TireManufacturingProcessTiresarenotjustroundandblacktheyaresophisticatedproductsthatcantakeyearsofresearchanddevelopmenttoproduce.Ifyouhaveeverwonderedhowtiresaremade,thefollowingisaroadmapfortheconstructionofaradialtire:StartwithRubberandAdditivesTireconstructionstartswhenrawchemicaladditivessuchassulfur,carbonblackandsolventsarecombinedwithnaturalandsyntheticrubber.Theprocesstakesplaceinalargemachinecalledabanbury.Inadditiontomixingandgrinding,thebanburyheatstherubbertomakeitworkableinpreparationforfurtherapplications.Therawproductemergesintheformoflong,flatbandsofrubber,whicharethenworkedinrollingmills.SixMainComponentsIttakesseveralmachinestoshapetherubberintotheindividualcomponentsofthetire:tread,ply,belts,beads,sidewalls,andinnerliner.Thetreadrubberisextrudedthroughatuber,thenmeasured,cooledandcutintopreciselengths.Sidewallsarealsoextrudedthroughtubers,alongwiththewhiterubberforawhitesidewallorwhiteletteredtireifrequired.Theplyisproducedinacalendermill,whichcombinesthinsheetsofrubberwithnylonorpolyestercordfabrics.Thelargesheetsarecuttowidth,rolledandtransportedtotheassemblyareawhereallthecomponentswillcometogether.Atthesametimeastherawrubberistransformedintothetreadandplies,thecreelroomequipsthetirewithitsbasicstrength.Finesteelwiregoesintothemanufactureofbeltsforthesteel-beltedradialtire.Rubberfromthemillsandsteelfromthecreelroomaremoldedtogetherintowideflatsheets,cutonthebias,rolled,andmovedtothetire-buildingmachine.Theinnerlinerisaimpermeablelayerofrubberontheinsideofatirewhichcreatesaairtightchamberwhenfittedtothevehiclewheel.Thislayereliminatestheneedforainnertube.Thelastmajorcomponentofthetireisthebead.Thebeadsarecreatedoutofwrappedsteelwire,coveredwithrubberandformedintohoops.Thebeadanchorsthefabricpliesofthetireandseatsthetirefirmlyonthewheel.TheGreenTireThesixcomponents(tread,ply,belts,sidewalls,linerandbeads)cometogetheronthetire-buildingmachine.Thesesixcomponentsareassembledintowhatisknownasanuncured,orgreen,tireintwostages.Thecarcassofthetire,includingbeads,plies,sidewallsandliner,isconstructedononesideofthemachine.Thetreadandtheunderlyingbeltsareassemblednexttothecarcassontheothersideofthemachine.Thetwosubassembliesarethenjoinedtogetherandtheresultisagreentire.VulcanizationThenextphaseisvulcanization,themoleculartransformationofthesoft,gummygreentireintothetough,andlongwearing,modernpassengertire.Thegreentireisplacedinacuringmoldandissubjectedtointensepressureandhighheatinternallyandexternallyforaspecifiedperiodoftime.Simultaneously,thetreadpatternisimprintedontotherubber.Whenitcomesfromthemold,thetireisreadyforfinalfinishandinspection.FinalFinishandInspectionForshowroomquality,anyexcessrubberistrimmedoffthecuredtire.Everytireisthoroughlyinspected.Thetirethenundergoesvariousuniformitycheckstoassessrideandcomfortquality.Oncethetireshavepassedallthechecksandinspections,theyaresenttothedistributionwarehouseforshipment.91WTireSizeHowToReadTireSidewallP205/55R16Example:P205/55R1691WPPidentifiesyourtireasaPassengerTire.ThePstandsforPMetric.IfyourtiresizestartswithLTratherthanaPthanitidentifiesthetireasalighttrucktire.205205identifiesthetiresectionwidth,whichisthemeasurementofthetirefromsidewalltosidewallinmillimeters.Thismeasurementvariesdependingontherimtowhichitisfitted.(Thereare25.4millimetersper1inch.)5555isthetwo-figureaspectratio.Thispercentagecompar...
