1、Designation: D 4218 96 (Reapproved 2008)Standard Test Method forDetermination of Carbon Black Content in PolyethyleneCompounds By the Muffle-Furnace Technique1This standard is issued under the fixed designation D 4218; the number immediately following the designation indicates the year oforiginal ad
2、option 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 compoun
3、ds 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.
4、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 hazar
5、dstatements are given in Section 7.NOTE 1There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:2D 883 Terminology Relating to PlasticsD 1603 Test Method for Carbon Black Content in OlefinPlasticsD 2741 Test Method for Susceptibility of PolyethyleneBottles to Soot A
6、ccumulationE 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test MethodIEEE/SI-10 Standard for Use of the International System ofUnits (SI): The Modern Metric System3. Terminology3.1 Definitions: For definitions of plastics terms used in thistest method, see Term
7、inology D 883.3.2 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 prod
8、uced 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 structur
9、es.3.3 Symbols:SymbolsUnits and symbols used in this testmethod are those recommended in Practice IEEE/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 polyme
10、r, the air in themuffle furnace becomes oxygen-deficient to prevent the com-bustion of the residual carbon black. Any soot, as defined inTest Method D 2741, produced by the initial combustion of thegases is consumed before the carbon black itself.4.2 After cooling and weighing for residual carbon bl
11、ack,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 met
12、hod 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.5.3 For referee requirements, the number of replicate mea-surements is increased. A
13、lternatively, a control sample ofknown carbon black content is tested with the unknownsample.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,
14、2008. Published December 2008. Originallyapproved in 1982. Last previous edition approved in 2001 as D 4218 96(2001).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
15、 the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 Test Method D 1603 is available for referee testingshould the involved parties so desire.6. Apparatus6.1 Fume Hood or Vent Ho
16、od.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 floor
17、of the furnace must not be used without 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 orEquivalent
18、This may be an integral part of newer mufflefurnaces or may be purchased separately to provide improvedcontrol on older furnaces.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
19、 sides and tabs on the rim are satisfactory.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 at
20、tempt to test plastics that evolve corrosivefumes 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 re
21、sulting fumes.8. Sample and Test Specimen8.1 Samples may originate from the manufacturers orpurchasers sampling regimens or from a specifically identifiedpart.8.2 The test specimens may be in the form of granules orpieces cut from an article such as pipe, jacket, film, moulding,etc. Soiled articles
22、must be washed, and printed articles, suchas films, 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
23、 Mark an aluminum weighing dish with an identifyingimpression 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 t
24、he analytical balance.Record the results as 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.10.9 After the elapsed time, remove the dish from the m
25、ufflefurnace 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 dish 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 a
26、nd contents into the mufflefurnace for a period of 10 min or longer until only light-coloredash remains.10.12 Transfer the dish and contents 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 de
27、terminations is made for eachsample.11. Calculation11.1 Calculate the percent carbon black content as follows:Carbon black, % 5W3 W1W2 W13 100 (1)orCarbon black, % 5W3 W4W2 W13 100 (2)where W1, W2, W3, and W4are described in Section 10.12. Report12.1 Report the following information:12.1.1 Complete
28、identification of material tested, includingtype, source, manufacturers code number, form, previoushistory, etc.12.1.2 Specific location of the specimen, if significant, forexample, from articles.12.1.3 Value of each determination and average.12.1.4 If more than one apparatus is available, identific
29、ationof the apparatus used.12.1.5 Value obtained from a control sample, if tested.12.1.6 Date.13. Precision and Bias313.1 PrecisionSix laboratories participated in an inter-laboratory evaluation of this test method. Each test sample wasrepaired by roll milling natural polyethylene and black mas-terb
30、atch to achieve 2, 2.5, or 3 % level of carbon black content.The milled crepe was reduced to fine particle size on a grinder.3Supporting data are available from ASTM Headquarters. Request RR:D20-1100.D 4218 96 (2008)2The ground material was blended before sampling for distri-bution. Six compounds we
31、re prepared in the above manner.Three compounds were based on polyethylene to give carbonblack 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 conte
32、nt (uncorrected for ash)were made on six materials that had been prepared with knowntarget values of carbon black. Table 1 summarizes the resultsobtained for Sr, SL, and SRas these parameters are defined inPractice E 691:NOTE 2Caution: The following explanations of r and R (13.2-13.2.3)are only inte
33、nded to present a meaningful way of considering theapproximate precision of this test method. The data in Table 1 should notbe rigorously applied to acceptance or rejection of material, as those dataare specific to the round robin and may not be representative of other lots,conditions, materials, or
34、 laboratories. Users of this test method shouldapply the principles outlined in Practice E 691 to generate data specific totheir laboratory and materials, or between specific laboratories. Theprinciples of 13.2-13.2.3 would then be valid for such data.13.2 Concept of r and RIf Srand SRhave been calc
35、ulatedfrom a large enough body of data, and for test results that wereaverages from testing one specimen:13.2.1 Repeatability Limit, r (Comparing two test resultsfor the same material, obtained by the same operator using thesame equipment on the same day)The two test results shouldbe judged not equi
36、valent if they differ by more than the r valuefor that material.13.2.2 Reproducibility Limit, R(Comparing two test re-sults for the same material, obtained by different operatorsusing different equipment in different laboratories)The twotest results should be judged not equivalent if they differ bym
37、ore than the R value 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 BiasThere are no recognized standards by which toestimate the bias of this test method.14. Keywords14.1 carbon black; muffle furnace;
38、polyethyleneASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such
39、 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 years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additi
40、onal standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the
41、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 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the a
42、boveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).TABLE 1 Precision DataMaterialTargetCarbonBlackAverage SrASRBrCRDD 2.00 2.0142 0.0272 0.03884 0.07698 0.10992A 2.00 2.0433 0.0342 0.06117 0.09679 0.17311E 2.50 2.5392 0.
43、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 isobtained by pooling the within-laboratory standard deviations of the test resultsfrom all of the participating laboratories.BSR= between-laboratories reproducibility, expressed as standard deviation,for the indicated material.Cr = within-laboratory repeatability limit = 2.8 Sr.DR = between-laboratories reproducibility limit = 2.8 SR.D 4218 96 (2008)3
