This Instron® presentation shares test types and solutions for testing the quality of tires.

1. Solutions for Testing Tires
Tire Testing
Applications

2. 22
Tire Manufacture
• Producing tires is an extremely complex manufacturing process
• Many immediately think of only rubber, but a tire is actually an advanced engineering
product comprised of many different materials.
• It requires the latest technology, heavy equipment and precision instruments
• Quality control is incredibly important throughout the whole manufacturing process
• Research and Development is critical for the companies success

3. 33
Example Manufacturing Process
• “Over 200 raw materials go
into the tire’s composition” –
Michelin
• Mechanical testing is required
for all of them – Production and
Research
• The effect of the different
material also needs to be
tested on the different
components of the tire (Inner
Liner, side wall’s etc.)
Source: http://www.michelinman.com/US/en/help/how-is-a-tire-made.html

4. 44
Tire Structure
Tread
Shoulder
Side wall
Tread Cap
Nylon Cap
Steel Belt
Inner Liner
Body/Carcass
Ply
Bead Wire
Bead FillerBead
Tread
Side wall
Tire Valve
Tire Valve
High Air Pressure
Side Wall
Protection

5. 66
Materials
• Natural rubber: the main component of all of the tread layers
• Synthetic rubber: make some part of the treads of car, van
and 4x4 tires
• Carbon black and silica: used as a reinforcing agent to
improve durability
• Metallic and textile reinforcement cables: forming the
geometric shape and providing rigidity.
• Varying chemical agents: for unique properties that may be
required such as low rolling resistance or ultra-high grip
25%
Natural
Rubber
25%
Synthetic
Rubber
17%
Fillers
15%
Chemicals
10%
Steel Cord
8%
Textiles
% Yearly
expenditure for
materials for a
typical tire
manufacturer

6. 77
Type of Tests
• Tension Test
• Adhesion
• Tear Test
• Rheology
• Impact
• Fatigue
• Wear/Life

7. Rubber
Tension Test

8. 99
Tension Test - Rubber
• ASTM D412 + ISO 37 main standards
• ISO37 - Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties
• ASTM D412 - Standard test methods for vulcanized rubber and thermoplastic elastomers -
tension
• ASTM D412: Two test methods
• Method A made for “dumbbell and straight specimens”
• Note: Straight specimens not advised as will likely break in jaw face
• Method B “Cut-ring specimens”
• ISO 37: 7 types of test piece are provided
• 5 geometries for dumbbell specimens (1,2,3,4 & 1A)
• 2 geometries for ring type (A & B)

9. 1010
ASTM D412 – Dumbbell Specimens
• Minimum of 5 specimens for testing
• 6 different specimen sizes
• Dependent on the Die (Die A-F available)
• Die C recommended unless otherwise specified
• Tab Width: 25mm
• Reduced Section Length: 33mm
• Recommends using extensometer for elongation
measurement
• Gripping mechanism needs to automatically exert a
uniform pressure across gripping surfaces

10. 1111
• Two different size specimens
• Type 1: Inside Circumference 50mm ± 0.01mm,
thickness 1-3.3mm
• Type 2: Inside Circumference 100mm ± 0.01mm,
thickness 1-3.3mm
• Crosshead extension used for elongation
measurement
• Set from initial separation calculated by
Circumference of specimen – circumference of
spindle) ÷
• “spindle” type grips used
• Important to lubricate the surface of the spindle
(ensuring suitable lubricant)
• Free to rotate (not driven)
ASTM D412 – Cut Ring Specimens

11. 1212
ASTM D412 - Test Speeds
Typical test rate is 500mm/min ± 50mm/min.
However, there are 4 other test rates prescribed:
1. 1000mm/min ± 100mm/min
2. 50mm/min ± 5mm/min (only used if yield elongation is less
than 20% when test at default rate)
3. 5mm/min ± 0.5mm/min (only used if yield elongation is
less than 20% when test at 50mm/min)
4. 100mm/min ± 10mm/min when using small ISO ring
specimens

