=surface+waviness&um=1&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=TCdlBeo7O7D5qM:&imgrefurl=http://procnc.com/resources/newsletter/august_2010_-_surface_roughness/&docid=PltloPXySljlUM&imgurl=http://procnc.com/images/content/texture.jpg&w=430&h=201&ei=0SvlUIbNGIWyrAeO8oCgAQ&zoom=1&iact=rc&dur=234&sig=111074418618254241189&page=2&tbnh=93&tbnw=200&start=15&ndsp=16&ved=1t:429,r:29,s:0,i:177&tx=116&ty=65http://www.google.co.in/imgres?q=surface+structure&um=1&hl=en&sa=N&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=spncrd6Kil074M:&imgrefurl=http://scriptedbypurpose.wordpress.com/participants/axel-kilian/&docid=9udR8MQNuhDYCM&imgurl=http://scriptedbypurpose.files.wordpress.com/2007/07/fish2m-g.jpg&w=400&h=253&ei=zyrlUMDWFs37rAf7nYHICw&zoom=1&iact=rc&dur=531&sig=111074418618254241189&page=1&tbnh=137&tbnw=242&start=0&ndsp=15&ved=1t:429,r:11,s:0,i:121&tx=109&ty=97


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LAY
http://en.wikipedia.org/wiki/File:Surface_finish_lay_patterns.png


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Surface Roughness

Consists of closely spaced , irregular

deviationson a scale smaller than that for

waviness

Measured using a profilometer
http://en.wikipedia.org/wiki/File:Mechanical_filtering_of_surface_finish_trace.svg


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Roughness expressions

CLA

RMS

CLA = (ya+ yb+yc+)

n

a b c

de f

g h

y

x

Surface Profile

Central ( Datum) line

(Ya+ y

b+y

c+)

n(Ya+ yb+yc+)

n


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RMS = [ (ya2+ yb

2 + yc2++ yn

2)/n]1/2

122

RMS 63 is a smooth surface finish, RMS 125 is an average

manufacturing surface, RMS 25 is a very clean smooth surface

finish.

My cell phone has an RMS of around 32, smoother would make it too slippery.

A magazine cover is about 16.

A business card is between 32 and a 16..

A mirror or window is about 4.

RMS value is generally 11% higher than the Ra value for the same surfaceroughness.


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Density measurements

Crystalline areas are generally more densely

packed than amorphous(irregular) areas.

This results in a higher density, up to 15%

depending on the material.


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High quality surfaces

possess low coefficient

of friction.


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Contaminant ( 1-100nm)

Adsorbed gas ( 1nm)

Oxide ( 10-100 nm)

Amorphous ( 1-100 nm)

Work hardened

( 1-100 micron)

METAL SUBSTRATE


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Ceramics

A ceramic is an inorganic, non-metallic solid prepared by the

action of heat and subsequent cooling.

Ceramic materials may have a crystalline or partly crystalline

structure, or may be amorphous (e.g., a glass).

Bearing parts from ceramics
http://en.wikipedia.org/wiki/File:Ball_Bearing2.jpghttp://en.wikipedia.org/wiki/File:Israel-2013-Jerusalem-Temple_Mount-Dome_of_the_Rock-Detail_01.jpghttp://en.wikipedia.org/wiki/File:Si3N4bearings.jpg


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Most chip resistors are of the so-called thick film construction, where patterns of

inks containing glass frit and a mix of metals and oxides are printed onto a

ceramic substrate


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o Simple crystal structurescontaining ionic or

covalent bonds, or a mixture of the two.

o Magnesium oxide (used for furnace linings)- is

an ionic compound with cubic structure

o Silicon carbide- Covalent bonds and a

tetrahedral structure similar to that ofdiamond.


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o Complex silicate structures: The majority

of ceramic materials, in particular thosederived from clay, sand or cement,

contain the element silicon in the form of

silicates.

o The arrangements are many, involving

both chains of silicate ions, double chains

and links in sheet form


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Technical ceramics can be classified into three distinct

material categories:

Oxides: alumina, beryllia, ceria, zirconia

Nonoxides: carbide, boride, nitride, silicide

Composite materials: particulate reinforced, fiber reinforced,

combinations of oxides and nonoxides

Carbon-Ceramic ( SiC) Disk Brake
http://en.wikipedia.org/wiki/File:PCCB_Brake_Carrera_GT.jpg


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Grain size

The main disadvantage of Ceramicsas compared to Metals is their low fracture

toughness.

Toughness is a bulk mechanical property of a material; however it correlates

with its wear resistance particularly when the wear is a result of abrasive action

.

Fine grain structure allows to decrease the size of the surface micro-asperities

after the surface finish operation resulting in lower coefficient of friction.

Silicon nitride rocker thruster

( Left: on test stand ; Right :test with

propellants)
http://www.substech.com/dokuwiki/doku.php?id=ceramicshttp://www.substech.com/dokuwiki/doku.php?id=metalshttp://www.substech.com/dokuwiki/doku.php?id=fracture_toughness_tests_of_ceramicshttp://www.substech.com/dokuwiki/doku.php?id=fracture_toughness_tests_of_ceramicshttp://www.substech.com/dokuwiki/doku.php?id=mechanisms_of_wearhttp://en.wikipedia.org/wiki/File:Si3N4thruster.jpghttp://www.substech.com/dokuwiki/doku.php?id=mechanisms_of_wearhttp://www.substech.com/dokuwiki/doku.php?id=fracture_toughness_tests_of_ceramicshttp://www.substech.com/dokuwiki/doku.php?id=fracture_toughness_tests_of_ceramicshttp://www.substech.com/dokuwiki/doku.php?id=metalshttp://www.substech.com/dokuwiki/doku.php?id=ceramics


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Toughness

Toughness is a measure of the energy a

sample can absorb before it breaks.

If the height of a triangle is strength, and the

base of the triangle is strain, then the area is

proportional to strength times strain.


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Since strength is proportional to the force

needed to break the sample, and strain ismeasured in units of distance (the distance the

sample is stretched), then strength times strain

is force times distance. Force times distance is energy!


