1、Designation: D 3349 06An American National StandardStandard Test Method forAbsorption Coefficient of Ethylene Polymer MaterialPigmented with Carbon Black1This standard is issued under the fixed designation D 3349; the number immediately following the designation indicates the year oforiginal adoptio
2、n 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. Scope*1.1 This test method measures the amount of light transmit-ted through a film
3、 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 infor
4、mation 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.
5、Referenced Documents2.1 ASTM Standards:2E60 Practice for Analysis of Metals, Ores, and RelatedMaterials by Molecular Absorption SpectrometryD 1248 Specification for Polyethylene Plastics ExtrusionMaterials for Wire and Cable3. Summary of Test Method3.1 The transmission of light of a specified wavele
6、ngththrough 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
7、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 p
8、roperties.NOTE 1This 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 particle size blacks.5. Apparatus5.1 SpectrophotometerAn instrum
9、ent in accordance withPractice E60is required.NOTE 2Consult 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 mo
10、ld 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 requi
11、redhaving 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 a
12、s 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
13、 2 of Fig. 3) over this composite.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 D 1248) containing about 1 %1This test method is unde
14、r 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 Cover-ings for Electrical and Telecommunications Wires and Cables.Current edition approved April 1, 2006
15、. Published April 2006. Originallyapproved in 1974. Last previous edition approved in 1999 as D 3349 99.2For 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 standard
16、s 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 CoIf you are aware of alternative suppliers, please provide this information to ASTMInternational Hea
17、dquarters. Your comments will receive careful consideration at ameeting of the responsible technical committee,1which you may attend.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,
18、United States.of a 20-nm carbon black (either channel or furnace type). Pressout a uniform film of this material and mount as in Section 8to meet the above requirements. Reference materials so pre-pared shall show no more than 6 4 % variation from theaverage absorbance value when measured at any poi
19、nt at 375nm in the instrument used for testing.6. Calibration and Standardization6.1 Allow the spectrophotometer to stabilize. Using thespectrophotomer manufacturers instructions, set the zero andinfinity values on the absorbance scale.6.2 Insert the mounted reference material in the spectropho-tome
20、r and place it into the light beam. Read and record theabsorbance value using the conditions that bring the valuenearest to zero on the absorbance scale. With the referencematerial still in the beam, readjust the slit width to bring thereading back to zero. Recheck the infinity value.7. Conditioning
21、7.1 No special conditioning is required.8. Specimen Preparation8.1 Prepare three test specimens from each lot of materialby hot-pressing the ethylene polymer at a suitable temperaturebetween highly polished plates, such as those shown in Figs. 1and 2, using a charge sufficient to yield a specimen 40
22、 to 50mm in diameter and approximately 0.01 mm in thickness.Double pressing expedites the preparation of satisfactoryspecimens, that is, pressing to approximately 0.05 mm thick-ness and then pressing a section of that sheet to the required0.01 mm thickness. Use of a silicone mold release agent is al
23、sorecommended. For each specimen in turn, carefully transfer thespecimen to the inner ring of the specimen holder (Ring 1, Fig.3). With the specimen positioned concentrically over the innerring, carefully press the outer ring (Ring 2, Fig. 3) down overit to complete the mounting operation. Mount the
24、 specimenfirmly, taut, and wrinkle-free. Visually examine the mountedtest specimen against a suitable light source. It must be uniformin color and free of clear spots or holes. Mark and identifythree points approximately 120 apart on the outer ring of eachspecimen.9. Procedure9.1 Bring the first mou
25、nted specimen into measuring posi-tion using the remaining outer position of the specimen holder,keeping the specimen as close to the receiver as possible.Position the specimen with one of the 120 marks at the top.Open the shutter, read and record the absorbance value v1. Theabsorbance value recorde