12. 1313
ISO 37– Dumbbell Specimens
• Minimum of 3 specimens shall be tested
• 5 different specimen sizes
• 1,2,3,4 & 1A
• Class 2 force measurement
• Elongation measurement recommends using
extensometer
• Class D extensometer of dumb-bell specimens (1, 1A
and 2)
• Class E extensometer of dumb-bell specimens (type 3
and 4)
• Gripping mechanism needs to automatically
exert a uniform pressure across gripping
surfaces

13. 1414
ISO 37– Ring Specimens
• Minimum of 3 specimens shall be tested
• 2 different specimen sizes
• The standard type A ring test piece shall have an
internal diameter of 44.6 mm ± 0.2mm
• The standard type B ring test piece shall have an
internal diameter of 8mm ± 0.1mm
• Crosshead extension used for elongation
measurement
• “pulley” type grips used
• One of the pulleys shall be free to turn with low
friction
• The other pulley should be driven to rotate the ring
between 10 – 15 rpm

14. 1515
ISO 37 - Test Speeds
The crosshead extension rate should be:
• 500mm/min of type 1A and type 2 test pieces.
• 200mm/min type 3 and type 4 test pieces
“When testing dumb-bells, the method of measuring the
extension might require the test machine to apply a small
prestress to the test piece to avoid it bending. In this case, the
machine shall be capable of applying the necessary prestress.”

15. 1616
Specimen Preparation
 Repeatable punch force
 Repeatable punch angle
Allows operators to work on more value-added
tasks, i.e. running tests
 Several times faster than manual systems
Safety shields prevent fingers from entering punch
area
Pneumatic Hollow Die Punch Machine

16. 1717
Gripping Dumbbell Specimens – Grip Extrusion
• All materials reduce in surface area when subjected to a tensile force.
• For elastomers with such high elongations this is exaggerated.
• It is important to increase clamping pressure during the test otherwise the
specimen will slip out of the grip.
• This is called grip extrusion – as can be seen in the following video:

17. 1818
Gripping Dumbbell Specimens
Eccentric Roller Grips: 1kN, 2kN, & 5kN
• Simple to use
• Easy to load specimens
• Cost efficient
• Compatible with chamber
Cons:
• No specimen alignment aids
• Grip separation point difficult to
define
• Varying clamping pressure between
operators

18. 1919
Gripping Dumbbell Specimens
Pneumatic Side Acting Grips:
50N, 250N, 1kN, 2kN, 5kN & 10kN
• Simple to use
• Easy to load specimens
• Reduced variability
• Specimen alignment stops
• Repeatable clamping pressure
• Available at high temperature

19. 2020
2712-04X Series Pneumatic Grips Continued
Unique check-nut design is quick and
comfortable to use
Enclosed mechanism resists dirt and
debris
Jaw face changes are simple and require
no tools or pins
Jaw face shields reduce pinch hazard
and feature graduations to aid specimen
placement

20. 2121
2712-04X Series Pneumatic Grips
Rotatable air inlet allows tidy hose runs and features
airflow adjustment
Integral air valve allows use without footswitch if
desired
Large throat size allows for easy specimen insertion

21. 2222
2712-04X Series Pneumatic Grips Jaw Faces

22. 2323
Dumbbell Specimen Strain Measurement
The properties that define a rubber or elastomeric
material can pose some intrinsic testing challenges:
• High travel required
• Survive specimen failure
• High accuracy
• Prevent damage to the specimen
• Ambient and non-ambient testing
• Not influence specimen failure

23. 2424
Crosshead Displacement
• The measurement of the crosshead movement to
determine strain is an indirect extension
measurement.
• This type of measurement includes compliance or
deformation in the total system.
• Bluehill® Universal provides ‘compliance correction’
where any of the constant deformation within the
system can be subtracted from the extension
result.