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Critical flaw size

Critical flaw size(the size of a flaw that results in rapid fracture)

Effect of flaw size on the fracture strength of a ceramic material is expressed by

the Griffith equation:

C=KIC/*Y( a)+where:

KICstress-intensity factor

athe flaw size;

Ygeometry factor

According to the equation flaws of lower size result in increased material

toughness and higher wear resistance.

Flaw size is generally proportional to the grain size.


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Homogeneous distribution of the matrix particles size and

pores size, second phaseparticles (toughening particles)

incorporated between the matrix particles, aid phase (binders,etc.) locating at the grains boundaries results in lowering the

flaw size and consequently in increase of the fracture strength

(according to the Griffith equation).

Higher fracture strength causes higher wear resistance.
http://www.substech.com/dokuwiki/doku.php?id=solid_solutionshttp://www.substech.com/dokuwiki/doku.php?id=solid_solutions


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Polymer surface

Does not corrode but degrade.

Strength is low compared to metals

but has low frictional

characteristics.

Used to make bearings, gears, seals

etc.
http://en.wikipedia.org/wiki/File:Professor_Calculus.pnghttp://en.wikipedia.org/wiki/File:Professor_Calculus.png


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Hard, strong

Hard, tough

Soft, tough
http://www.google.co.in/imgres?q=polymers&start=184&um=1&hl=en&sa=N&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=-Jmvvwk8xP6b5M:&imgrefurl=http://www.snpinc.com/&docid=7KdD6iLAlQoZhM&imgurl=http://www.snpinc.com/images/home-promo-think-green.jpg&w=442&h=402&ei=ru_sUOO6B4PukQWFp4DYBw&zoom=1&iact=rc&dur=16&sig=111074418618254241189&page=12&tbnh=146&tbnw=160&ndsp=16&ved=1t:429,r:94,s:100,i:286&tx=86&ty=105


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Brinell Hardness Number

A steel or tungsten carbide ball of 10 mm dia is pressed against

a surface with a load ( kg).

The ratio of load P to the curved area of indentation is Brinell

Hardness

HB = 2P/{ (D) [ D- (D2 - d2)1/2 } kg/mm2

D is the diameter of the ball and d is the diameter of the

impression in mm


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Hardness and Resilience

H= cY

where Y is the yield stress, c= constant

Modulus of Resilience= Y2/2E

E= Youngs modulus


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A piece of steel has a hardness of 480 HB

( kg/mm2). Find the modulus of resilience

of this material , If E= 1400 MPa.

Take C = 3.

(MULTIPLY kg/mm2 WITH 9.807 TO CONVERT

INTO MPa)


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WE ARE GOING THROUGH AUGUST 2014!

Augusts birth flower is gladiolus or poppy,meaning:

beauty

strength of character and

love
http://en.wikipedia.org/wiki/File:Gladiolus_imbricatus1002.jpg


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BASE OILS

Lubricants and adhesives are developed

based on different oils

Their flow features control the wetting of

the surfaces ( metal, ceramic or polymer)for effective application


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We now deal with:

Surface Tension

Viscosity Measurement

Newtonian and NonNewtonian Fluids

Melt Flow etc.
http://en.wikipedia.org/wiki/File:Drop_0.jpg


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Surface Tension

The force in Newton acting at right angles

along the surface of a liquid one metre in

length.

N/m
http://www.google.co.in/imgres?q=surface+tension&um=1&hl=en&sa=N&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=HdhDSu8mqOAYVM:&imgrefurl=http://www.gutterremedy.com/howitworks.html&docid=f7eHZkH_adnR9M&imgurl=http://www.gutterremedy.com/images/surface-tension-floating-coin.jpg&w=200&h=260&ei=WWjqULaNJYuykgX0mICABA&zoom=1&iact=hc&vpx=2&vpy=2&dur=15241&hovh=208&hovw=160&tx=82&ty=63&sig=111074418618254241189&page=2&tbnh=144&tbnw=111&start=10&ndsp=18&ved=1t:429,r:22,s:0,i:187


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Surface tension- Determination

Stalagmometer method Compares an experimental liquid with a reference

liquid

e = r x (nrde/ nedr)

ne = number of drops of experimental liquid in acertain volume

nr = number of drops of reference liquidde = density of experimental liquid

dr = density of the reference liquid


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Equal volumes of ethyl alcohol and water gave

50 drops and 30 drops respectively. Calculate

the surface tension of ethyl alcohol.

Given that surface tension of water is

7.2 x 10-2 Nm-1, density of water 996 kg/m3

and that of ethyl alcohol is 865 kg/m3.

How many times a water drop is heavier than a

drop of ethyl alcohol?


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3.75 x 10-2 N/m

mr/me = r/ e

= 1.92


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Capillary rise method

= rhdg/(2cos )

r= inner radius of capillary

h= height to which the liquid rises in the

capillary

d= density of the liquid

g= acceleration due to gravity= contact angle


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A liquid having density of 0.90 g/cm3 rises in a

capillary of radius 0.1 mm upto a height of 8

cm .Assume perfect wetting . Find the surface

tension.


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3.53 x 10-2 kg/s2 ( F= ma ; 1N= 1 kg m s-2)

3.53 x 10-2 N/m


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Viscosity- Capillary viscometers

These devices also are known as glass capillary viscometers

or Ostwald viscometers, named after Wilhelm Ostwald.Another version is the Ubbelohdeviscometer.

U-shaped glass tube held vertically in a controlled

temperature bath.. The time taken for the level of the liquid to pass between

two designated marks is proportional to the kinematic

viscosity
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Viscosity

Falling Sphere method

Stokes law is the basis of the falling sphere viscometer,.

The fluid is kept stationary in a vertical glass tube.

A sphere of known size and density is allowed to descend

through the liquid.

If correctly selected, it reaches terminal viscosity, which can

be measured by the time it takes to pass two marks on the

tube.

A series of steel ball bearings of different diameter is normally

used in the classic experiment to improve the accuracy of the

calculation.


