ASTM_D_8137_-_18.pdf

Designation:D813718Practice forAccelerated Aging of Leather1This standard is issued under the fixed designation D8137;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.Scope1.1 This practice is based on studies relating the rate ofdeterioration of leathers having known durabilities from long-term storage of samples,to the deterioration experienced bylaboratory exposure of specimens to known contents of acidgases in air or oxygen.This is accomplished by measuring thedeterioration(reduction in tensile strength)of leather speci-mens when they are subjected to exposure to a mixture of air,moisture and sulfur dioxide at a given temperature and pressureand for a given exposure time.The loss of tensile strength ofthe specimens resulting from this exposure is compared to thatexperienced by a variety of leathers having various tannagesand having historically long and short service lifetimes.Theinitial tensile strength and the degree of loss of tensile strengthis related to what service life can be anticipated from a givenleather.1.2 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,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.3 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D1517 Terminology Relating to LeatherD1610 Practice for Conditioning Leather and Leather Prod-ucts for TestingD1813 Test Method for Measuring Thickness of LeatherTest SpecimensD2209 Test Method for Tensile Strength of Leather3.Terminology3.1 For definitions of leather terms used in this Practicerefer to Terminology D1517.4.Reagents4.1 Sulfur Dioxide(SO2),Anhydrous,99.9%pure.4.2 Air,From compressor,filtered,stored at 21C(satu-rated water vapor conditions)90 to 100 psi delivery pressure.5.Summary of Practice5.1 Specimens are prepared and placed in a pressure cham-ber containing known or constant quantities of air,moistureand SO2.They are held in the chamber at a constant tempera-ture for a given time period.After that processing,the tensilestrengths of the specimens are measured along with the tensilestrengths of unprocessed specimens of the same leather.Theloss of tensile strength resulting from the processing relative tothat of the unprocessed specimens(%)is determined and maybe directly compared to that of other leathers considered for anapplication.Where applicable,the results may also be consid-ered as the basis for projected service lifetimes as shown inSection 11.6.Significance and Use6.1 A substantial difficulty in using leather in applicationsrequiring very long service lives is estimating how well aparticular leather will actually hold up in service.Suchapplications may include use in musical instruments such aspipe organs,bookbinding leathers,etc.Use of leather in pipeorgans in the past(prior to approximately 1930)demonstratedservice lives frequently over 100 years,and the consequencesof short service lives can result in extremely costly repairs.Many post-1930 leathers have had short service lives(as littleas 15 years)due to the use of various more modern tannagesand processing methods.Identifying exactly what tannage andprocessing was used in a particular leather and how successfulthis tanning and processing was can be very difficult.Failure ofbookbinding and upholstery leathers formed the impetus forextensive work by leather chemists in the 1940s to identifytests that could be used to verify the durability of leather1This practice is under the jurisdiction ofASTM Committee D31 on Leather andis the direct responsibility of Subcommittee D31.05 on Upholstery.Current edition approved June 15,2018.Published August 2018.DOI:10.1520/D8137-182For 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 StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 samples.Early st