24. 2525
Long Travel Manual Extensometer
• High Travel – 750mm
• ASTM E83 Class C
• ISO 9513 Class 1
• Counter balanced arms
• Weight of extensometer does not
affect the specimen
• Adjustable clamping pressure
• Preventing damage to the specimen
• Quick release clamps
• Very easy to setup
• Durable

25. 2626
Manual Extensometers
• Manual extensometers require an operator
to install the extensometer
• Incorrect setting of gauge length
• Operator attaching to the specimen adds
errors to data and also takes time
• Using an automatic extensometer removes
the operator influence and will give more
reliable results
Automatic
Extensometer
Manual
Extensometer

26. 2727
AutoX750 Automatic Contacting Extensometer
• High Travel – 750mm
• Resolution – 0.1um
• Accuracy - +/- 1um
• Counter balanced arms
• Weight of extensometer does not effect the specimen
• Adjustable clamping pressure
• Preventing damage to the specimen
• Automatic open and closing of arms
• Very easy to setup
• Durable
• Optional knife edges
• Rubber knife edges can prevent specimen damage
AutoX750

27. 2828
Contacting Extensometers
Knife Edge Contacts
Any contact with the specimen can have an
adverse effect on specimens.
Best Practices:
• Check for small nicks and imperfections
in knife edges
• Handle devices with care
• Carefully remove extensometer during
test

28. 2929
AVE 2 Non-contacting Video Extensometer
• Large Focal Length – 620mm
• ASTM E83 Class C
• ISO 9513 Class 1
• Data Rate – 490Hz
• Results are repeatable between operators
• Works in any lab, regardless of lighting or
temperature
• Apply dots or lines to the specimen very easily
• Specimen failure can’t damage extensometer
• Can be used to measure strain in a chamber
• Can be used on ANY testing machine using 0-10V
AVE 2

29. 3030
AVE 2 Non-contacting Video Extensometer
• Moving air can distort images, like pavement on a hot day
• Labs have many sources of air flow, like AC or doors opening and closing
• The AVE 2 uses constant density air tubes (CDAT’s) to create constant air flow
around the specimen
• This is a patented Instron technology
Image without CDAT Image with CDAT

30. 3131
AVE 2 Non-contacting Video Extensometer
• PROBLEM: Lighting conditions in labs vary wildly and can affect results
• To negate effects of lighting the AVE 2 uses High Intensity Pulsed Red Light Source
which floods the test space.
• Then the lens uses a filter to only see the polarized light
• The camera can’t see other lights and is therefore unaffected by lighting conditions
• Instron has a patent on this and is the only supplier that can provide

31. 3232
AVE 2 Non-contacting Video Extensometer
• During elongation on elastomers the material
will reduce in area significantly
• This can cause deformation to the mark/dot
on the specimen
• Instron® developed advanced tracking
algorithm to always track the center of the dot
as it elongations and stretches

32. 3333
Tension Test - Rubber Tear
• ASTM D624 & ISO 34 main standards
• ASTM D624 - Standard Test Method for Tear Strength of Conventional Vulcanized Rubber and
Thermoplastic Elastomers
• ISO34 - Rubber, vulcanized or thermoplastic — Determination of tear strength
• ASTM D624 – 5 different tests
• Type A/B/C require maximum force to rupture the test piece with different cuts in the specimen
geometry
• Type T for ‘trouser’ type tear
• Type CP for constrained path tear strength
• ISO 34: 3 different tests
• Method A: Trouser test piece
• Method B: Angle test piece
• Method C: Crescent test piece

33. 3434
Tension Test - Rubber Tear

34. 3535
Bluehill® Universal TestCam
• The TestCam Video Recording and Playback module is used in conjunction with
Bluehill Universal Software to effortlessly record any test with a webcam and then
replay it back along with the test data for further analysis

35. Environmental Tests

36. 3737
Environmental Chambers
• Maximum Temperature
• +350°C (660°F)
• Minimum Temperature
• -100°C (-150°F) - LN2
• -70°C (-95 °F) - CO2
• Heated optical glass
• Temperature Stability
• ±2°C (±3.6°F)
• Suitable elastomer grips compatible
• Fast heat up times
• Specimen racks available for soaking
Environmental Chambers & Furnaces

37. 3838
Environmental Chambers – Strain
• AVE non-contacting extensometer
can attach to the front of the
chamber to provide accurate strain
data
• Triple-pane, optical quality
borosilicate glass window with twin
cartridge heaters for minimizing
frosting and misting when testing
at low temperatures

38. 3939
Environmental Chambers – Bluehill® Universal Software
• Save time with automatic
temperature soaking with Bluehill
Universal
• Set the control mode for the
machine, the time you want to
soak and the temperature. Then it
will automatically start the test
once complete.