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Viscosity

Stokes Law

= *2 g r2(ds - dl)]/ 9v

A steel ball ( density= 8 x 10 3 kg/m3) with 1 mm radius falls 10 cm

through a viscous liquid ( density = 2 x 10 3 kg/m3) in 20 seconds.

Find the absolute viscosity of the liquid.

2.6 kg m-1s-1

2.6 Pa s


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Newtons law

Laminar ( streamlined ) flow

The tangential force depends on:

Area of contact between two adjacent layers (A)

Velocity difference between the adjacent layers(dv)

The distance between adjacent layers (dx)

Hence F A dv/dx

F= A dv/dx

S l


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Supplementary notes..

Dimensions

F A dv/dx

F= A dv/dx

= F/ A (dv/dx)

= F dx/ A dv

= Nm/m2 ( m/s)

= N s m-2

= Pa.s

CGS: 1 Poise = 1 dynes s cm-2 = 0.1 Ns m-2
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Viscosity coefficients

Viscosity coefficients can be defined in two ways:

Dynamic viscosity, also absolute viscosity, the more usual one(typical units Pas, Poise, P);

Kinematic viscosityis the dynamic viscositydivided by thedensity (typical units cm2/s, Stokes, St).

Viscosity is a tensorial quantity that can be decomposed indifferent ways into two independent components. The mostusual decomposition yields :

Shear viscosity

bulk viscosity
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Shear viscosity, the most important one, often

referred to as simply viscosity, describing the

reaction to applied shear stress; simply put, it

is the ratio between the pressure exerted onthe surface of a fluid, in the lateral or

horizontal direction, to the change in velocity

of the fluid as you move down in the fluid (thisis what is referred to as a velocity gradient.).
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Volume viscosity(also called bulk viscosityorsecond viscosity) becomes important only forsuch effects where fluid compressibility isessential.

Extensional viscosity, a linear combination ofshear and bulk viscosity, describes the reaction toelongation, widely used for characterizingpolymers.

For example, at room temperature, water has adynamic shear viscosity of about 1.0103Pasand motor oil of about 250103Pas.
http://en.wikipedia.org/wiki/Extensional_viscosityhttp://www.google.co.in/imgres?q=moving+surfaces+need+lubrication&start=712&um=1&hl=en&sa=N&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=jQoBt37E7l4dJM:&imgrefurl=http://www.fabricatingandmetalworking.com/2011/06/stick-slip-or-what-makes-slideways-and-violins-different/&docid=FcYlBGR7zJiZIM&imgurl=http://www.fabricatingandmetalworking.com/cms/wp-content/uploads/2011/06/300-figure-1.jpg&w=300&h=219&ei=xIPlUJnnGMKNrgei-YCYCw&zoom=1&iact=rc&sig=111074418618254241189&page=41&tbnh=119&tbnw=163&ndsp=23&ved=1t:429,r:27,s:700,i:85&tx=71&ty=60http://en.wikipedia.org/wiki/Extensional_viscosity


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Viscosities of materials

Substance Viscosity

( MPa s)

Air 10-5

Water 10-3

Glycerol 10

Polymer melts 102

-106


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Viscosity of blendsThe viscosity of the blend of two or more liquids can be estimated using the

Refutas equation.The calculation is carried out in three steps.

The first step is to calculate the Viscosity Blending Number (VBN) (also called the

Viscosity Blending Index) of each component of the blend:

where vis the kinematic viscosity in centistokes (cSt). It is important that the

kinematic viscosity of each component of the blend be obtained at the sametemperature.

The next step is to calculate the VBN of the blend, using this equation:

wherexX

is the mass fraction of each component of the blend.

Once the viscosity blending number of a blend has been calculated using equation

(2), the final step is to determine the kinematic viscosity of the blend by the equation

for v:where VBNBlendis the

viscosity blending

number of the blend.


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shear stress

shear rate

According to

Newton


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r

Pseudoplastic : shear-thinning fluids

Dilatant : shear-thickening fluids


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n> 1 Dilatants

log n=1 Newtonian

n


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Time dependa(e)nt and time independa(e)nt

fluids

Rheopectic fluid: increases with increasing t

Thixotropic fluid, decreases with increasing t


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Leonardo da vinci (1452-1519)

Proposed the fundamental principles

of friction and lubrication
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Classical laws of friction

Frictional force is proportion to the appliedload

Coefficient of friction is independent of the

apparent area of contact Static coefficient is greater than dynamic

coefficient

Coefficient of friction is independent of slidingspeed

Coefficient of friction is material dependent
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Types of lubrication

Thick-film lubricationInterposing a fluid film that completely

separates the sliding surfaces.

Hydrodynamic lubrication.

In this, the two moving parts are separated by a thick film of

lubricant, about 1000A thick.

This type of lubrication occurs in machine parts of low load and

high speed such as in clocks, sewing machines (delicateinstruments).

The coefficient of friction is low; typically 0.001 to 0.03.
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Boundary lubrication

A condition that lies between unlubricated sliding and fluid

film lubrication is referred to asboundary lubrication. Thin film lubrication

It occurs in machine parts of high load and low speed. Here

thick film of lubricant cannot be maintained between the

moving surfaces but the lubricants are adsorbed physically /

chemically on the metal surfaces. The lubricant film thickness is

as low as 2-3-molecule thickness with the frictional coefficient

being 0.05 to 0.15.

Extrerme pressure lubrication
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Extrerme pressure lubrication

This mechanism occurs under conditions of high load and high speed.

Under these conditions, the lubricant may vaporize / decompose due

to local heat. Special additives called extreme pressure additives are used with

lubricants to overcome this difficulty.

Organic compounds containing active groups such as chlorine,

phosphorous, sulphur are used as extreme pressure additives.

At high temperatures, the additives react with metals giving metallic

chlorides / sulphides / phosphides possessing high melting points.

Variation of (viscosity)
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Variation of (viscosity)

with temperature T

Viscosity

Temperature


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Too Thick

whencold

Viscosity / Temperature Relationship

Thick

SAE 40

SAE10W40

SAE

10W

Too Thinwhen

hot

Increasing

Viscosity

Thin

Winter starting

temperature

Engine operating

temperature100oc0oc

Viscosity index
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Viscosity index

Measure of fluids change of viscosity with

temperature.

