1、Designation:D334906 Designation: D3349 12An American National StandardStandard 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
2、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 transmitte
3、d through a film of carbon black pigmented ethylene polymer.1.2 After calculation of the amount of light and film thickness, an absorption coefficient is calculated.1.3 Whenever two sets of values are presented, in different units, the values in the first set are the standard, while those inparenthe
4、ses are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations p
5、rior to use.2. Referenced Documents2.1 ASTM Standards:2E60 Practice for Analysis of Metals, Ores, and Related Materials by SpectrophotometryD1248 Specification for Polyethylene Plastics Extrusion Materials for Wire and Cable3. Summary of Test Method3.1 The transmission of light of a specified wavele
6、ngth through thin ethylene polymer film is measured. The result is used tocalculate an absorption coefficient that is a reciprocal function of transmission after correction for thickness.4. Significance and Use4.1 The absorption coefficient of polyolefin polymer pigmented with carbon black is useful
7、 to judge the degree and uniformityof dispersion of the pigment, and the adequacy of the quantitative level of pigment addition. These factors are used to predict theperformance of the polymer material in response to prolonged exposure to ultraviolet light as evidenced by minimal changes inspecific
8、properties.NOTE 1This test method was developed to evaluate ethylene polymer materials pigmented with small particle size carbon blacks suitable for UVprotection. It is not known how accurate and reproducible the test would be with larger (35 nm or greater) particle size blacks.5. Apparatus5.1 Spect
9、rophotometerAn instrument in accordance with Practice E60 is required.NOTE 2Consult the spectrophotometers operation manual or consult the manufacturer of the instrument for the calibration procedure.5.2 MoldA mold in accordance with Figs. 1 and 2. Make the mold of Ketos steel (or equivalent) harden
10、ed to Rockwell C45,with mold surfaces chromium plated to 0.005-mm (0.0002-in.) minimum thickness.5.3 Specimen HolderCut two concentric rings from phenolic-paper laminate or other suitable material to the dimensionsshown in Fig. 3. Slip fit the rings snugly one within the other.5.4 Reference Material
11、A reference material is required having an absorbance value of 1.0 to 1.2 at 375 nm as measured bythe instrument used for testing.1This test method is under the jurisdiction of ASTM Committee D09 on Electrical and Electronic Insulating Materials and is the direct responsibility of SubcommitteeD09.18
12、 on Solid Insulations, Non-Metallic Shieldings, and Coverings for Electrical and Telecommunications Wires and Cables.Current edition approved AprilJan. 1, 2006.2012. Published April 2006.February 2012. Originally approved in 1974. Last previous edition approved in 19992006 asD334999.D3349 06. DOI: 1
13、0.1520/D3349-06.10.1520/D3349-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.1This document is not an A
14、STM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In
15、all cases only the current versionof the standard as published by ASTM is to be considered the official document.*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, United States.5.4.1 N
16、eutral 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, it cannot be mounted as described in Section 7. Instead, a specialmount must be prepared by cutting Ring 1 of Fig. 3 in half ar
17、ound its circumference to give two rings about 2 mm (0.08 in.) thick.Cut a 22-mm (0.87-in.) circle from the laminated filter, sandwich this between the two 2-mm rings, and slide the outer ring (Ring2 of Fig. 3) over this composite.5.4.2 An alternative reference material can be prepared by any user o
18、f this test method. Prepare an alternative reference materialconsisting of a highly uniform sample of ASTM Type I polyethylene (see Specification D1248) containing about 1 % of a 20-nmcarbon black (either channel or furnace type). Press out a uniform film of this material and mount as in Section 8 t
19、o meet the aboverequirements. Reference materials so prepared shall show no more than 6 4 % variation from the average absorbance value whenmeasured at any point at 375 nm in the instrument used for testing.6. Calibration and Standardization6.1 Allow the spectrophotometer to stabilize. Using the spe
20、ctrophotomer manufacturers instructions, set the zero and infinityvalues on the absorbance scale.6.2 Insert the mounted reference material in the spectrophotomer and place it into the light beam. Read and record theabsorbance value using the conditions that bring the value nearest to zero on the abs
21、orbance scale. With the reference material stillin the beam, readjust the slit width to bring the reading back to zero. Recheck the infinity value.7. Conditioning7.1 No special conditioning is required.8. Specimen Preparation8.1 Prepare three test specimens from each lot of material by hot-pressing
22、the ethylene polymer at a suitable temperature3The sole source of supply of the apparatus known to the committee at this time is The Kodak neutral density filter, No. 5, available from the Eastman Kodak Co Ifyou are aware of alternative suppliers, please provide this information to ASTM Internationa
23、l Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee, which you may attend.FIG. 1 Mold, Top PlatenD3349 122between highly polished plates, such as those shown in Figs. 1 and 2, using a charge sufficient to yield a specimen 40 to 50 mmin
