ASTM_D_3349_-_12.pdf

Designation:D334912Standard Test Method forAbsorption Coefficient of Ethylene Polymer MaterialPigmented with Carbon Black1This standard is issued under the fixed designation D3349;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.Scope*1.1 This test method measures the amount of light transmit-ted through a film of carbon black pigmented ethylene poly-mer.1.2 After calculation of the amount of light and filmthickness,an absorption coefficient is calculated.1.3 Whenever two sets of values are presented,in differentunits,the values in the first set are the standard,while those inparentheses are for information only.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.2.Referenced Documents2.1 ASTM Standards:2E60 Practice for Analysis of Metals,Ores,and RelatedMaterials by SpectrophotometryD1248 Specification for Polyethylene Plastics ExtrusionMaterials for Wire and Cable3.Summary of Test Method3.1 The transmission of light of a specified wavelengththrough thin ethylene polymer film is measured.The result isused to calculate an absorption coefficient that is a reciprocalfunction of transmission after correction for thickness.4.Significance and Use4.1 The absorption coefficient of polyolefin polymer pig-mented with carbon black is useful to judge the degree anduniformity of dispersion of the pigment,and the adequacy ofthe quantitative level of pigment addition.These factors areused to predict the performance of the polymer material inresponse to prolonged exposure to ultraviolet light as evi-denced by minimal changes in specific properties.NOTE1This test method was developed to evaluate ethylene polymermaterials pigmented with small particle size carbon blacks suitable for UVprotection.It is not known how accurate and reproducible the test wouldbe with larger(35 nm or greater)particle size blacks.5.Apparatus5.1 SpectrophotometerAn instrument in accordance withPractice E60 is required.NOTE2Consult the spectrophotometers operation manual or consultthe manufacturer of the instrument for the calibration procedure.5.2 MoldA mold in accordance with Figs.1 and 2.Makethe mold of Ketos steel(or equivalent)hardened to RockwellC45,with mold surfaces chromium plated to 0.005-mm(0.0002-in.)minimum thickness.5.3 Specimen HolderCut two concentric rings fromphenolic-paper laminate or other suitable material to thedimensions shown in Fig.3.Slip fit the rings snugly one withinthe other.5.4 Reference MaterialA reference material is requiredhaving an absorbance value of 1.0 to 1.2 at 375 nm asmeasured by the instrument used for testing.5.4.1 Neutral Density Filter,3M-type carbon 0.85 density,laminated between cellulose acetate sheets has been foundsatisfactory.Since this material is furnished as a rigid sheet,itcannot be mounted as described in Section 7.Instead,a specialmount must be prepared by cutting Ring 1 of Fig.3 in halfaround its circumference to give two rings about 2 mm(0.08in.)thick.Cut a 22-mm(0.87-in.)circle from the laminatedfilter,sandwich this between the two 2-mm rings,and slide theouter ring(Ring 2 of Fig.3)over this composite.1This test method is under the jurisdiction of ASTM Committee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.18 on Solid Insulations,Non-Metallic Shieldings and Coveringsfor Electrical and Telecommunication Wires and Cables.Current edition approved Jan.1,2012.Published February 2012.Originallyapproved in 1974.Last previous edition approved in 2006 as D3349 06.DOI:10.1520/D3349-12.2For 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 sole source of supply of the apparatus known to the committee at this timeis The Kodak neutral density filter,No.5,available from the Eastman Kodak Co.If you are aware of alternative suppliers,please provide this information to ASTMInternational Headquarters.Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 5.4.2 An alternative reference material can be prepared byany user of this test method.Prepare an alternative referencematerial consisting of a highly uniform sample of ASTM TypeI polyethylene(see Specification D1