Empirical number

Higher the VI lower will be the change of viscositywith temperature

Indicator of temperature range of operations
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SUV ( Saybolt Universal Viscosity)

Cylindrical brass cup in the bottom of which

is an orifice of specific dimension.

The cup is surrounded by an oil bath.

At the test temperature, the time requiredfor 50 mil of the liquid to run down through

the orifice is noted.

Unit is sec.
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Calculation

VI= [( L-U)/ (L-H) ] x 100

VI = Viscosity Index of the oil under test

L= Viscosityof a low viscosity standard oil

having a low VI at 100 F ( Typically gulfoil)

H = Viscosityof a high viscosity standard oil

having a high VI at 100 F ( Typically Pennsylvanian

oil)

U = Viscosity of the test oil at 100 F
http://www.terragalleria.com/pictures-subjects/refineries/picture.refineries.usnv54818.html


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Try it

An oil has a SUV of 600 seconds at 100 F.

Pennsylvanian oil has a SUV of 500 sec at 100 F

while gulf oil has a SUV of 800 sec at 100 F.

Find the viscosity index of the experimental oil.

VI = 66.67
http://www.terragalleria.com/pictures-subjects/refineries/picture.refineries.usca9426.html


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API gravity

A measure of how heavy or light a petroleumliquid is comparedto water.

If its API gravity is greater than 10, it is lighter and floats on

water; if less than 10, it is heavier and sinks.

API gravity is thus an inverse measure of the relative density of a

petroleum liquid and the density of water, but it is used to

compare the relative densities of petroleum liquids.

For example, if one petroleum liquid floats on another and is

therefore less dense, it has a greater API gravity.
http://en.wikipedia.org/wiki/Petroleumhttp://en.wikipedia.org/wiki/List_of_crude_oil_productshttp://en.wikipedia.org/wiki/List_of_crude_oil_productshttp://en.wikipedia.org/wiki/Petroleum


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The formula to obtain API gravity ofpetroleumliquids, from specific gravity(SG), is:


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Effect of additives

Hydrodynamic effect

1. Einstein Equation (1906)

Viscosity of a dispersion can be represented as:

f = u(1+2.5C)

C= volume fraction of spheres

u= viscosity of the liquid where uniformly spherical

particles are distributed


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2. Guth and Gold Equation ( 1938)

f = u(1+2.5C+14.1 C2)

3. Guth Equation ( 1945) [ For non-spherical

particles]

f = u(1+0.67 f C+ 1.62f2C2)

f is the shape factor, the ratio of the longest

to the shortest diameter of the particles

Flash Point


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Flash Point

Lowest temperature at which the vapor above theliquid will ignite under flame

Indicated safe maximum temperature of

operation. Indicator of volatility

Measured in C

h ?
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Why is it important?

The flash pointof a volatilematerial is the

lowest temperatureat which it can vaporize to

form an ignitable mixture in air.

Measuring a flash point requires an ignitionsource.

At the flash point, the vapor may cease to burn

when the source of ignition is removed.

h ?
http://en.wikipedia.org/wiki/Volatility_(chemistry)http://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Airhttp://www.google.co.in/imgres?imgurl=http://images.wisegeek.com/motor-oil-being-poured-out.jpg&imgrefurl=http://www.wisegeek.org/what-are-the-different-types-of-lubricants.htm&usg=__s7R1CZGP0EFC1PYcANhnvhiurOk=&h=1302&w=1000&sz=65&hl=en&start=263&zoom=1&tbnid=MrF_EXSRD_A3wM:&tbnh=150&tbnw=115&ei=y54kUZbeAZHorQeU-4H4CA&prev=/search?q=lubricating+oils-+cartoon&start=260&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CC0QrQMwAjiEAghttp://en.wikipedia.org/wiki/Airhttp://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Volatility_(chemistry)


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Why is it important.?

The flash point is not to be confused with the

autoignition temperature, which does not require an

ignition source, or the fire point, the temperature at

which the vapor continues to burn after being ignited.

Neither the flash point nor the fire point is dependent

on the temperature of the ignition source, which is

much higher.

h i i i ?
http://en.wikipedia.org/wiki/Autoignition_temperaturehttp://en.wikipedia.org/wiki/Fire_pointhttp://en.wikipedia.org/wiki/Fire_pointhttp://en.wikipedia.org/wiki/Autoignition_temperaturehttp://en.wikipedia.org/wiki/Autoignition_temperaturehttp://en.wikipedia.org/wiki/Autoignition_temperature


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Why is it important?

The flash point is often used as a descriptive characteristicof liquids, and it is also used to help characterize the fire

hazards of liquids.

Flash point refers to both flammableliquids and

combustibleliquids. There are various standards for

defining each term.

Liquids with a flash point less than 37.8 C (100 F) areconsidered flammable, while liquids with a flash point

above it are considered combustible.

H i fl h ?
http://en.wikipedia.org/wiki/Flammabilityhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Combustionhttp://en.wikipedia.org/wiki/Flammabilityhttp://www.google.co.in/imgres?imgurl=http://abiramiengg.com/transformer/flashpoint.jpg&imgrefurl=http://abiramiengg.com/transformer-oil-test-lab.htm&usg=__vKRPhfLTQb87irT68Mhd_RW7Ruo=&h=241&w=250&sz=78&hl=en&start=66&zoom=1&tbnid=jKthbrMSmX_GqM:&tbnh=107&tbnw=111&ei=Gl4kUaeyDIz9rAeXkYGAAg&prev=/search?q=flash+point+of+lubricating+oils&start=60&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDMQrQMwBTg8


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How it flashes?Every liquidhas a vapour pressure, which is a functionof that

liquid's temperature.

As the temperature increases, the vapour pressure increases.

As the vapor pressure increases, the concentration of vapor of

the flammable liquid in the air increases. Hence, temperaturedetermines the concentration of vapour of the flammable

liquid in the air.

