RUBBER COMPOUNDING
1. BHUKYA KIRANKUMAR
B120485CH
2. JOBIN VARGHESE JACOB
B110733CH
3. SANDEEP SUKUMARAN
B110819CH
Rubber :
 Rubbers
are described as materials which show
“elastic” properties.
 Products
made from rubber have a flexible and
stable 3–dimensional chemical structure and
are able to withstand under force large
deformations.
APPLICATION OF RUBBER:

Today, rubber is as widely used as wood and this is
largely due to its beneficial proprieties like strength,
long lasting, water resistance and heat resistance
all these benefits makes this material perfect for tire
production.

playground equipment, shoes, mats, flooring,
healthcare supplies, household supplies, balls, toys
and thousands of other rubber products
RAW MATERIALS :
A typical rubber formation based on parts per
hundred is:
Polymer
100 phr
Filler
30 – 60 phr
Antioxidant
1 – 3 phr
Antiozonants 1 – 3 phr
Oil
5 – 30 phr
Cure
5 - 10 phr
OPEN OR INTERNAL MIXERS :
 Rubber compounding is generally carried out on open mills or internal mixers.
Polymers :
Most important ingredient in rubber compound is polymer.
Act as the basis for physical , chemical and molding
properties.
Polymers are distinguished by chemical perfomence and
viscosity rating.
Filler :
 Gives
the rubber compounds physical
strength and black colour .
 They have various particle sizes and surface
activity.
 Change in particle size can increase physical
properties .
 Carbon black is most common filler.
 Mineral fillers helps to make the compound
white to add the desired colour.
Antioxidant :


Protect the compound from high temperature.
They absorb free radicals which cause the polymer
bonds to break and reduce service life of the
compound.
Antiozonants :
 used to prevent rubber from ozone effect
 Surface of new tyres will have wax feel or shows slight
haze
 Most common antioxidant is wax ,which is used on the
surface after molding.
Oils( processing aids):

Oils are used to incorporate all dry ingredients in rubber
coumpounding.

They reduce viscosity of overall compound to help with
molding.

More oil helps to reduce hardness of rubber.
Cures :
 Vulcanization
formed.
 Peroxide
– bonds of carbon –sulphur –carbon
vulcanizing agent creates direct bonds to the
carbon chains forming carbon carbon bonds.
Rubber Compounding (Def) :
Compounding is the operation of bringing
together all the ingredients required to mix
a batch of rubber compound.
A rubber compound is obtained by mixing
a base polymer or crude mixture with a
series of additives.
 A rubber compound could be a combination
of 3 to 15 different ingredients of thousands of
different compositions and vendors.
Types of rubbers :
1.CPE ( chlorinated polyethylene )
PROPERTIES :

Offers excellent flexibility

Resistance to ignition

Resistance to low temperatures,abrasion and weathering

Has high filler acceptance , tensile strength

Low cost
USES :

Wire and cable jackets

Coated fabrics
EDPM ( ethylene propylene diene
monomer) :
PROPERTIES :

Have outstanding resistance to heat ,ozone and weather .

Resistance to water glycol steam and polar chemicals.

Excellent electrical insulating properties.
USES :
1.
For roofing membranes geomembranes .
2.
Used in radiators and for electrical insulation.
Natural rubber :
PROPERTIES :

Has good resilience and surface friction properties

Has low hysteresis and high fatigue resistors

Has poor resistance to oil sunlight and ozone
USES :
1.
Used in high performance tires for race cars,trucks and air
craft
2.
For tank lining and vibration dampening
NBR ( nitrile butadiene rubber) :
PROPERTIES :

Good elongation

Adequate resilience

Tensile strength
USES :
1.
It is used to create oil and gas exploration and recovery
parts
2.
Used for foot wear and molded goods
3.
Carboxilated nitrile rubber has high tear and abrasion
resistance
SBR ( styrene butadiene rubber):
PROPERTIES :

Good abrasion and ageing resistance when protected by
additives

Good heat and oil resistance
USES :
1.
Foot wear
2.
Adhesives
3.
Floor tyles
4.
Rubber goods
Classification of materials :
 Elastomers
 Vulcanizing
or cross linking agents
 Accelerators
 Activator/retarders
 Process
aids
 Softners
and plasticizers
 Reinforces
/ fillers