ASTM_D_3395_-_99.pdf

Designation:D 3395 99Standard Test Methods forRubber DeteriorationDynamic Ozone Cracking in aChamber1This standard is issued under the fixed designation D 3395;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon(e)indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods are used to estimate the crackingresistance of vulcanized rubber exposed under dynamic strainconditions to a chamber atmosphere containing ozone at a fixedpartial pressure.The effect of sun or ultraviolet light isexcluded.1.2 These test methods are not applicable to materialsordinarily classed as hard rubber,but are adaptable to moldedor extruded soft rubber.1.3 This standard may involve hazardous materials,opera-tions,and equipment.This standard does not purport toaddress all of the safety concerns associated with its use.It isthe responsibility of whoever uses this standard to consult andestablish appropriate safety and health practices and deter-mine the applicability of regulatory limitations prior to use.For a specific hazard statement,see Note 1 and 5.1.NOTE1WarningOzone is a hazardous chemical.2.Referenced Documents2.1 ASTM Standards:D 1149 Test Method for Rubber DeteriorationSurfaceOzone Cracking in a Chamber2D 3182 Practice for RubberMaterials,Equipment,andProcedures for Mixing Standard Compounds and Prepar-ing Standard Vulcanized Sheets2D 4575 Test Methods for Rubber DeteriorationReferenceandAlternative Method(s)for Determining Ozone Level inLaboratory Test Chambers23.Summary of Methods3.1 The methods appear as follows:SectionsMethod ATensile Elongation5 to 8Method BBelt Flex9 to 123.2 In MethodA,rectangular test specimens are subjected todynamic maximum amplitude tensile strain of 25 6 3%at afixed frequency of 0.5 Hz(30 cpm).In Method B,flat-sheettest specimens are affixed to a fabric belt and the belt is runover a set of two pulleys that induce a surface strain(due to thebending)during passage over the pulleys.3.3 Refer to Test Method D 4575 for the reference andoptional alternative methods for the measurement of the ozonepartial pressure in laboratory test chambers.4.Significance and Use4.1 The significance of these tests is mainly in their abilityto differentiate,in a comparative sense,between differentdegrees of ozone resistance under the limited and specifiedconditions of the accelerated tests.4.2 These test methods may not give results correlatingexactly with outdoor exposure tests or service performancesince the correlation of accelerated ozone tests with suchperformance is highly dependent upon the specific conditionsof both the accelerated ozone and outdoor exposures.Condi-tions that influence the accelerated tests are ozone partialpressure,air flow,temperature,stress-relaxation,and the bloomof additives.4.3 Outdoor or service performance is influenced by suchweather conditions as rainfall,ambient temperature,sun light,and the strain cycles imposed.METHOD ATENSILE ELONGATION TEST5.Hazards5.1 WarningOzone is a hazardous substance.Consultand follow all applicable laws,rules,and regulations re-garding exposure to ozone.6.Apparatus6.1 Flexing Device:36.1.1 The device used for this test consists of a flexingframework,a motor with gear head reducer,and an eccentri-cally driven vertical shaft with a reciprocating stroke of 25 mm(1 in.).To the end of this shaft,a parallel bar is attached and tothis a series of four dual clamps.Above and below the travelingbar are two stationary bars that contain four clamps each.Theseconstitute the flexing framework.6.1.2 The action of the flexing apparatus is to impart astraight-line motion to the clamps holding the test specimens;1These test methods are under the jurisdiction of ASTM Committee D-11 onRubber and are the direct responsibility of Subcommittee D11.15 on DegradationTests.Current edition approved Nov.10,1999.Published January 2000.Originallypublished as D 3395 75.Last previous edition D 3395-86(1997).2Annual Book of ASTM Standards,Vol 09.01.3Model 701-1 Flexer,available from the Mast Development Co.,Inc.,2212 E.12th St.,Davenport,IA 32803,has been found satisfactory for this method.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.four specimens on the top bar,four on the bottom bar.Thismotion is in the plane of the common centerline of each set ofopposing grips(see Fig.1).6.2 Ozone Chamber The ozone chamber shall conform tothe requirements specified in Test Method D 1149.It shall beequipped to permit flexing of the specimens from 0 to 25 63%extensions at a rate of 0.5 Hz(30 cpm).6.3 Apparatus for Measuring Ozone Partial PressureTheapparatus for measuring ozone partial pressure shall conformto the requirements specified in Test Method D 4575.7.Test Specimens7.1 The test specimens shall be rectangular strips 10.00 60.03 mm(0.40 6 0.01 in.)wid