A certain concentration of vapour in the air is necessary tosustain combustion, and that concentration is different for each

flammable liquid. The flash point of a flammable liquid is the

lowest temperature at which there will be enough flammable

vapour to ignite when an ignition source is applied.

Measurement-
http://en.wikipedia.org/wiki/Liquidhttp://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Function_(mathematics)http://en.wikipedia.org/wiki/Temperaturehttp://www.google.co.in/imgres?imgurl=http://abiramiengg.com/transformer/flashpoint.jpg&imgrefurl=http://abiramiengg.com/transformer-oil-test-lab.htm&usg=__vKRPhfLTQb87irT68Mhd_RW7Ruo=&h=241&w=250&sz=78&hl=en&start=66&zoom=1&tbnid=jKthbrMSmX_GqM:&tbnh=107&tbnw=111&ei=Gl4kUaeyDIz9rAeXkYGAAg&prev=/search?q=flash+point+of+lubricating+oils&start=60&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDMQrQMwBTg8http://en.wikipedia.org/wiki/Temperaturehttp://en.wikipedia.org/wiki/Function_(mathematics)http://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Vapor_pressurehttp://en.wikipedia.org/wiki/Liquid


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Measurement

open cup and closed cup

There are two basic types of flash pointmeasurement: open cup and closed cup.

In open cup devices the sample is contained in anopen cup which is heated, and at intervals a flame isbrought over the surface. The measured flash pointwill actually vary with the height of the flame abovethe liquid surface, and at sufficient height the

measured flash point temperature will coincide withthe fire point. The best known example is theCleveland open cup(COC).
http://en.wikipedia.org/wiki/Fire_pointhttp://en.wikipedia.org/wiki/Cleveland_open_cup_methodhttp://en.wikipedia.org/wiki/Cleveland_open_cup_methodhttp://en.wikipedia.org/wiki/Fire_point


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Closed cup testers

There are two types of closed cup testers: non-equilibrium,such as Pensky-Martens where the vapours above the liquidare not in temperature equilibrium with the liquid, andequilibrium, such as Small Scale (commonly known asSetaflash) where the vapours are deemed to be in

temperature equilibrium with the liquid.

In both the above types, the cups are sealed with a lidthrough which the ignition source can be introduced.

Closed cup testers normally give lower values for the flash

point than open cup (typically 5

10 C lower, or 9

18 F lower)and are a better approximation to the temperature at whichthe vapour pressure reaches the lower flammable limit.

ASTM D93 ISO 2719 DIN 51758
http://en.wikipedia.org/wiki/Lower_flammable_limithttp://en.wikipedia.org/wiki/Lower_flammable_limit


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ASTM D93, ISO 2719, DIN 51758

Methods for determining the flash point of a liquid arespecified in many standards. For example, testing by the

Pensky-Martens closed cupmethod is detailed in ASTM D93,

ISO 2719, DIN 51758.

Fuel Flash point
http://en.wikipedia.org/wiki/Pensky-Martens_closed_cuphttp://www.google.co.in/imgres?imgurl=http://www.infovisual.info/05/img_en/002%20Anatomy%20of%20an%20automobile.jpg&imgrefurl=http://www.mahjoob.com/en/forums/showthread.php?t=204338&usg=__zPu6_llPCJ7Eqe4Q_hkIZSv_oDs=&h=391&w=682&sz=98&hl=en&start=18&zoom=1&tbnid=VFyMQXRpC2qmHM:&tbnh=80&tbnw=139&ei=mpokUfymIcPtrAf2pIDwBQ&prev=/search?q=lubrication+system+in+ic+engines&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CEsQrQMwEQhttp://en.wikipedia.org/wiki/Pensky-Martens_closed_cuphttp://en.wikipedia.org/wiki/Pensky-Martens_closed_cuphttp://en.wikipedia.org/wiki/Pensky-Martens_closed_cup


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p

Ethanol(70%) 16.6 C (61.9 F)

Diesel>62 C (144 F)

Jet fuel>60 C (140 F)

Kerosene(paraffin) >3872 C (100162 F)

Vegetable oil(canola) 327 C (621 F)

Cloud Point and Pour Point
http://en.wikipedia.org/wiki/Ethanolhttp://en.wikipedia.org/wiki/Diesel_fuelhttp://en.wikipedia.org/wiki/Jet_fuelhttp://en.wikipedia.org/wiki/Kerosenehttp://en.wikipedia.org/wiki/Vegetable_oilhttp://www.google.co.in/imgres?imgurl=http://lh4.ggpht.com/_EhOQGW2GHBg/SmA9_aji8tI/AAAAAAAAHoc/Ix8sdLWEpno/clip_image0063.gif?imgmax=800&imgrefurl=http://www.meadinfo.org/2009/07/design-and-fabrication-of-ic-engine.html&usg=__XH3flnrdT51qhzZleFSfprYmpew=&h=330&w=499&sz=62&hl=en&start=55&zoom=1&tbnid=QQoQdplcc4-6rM:&tbnh=86&tbnw=130&ei=2ZokUcOiNsn3rQe7yoEI&prev=/search?q=lubrication+system+in+ic+engines&start=40&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CEUQrQMwDjgohttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Kerosenehttp://en.wikipedia.org/wiki/Jet_fuelhttp://en.wikipedia.org/wiki/Diesel_fuelhttp://en.wikipedia.org/wiki/Ethanol


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Cloud point- Temperature at which cloudinessappears

Pour Point -Lowest temperature at which a fluid

will flow Latter indicates lowest operating temperature

Measured in C

A d l b i t
http://www.google.co.in/imgres?imgurl=http://enkaymachine.com/images/EKE503.jpg&imgrefurl=http://enkaymachine.com/eke503.htm&usg=__LJa5k6QDkgzaGoMO7oX8LHMJYB4=&h=450&w=300&sz=35&hl=en&start=4&zoom=1&tbnid=Phi0Pc8gwfWF8M:&tbnh=127&tbnw=85&ei=jyQSUf6PD9GGrAfA9oHIBA&prev=/search?q=pour+point+cloud+point+apparatus&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1


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A good lubricant possesses ..