39. 4040
Environmental Chambers – Bluehill® Universal TestProfiler
• Using TestProfiler you can automatically control the chamber temperature
during the test
• Utilizing ramps to temperature, temperature holds or cycling between
temperatures.
3119-600 Chamber

40. How to Improve Efficiency?

41. 4242
Improve Efficiency– Robot Automated Solutions
Automatic Specimen
Measurement
Device
Automatic Specimen
Marking Device
(Use with AVE)
Ink Transfer Pads
Pads sized to capture
required GL dots
Cliché
Contains ink wells for
required GL dots
Automated Testing Solutions

42. 4343
Improve Efficiency– Multi-head System
O-Ring Type Specimens Dumbbell Type Specimens

43. 4444
Improve Efficiency – Multi-head System with Chamber
Manual Grips Pneumatic Grips

44. 4545
Time Savings
COST
EFFECTIVENESS
Bluehill® Universal with
Operator Dashboard
Pneumatic Grips
Integrated Measurement
Automatic
Extensometry
Multi-head System
Full Automation
Specimen Stops

45. Tire Rubber
Rheology

46. 4747
Rubber Compound Rheology & Swelling
• Natural or synthetic rubber are typically the primary
material used in tire production, However,
thermoplastic elastomers are often used to produce
tires
• Determine rubber compound for its viscosity
properties and swelling at the exit of the die
• Typically elastomers, combined with carbon black
and additives
• As well as determining the rheological curve
(viscosity vs. shear rates), it is often useful to study
the extrudate swelling characteristics

47. 4848
CEAST SR Series
• SR20 and SR50
• 1 to 50 kN load cells
• Single or Twin bore barrel
• Standard temperature: 450 C
• Crosshead speed 0.0024 to 1200 mm/min
• Interchangeable force transducers

48. Tire Rubber
Impact Test

49. 5050
Collisions with Curbs
• An impact break involves damage to the carcass
(the casing of the tire) inflicted when the tire is in
contact with certain obstacles
• Usually an externally visible bulge on the sidewall of
the tire indicates that cords have been destroyed
inside the carcass
• This over stresses the carcass and can cause
individual cords to break
• The extent of the damage depends on the speed
and angle of impact and on the size of the obstacle

50. 5151
Case Study – Truck Tire Research
• Composites made of rubber and steel belts
• Study involved damage under impact at high strain
rates
• Drop weight tests were conducted to observe the
damages on the unidirectional ply and the laminate
composite.
• The impact testing results were used to understand
the damage mechanisms
• The cord rubber composite structures are optimized
in order to improve the shock and perforation
resistance-Improvement of truck tires

51. 5252
Drop Weight Impact on Tire Rubber
• Piece of the rubber was cut along the whole length
• Machine configuration similar to that of ISO 6603
was used
• Specimens was placed into a standard clamping
ring system
• 20 mm insert was used to impact it from different
heights
• A variation in the impact height and the tup
release position allowed to achieve different
impact energies
• Imparted energy varied from 1.5 to 4 J

52. 5353
CEAST 9300 Drop Weight Series
• Velocity: 0.77 to 24 m/s
• 3 to 29.4 m
• Energy: 0.25 to 1800 J
• Masses: 0.83 to 70 kg
CEAST 9350
(High Energy)
CEAST 9340 CEAST 9350CEAST 9310

53. Textile Tire Cord
Tension Test

54. 5555
Cord Tension Test Standard – ASTM D885
Standard Test Methods for Tire Cords, Tire Cord Fabrics,
and Industrial Filament Yarns Made from Manufactured
Organic-Base Fibers
• Gauge Length 250 ± 1 mm (alternate 500 ± 2 mm)
• Preload of 5 ± 1 mN/tex [0.05 ± 0.01 gf/den]
• Test speed in mm/min is 120 % (100 % or 50%
alternate) of the nominal gage length in millimeters of
the specimen
• Tenacity = force / linear density
• Units: gf/denier, gf/Tex, N/Tex, CN/Tex etc.

