1、Designation: D4218 15Standard 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 ca
2、se 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 channe
3、l or furnace black.It is not applicable to thermal black.1.2 This test method is not suitable for plastics that char onpyrolysis.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 us
4、e. 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.NOTE 1There is no known ISO equivalent to this standard.2. Reference
5、d 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Carbon Black Content in OlefinPlasticsD2741 Test Method for Susceptibility of PolyethyleneBottles to Soot Accumulation (Withdrawn 2011)3E691 Practice for Conducting an Interlaboratory Study toDetermine the Prec
6、ision 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 black
7、those 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 th
8、ermal 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 Pra
9、ctice 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
10、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 are reinserted into the muffle furnace todetermine ash content
11、 and the results used to determine truecarbon black content. This is done only if the compound issuspected of containing mineral fillers as well as carbon 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 content
12、determination.5.2 This test method is suitable for manufacturing qualitycontrol, technical service, and research work.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 Te
13、st Method D1603 is available for referee testing.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 Dec. 1, 2015. Published December 2015. Originallyapp
14、roved in 1982. Last previous edition approved in 2008 as D4218 96(2008).DOI: 10.1520/D4218-15.2For 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
15、 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 States16. Apparatus6.1 Fume Hood or Vent Hood.6.2 Muffle Furnace, approximat
16、ely 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 w
17、ithout additional electricalsafety precautions.6.3 Screen, 20-Mesh, approximately 120 by 100 mm. Folddown approximately 10 mm of the long dimension to providea raised platform to fit inside the muffle furnace.6.4 Thermocouple-Probe Temperature Controller orEquivalentThis is an integral part of newer
18、 muffle furnacesor is purchased separately to provide improved control on olderfurnaces.6.5 Desiccator (for example, 255 mm), with alumina orequivalent desiccant.6.6 Laboratory Interval Timer, with alarm.6.7 Disposable Aluminum Weighing DishDishes withcrimped sides and tabs on the rim are satisfacto
19、ry.6.8 Long Tongs or Tweezers (250 to 300 mm).6.9 Analytical Balance, capable of measuring to 0.1 mg.7. Hazards7.1 Do not use a muffle furnace with bare heating elementson the floor of the furnace. Take steps to make the furnaceelectrically safe.7.2 Do not attempt to test plastics that evolve corros
20、ivefumes on pyrolysis.7.3 Do not open the muffle furnace door during the test.Opening the door while fumes are being emitted from the doorseal will cause ignition of the fumes.7.4 This test must be conducted in a fume hood or under avent hood to remove the resulting fumes.8. Sample and Test Specimen
21、8.1 Samples are obtained from the manufacturers or pur-chasers sampling regimens or from a specifically identifiedpart.8.2 The test specimens are in the form of granules or piecescut from an article such as pipe, jacket, film, molding, etc.Soiled articles must be washed, and printed articles, such a
22、sfilms, are wiped clean with a suitable solvent.9. Conditioning9.1 Conditioning is unnecessary.10. Procedure10.1 Place the muffle furnace in a fume hood or under a venthood.10.2 Set the controller indicator to 600C and let it stabilizefrom 600 to 610C.10.3 Mark an aluminum weighing dish with an iden
23、tifyingimpression on the tab.10.4 Place the dish on the screen in the muffle furnace andburn off the surface oil for 2 min, as indicated by timer.10.5 Transfer the dish to the desiccator and let it cool for atleast 2 min.10.6 Weigh the dish accurately on the analytical balance.Record the results as
24、W1.10.7 Add about1gofspecimen and reweigh the dish andcontents accurately. Record the results as W2.10.8 Place the weighed dish and contents into the mufflefurnace and set the interval timer for 3 min. If there are noknown ashable fillers, then this time is sufficient. If there areother or additiona
25、l fillers that will oxidize further, then followthe procedure at 10.11 to obtain a more complete pyrolysis.10.9 After the elapsed time, remove the dish from the mufflefurnace and place it in the desiccator to cool for at least 2 min.Longer cooling periods do not affect the test.10.10 Reweigh the dis
