1、Designation: D 4218 96 (Reapproved 2001)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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of blackpolyethylene compou
3、nds 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 haza
5、rdstatements are given in Section 7.NOTE 1There is no similar or equivalent ISO standard.2. Referenced Documents2.1 ASTM Standards:D 883 Terminology Relating to Plastics2D 1603 Test Method for Carbon Black in Olefin Plastics2D 2741 Test Method for Susceptibility of PolyethyleneBottles to Soot Accumu
6、lation3E 380 Practice for Use of the International System of Units(SI) (The Modernized Metric System)4E 691 Practice for Conducting an Interlaboratory Study toDetermine the Precision of a Test Method53. Terminology3.1 Definitions: For definitions of plastics terms used in thistest method, see Termin
7、ology 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 produc
8、ed 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
9、.3.3 Symbols:SymbolsUnits and symbols used in this testmethod are those recommended in Practice E 380.4. 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
10、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 black,the
11、 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
12、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 di
13、rect responsibility of Subcommittee D20.70 on Analytical Methods(Section D20.70.01).Current edition approved July 10, 1996. Published September 1996. Originallypublished as D 4218 82. Last previous edition D 4218 91.This revision includes the addition of an ISO equivalence statement and anexpanded t
14、erminology section.2Annual Book of ASTM Standards, Vol 08.013Annual Book of ASTM Standards, Vol 08.02.4Discontinued; see 1997 Annual Book of ASTM Standards, Vol 14.04.5Annual Book of ASTM Standards, Vol 14.02.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19
15、428-2959, United States.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 D 1603 is available for referee testingshould the involved parties so desire.6. Appa
16、ratus6.1 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 ba
17、re 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 approximately 10 mm of the long dimension to providea raised platform to fit inside the muffle furnace.6.4 Thermocouple-Probe Temper
18、ature Controller orEquivalentThis 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 We
19、ighing DishDishes withcrimped 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 furnaceel
20、ectrically safe.7.2 Do not attempt 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 unde
21、r avent hood to remove the resulting 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, m
22、oulding,etc. Soiled articles 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 s
23、tabilizefrom 600 to 610C.10.3 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 W
24、eigh the dish accurately on the 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 tim
25、e, 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 dish and remaining carbon black accu-rately. Record the results as W3.10.11 If ashable mineral fillers are suspected to be present inthe
26、 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 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
27、 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, % 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
28、 information:12.1.1 Complete 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 appa
29、ratus is available, identificationof the apparatus used.12.1.5 Value obtained from a control sample, if tested.12.1.6 Date.13. Precision and Bias613.1 PrecisionSix laboratories participated in an inter-laboratory evaluation of this test method. Each test sample was6Supporting data are available from
30、 ASTM Headquarters. Request RR:D20-1100.D 42182repaired by roll milling natural polyethylene and black mas-terbatch 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-butio
31、n. Six compounds were 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
32、 carbon black content (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 (13.2-1
33、3.2.3)are only intended 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,condit
34、ions, materials, or 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 Sra
35、nd 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 (Comparing two test resultsfor the same material, obtained by the same operator using thesame equipment on the same day)The two test results shoul
36、dbe judged not equivalent 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
37、 if they differ bymore 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 blac
38、k; 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 this standard are expressly advised that determination of the validity of any such patent rights, and the riskof i
39、nfringement 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 years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this sta
40、ndard or for additional 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
41、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 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by conta
42、cting 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).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 0.17
43、311E 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 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 42183
