Basics of tire manufacturing

Transcription

1 Basics of tire manufacturing BME - Guest lecture, 2017 Oláh Szabolcs Hankook Tire Hungary

2 Content Classification of tires Construction of tires Manufacturing process Raw materials of rubber compounds Curing Inspection of rubber compounds Requirements / EU Labeling System EU) Development Team 2 2

3 Classification of tires

4 Classification of tires 1. Groups by vehicle Passenger car (PC) Light truck (LT) Truck and bus (TB) Aircraft (AC) Agriculture ( AG) Off-the-Road (OTR) Industrial (ID) Motorcycle (MC)

5 Classification of tires 2. Groups by season Ventus V12 Evo2 icept Evo2 Optimo 4S Summer Winter All season Not usable in winter conditions (below 7 C) Has to provide a good performance at high speed Most important performance indicators: noise, handling, driving experience Best performance on snow (handling, braking, traction) Bad wear resistance in summer conditions (above 7 C) Compromise between summer and winter tires Popular in countries with short and mild winter

6 Classification of tires 3. Groups by structure Diagonal - Carcass plies run diagonally; - The direction of plies is 40 to the symmetry axis. Radial - The direction of textile cords is 90 to the symmetry axis and the bead; - Application of steel belts for better stability.

7 Structure of tire

8 Structure of tire Sidewall Tread Jointless belt Steel belt Carcass Belt edge cushion Inner liner Bead filler Bead Rim cushion

9 Structure of tire Carcass Tread Jointless belt (JLB) Bead filler Bead wire: * The edge of the tire that sits on the rim * A rubber coated bundle of wires Bead filler: * A stiff, extruded profile connected to the bead wires * Bead profile height has a great infleunce on tire handling and comfort Steel belt Belt edge cushion Inner liner Rim cushion Bead wire Sidewall Belt edge cushion: * A calendered rubber strip applied on belt * Absorbs the tension at the edge, and prevents belt separation Inner liner: * Maintains air pressure * Special raw material: halobutyl rubber Tread: * Cap tread: top part of the tread; contact with road surface * Sub tread: gives adhesion to cap tread * Tread wing: adhesion at the sides JLB: * 10 mm wide band which prevents separation of steel belts * Different target performance different covering structure Steel belts: * 2 layers of rubber coated steel cord between tread and carcass * Enhance tire strength * Endure exterior shock * Orientation of cords (after cutting): ±20~30 to the center line Carcass: * Rubber coated textile cord which gives the base structure of the tire * Gives strength to the tire Sidewall: * Protects the carcass from external shocks and transmits torque to the tread Rim cushion: * Protects the carcass at the rim, and gives support to the sidewall

10 Tire manufacturing process

11 Rubber manufacturing process Mixing Raw materials Mixing polymers, fillers and other chemicals Polymers, Fillers, Chemicals... Cord, Wire Extrusion Bead Calendering Cutting Production of tread and sidewall Topping of bead wire with uncured rubber; profile extrusion Topping of textile & steel cord with uncured rubber Cutting a calendered cord in a given size Inspection Tire inspection: *Visual insp. *Uniformity * Dynamic balance Curing Curing of green tire (vulcanization) Building Assembling of semi-finished products Green tire

12 Mixing Internal mixer (Banbury Mixer)

13 Mixing Intermeshing Tangential

14 Extrusion Extruded semi-finished materials: Tread Sidewall Bead filler Hopper Compression zone Pressure build-up Plasticization zone Feeding Conveying solid state materials

15 1-2-5 Hengerlési folyamat Calendering Calendering process: topping the textile or steel cords with a thin layer of rubber. Due to better adhesion, cords have to be treated and/or coated with special materials. 1.) Textile Carcass the base of the tire 2.) Steel Belt - reinforcement

