Tire Testing Applications & Solutions
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This document discusses tire testing and the manufacturing process. It covers: - Tire manufacturing is a complex process involving over 200 raw materials. Quality control and R&D are critical. - Common tire tests include tension, adhesion, tear, fatigue and wear tests. Tension tests are often done according to ASTM D412 or ISO 37 standards using dumbbell or ring specimens at 500mm/min. - Proper gripping, extensometers, and environmental controls are needed to get accurate tension test results, especially for rubber's high elongations. Both contacting and non-contacting extensometers are used.
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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.](https://image.slidesharecdn.com/tiretestingapplicationsfinal-171006193243/85/Tire-Testing-Applications-Solutions-54-320.jpg)
Tire Testing Applications & Solutions
- 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
- 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
- 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
- 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
- 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
- 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
- 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