ASTM_F_724_-_94a_2010e1.pdf

Designation:F72494a(Reapproved 2010)1Standard Test Method forOutdoor Evaluation of Tire Sidewall Component CrackingResistance1This standard is issued under the fixed designation F724;the number immediately following the designation indicates the year of originaladoption or,in the case of revision,the year of last revision.Anumber in parentheses indicates the year of last reapproval.Asuperscriptepsilon()indicates an editorial change since the last revision or reapproval.1NOTEEditorially corrected 1.3 and Fig.2 in April 2010.1.Scope1.1 This test method covers procedures for evaluating pas-senger car tires for sidewall component integrity and crackingresistance,using an outdoor roadwheel.1.2 This test method evaluates the resistance of tire side-walls to dynamic weathering,atmospheric ozone cracking,fatigue cracking,or openings of splices within,or of juncturesbetween,sidewall components and cracking at molded side-wall elements.1.3 This test method is useful for evaluating tire blacksidewalls,white,or other colored,sidewalls,and coverstrips.1.4 This test method is limited to comparative performancetesting between a“control”sidewall component or assemblyand one or more experimental alternatives that are built ontothe same tire(“multisection”)or onto tires that are identical inall respects other than the sidewall variation.1.5 This test method is not applicable to evaluation ofsidewall resistance to abrasion,as may be experienced insevere cornering or curb scuffing.1.6 The values stated in SI units are to be regarded as thestandard.1.7 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.For specificprecaution statements,see 5.2.2.Referenced Documents2.1 ASTM Standards:2D518 Test Method for Rubber DeteriorationSurfaceCracking(Withdrawn 2007)3D1149 Test Methods for Rubber DeteriorationCracking inan Ozone Controlled EnvironmentD1171 Test Method for Rubber DeteriorationSurfaceOzone Cracking Outdoors or Chamber(Triangular Speci-mens)D3395 Test Methods for Rubber DeteriorationDynamicOzone Cracking in a Chamber(Withdrawn 2007)3F538 Terminology Relating to the Characteristics and Per-formance of Tires3.Terminology3.1 Definitions:3.1.1 black sidewall,na sidewall on which only blackcompounds comprise the outer visible surface of a tire.F5383.1.2 clinch strip,nhigh-modulus or high-hardness com-pound applied between the carcass and the sidewall in the beadarea to reinforce the bead.F5383.1.3 coverstrip,na thin layer of black compound thatcovers the unexposed white sidewall portion of a finished tire.F5383.1.4 crazing,nminute,closely grouped,generally super-ficial cracks that usually result from light-activated oxidation.F5383.1.5 flex cracking,vcracking primarily caused by appli-cation of mechanical stress-strain cycling.F5381This test method is under the jurisdiction of ASTM Committee F09 on Tiresand is the direct responsibility of Subcommittee F09.30 on Laboratory(Non-Vehicular)Testing.Current edition approved April 1,2010.Published February 2011.Originallyapproved in 1981.Last previous edition approved in 2004 as F724 94a(2004).DOI:10.1520/F0724-94AR10E01.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.1.6 juncture,nthe interface between two different tirecomponents or different compounds within the samecomponent.F5383.1.7 juncture cracking,na crack with opening originatingat a juncture between two components.F5383.1.8 juncture opening,na separation developing in ajuncture.F5383.1.9 rim strip,na layer of compound,with or withoutfabric reinforcement,that is applied at the bead to protect thecarcass plies against damage from mounting tools and from rimchafing during service.F5383.1.10 sidewall,nof a tire,that portion of a tire betweenthe tread and the bead.F5383.1.11 sidewall component,nan individual part of thesidewall construction,either a separate compound or a sepa-rately assembled piece.F5383.1.12 sidewall rubber,nthe exterior rubber layer of a tirethat extends over the sidewall part of the carcass.F5383.1.13 splice,nthe joint formed either by overlapping orbutting the ends of a given tire component in the course ofassembling the tire.F5383.1.14 splice crack,na crack originating at a splice.F5383.1.15 splice opening,na parting of a splice along theinterface of the assembled ends of a given component.F5383.1.16 veneer,na thin layer of rubber covering the surfaceof the tire sidewall.F5383.1.17 weather cracking,ndistinct su