ASTM_D_7232_-_06_2012.pdf

Designation:D723206(Reapproved 2012)Standard Test Method forRapid Determination of the Nonvolatile Content of Coatingsby Loss in Weight1This standard is issued under the fixed designation D7232;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 is used to obtain rapid determination ofthe weight percent nonvolatile(solids)content via instrumentalloss in weight technology.It is not meant as a replacement forTest Method D2369.1.2 This test method is principally intended for qualitycontrol labs and manufacturing environments where previouslycharacterized materials will be tested repeatedly for differentbatches or lots.1.3 This test method can be used for waterborne andsolventborne resins,intermediates and finished paint products.This test method may not be applicable to all types of coatings.1.4 The values stated in SI units are to be regarded as thestandard.The values given in parentheses are for informationonly.1.5 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 and health practices and to determine theapplicability of regulatory limitations prior to use.NOTE1There is no similar or equivalent ISO standard.2.Referenced Documents2.1 ASTM Standards:2D16 Terminology for Paint,Related Coatings,Materials,andApplicationsD2369 Test Method for Volatile Content of CoatingsE180 Practice for Determining the Precision of ASTMMethods for Analysis and Testing of Industrial and Spe-cialty Chemicals(Withdrawn 2009)33.Terminology3.1 Definitions:3.1.1 The definitions used in this test method are in accor-dance with Terminology D16.3.1.2 nonvolatile content,nthe coating material that re-mains in the pan at the conclusion of the test.3.2 Definitions of Terms Specific to This Standard:3.2.1 flip and squish,na testing technique that may beused when the expected nonvolatile content is greater than40%,or when the sample is highly viscous and does notabsorb well into the filter paper.3.2.1.1 DiscussionThe specimen is applied to the filterpaper on the sample pan,the filter paper is“flipped”over andthe specimen is then“squished”between the filter paper andthe sample pan in order to more uniformly distribute thespecimen.In addition,use of this technique forces the glassfibers of the filter paper into the specimen,helping to createpathways for volatiles release from the specimen and avoidingincomplete volatiles removal due to“skinning over”of thesample material.3.2.2 lift,nthe result of convection currents created duringthe heating of the specimen that raises the sample pan off of itssupport and falsely indicates a weight loss.3.2.2.1 DiscussionThis effect is compensated for by theuse of an algorithm that is applied to the digital data.3.2.3 syringe tare,na testing technique that may be usedwhen the expected nonvolatile content is less than 40%,orwhen the sample is highly volatile and tends to evaporaterapidly.3.2.3.1 DiscussionThe specimen weight is determinedusing an external balance by calculating the difference betweenthe syringe weight before(initial weight)and after(finalweight)the specimen is applied to the pan.This differencebetween initial and final weight is the actual weight ofspecimen(see 10.2),and is used to minimize error due to rapidchange of the specimen weight after addition to a heatedsample pan.1This test method is under the jurisdiction of ASTM Committee D01 on Paintand Related Coatings,Materials,and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1,2012.Published July 2012.Originally approvedin 2006.Last previous edition approved in 2006 as D7232 06.DOI:10.1520/D7232-06R12.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 4.Summary of Test Method4.1 The specimen is spread onto a sample pan that issupported on a balance in a heating chamber that has beenpreheated and equilibrated to the specified idle temperature.Itis then heated to the specified test temperature to vaporize thevolatiles.The analysis is completed when the indicated rate ofweight loss falls below a rate specified in the test conditions.The total weight loss is calculated and reported as weightpercent nonvolatiles.Both the analyzers balance and heaterare calibrated with NIST-traceable