26、d is equal to that indicated on themeter plus the measured value for the reference material.FIG. 1 Mold, Top PlatenD33490629.2 Close the shutter and recheck the reference material.Rotate the specimen to bring the next 120 mark to the top andobtain the absorbance value v2. Repeat the procedure with t
27、hethird 120 mark at the top to obtain the value v3. Average thevalues v1,v2, and v3to obtain the average absorbance v.Ifanyvalue of v differs from v by more than 10 %, discard thespecimen and replace it.9.3 Remove the film from the specimen mounting rings bycutting it carefully along the boundary be
28、tween the two ringsand weigh it to the nearest 0.0001 g. The No. 11 Bard-Parkerscalpel blade4in a suitable handle has been found veryeffective for the cutting operation. Measure the diameter andcalculate the area of the specimen. Calculate average specimenthickness as follows:t 5 102 2W!/DA! (1)wher
29、e:t = thickness, m,W = weight, g,D = density, g/cm3, andA = area, cm2.NOTE 3The nominal density value for black low density ethylenepolymer is 0.932 g/cm3.9.4 Repeat 9.1-9.3 for the second and third specimens.10. Calculation10.1 Calculate the absorption coefficient of each specimen,in turn, as follo
30、ws:a 5 102 32.303v!/t! (2)where:a = absorption coefficient, 1000 (absorbance/metre), at 375nm,v = average absorbance as found in 9.2, andt = thickness, m, as found in 9.3.10.2 Average the three values, a, for the three specimens toobtain the value for the sample.4The sole source of supply of the app
31、aratus known to the committee at this timeis the No. 11 Bard-Parker scalpel blade, available from most laboratory supplyhouses. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting
32、 of the responsible technical committee,1which you may attend.FIG. 2 Mold, Bottom PlatenD334906311. Report11.1 Report the following:11.1.1 Complete identification of the material tested,11.1.2 Nominal density of the material tested,11.1.3 Calculated absorption coefficient of each specimentested,11.1
33、.4 Average absorption coefficient of three specimenstested, which is the value for the sample, and11.1.5 Type and model of spectrophotometer used.11.1.6 Date of test11.1.7 Name of operator12. Precision and Bias12.1 Precision:12.1.1 In the early 1970s, a round-robin study was con-ducted by five labor
34、atories using one sample of carbonblack-pigmented ethylene polymer and the same make andmodel of spectrophotometer. Each laboratory molded from twoto five test specimens from the sample and determined theabsorption coefficient of each. The following statistics, eachexpressed in the units of 1000 (ab
35、sorbance/metre), werederived from the data submitted for this one sample.Mean = 443Sr=24SR=4312.1.2 Interpretation of the data for the intervals Srand SRgiven above are as follows.12.1.2.1 RepeatabilityIn comparing two averages (ofthree specimens each) for the sample obtained in one labora-tory by o
36、ne operator on the same day, the averages are judgedas not equivalent if they differ by more than Sr.12.1.2.2 ReproducibilityIn comparing two averages (ofthree specimens each) for the sample obtained in differentlaboratories by different operators on different days, the aver-ages are judged as not e
37、quivalent if they differ by more than SR.12.1.2.3 The judgments in 12.1.2.1 and 12.1.2.2 will becorrect in approximately 95 % of such comparisons.12.2 Bias:NOTE 1Adjustments to the inside diameter of Ring 2 or outside diameter of Ring 1 may be necessary to obtain a snug fit of pressed film.FIG. 3 Sp
38、ecimen Mounting RingsD334906412.2.1 In the round-robin study, it was found that differentmakes and models of spectrophotometer can produce system-atically different results for the average absorbance of aspecimen, with the maximum consistent difference being 6 %relative for the four types of instrum
39、ent used in the study.12.2.2 In critical applications, such as conformance of amaterial to a specification, it is necessary for the buyer andseller to agree upon the instrument that is to be used or toestablish a correlation between the two types of instruments inuse.13. Keywords13.1 absorption coef
40、ficient; carbon black; ethylene polymerSUMMARY OF CHANGESCommittee D09 has identified the location of selected changes to this test method since the last issue,D 3349 06, that may impact the use of this test method. (Approved April 1, 2006)(1) Revised Section 1, Section 5, Section 8, Section 11, and
41、Section 12.ASTM 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
42、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 additio
43、nal 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 A
44、STM 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 aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).D3349065
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