16 Building Carcass cutting Carcass winding

17 1-2-7 Összeszerelési folyamat Building Belt winding Applicator

18 1-2-7 Összeszerelési folyamat Building Belt drum Carcass drum

19 1-2-7 Összeszerelési folyamat Building Set the beads to BSD position Bladder shaping

20 1-2-7 Összeszerelési folyamat Building Turn up sidewall Turn up sidewall

21 1-2-7 Összeszerelési folyamat Building TRF with 2nd case Combi stitcher stitching

22 Curing (Vulcanisation) 2 piece mold Sectional mold Main parameters: time, temperature, pressure

23 Raw materials of rubber compounds

24 Raw materials of rubber compounds Non-pro compound ( A ) Rubber (Natural, Synthetic) Fillers (Carbon black, Silica) Processing aids (Oil, Additives) Tackifiers (Resins) Anti-aging agents (Waxes) Final compound ( Q ) Vulcanizing agents (curatives) (Vulcanizing medium, accelerator, activator, retarder) Filler Processing aid Activators Anti-aging agents Curatives PHR : Parts per Hundred Rubber

25 Raw materials of rubber compounds Natural Rubber (NR) - 99% of cis-polyisoprene Good processability Good green tackiness Good wear resistance Toughness Easily gets oxidized

26 Raw materials of rubber compounds 1. Butadiene rubber (BR) + Good wear resistance + Excellent elasticity - Low green tackiness - Low green strength 2. Styrene-butadiene rubber (SBR) The ratio of styrene and butadiene determines the physical properties + Good processability + Very good wear resistance - High heat generation - Low green tackiness 26

27 Raw materials of rubber compounds 3. Poly(isobutylene-isoprene) (Butyl - IIR) Very low tensile strength + Very low air permeability + Good resistance of chemicals - Incompatible with other polymers Inner liner Special production criterias! (Mixer cleaning before and after butyl production) 27

28 A gumikeverék alapanyagai Fillers: Properties: insoluble in rubber, they form a solid phase. Functions: Better processability Better technical properties in the rubber compound Price control Carbon black: Cheap Physical interaction with polymers Used for all the semi-finished products Silica: Expensive Chemical bond with polymers Usage: cap tread Improved wet traction Lower rolling resistance 28

29 Raw materials of rubber compounds Carbon Black (CB) Particle size Structure Surface area Surface activity Nomenclature N660 Normal cure speed Particle size nm Structure 29

30 Raw materials of rubber compounds Silica Specific area Moisture content Structure ph 30

31 Raw materials of rubber compounds Chemical reaction of silanization: time (3-15 min) and temperature ( C) 31

32 Raw materials of rubber compounds Processing Aids Softening Homogenization Oil Petroleum oil Natural oil Naphtenic oil Paraffin oil Cashew oil Castor oil Additives 1.) Tackifiers Natural Synthetic 3.) Anti-aging agents Antioxidant Antiozonant Resins Increase hardness and stickiness Support vulcanization 2.) Adhesion Promoters Improved adhesion between rubber and steel (steel cords, bead wires) Waxes Prevents degradation of polymer chains (Heat, UV, Oxigene)

33 A gumikeverék alapanyagai Vulcanizing medium (Sulfur) Grounded sulfur Sulfur Forming sulfur-bonds Sulfur Zinc-oxide Only for IIR (butyl) Insoluble sulfur Accelerators Increasing the speed of vulcanization Sulfur compounds (MBTS, CBS, TBBS, TMTD...) Activator Activation of accelerators ZnO, Stearic acid Retarder Prevents premature vulcanization Prevents scorching