55. 5656
Tension Test - Cord
• Capstan grips need to have smooth, curved faces that
distribute stress evenly along a large section of the
specimen
• Adjustable clamping pressure
• Typically no strain measurement
• Standards have been largely unchanged in recent years

56. 5757
Tension Test - Cord

57. 5858
Tension Test – Cord Grips
• Cord and yarn grips offered in 50N,
1kN, 2kN, 5kN, and 10kN capacities,
some with different types of faces
• Capstan snubbing grips offered in
2kN, 36kN, 50kN, and 90kN
capacities
• Bollard grips offered in 50kN capacity,
with different styles of bollard faces

58. Metallic Tire Cord/Bead Wire
Tension Test

59. 6060
Tensile Test – Metal Strand
• For larger strength cable we have
solutions up to 1500kN for
stranded wire
• Using side acting hydraulic grips
and surfalloy coated faces for
maximum bite
• Adjustable clamping pressure to
reduce jaw face breakage

60. 6161
Tensile Test – Metal Strand
• Capstan snubbing grips offered in 2kN, 36kN, 50kN,
and 90kN capacities
• Bollard grips offered in 50kN capacity, with different
styles of bollard faces

61. Metallic Tire Cord/Bead Wire
Impact Test

62. 6363
Impact Strength of Steel Tire Cord
• Test requires the cord to be gripped in tension supported
across pulleys
• The Tup will then drop and impact the cord in the center of
the pulleys applying an impact whilst simulating the tension
it would be under in its application

63. 6464
Impact Strength of Steel Tire Cord
Wedge Action Grips
Pulleys
Load Cell
Tire Cord
Base of 9350

64. Textiles
Tension Test

65. 6666
Tension Test - Textiles
• Same challenges as cord and bead in that
gripping needs to be optimized to prevent jaw
face failure as well as slippage
• Can be high strength and hardness making
gripping challenging
• Using pneumatics grips with adjustable
pressure is ideal
• Smooth faces

66. 6767
Tension Test - Textiles Jaw Faces
“Wavy” vs Standard Jaw
Faces
20% More Contact Area

67. 6868
Tension Test - Textiles Jaw Faces

68. Adhesion Tests

69. 7070
Adhesions Test’s
• Tires are made of many different layers that
are all ‘adhered’ to each other; therefore,
some of the most critical tests are their
adhesion properties
• The applications are extremely varied—from
adhesion between layers to adhesion of cord
to the rubber.
• There are many different types of adhesion
testing

70. 7171
Adhesion Specimens
Rubber T-Peel Layers Peel
• Between raw material • Between different layers
• Between rubber and the tire
cord or belts
Pullout
• Between individual strands of textile or metal
• Cut out one at a time or multiple installed into fixture

71. 7272
Adhesions Test’s – T Peel
Pneumatic Grips

72. 7373
Adhesions Test’s – T Peel
Screw Action Grips

73. 7474
Adhesions Test’s – T Peel
Versa Grips

74. 7575
Adhesion Test - Curing
• To determine curing properties a test can be
conducted where a plastic layer is put
between two layers of rubber
• There is a specific sized hole cut out of the
plastic to adhere only one small defined area
• Then it is cured in an oven
• Then the test can be to pull them apart to
give the cured adhesion values
Cured
Adhesion Area

75. 7676
Adhesions Test’s – Single Pullout
• To determine the adhesion strength to the
tire cords it is critical to test the pullout
strength
• This is where a single tire cord or tire bead is
adhered to the rubber material and then
axial load applied to determine the pull out
force
• This fixture is made for doing one at a time
simply and easily

76. 7777
Adhesions Test’s – Multiple Pullout

77. Additional Tests

78. 7979
Tire Valve Tension/Torsion

79. 8080
Torsion Test for Tire Cord
Interlocked
Guard
Emergency
Stop
5900 Control
Handset
Load/Torque
Cell
Grips

80. 8181
Biaxial Wheel Test (ZWARP)

81. Visit our new Automotive site at go.instron.com/automotive
Contact Instron® with any questions