ASTM_D_6020_-_00_2020.pdf

Designation:D602000(Reapproved 2020)Standard Practice forCalculation of(Non-Mineral)Combined Tanning Agents andDegree of Tannage1This standard is issued under the fixed designation D6020;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 U.S.Department of Defense.1.Scope1.1 This practice covers the determination of the combinedtannin and nonextractable organic resins and the degree oftannage of all types of vegetable-tanned leather and leatherwith organic retannages.This practice does not apply to wetblue.1.2 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:2D2868 Test Method for Nitrogen Content(Kjeldahl)andHide Substance Content of Leather,Wet Blue and WetWhiteD2875 Test Method for Insoluble Ash of Vegetable-TannedLeatherD2876 Test Method for Water-Soluble Matter of Vegetable-Tanned LeatherD3495 Test Method for Hexane Extraction of Leather3.Significance and Use3.1 This practice may be used to determine non-protein ornon-nitrogen containing organic matter in leather which is notextractable with water or hexane.Examples would be veg-etable tannins and acrylic lubricants.4.Procedure4.1 The chloroform and water extractable materials andinsoluble ash in the specimen for test shall be determined inaccordance with Test Methods D2875,D2876,and D3495.4.2 The hide substance in the specimen for test shall bedetermined in accordance with Test Method D2868.5.Calculation of Results5.1 The percentage of combined tannin in the specimenshall be calculated as follows:Combined tannin,percent5 1002A1B1C1D!(1)where:A=percent of chloroform-soluble material(mfb),B=percent of water-soluble material(mfb),C=percent of insoluble ash(mfb),andD=percent of hide substance(mfb).(mfb)=moisture free basis.5.2 The degree of tannage shall be calculated as follows:Degree of tannage5TD3100(2)where:T=percent of combined tannin,andD=percent of hide substance.6.Report6.1 The combined tannin in the specimen shall be reportedto the nearest 0.1%.6.2 The degree of tannage in the specimen shall be reportedto the nearest 0.5.7.Precision and Bias7.1 This practice is adopted from Federal Test Standard No.311 Method 6631,where it has long been in use and wasapproved for publication before the inclusion of precision andbias statements was mandated.The user is cautioned to verifyby the use of reference materials,if available,that the precisionand bias(or reproducibility)of this practice is adequate for the1This practice is under the jurisdiction ofASTM Committee D31 on Leather andis the direct responsibility of Subcommittee D31.01 on Vegetable Leather.Current edition approved Dec.1,2020.Published December 2020.Originallyapproved in 1996.Last previous edition approved in 2016 as D6020-00(2016).DOI:10.1520/D6020-00R20.2For 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.1contemplated use.The user should also consider precision andbias statements from each of the methods used to make thiscalculation.8.Keywords8.1 combined tannins;degree of tannage;leather;tanninanalysis;vegetable-tanned leatherASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard.Users of this standard are expressly advised that determination of the validity of any such patent rights,and the riskof infringement of such rights,are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,either reapproved or withdrawn.Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of theresponsible technical committee,which you may attend.If you feel tha