Tire building is the process of assembling all the individual
components of the tire to produce green tire.
It is the section where different components of the tire such
as bead, plies, tread, sidewall etc are assembled together to
form the green tire .
COMPONENTS
Drum squeegee
Plies
Bead
Breaker
Chafer
Tread
Sidewall
BIAS TIRES
In this type the reinforcing cords extend diagonally across the
tire from bead to bead.
The bias angle of the cord path to the centerline of the tire
generally ranges from 25 to 40 degrees.
The cords run in opposite directions in each successive layer
(or ply) of reinforcing material, resulting in a criss-cross
pattern.
Carcass
A bias tire has a carcass, which is made of reinforcement layersof
fabric cords crossed over each other to the tread centerline.
Load carrying capacity and related inflation pressure requirement for a tire
in service determines the ply requirement. The number of plies varies from
2 plies for scooter tire to as much as 40 plies or more in an earthmover
tire
The fabric cords generally used are Rayon, Nylon and Polyester. A bias
construction is continuous in its carcass structure from bead tobead.
It provides the necessary strength to the tire: radially to hold inflation
pressure, circumferentially for efficient transmission of traction/braking
force and laterally to counter centrifugal forces while cornering/driving.
The rubber matrix holds the fabric structure in its relative position and
absorbs the shear strain while undergoing radial, circumferential and lateral
deformation.
Carcass is thus a high strength flexible membrane
Breaker:
Breakers have nearly the same angle as the carcass plies and do
not restrict the carcass plies.
A low denier, low EPI fabric is used for the breakers. A lower EPI
fabric, due to the additional gap between cords takes up more
rubber thereby providing better bond between tread and casing as
well as it provides impact resistance.
This also helps in providing stability to the tread and in
distributing forces uniformly throughout the structure. Breakers
improve the plunger strength of a tire.
Drum Squeegee
Usually for tube type tires, the drum squeegee is a thin layer
of compound usually calendered direct on to the under side of
the first ply or applied separately.
Drum sgueegee serves to insulate fully the tire cords from the
inner tube and thereby prevent tube chafing damage.
It also protects the cords from possible degradation due to
atmospheric moisture absorption.
Drum squeegee also prevents the diffusion of mould release
agent into the carcass plies during tire curing, thus preventing
problems with ply adhesion.
In tubeless tires, the inner lining in the air-retaining member
and is usually calendered as a two layer laminate having
stepped edges.
Bead:
Bead consists of rigid steel wire rings on either side of the tire
around which the flexible torroidal carcass is tied.
The bead is dimensionally rigid and hence offers a firm fit on to the
steel rims. This in turn enables faithful transmission of engine,
brake, and steering torques from the rim on to the flexible carcass.
Bead Apex:
The bead apex is a high modulus rubber compound, located on
the top face of the bead.
Its primary function is to pack out the area of the structure
immediately above the bead coil and so provide a steady
gradation of thickness between the latter and the sidewall zone,
the thickness of which is only that of the casing plies and
sidewall rubber.
Bead Flipper:
Flipper is a rubber-coated fabric that encloses the bead and
acts as a further reinforcement to the bead portion.Emphasis
is on the avoidance of localisedcircumferential stress lines,
which could promote looseness, or cord break up under
constant flex conditions Usually flippers are used only in large
tires like, truck tires, rear tractor tires, etc
Tread
It is the rubbery mass moulded on to the crown of the toroidal
carcass and is the wearing portion of the tire.
Tread is an extruded component with a definite profile or shape.
Sidewall
Sidewall is a thin layer of rubber on either sides of the carcass
essentially to protect the carcass from external degrading agent
like moisture, oxygen, ozone etc. and also from physical
damages.
Side wall also is an extruded component with a definite profile
or shape.
It also acts as the billboard of the tire wherein all the necessary
markings are put
Chafer
Chafer is a square woven coated nylon fabric applied around the
carcass in the bead area to protect it from chaffing against the rim.
It also protects the carcass from damages during
mounting/demounting operations.
What are the different types of tire building machines?
Broadly classifying, there are two types of tire building machines namely – single
stage tire building machine and second stage tire building machine.
components of the tire to produce green tire.
It is the section where different components of the tire such
as bead, plies, tread, sidewall etc are assembled together to
form the green tire .
COMPONENTS
Drum squeegee
Plies
Bead
Breaker
Chafer
Tread
Sidewall
BIAS TIRES
In this type the reinforcing cords extend diagonally across the
tire from bead to bead.
The bias angle of the cord path to the centerline of the tire
generally ranges from 25 to 40 degrees.
The cords run in opposite directions in each successive layer
(or ply) of reinforcing material, resulting in a criss-cross
pattern.
Carcass
A bias tire has a carcass, which is made of reinforcement layersof
fabric cords crossed over each other to the tread centerline.
Load carrying capacity and related inflation pressure requirement for a tire
in service determines the ply requirement. The number of plies varies from
2 plies for scooter tire to as much as 40 plies or more in an earthmover
tire
The fabric cords generally used are Rayon, Nylon and Polyester. A bias
construction is continuous in its carcass structure from bead tobead.
It provides the necessary strength to the tire: radially to hold inflation
pressure, circumferentially for efficient transmission of traction/braking
force and laterally to counter centrifugal forces while cornering/driving.
The rubber matrix holds the fabric structure in its relative position and
absorbs the shear strain while undergoing radial, circumferential and lateral
deformation.
Carcass is thus a high strength flexible membrane
Breaker:
Breakers have nearly the same angle as the carcass plies and do
not restrict the carcass plies.
A low denier, low EPI fabric is used for the breakers. A lower EPI
fabric, due to the additional gap between cords takes up more
rubber thereby providing better bond between tread and casing as
well as it provides impact resistance.
This also helps in providing stability to the tread and in
distributing forces uniformly throughout the structure. Breakers
improve the plunger strength of a tire.
Drum Squeegee
Usually for tube type tires, the drum squeegee is a thin layer
of compound usually calendered direct on to the under side of
the first ply or applied separately.
Drum sgueegee serves to insulate fully the tire cords from the
inner tube and thereby prevent tube chafing damage.
It also protects the cords from possible degradation due to
atmospheric moisture absorption.
Drum squeegee also prevents the diffusion of mould release
agent into the carcass plies during tire curing, thus preventing
problems with ply adhesion.
In tubeless tires, the inner lining in the air-retaining member
and is usually calendered as a two layer laminate having
stepped edges.
Bead:
Bead consists of rigid steel wire rings on either side of the tire
around which the flexible torroidal carcass is tied.
The bead is dimensionally rigid and hence offers a firm fit on to the
steel rims. This in turn enables faithful transmission of engine,
brake, and steering torques from the rim on to the flexible carcass.
Bead Apex:
The bead apex is a high modulus rubber compound, located on
the top face of the bead.
Its primary function is to pack out the area of the structure
immediately above the bead coil and so provide a steady
gradation of thickness between the latter and the sidewall zone,
the thickness of which is only that of the casing plies and
sidewall rubber.
Bead Flipper:
Flipper is a rubber-coated fabric that encloses the bead and
acts as a further reinforcement to the bead portion.Emphasis
is on the avoidance of localisedcircumferential stress lines,
which could promote looseness, or cord break up under
constant flex conditions Usually flippers are used only in large
tires like, truck tires, rear tractor tires, etc
Tread
It is the rubbery mass moulded on to the crown of the toroidal
carcass and is the wearing portion of the tire.
Tread is an extruded component with a definite profile or shape.
Sidewall
Sidewall is a thin layer of rubber on either sides of the carcass
essentially to protect the carcass from external degrading agent
like moisture, oxygen, ozone etc. and also from physical
damages.
Side wall also is an extruded component with a definite profile
or shape.
It also acts as the billboard of the tire wherein all the necessary
markings are put
Chafer
Chafer is a square woven coated nylon fabric applied around the
carcass in the bead area to protect it from chaffing against the rim.
It also protects the carcass from damages during
mounting/demounting operations.
What are the different types of tire building machines?
Broadly classifying, there are two types of tire building machines namely – single
stage tire building machine and second stage tire building machine.
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