ASTM_D_750_-_12.pdf

Designation:D75012Standard Practice forRubber Deterioration Using Artificial Weathering Apparatus1This standard is issued under the fixed designation D750;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()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 This practice covers specific variations in the testconditions and procedures that shall be applicable whenPractice G151 plus either Practice G152,G153,G154,or G155are employed for exposure of vulcanized rubber compounds.Italso covers the preparation of test specimens and the evaluationof results.1.2 The values stated in SI units are to be regarded asstandard.The values given in parentheses are for informationonly.1.3 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.2.Referenced Documents2.1 ASTM Standards:2D412 Test Methods for Vulcanized Rubber and Thermoplas-tic ElastomersTensionD3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD3183 Practice for RubberPreparation of Pieces for TestPurposes from ProductsD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesG151 Practice for Exposing Nonmetallic Materials inAccel-erated Test Devices that Use Laboratory Light SourcesG152 Practice for Operating Open Flame Carbon Arc LightApparatus for Exposure of Nonmetallic MaterialsG153 Practice for Operating Enclosed Carbon Arc LightApparatus for Exposure of Nonmetallic MaterialsG154 Practice for Operating Fluorescent Ultraviolet(UV)Lamp Apparatus for Exposure of Nonmetallic MaterialsG155 Practice for Operating Xenon Arc Light Apparatus forExposure of Non-Metallic Materials3.Significance and Use3.1 This practice describes procedures to use in determiningthe effects of an open-flame carbon-arc light source,anenclosed carbon-arc light source,a xenon-arc light source,or afluorescent UV source along with heat and moisture on rubberspecimens held in a jig or holder with or without a specifiedstrain.The purpose is to attempt to accelerate the effectsproduced by light,heat,and moisture in the natural environ-ment.Exposures are not intended to simulate the deteriorationcaused by localized weather phenomena,such as atmosphericpollution,biological attack,and saltwater exposure.The Sig-nificance and Use section in Practice G151 and the standard forthe appropriate apparatus,that is,Practices G152,G153,G154,or G155 should be consulted for additional information onsignificance and use of the exposure tests.3.2 The primary criterion used in estimating resistance toweathering is the percentage decrease in tensile strength and inelongation at break.A supplementary criterion for estimatingresistance to weathering is the observed extent of surfacecrazing and cracking.3.3 Results obtained by use of these test procedures shouldnot be represented as equivalent to those of any naturalexposure test until the degree of quantitative correlation hasbeen established for the material in question.3.4 Because of differences in the spectral power distribu-tions of the exposure sources as well as the other conditions inthe different types of laboratory weathering tests,the differentprocedures may not result in the same performance rankings ortypes of failure modes of the materials.Comparisons shall notbe made of relative stabilities of materials exposed in differenttypes of apparatus.3.5 When conducting exposures in devices that use labora-tory light sources,it is important to consider how well theartificial weathering conditions will reproduce propertychanges and failure modes caused by end-use environments onthe materials being tested.1This test method is under the jurisdiction of ASTM Committee D11 on Rubberand is the direct responsibility of Subcommittee D11.15 on Degradation Tests.Current edition approved Dec.15,2012.Published February 2013.Originallyapproved in 1943.Last previous edition approved in 2006 as D750 06.DOI:10.1520/D0750-12.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 3.6 Practices G151,G152,G153,G154,and G155 recom-mend that a similar material of known performance(a control)be exposed simultaneously with the test specimen to provide astandard fo