34 Vulcanization

35 Vulcanization 35

36 Vulcanization 1.) 3.) 2.) 36

37 Vulcanization

38 Inspection of rubber compounds

39 Inspection of rubber compounds Phys.Properties: Spec (example) Connection ML1+4 (100 C) Mooney viscosity MV Q Step t5 (138 C) t35 (138 C) Scorch time RPA (ref:41.7) DOH min.70 Filler dispersion Tmin Viscosity Tmax Curatives Rheo t30 (160 x40min) t Vulcanization speed t ts2 Scorching HD %M 50%M SS 100%M Handling (168 x10min) 200%M 300%M Elong min.320 Wear / Chip-cut T/S min. 160 Handling / Endurance ARES (10Hz, 0.5%) 0 60 G' G" tanδ min Wet / Breaking G' G" tanδ Rolling resistance Spec. gravity g/cm Raw materials

40 Mooney viscosity Constant temperature preheated mold The uncured specimen goes between two fixed plates, and there s a rotor rotating inside of the mold. The equipment registers the torque (deformation is constant). ML1+4: viscosity measurement. 1 minute preheating + 4 minutes measurement 100 C temperature Scorch time (t5) Specific time when the torque gets 5 MU higher than the minimum of the curve 138 C temperature

41 Rheology MDR: Moving Die Rheometer Vulcanization of the specimen between a fixed and an oscillating plate The equipment registers the torque (constant deformation) 180 C x 4 min: batch inspection Each batches get measured Only to detect serious nonconformities 160 C x 30 or 40 min: more accurate result Tmin: Minimum torque during vulcanization; connected to viscosity Tmax: Maximum torque during vulcanization; connected to the amount and dispersion of curatives (and fillers). ts2: Specific time when the instantaneous torque gets 2 unit hig her than the minumum of the curve. Connected to scorch time. t90: Specific time needed to reach 90% of maximum torque. Technically we use it as the end of vulcanization.

42 Tensile measurement (stress-strain) The cured specimen has to be clamped. There s a fixed clamp, and the other one moves with a specific, constant speed until the sample brakes. Elongation and force are registered Specific properties: Mod300%, Elongation at break, Tensile strength We also measure the Shore A hardness Hardness and modulus are in connenction with the handling and wear resistance of the tire.

43 Viscoelasticity, hysteresis, ideal materials Solid Liquid Spring Instantaneous deformation Energy recovered Piston Deformation is permanent in time Energy lost Real materials are between these two phases. Asphalt in bus stops Old windows Doing a belly flop into the pool

44 Viscoelasticity, hysteresis, real materials Solid Liquid Spring Instantaneous deformation Energy recovered Piston Deformation is permanent in time Energy lost Real materials - Polymers Stress Deformation Time Time

45 Viscoelasticity, hysteresis, periodical deformation Solid Liquid Periodical deformation Stress and deformation are in the same phase! 90 phase lag! The tanδ value shows the behaviour of real materials between ideal solid and liquid phase.

46 Viscoelasticity - Measurement Tg

47 Viscoelasticity RR (Rolling resistance) RR is lower when more energy is recovered after deformation. Lower 60 C means lower RR. Wet traction, braking Traction is better when more energy is lost after deformation. Higher tanδ or loss modulus (G 0 C means better traction. Magic triangle!

48 Requirements of tires - EU Labeling System

49 Requirements of tires Functions of the tire Carrying loads Transmission of forces to the road surface Decreasing the roughness of road surface Handling, cornering

50 Requirements of tires Required properties of tires Stability 1. Durability 2. Resistance of external forces 3. Low air-permeability 4. Handling stability Economy 1. Resistance of damages 2. Wear resistance 3. Fuel economy Comfort 1. Low noise 2. Absorption of vibration 3. Handling Environment 1. Low noise 2. Environmental friendly raw materials

51 60 C 0 C Abroncs tulajdonságok ~0,1 dl / 100km / grade ~240g CO 2 ~3 m / grade

52 Responsibilites of material engineers Control of manufacturing processes Development of mixing Industrialization of raw materials and rubber compounds Optimization of manufacturing process Planning and performing trials, evaluation and reporting of results 52

53 End of The Document 이문서는한국타이어주식회사의영업비밀로보호되고있으므로일부또는전부를무단으로전제, 복사, 유출하는것을금합니다.