:

High boiling point ( Flash point)

Low freezing point ( Pour point)

High viscosity index

Thermal stability

Hydraulic StabilityDemulsibility

Corrosion prevention

High resistance to oxidation
http://en.wikipedia.org/wiki/Viscosity_indexhttp://en.wikipedia.org/wiki/Oxidationhttp://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg2p3792702chttp://en.wikipedia.org/wiki/Oxidationhttp://en.wikipedia.org/wiki/Viscosity_index


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Degradation/Combustion

Calculations

Flue gas analysis


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Essentially an exothermic reaction

Oil + Oxygen = Products + Heat

More heat content Lower heat content

Typically,

C(S) + O2 (g) CO2(g) + 97 kcal
http://www.google.com/imgres?q=kerala%27s+greenery&hl=en&authuser=0&biw=1280&bih=570&tbm=isch&tbnid=41W7mdxsdSXwhM:&imgrefurl=http://www.traveltocare.net/Holiday-Packages/India/Kerala-Greenery.aspx&docid=627DGMh-dq-XpM&imgurl=http://www.traveltocare.net/Image.aspx?ID=16116&md=p&w=600&h=300&ei=YtrPUeT6PI7yrQfvzICgAQ&zoom=1&iact=rc&dur=218&page=1&tbnh=137&tbnw=252&start=0&ndsp=18&ved=1t:429,r:16,s:0,i:127&tx=88&ty=39


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http://www.google.co.in/imgres?q=unity+is+strength&start=97&um=1&hl=en&tbo=d&biw=1069&bih=495&tbm=isch&tbnid=b8ltHtVwlxRBsM:&imgrefurl=http://www.downvids.net/unity-is-strength-51280.html&docid=QrmukyQg53kucM&imgurl=http://www.downvids.net/fimagef/unity-is-strength.jpg&w=320&h=180&ei=l_3sUNKxNMOekwXvlIHIAg&zoom=1&iact=rc&dur=628&sig=111074418618254241189&page=7&tbnh=138&tbnw=251&ndsp=20&ved=1t:429,r:4,s:100,i:16&tx=121&ty=96


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Combustion Wt. of oxygen needed

(g)

Volume of oxygen ( m3)

C + O2 CO2

a g or m3

(a x 32)/ 12 a x 1

H2 + O.5 o2 H2oy g or m3

(y x 16)/2 Y x 0.5

CO + O.5 o2 CO2

z g or m3

(z x 16)/28 Z x .0.5

S+ O2 SO2

p g or m3

(p x 32)/32 P x 1


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3. Air contains 21 % of oxygen by volume and 23 % oxygenby mass.

1kg of oxygen is supplied by (1 x 100)/23 = 4.35 kg of air

1 m3 of oxygen is supplied by (1 x 100)/21 = 4.76 m3 ofair

4. 28.94 g/ mol is taken as the molar mass of air

5. Minimum oxygen required for combustion is:Theoretical oxygen - Oxygen present in the fuel

FUNCTIONAL POLYMERS 2011

Problem 1


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Problem 1

What could be the weight and volume of airrequired for the combustion of 1 kg of

carbon?


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12 g of C needs 32 g of oxygen.

1kg of carbon needs (32/12) x 1000= 2667 g =

2.667 kg

Wt of air required = (100/23) x 2.667 = 11.59

kg


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32 g of oxygen occupies 22.4 l.

2667 g will occupy 22.4/32 x 2667 = 1866.9 L

Volume of air = (100/21) x 1866.9 = 8890 L =

8.89 m3

Carbon residue


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Carbon residue

Weighed amount of lubricant is heated in asilica crucible having a close fitting cover with

a small opening.

Carbon residue= (wt of residue/wt of sample)

x 100

Liquid lubricants
http://www.google.co.in/imgres?imgurl=http://media.zenfs.com/en_us/News/ScientificAmerican/testTube_monkey_transparent_640px.jpg&imgrefurl=http://news.yahoo.com/peerj-just-another-game-player-game-changer-120200176.html&usg=__I47i6YE8_vJWXSjI9hfySa82g3c=&h=371&w=336&sz=17&hl=en&start=10&zoom=1&tbnid=l2-Gj7J-ogEAnM:&tbnh=122&tbnw=110&ei=ZrAkUeuBOYKJrAelqYGoAQ&prev=/search?q=monkey+with+a+test+tube&um=1&hl=en&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDsQrQMwCQhttp://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg4p4226433c


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Liquid lubricants

Liquid lubricants are fluidsthat preventfriction and wear between two machine

parts. Common liquid lubricants include water-

based lubricants and synthetic oils.

Many liquid lubricants can pollute theenvironment, so proper disposal of used

lubricant is essential.

Mineral Oils
http://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg4p4226433chttp://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg2p6436542c


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Mineral oils are usually made from

crude(impure) petroleum, which can beprocessed to create fluids with varying

viscosity.

TYPICAL COMPOSITION OF
http://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg2p6436542c


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AN ENGINE OIL

Components Base oils

Dispersants

Detergents

Anti-wear

Anti-oxidant

Pour point depressant

Anti-foam

Viscosity Improver

Quality oil

%

>70

0 to 7

0 to 3

0 to 20 to 3

0.2

0.001

5 to 15

100%


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SMART LUBRICANTS

SAE Coding


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SAE Coding

The Society of Automotive Engineers (SAE) has established anumerical code system for grading motor oils according to theirviscosity characteristics.

SAE viscosity gradings include the following, from low to highviscosity: 5, 10, 15, 20, 25, 30, 40, 50 or 60.

The numbers 5, 10, 15 and 25 are suffixed with the letter W,designating they are "winter" (not "weight") or cold-startviscosity, at lower temperature.

Ref: Thomas R. Lynch, Process Chemistry of Lubricant Base Stocks,CRC Press, Boca Raton, FL, 2008.

