ASTM_D_4218_-_96_2008.pdf

Designation:D421896(Reapproved 2008)Standard Test Method forDetermination of Carbon Black Content in PolyethyleneCompounds By the Muffle-Furnace Technique1This standard is issued under the fixed designation D4218;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 blackpolyethylene compounds containing channel or furnace black.It is not applicable to thermal black.1.2 This test method is not suitable for plastics that char onpyrolysis and should not be attempted for plastics that generatecorrosive fumes on pyrolysis.1.3 The values stated in SI units are to be regarded as thestandard.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 and health practices and determine the applica-bility of regulatory limitations prior to use.Specific hazardstatements are given in Section 7.NOTE1There is no similar or equivalent ISO standard.2.Referenced Documents2.1 ASTM Standards:2D883 Terminology Relating to PlasticsD1603 Test Method for Carbon Black Content in OlefinPlasticsD2741 Test Method for Susceptibility of PolyethyleneBottles to Soot Accumulation(Withdrawn 2011)3E691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodIEEE/ASTM SI-10 Standard for Use of the InternationalSystem of Units(SI):The Modern Metric System3.Terminology3.1 DefinitionsFor definitions of plastics terms used inthis test method,see Terminology D883.3.2 Definitions of Terms Specific to This Standard:3.2.1 channel blackthose carbon blacks produced by aprocess that operates in an open system in which a multitude ofsmall diffusion flames burn in air and carbon is deposited oncooled surfaces.3.2.2 furnace blackthose carbon blacks produced usingthe principle of continuous oxidative combustion in closedsystems.3.2.3 thermal blackthose carbon blacks based on a pro-cess that uses thermal decomposition in the absence of oxygenand operates in a closed system.Particles grow very slowly andcan become very large and filamentous structures.3.3 SymbolsUnits and symbols used in this test methodare those recommended in Practice IEEE/ASTM SI-10.4.Summary of Test Method4.1 Black polyethylene compound contained in a disposablealuminum weighing dish is pyrolyzed in a muffle furnace for ashort period.During the pyrolysis of the polymer,the air in themuffle furnace becomes oxygen-deficient to prevent the com-bustion of the residual carbon black.Any soot,as defined inTest Method D2741,produced by the initial combustion of thegases is consumed before the carbon black itself.4.2 After cooling and weighing for residual carbon black,the dish and contents may be reinserted into the muffle furnaceto determine ash content and the results used to determine truecarbon black content.This should be done only if the com-pound is suspected of containing mineral fillers as well ascarbon black.5.Significance and Use5.1 This test method is capable of yielding duplicate testdata,in 20 min or less,for a simple carbon black contentdetermination.5.2 This test method is suitable for manufacturing qualitycontrol,technical service,and research work.1This test method is under the jurisdiction of ASTM Committee D20 on Plasticsand is the direct responsibility of Subcommittee D20.70 on Analytical Methods(Section D20.70.01).Current edition approved Nov.1,2008.Published December 2008.Originallyapproved in 1982.Last previous edition approved in 2001 as D4218 96(2001).DOI:10.1520/D4218-96R08.2For 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 5.3 For referee requirements,the number of replicate mea-surements is increased.Alternatively,a control sample ofknown carbon black content is tested with the unknownsample.5.4 Test Method D1603 is available for referee testingshould the involved parties so desire.6.Apparatus6.1 Fume Hood or Vent Hood.6.2 Muffle Furnace,approximately 100 mm in the threeinternal dimensions.Furnaces with larger internal dimensionshave been found to be unsuitable.The seal at the door must befree of gaping cracks or chips that will allow air into thefurnace.A muffle furnace with bare heating wires on the floorof the furnace must not be used without additional electricalsafety precautions.6.3 Screen,20-Mesh,approximately 120 by 100 mm.Folddown approx