The document discusses quality control and inspection processes for tires. It describes the structure of tires and key manufacturing steps like compounding, component separation, tire building, and curing. Important inspection steps are outlined like pre-production, materials, production, visual, weight and measurement, and final inspections. Key parameters tested are rolling resistance, balance, and high speed performance. Standards like ISO are referenced.

1. QUALITY CONTROL
AND INSPECTION
OF TYRES
SAI ANJANEYA

2. CONTENTS
• Structure of Tyres
• Manufacturing Processes Involved
• Inspection Processes
• Pre-Production Inspection
• Materials Inspection
• Production Inspection
• Visual Inspection
• Weight and Measurement Inspection
• Final Inspection
• Parameters of Testing
• Machines Used
• ISO Standards
• References and Gallery

3. STRUCTURE OF A TYRE
Different parts of the Tyre are:
• Tread: The part of the tire in contact with the ground. It must provide traction,
long wear and cut resistance. The tread depth and design vary based on site and
application.
• Carcass: Contains the inflation medium. The greater its strength, the greater the
pressure it can hold.
• Breakers (Belts): These are placed between the tread and carcass. They help to
join these parts. They also distribute road shock to protect the carcass. In
bias/belted and radial constructions, they control the diameter of the tire.
• Bead: Bundles of high tensile steel wire. They anchor the tire to the rim.
• Sidewalls: The protective rubber covers on the side of a tire.
• Inner liner: A specially formulated rubber compound inside the tire that
minimizes permeation. It works with the rim and O-ring to contain the inflation
medium in tubeless designs.

5. MANUFACTURING PROCESSES
Manufacturing Processes Involved:
• Compounding and mixing:
Compounding is the operation of bringing together all the ingredients
required to mix a batch of rubber compound. Each component has a
different mix of ingredients according to the properties required for that
component.
Mixing is the process of applying mechanical work to the ingredients in
order to blend them into a homogeneous substance. The mixing is done in
three or four stages to incorporate the ingredients in the desired order.
The ideal compound at this point would have a highly uniform material
dispersion; however in practice there is considerable non-uniformity to the
dispersion

6. • Component Separation:
Components fall into three classes based on manufacturing process:
calendaring, extrusion, and bead building. The extruder machine consists of
a screw and barrel, screw driver, heaters, and a die.
The extruder applies two conditions pressure. The extruder screw also
provides for additional mixing of the compound through the shearing action
of the screw.
The calendar is a set of multiple large-diameter rolls that squeeze rubber
compound into a thin sheet, usually of the order of 2 metres wide.
• Tire building:
Building is the process of assembling all the components onto a tire building
drum.
Typical TBM operations include the first-stage operation, where inner liner,
body plies, and sidewalls are wrapped around the drum, the beads are
placed, and the assembly turned up over the bead. In the second stage
operation the belt package and tread are applied and the green tire is
inflated and shaped.

7. • Curing:
Curing is the process of applying pressure to the green tire in a mould in
order to give it its final shape, and applying heat energy to stimulate the
chemical reaction between the rubber and other materials.
• Final Finish:
After the tire has been cured, there are several additional
operations. Tire measurement is a test where the tire is automatically
mounted on wheel halves, inflated, run against a simulated road surface,
and measured for force variation. Tire balance measurement is a test where
the tire is automatically placed on wheel halves, rotated at a high speed and
measured for imbalance.
Large commercial truck/bus tires, as well as some passenger and light truck
tires, are inspected by X-ray or magnetic induction based inspection
machines that can penetrate the rubber to analyze the steel cord structure.
In the final step, tires are inspected by human eyes for numerous visual
defects such as incomplete mould fill, exposed cords, blisters, blemishes,
and others.

8. TYRE INSPECTION PROCESSES
• Pre-Production Inspection:
As per SAE J 332, each machine to be used for composition and
manufacturing of different tire types will be thoroughly inspected for any
damage or defects and any other potential damaging factors detected.
The purpose of this inspection process is to verify that all of the equipment
and devices to be used for tire production is in working order to ensure
quality products.
Machines that show damage and/or defects should not be used for
production to ensure that no production anomalies will take place as much
as possible.

9. TYRE CODE

10. • Materials Inspection
All of the materials to be used for tire construction will be thoroughly
inspected for any imperfections to avoid defective products the soonest it
has been detected. The purpose of this inspection process is to ensure that
all of the materials to be used are free from damage and/or defects.
Materials that show signs of damage or defects will be automatically
rejected and will not be used throughout the entire production process.

11. • Production Inspection:
All of the materials that pass the inspection process will be then transferred
to the assembly line where the entire tire manufacturing process is initiated.
Throughout the duration of the manufacturing process, each material will
undergo different departments before getting the final product.
These departments are:
• Mixing and Compounding – rubber materials to be used will be mixed with
different agents to form a rubber compound to be used for tires.
• Calendar, Extrusion and Bead Building – all of the needed components for
tire manufacturing will be prepared during this production queue to ensure
all of the materials are complete prior to the next production process.
• Tire Assembly – after, all of the materials have been prepared and gathered,
tire building will be performed and will be inspected on a regular basis until
all of the components are properly coated.
• Curing – all of the tires that are halfway finished will undergo curing process
where immense pressure will be applied in a mould in order to create the
suitable shape of the tire. By using a machine to assist with the roundness,
the success rate of curing items is above 80 percent.