NR + SAE


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ISNR -5 was dissolved in SAE OilSample Code Amount of SAE 30 Oil

(ml)

Amount of NR

(g)

A1 250 5

A2 250 10

A3 250 15

A4 250 20

A5 250 25


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105/126


106/126


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SAMPLE POUR

POINT (c)

SAE

30(TURBO)

-9

A1 -11

A2 -14

A3 -17

A4 -19

A5 -21

SAE 60 -29

Synthetic Oils


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Synthetic oils are man-made lubricants that have

greater operating ranges than mineral oil lubricants.

As a result, synthetic oils are better choices than

mineral oils in certain circumstances. Esters, silicone fluid and fluorocarbons are examples

of synthetic oils.

Silahydrocarbonsare synthetic oils composed, as the

name suggested, from hydrogen, silicon and carbon.Silahydrocarbons have the potential to provide fluidity

and lubrication in space machinery.

Vegetable-Based Liquid Lubricants


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Liquid lubricants can also be manufactured from

plant life. Sources of vegetable-based lubricants

include:

canola

palm oil

rapeseed

sunflower seed.

While more environmentally friendly than mineral and

synthetic oils, vegetable-based liquid lubricants are

rarel used in vehicles or machiner
http://www.encyclopedia.com/topic/oils.aspxhttp://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg2p5546631c


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Semi-solids

Grease

Grease is defined as a solid or semi-fluid

product which is a dispersion of athickening agent in a liquid lubricant alongwith some additives.
http://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg2p5546631chttp://www.google.co.in/imgres?imgurl=http://2.imimg.com/data2/WW/XT/MY-329061/thixotropic-moly-grease-250x250-500x500.jpg&imgrefurl=http://www.mrsilicone.in/moly-grease.html&usg=__Kru_0SSbrfX5w44RS4svFIjlH4M=&h=250&w=250&sz=14&hl=en&start=118&zoom=1&tbnid=E6J8KHCz7KHymM:&tbnh=111&tbnw=111&ei=L6EkUf3nJMnJrAfm2YDAAQ&prev=/search?q=solid+lubricants-+graphite+and+molybdenum+sulphide&start=100&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CEsQrQMwEThkhttp://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg3p9776293c


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Greaseis a semisolidlubricant.

It generally consists of a soapemulsified

with mineralor vegetable oil.

The characteristic feature of greases is that

they possess a high initial viscosity, which

upon the application of shear, drops with

time. This change in viscosity, as we have

seen earlier , is called thixotropy.

Why use a Grease?
http://en.wikipedia.org/wiki/Quasi-solidhttp://en.wikipedia.org/wiki/Lubricanthttp://en.wikipedia.org/wiki/Soaphttp://en.wikipedia.org/wiki/Emulsionhttp://en.wikipedia.org/wiki/Mineral_oilhttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Thixotropyhttp://www.crystalgraphics.com/powerpictures/Image.Search.Details.asp?product=cg3p9776293chttp://en.wikipedia.org/wiki/Thixotropyhttp://en.wikipedia.org/wiki/Viscosityhttp://en.wikipedia.org/wiki/Vegetable_oilhttp://en.wikipedia.org/wiki/Mineral_oilhttp://en.wikipedia.org/wiki/Emulsionhttp://en.wikipedia.org/wiki/Soaphttp://en.wikipedia.org/wiki/Lubricanthttp://en.wikipedia.org/wiki/Quasi-solid


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Why use a Grease?

Grease offers unique characteristics which makes it

particularly useful in machine elementsStay where it is putAllows unattended service for long periods(sealed for life)Requires less frequent application for areas ofpoor accessibilitySeals out contaminantsOperate over a wide temperature rangeSolid additives can be used without concern of

settling outLow leakage means they are effective in wornequipment

Advantages over Oil


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g

Grease stays in place because of semisolid nature

whereas oils flow awayBearing designs simplified and maintenance workreduced as there is no oil pump/sump

For long time or packed for life applications grease ispreferred e.g.. electric motors, wheel bearings of new

generation passenger cars, etc.Grease works as a sealant in -

Dusty environment, cement plants, mining industriesetc.

Corrosive water in paper mills

Corrosive gases/liquids in chemical industries.


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Sodium Based Calcium Based

Lithium Base Non-Soap / Synthetic

Greases

Scheme


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Scheme

Oil

Soap

Grease -Additives


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Teflonis added to some greases to improve their lubricating properties.

Gear greases consist of rosinoil, thickened with limeand mixed with mineral oil,with some percentage of water. Special-purpose greases contain glycerolandsome esters. They are used, for example, in low-temperature conditions.

Some greases are labeled "EP", which indicates "extreme pressure". Under high

pressure or shock loading, normal grease can be compressed to the extent thatthe greased parts come into physical contact, causing friction and wear.

EP grease contains solid lubricants, usually graphite and/or molybdenumdisulfide, to provide protection under heavy loadings. The solid lubricants bondto the surface of the metal, and prevent metal-to-metal contact and theresulting friction and wear when the lubricant film gets too thin.

Copperis added to some greases for high pressure applications, or wherecorrosion could prevent dis-assembly of components later in their service life.

Scheme
http://en.wikipedia.org/wiki/Teflonhttp://en.wikipedia.org/wiki/Rosinhttp://en.wikipedia.org/wiki/Calcium_oxidehttp://en.wikipedia.org/wiki/Glycerolhttp://en.wikipedia.org/wiki/Glycerolhttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Copperhttp://www.google.co.in/imgres?imgurl=http://cache1.asset-cache.net/gc/152407287-monkey-holding-test-tube-gettyimages.jpg?v=1&c=IWSAsset&k=2&d=eVIekUjLgTIytqnpQqTIv1pquk67ezOQ34U7wp501Q/5r+K8bG7obO5kHlFJrUL9&imgrefurl=http://www.gettyimages.com/detail/illustration/monkey-holding-test-tube-royalty-free-illustration/152407287&usg=__XJztIXLkm00k9AG6PqM5lL-oZRg=&h=463&w=370&sz=62&hl=en&start=7&zoom=1&tbnid=B3HfkYJ4eFUjzM:&tbnh=128&tbnw=102&ei=ZrAkUeuBOYKJrAelqYGoAQ&prev=/search?q=monkey+with+a+test+tube&um=1&hl=en&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDUQrQMwBghttp://en.wikipedia.org/wiki/Copperhttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Molybdenum_disulfidehttp://en.wikipedia.org/wiki/Glycerolhttp://en.wikipedia.org/wiki/Calcium_oxidehttp://en.wikipedia.org/wiki/Rosinhttp://en.wikipedia.org/wiki/Teflon


