ASTM_D_6658_-_08_2020.pdf

Designation:D665808(Reapproved 2020)Standard Test Method forVolatile Matter(Moisture)of Wet Blue by Oven Drying1This standard is issued under the fixed designation D6658;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 covers the determination of volatilematter(moisture)in all types of wet blue and wet white.1.2 This test method was originally developed for wet blue,however,this test method can be used to test wet white.For wetwhite testing,substitute the term wet white for wet blue in thestandard.1.3 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.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 Tests3.Summary of Test Method3.1 The prepared wet blue or wet white specimen is heatedin a forced air oven for 8 to 24 h at 100-105 C,placed in adesiccator,cooled,and reweighed.The loss in weight repre-sents the volatile matter.4.Significance and Use4.1 The result obtained by this test is normally considered tobe the moisture content of the wet blue or wet white sample.This result is used to correct all other chemical tests to amoisture-free basis.4.2 Materials that are volatile under these conditions,otherthan water,may be present in the wet blue,although theiramount in any normal wet blue would be expected to be a verysmall percentage of the total volatile matter.4.3 Under the conditions of this test,certain materials in wetblue,such as protein fiber and chromium tanning salts,mayretain moisture.Other materials,such as natural animal fats,may be oxidized.Both of these effects produce negative errorsin the moisture determination.4.4 The amount of volatile matter(moisture)released by agiven sample varies with(a)method and time of samplepreparation,(b)weight of sample taken,(c)temperature andtime of the oven drying,(d)type of oven(gravity versusmechanical convection)used.4.5 Because of the above unknown errors,the result of thistest is a purely arbitrary value for the moisture content of thesample.It is,therefore,essential that the method be followedexactly in order to obtain reproducible results among labora-tories.This is particularly true if other chemical analytical testsbeing performed on the same sample are reported on themoisture-free basis.5.Apparatus5.1 Appropriately sized weighing container with cover suit-able for oven use.5.2 Oven,forced air capable of attaining a steady 100-105C,with a thermoregulator system.A thermometer accurate to1 C should be used to check and monitor the oven set point.5.3 Balance,capable of weighing up to 100 g with anaccuracy of 6 0.001 g.5.4 Desiccator,any convenient form or size,using anynormal desiccating agent such as calcium sulfate,calciumchloride,or silica gel.6.Sampling6.1 The leather shall be sampled in accordance with PracticeD6659.1This 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 April 1,2020.Published April 2020.Originallyapproved in 2001.Last previous edition approved in 2013 as D6658 08(2013).DOI:10.1520/D6658-08R20.2For 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.7.Procedure7.1 Insert the empty weighing container and cover in theoven at 100-105 C for 1 h or more to insure dryness.7.2 Remove the container and cover from the oven andplace in a desiccator and cool to ambient temperature.7.3 Weigh the container and cover and recor