12. TYRES IN
ASSEMBLY LINE
CURING

13. • Visual Inspection:
After the production process, all of the finished products will undergo a
thorough inspection regarding the condition and overall quality and design
of each tire. The purpose of this inspection process is to verify that all of the
tires out of production show no signs of damage or defects to ensure
product reliability and durability as per quality control standards.
It is important that each surface area of the tire on queue must be visually
inspected and machine tested to ensure that no hidden damage is detected.
• Tread Depth – the surface area of each tire will be inspected thoroughly to
ensure that there are no cracks, moulds or bubbles detected.
• X-RAY inspection – the internal parts of the tire will be inspected for any
underlying defects that could take place during initial use to ensure that all
of the tires are structurally sound and reliable right out of production.

14. • Weight and Measurement Inspection:
Each tire will be measured will deflated and once again once inflated to
properly specify the gross and net weight of each tire according to its
category.
• Tire Uniformity Analysis – tires under the same category will be measured
and weighed according to its product specification to ensure durability,
reliability and strict quality control standards.
• Tire balance – tires, regardless of type, will be attached to a machine that
emulates the vehicle will be used in order to properly measure the
specifications of each tire assembly. Tires that are out of balance will be
checked for air pressure and overall build to ensure proper size and weight
on all tires.
Items that fail the weight and measurement inspection protocol will be
evaluated for alternative repairs and reconstruction (depending on the
damage) to save overall production time if applicable. Items that are beyond
repair will be automatically marked as “DEFECTIVE

15. • Final Inspection:
The purpose of this inspection process is to verify that all of the tires under
the production process will undergo a series of performance and battery
tests while maintaining a defect-free product at the end of the testing and
inspection phase. The common tests involved for this inspection process are:
• Tire Balance and Performance Analysis – all of the tires will be placed on
mechanisms to emulate the vehicle specified to check tire balance and if
tires are structurally sound and round.
• Tire rotation analysis – each tire will be put into spinning action to evaluate
and analyze the behaviour of the tire being inspected while in operation to
properly assess the condition of the tire and its overall composition.
• High-Speed Test – all of the tires will be tested on a road-like area where
tires will be tested under high speeds to check tire balance and roundness at
high speeds of at least 70 miles per hour.
• Damage-Rate Inspection – tires that have finished the entire inspection
process will be re-analyzed for any incomplete mould fill and will be checked
for damages like blemishes, blisters, exposed cords and other post-
production anomalies that have taken place.

17. PARAMETERS OF TESTING
• Outdoor
• Braking on a dry surface (also for motorcycles, trucks and buses)
• Handling on a dry surface (also for motorcycles)
• Handling on a wet surface
• Braking on a wet surface ECE R 117 / EC 1222/2009 (also for trucks and
buses)
• Longitudinal aquaplaning
• Lateral aquaplaning
• Steady-state circular test on a wet surface (also for trucks and buses)
• Indoor
• Rolling resistance
• Measurement of force and torque
• Temperature (online measurement of the temperature inside the tyre, on
the inner liner and at the tyre surface)

18. AQUAPLANING
• Aquaplaning or Hydroplaning by tyres of a road vehicle occurs when a layer
of water builds between the wheels of the vehicle and the road surface,
leading to a loss of traction that prevents the vehicle from responding to
control inputs.
• Aquaplaning is different phenomenon from water on the roadway merely
acting as a lubricant.

19. MACHINES USED
• Tire Component Profilometer

20. • Tire Colour Inspection Tire Length Inspection
• Tire Component Offline Profilometer Tire Component Profilometer

21. • Tire Piece Weight Inspection
• Tire Component Profilometer

22. STANDARDS

23. REFERENCES
• http://www.intouch-quality.com/blog/tire-inspection-qc-china/
• http://www.issia.cnr.it/wp/?portfolio=ndt-quality-control-of-tyres
• http://www.micro-epsilon.com/download/products/cat--systems--rubber-tire--en.pdf
• https://www.iso.org/obp/ui/#iso:std:63769:en
• http://www.iso.org/iso/home/store/catalogue_tc/catalogue_tc_browse.htm?commid=47686
• http://optotechnik.zeiss.com/en/products/tire-testing-intact/intact-otr
• http://www.tuv-sud.com/industry/automotive-transportation/automotive-
solutions/automotive-component-testing/tyre-testing#tab_1427765935891907481211
• http://www.dunlop.eu/dunlop_ie/what-makes-dunlop-different/tire-tests/
• http://www.michelinman.com/US/en/safe-driving/tire-safety/inspection.html
• https://www.researchgate.net/publication/258807136_Identification_and_quality_control_of_
marks_on_tires_through_artificial_vision

24. GALLERY
An opened tire mould being cleaned. The
deflated rubber bladder is on the central post

25. Structure of a Tyre
Inspection in process

26. Inspection in process
Tyre Balance Inspection