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Scheme

Oil

Polymer

GREASES COMPOSITION


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BASE OIL + THICKENER+ADDITIVES

( 75-85%) ( 10-15 %) ( 0-5%)

MINERAL

SYNTHETICVEGETABLE

SOAP BASE

NON-SOAPPOLYMERS

ANTI-OXIDANT

ANTI-CORROSIONEP/ANTI-WEAR

TACKINESS AGENT

SOLID FILLER

METAL DEACTIVATOR

STRUCTURE MODIFIER

Silicone grease
http://www.google.co.in/imgres?imgurl=http://img.photobucket.com/albums/v51/MarieAlice/cartoon-car-rhs.jpg&imgrefurl=http://www.ayearfromoakcottage.org/2009_03_01_archive.html&usg=__Eqa6GinFKBXVWmAYLAmuPr9eGlw=&h=427&w=490&sz=32&hl=en&start=65&zoom=1&tbnid=fyc9NAASXJ0fnM:&tbnh=113&tbnw=130&ei=KbAkUYLfLoHPrQfbhICgAQ&prev=/search?q=greased+car+cartoons&start=60&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDEQrQMwBDg8


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Silicone grease

It is a waterproof greasemade by combining asilicone oilwith a thickener.

Most commonly, the silicone oil is

polydimethylsiloxane and the thickener isamorphousfumed silica.

Using this formulation, silicone grease is atranslucent white viscous paste, with exact

properties dependent on the type andproportion of the components.
http://en.wikipedia.org/wiki/Grease_(lubricant)http://en.wikipedia.org/wiki/Silicone_oilhttp://en.wikipedia.org/wiki/Polydimethylsiloxanehttp://en.wikipedia.org/wiki/Amorphoushttp://en.wikipedia.org/wiki/Fumed_silicahttp://en.wikipedia.org/wiki/Fumed_silicahttp://en.wikipedia.org/wiki/Fumed_silicahttp://en.wikipedia.org/wiki/Fumed_silicahttp://en.wikipedia.org/wiki/Amorphoushttp://en.wikipedia.org/wiki/Polydimethylsiloxanehttp://en.wikipedia.org/wiki/Silicone_oilhttp://en.wikipedia.org/wiki/Silicone_oilhttp://en.wikipedia.org/wiki/Silicone_oilhttp://en.wikipedia.org/wiki/Grease_(lubricant)


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Silicone grease is commonly used forlubricating and preserving rubber parts, suchas O-rings.

Additionally, silicone grease does not swell orsoften the rubber, which can be a problemwith hydrocarbonbased greases.

It functions well as a corrosion-inhibitor and

lubricant for purposes that require a thickerlubricant.

Dropping point
http://en.wikipedia.org/wiki/O-ringhttp://en.wikipedia.org/wiki/Hydrocarbonhttp://en.wikipedia.org/wiki/Hydrocarbonhttp://en.wikipedia.org/wiki/O-ringhttp://en.wikipedia.org/wiki/O-ringhttp://en.wikipedia.org/wiki/O-ring


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Dropping point

The lowest temperature at which a grease , whenheated under specific conditions, becomes

sufficiently fluid so that a drop will fall from a cup

having a hole of specific dimensions.

Shows the thermal stability of grease.

Lime soap greases have lower dropping point

than greases of sodium, lithium.

Can be increased by adding thickeners such as

carbon black.

Solid lubrication


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Solid lubrication

Solids such as graphite and molybdenum

disulfide are widely used when normal

lubricants do not possess sufficientresistance to load or temperature

extremes.

How is a Lubricant made?
http://www.google.co.in/imgres?imgurl=http://www.pexashop.com/images/uploads/cog-sml.jpg&imgrefurl=http://www.pexashop.com/dry-film-lubricants/cat_3.html&usg=__sKtq9SX6USMnFhsGWWvRmvfHXyo=&h=150&w=150&sz=4&hl=en&start=146&zoom=1&tbnid=yar4IGhB7MS0DM:&tbnh=96&tbnw=96&ei=aqEkUfejJITJrAeHyYG4Dw&prev=/search?q=solid+lubricants-+graphite+and+molybdenum+sulphide&start=140&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CDMQrQMwBTiMAQhttp://www.google.co.in/imgres?imgurl=http://i00.i.aliimg.com/photo/v1/489227460/MoS2.jpg_140x140.jpg&imgrefurl=http://www.alibaba.com/showroom/mos2.html&usg=__yfseDcB-q0-638Ox6rEdwflAdQE=&h=140&w=140&sz=6&hl=en&start=84&zoom=1&tbnid=RL-GqF3NTEfSnM:&tbnh=93&tbnw=93&ei=BKEkUb7nBs7MrQeo34DYAQ&prev=/search?q=solid+lubricants-+graphite+and+molybdenum+sulphide&start=80&um=1&hl=en&sa=N&gbv=2&tbm=isch&um=1&itbs=1&sa=X&ved=0CC8QrQMwAzhQ


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How is a Lubricant made?

BASE MATERIAL + ADDITIVES

FINISHED LUBRICANT

Peer reviewed

JOURNALS


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JOURNALS

Tribology Transactions

Journal of Synthetic Lubricants

Tribology Letters

Lubrication Science

AN INTERESTING SITE BY TOTAL


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AN INTERESTING SITE BY TOTAL

http://www.total-

s.com/lub/content/NT0012EE62.pdf

Sense the true engineering!


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Se se t e t ue e g ee g

Indias first indigenousaircraft carrier gets

launched for Indian

Navy at CochinShipyard

(12/8/2013)

VIKRANT

Lubricants and Adhesives

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Transcript of Lubricants and Adhesives