26、h and remaining carbon black accu-rately. Record the results as W3.10.11 If ashable mineral fillers are suspected to be present inthe compound, replace the dish and contents into the mufflefurnace for a period of 10 min or longer until only light-coloredash remains.10.12 Transfer the dish and conten
27、ts from the muffle furnaceto the desiccator and let it cool for 2 min.10.13 Reweigh the dish and ash accurately. Record theresults as W4.10.14 A minimum of two determinations is made for eachsample.11. Calculation11.1 Calculate the percent carbon black content as follows:Carbon black, % 5W32 W1W22 W
28、13100 (1)orCarbon black, % 5W32 W4W22 W13100 (2)where W1, W2, W3, and W4are described in Section 10.12. Report12.1 Report the following information:12.1.1 Complete identification of material tested, includingtype, source, manufacturers code number, form, previoushistory, etc.12.1.2 Specific location
29、 of the specimen, if significant, forexample, from articles.12.1.3 Value of each determination and average. When thespecimen requires the longer time for complete ashing, thenreport the time and the ash content as part of the result.12.1.4 If more than one apparatus is available, identificationof th
30、e apparatus used.12.1.5 Value obtained from a control sample, if tested.D4218 15212.1.6 Date.13. Precision and Bias413.1 PrecisionSix laboratories participated in an inter-laboratory evaluation of this test method. Each test sample wasrepaired by roll milling natural polyethylene and black mas-terba
31、tch to achieve 2, 2.5, or 3 % level of carbon black content.The milled crepe was reduced to fine particle size on a grinder.The ground material was blended before sampling for distri-bution. Six compounds were prepared in the above manner.Three compounds were based on polyethylene to give carbonblac
32、k contents of 2, 2.5, and 3 %. A similar set of threecompounds was prepared using polyethylene containing 3 %vinyl acetate and a different grade of carbon black. Duplicatedeterminations of carbon black content (uncorrected for ash)were made on six materials that had been prepared with knowntarget va
33、lues of carbon black. Table 1 summarizes the resultsobtained for Sr, SL, and SRas these parameters are defined inPractice E691:NOTE 2Caution: The following explanations of r and R (13.2 13.2.3) are only intended to present a meaningful way of considering theapproximate precision of this test method.
34、 Do not apply the data in Table1 rigorously to acceptance or rejection of material, as those data arespecific to the round robin and are not representative of other lots,conditions, materials, or laboratories. Apply the principles outlined inPractice E691 to generate data specific to their laborator
35、y and materials, orbetween specific laboratories. The principles of 13.2 13.2.3 would thenbe valid for such data.13.2 Concept of r and RIf Srand SRhave been calculatedfrom a large enough body of data, and for test results that wereaverages from testing one specimen:13.2.1 Repeatability Limit, r(Comp
36、aring two test resultsfor the same material, obtained by the same operator using thesame equipment on the same day)The two test results are notequivalent if they differ by more than the r value for thatmaterial.13.2.2 Reproducibility Limit, R(Comparing two test re-sults for the same material, obtain
37、ed by different operatorsusing different equipment in different laboratories)The twotest results are not equivalent if they differ by more than the Rvalue for that material.13.2.3 Any judgement in accordance with 13.2.1 or 13.2.2would have an approximate 95 % (0.95) probability of beingcorrect.13.3
38、BiasThere are no recognized standards by which toestimate the bias of this test method.14. Keywords14.1 carbon black; muffle furnace; polyethyleneASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of
39、 this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five
40、 years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical co
41、mmittee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA
42、19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the
43、 standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ data are available from ASTM Headquarters. Request RR:D20-1100.TABLE 1 Precision DataMaterialTargetCarbonBlackAverage SrASRBrCRDD 2.00 2.0142 0.0272 0.03884 0.07698 0.
44、10992A 2.00 2.0433 0.0342 0.06117 0.09679 0.17311E 2.50 2.5392 0.0250 0.05963 0.07075 0.16874B 2.50 2.5517 0.0410 0.05808 0.11603 0.16437F 3.00 3.0242 0.0364 0.06892 0.10301 0.19506C 3.00 3.0710 0.0270 0.0613 0.07641 0.18149ASr= within-laboratory standard deviation for the indicated material. It is
45、obtainedby pooling the within-laboratory standard deviations of the test results from all ofthe participating laboratories.BSR= between-laboratories reproducibility, expressed as standard deviation, forthe indicated material.Cr = within-laboratory repeatability limit = 2.8 Sr.DR = between-laboratories reproducibility limit = 2.8 SR.D4218 153
