ASTM_D_7477_-_16_2021.pdf

Designation:D747716(Reapproved 2021)Standard Test Method forDetermining the Area Stability of Wet Blue Submersed inBoiling Water1This standard is issued under the fixed designation D7477;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 test method provides a standard procedure fordetermination of the dimensional stability or area shrinkage ofa specimen of Wet Blue that is submersed in boiling water fora specified time period.This test method is applicable to alltypes of Wet Blue.1.2 The values given in SI units are to be regarded as thestandard.The inch-pound units given in parentheses are forinformation only.1.3 This test method does not apply to Wet White.1.4 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.1.5 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:2D6659 Practice for Sampling and Preparation of Wet Blueand Wet White for Physical and Chemical TestsE691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodE177 Practice for Use of the Terms Precision and Bias inASTM Test Methods3.Summary of Test Method3.1 Asample cutting of Wet Blue is either taken directly outof the tanning drum or else is pre-soaked in water for 30 minor until it is completely re-hydrated(see 9.1 for details onre-hydration).The specimen to be tested is cut out from thisthoroughly hydrated sample cutting.The test specimen is thentotally submerged and suspended in boiling water.The testspecimen is removed 3.0 min after the water temperaturereaches 100 C and begins to re-boil.As soon as the specimenhas cooled sufficiently to allow comfortable handling the arealoss is determined.4.Significance and Use4.1 Determination of the hydro-thermal area stability of WetBlue provides information concerning the efficacy of thetanning process as well as the adequacy of the Wet Blue forintended end use applications where area stability is a particu-lar requirement.Relative area stability of chrome-tannedleather is a requirement for many applications such asbookbinding,shoe and boot components,upholstery,seals andgaskets,etc.4.2 This test method is suitable for use in development workand process control in the tannery and for specification testingof Wet Blue for domestic and international commercial pur-poses.5.Apparatus5.1 Beaker,standard,IL capacity.Other suitable containersmay be used so long as the dimensions are sufficiently large toenable suspension of the completely immersed test specimenwith no contact occurring with the sides and bottom of thecontainer during the test.Particularly when non-standard testspecimens are used,the size and shape requirements of thecontainer are dependent on the dimensions of the specimen tobe tested.5.2 Thermometer,with a minimum scale reading to+110C,graduated in 1 C,and having a 0.5 C tolerance.5.3 Timer,with minimum 3 min capacity and 1.0 s resolu-tion.5.4 Metal die,to cut specimens.The die should be con-structed of highly corrosion resistant alloy metal and must bemaintained in a clean and sharp condition to minimize distor-tion of the Wet Blue sample that may occur during thespecimen cutting operation.The recommended specimen is a1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.02 on Wet Blue.Current edition approved Sept.1,2021.Published October 2021.Originallyapproved in 2008.Last previous edition approved in 2016 as D7477-16.DOI:10.1520/D7477-16R21.2For 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 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.1square 76.2 by 76.2 mm(3.00 by 3.00 in.).However,other sizeand shape specimens can be used so long a