1、Designation:D287500(Reapproved 2020)Standard Test Method forInsoluble Ash of Vegetable-Tanned Leather1This standard is issued under the fixed designation D2875;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision
2、.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 covers the determination of the in-soluble ash in all types of vegetable-tanned leathers.This testmethod does not apply
3、 to wet blue.1.2 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 estab
4、lish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles fo
5、r 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:2D2617 Test Method for Total Ash in LeatherD2876 Test Method for Water-Soluble Matter of Vegetable-Tanned L
6、eather3.Summary of Test Method3.1 The specimen from which the water-soluble matter hasbeen removed is heated at 600 6 25C until carbon is removedand constant weight is attained.The weighed residual matter istermed“insoluble ash”and is calculated as a percentage of theoriginal sample.4.Significance a
7、nd Use4.1 This test method gives the amount of ash remaining inthe specimen after water extraction to remove water solublesfrom the leather in accordance with Test Method D2876.Theinsoluble ash is used in calculating the combined tanninbecause it is part of the tanned fiber structure that does notle
8、ach from the leather during water extraction.5.Apparatus5.1 Crucible,porcelain or platinum,large enough to holdthe leather specimen.5.2 Electric Muffle Furnace,with temperature controllerand pyrometer,capable of maintaining a temperature of 600 625C.6.Test Specimen6.1 The specimen shall consist of t
9、he 5-g leather sampleremaining after water extraction as directed in Test MethodD2876.Any deviation from this sample size should be includedwith the analytical results.7.Procedure7.1 Remove the specimen quantitatively from the extractiontube,dry at room temperature,transfer to the crucible,place ina
10、 cold muffle furnace,and ash at 600 6 25C until the crucibleand contents have reached constant weight as directed in TestMethod D2617.Remove the crucible to a desiccator,cool,andweigh.8.Calculation8.1 Calculate the percentage of insoluble ash in the leatheras follows:Insoluble ash,%5W32 W2!/W1#3100(
11、1)where:W1=weight of specimen(15 g),1This test method is under the jurisdiction of ASTM Committee D31 on Leatherand is the direct responsibility of Subcommittee D31.01 on Vegetable Leather Thistest method was developed in cooperation with the American Leather ChemistsAssn.Current edition approved De
12、c.1,2020.Published December 2020.Originallyapproved in 1970.Last previous edition approved in 2016 as D2875 00(2016).DOI:10.1520/D2875-00R20.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume i
13、nformation,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
14、 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.W2=weight of the crucible,andW3=weight of the crucible plus ash.9.Precision and Bias39.1 The precision
15、of this test method is limited by the lackof homogeneity of the sample in a complex material such asleather.It will also vary with the insoluble ash content.9.1.1 At the 95%confidence level,duplicate determina-tions by the same operator should not differ by more than 0.1%insoluble ash.9.1.2 At the 9
16、5%confidence level,the average of duplicatedeterminations in each of two laboratories by different opera-tors should not differ by more than 0.1%insoluble ash.9.2 Inasmuch as all leathers contain an unknown amount ofnatural or inherent ash,no meaningful statement can be madewith respect to bias.10.Keywords10.1 ash content;insoluble ash;leather;vegetable tannedleatherASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin
