ASTM_D_5419_-_14a.pdf

Designation:D541914aStandard Test Method forEnvironmental Stress Crack Resistance(ESCR)of ThreadedPlastic Closures1This standard is issued under the fixed designation D5419;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.1.Scope*1.1 This test method determines the susceptibility ofthreaded plastic closures to failure due to environmental stresscracking(ESC).1.2 In use,threaded plastic closures can contact agents thatappreciably reduce the stress at which cracks form.Examplesof such agents are:soaps,detergents,oils,and liquid bleaches.1.3 Major factors that influence environmental stress crackresistance(ESCR)of threaded plastic closures include theclosure material(s),closure design,molded-in stress,andapplied stress.1.4 This procedure can be applied to all closures,but isparticularly applicable to closures made from plastics based onpolypropylene(PP)or polystyrene(PS).1.5 The values stated in inch-pound units are to be regardedas the standard.The values given in parentheses are forinformation only.1.6 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.Specific precau-tionary statements are given in Section 8 and 6.2.NOTE1There is no known ISO equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD883 Terminology Relating to PlasticsD1600 Terminology forAbbreviated Terms Relating to Plas-ticsD2911 Specification for Dimensions and Tolerances forPlastic BottlesE145 Specification for Gravity-Convection and Forced-Ventilation OvensE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method3.Terminology3.1 DefinitionsExcept for those terms below,see Termi-nologies D883 and D1600.3.2 Definitions of Terms Specific to This Standard:3.2.1 assemblyclosure applied to a bottle finish.3.2.2 failureduring this test,any visible crack.3.2.2.1 DiscussionA crack does not have to penetrate theclosure wall to be considered a failure.3.2.3 finishfixture representing the threaded portion of thebottle.3.2.4 threaded closurepart applied to seal bottle as speci-fied in Specification D2911.4.Summary of Test Method4.1 This test method consists of applying closures at aspecified application torque to rigid finishes(of polysulfone orother appropriate resin),immersing the assembly in a potentialstress-cracking agent,and observing and reporting time-to-failure.5.Significance and Use5.1 This test method compares closures for ESCR.Suitablevariables are:closure materials,closure designs,processes,applied torque,and stress-crack agents.5.2 Results can be used for estimating shelf life of closuresin terms of ESCR.This requires that the user has calibratedfailure time in this test to failure time in the field for actualpackaging systems.6.Apparatus6.1 Wide-Mount Gallon Jars,glass,PET,or other suitablematerial.Must have lined closures to ensure air-tight seal.Useone jar per sample.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.19 on Film,Sheeting,andMolded Products.Current edition approved Dec.1,2014.Published December 2014.Originallyapproved in 1993.Last previous edition approved in 2014 as D5419 14.DOI:10.1520/D5419-14A.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.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.2 Circulating-Air Oven,capable of maintaining a tem-perature of 50 6 1C(critical in this application).SeeSpecification E145 for a procedure for confirming satisfactoryuniformity of temperature within the oven.There is no air-flowrequirement in this application.An environmental room withthese properties is also suitable.(WarningA high-temperature safety switch is highly recommended on this oven.Some test liquids can cause extreme pressure to build up uponheating.Under these conditions it is possible that the test jarswill rupture with explosive force.Set the override cutoff switchto turn off the oven if the test temperature is exceeded by 10Cor more.)6.3 Tongs,for sample removal and inspection.6.4 Bottle Finishes,polysulfone or other material of equiva-lent stiffness and thermal coefficient of expansion,to whichclosures are applied.These can be made by injection moldingor by machi