24、diameter and approximately 0.01 mm in thickness. Double pressing expedites the preparation of satisfactory specimens, that is,pressing to approximately 0.05 mm thickness and then pressing a section of that sheet to the required 0.01 mm thickness. Use ofa silicone mold release agent is also recommend
25、ed. For each specimen in turn, carefully transfer the specimen to the inner ringof the specimen holder (Ring 1, Fig. 3). With the specimen positioned concentrically over the inner ring, carefully press the outerring (Ring 2, Fig. 3) down over it to complete the mounting operation. Mount the specimen
26、 firmly, taut, and wrinkle-free. Visuallyexamine the mounted test specimen against a suitable light source. It must be uniform in color and free of clear spots or holes.Mark and identify three points approximately 120 apart on the outer ring of each specimen.9. Procedure9.1 Bring the first mounted s
27、pecimen into measuring position using the remaining outer position of the specimen holder, keepingthe 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. The absorbance value recorded is
28、equal to that indicated on the meter plus the measuredvalue for the reference material.9.2 Close the shutter and recheck the reference material. Rotate the specimen to bring the next 120 mark to the top and obtainthe absorbance value v2. Repeat the procedure with the third 120 mark at the top to obt
29、ain the value v3. Average the values v1,v2, and v3to obtain the average absorbance v. If any value of v differs from v by more than 10 %, discard the specimen and replaceit.9.3 Remove the film from the specimen mounting rings by cutting it carefully along the boundary between the two rings andFIG. 2
30、 Mold, Bottom PlatenD3349 123weigh it to the nearest 0.0001 g. The No. 11 Bard-Parker scalpel blade4in a suitable handle has been found very effective for thecutting operation. Measure the diameter and calculate the area of the specimen. Calculate average specimen thickness as follows:t 5 102 2W!/DA
31、! (1)where:t = thickness, m,W = weight, g,D = density, g/cm3, andA = area, cm2.NOTE 3The nominal density value for black low density ethylene polymer 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 tur
32、n, as follows:a 5 102 32.303v!/t! (2)4The sole source of supply of the apparatus known to the committee at this time is the No. 11 Bard-Parker scalpel blade, available from most laboratory supply houses.If you are aware of alternative suppliers, please provide this information to ASTM International
33、Headquarters. Your comments will receive careful consideration at a meetingof the responsible technical committee, which you may attend.NOTE 1AIf required, adjustm enitsher to the inside diameter of Ring 2 or outside diameter of Ring 1 may be necessary to obtain a snug fit of pressedfilm.FIG. 3 Spec
34、imen Mounting RingsD3349 124where:a = absorption coefficient, 1000 (absorbance/metre), at 375 nm,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 to obtain the value for the sample.11. Report11.1 Report the followi
35、ng: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 specimen tested,11.1.4 Average absorption coefficient of three specimens tested, which is the value for the sample, and11.1.5 Type and model of spec
36、trophotometer 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 conducted by five laboratories using one sample of carbon black-pigmentedethylene polymer and the same make and model of spectrophotometer. Each labora
37、tory molded from two to five test specimensfrom the sample and determined the absorption coefficient of each. The following statistics, each expressed in the units of 1000(absorbance/metre), were derived from the data submitted for this one sample.Mean = 443Sr=24SR=4312.1.2 Interpretation of the dat
38、a for the intervals Srand SRgiven above are as follows.12.1.2.1 RepeatabilityIn comparing two averages (of three specimens each) for the sample obtained in one laboratory by oneoperator on the same day, the averages are judged as not equivalent if they differ by more than Sr.12.1.2.2 Reproducibility
39、In comparing two averages (of three specimens each) for the sample obtained in different laboratoriesby different operators on different days, the averages are judged as not equivalent if they differ by more than SR.12.1.2.3 The judgments in 12.1.2.1 and 12.1.2.2 will be correct in approximately 95
40、% of such comparisons.12.2 Bias:12.2.1 In the round-robin study, it was found that different makes and models of spectrophotometer can produce systematicallydifferent results for the average absorbance of a specimen, with the maximum consistent difference being 6 % relative for the fourtypes of inst
41、rument used in the study.12.2.2 In critical applications, such as conformance of a material to a specification, it is necessary for the buyer and seller toagree upon the instrument that is to be used or to establish a correlation between the two types of instruments in use.13. Keywords13.1 absorptio
42、n coefficient; carbon black; ethylene polymerSUMMARY OF CHANGESCommittee D09 has identified the location of selected changes to this test method since the last issue,D3349 06, that maycan impact the use of this test method. (Approved AprilJanuary 1, 2006)2012)(1) Revised Section 1, Section 5, Sectio
43、n 8, Section 11, and Section 12) Corrected non-mandatory language and clarified Note 1.(2) Changed note in Fig. 3.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 adv
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46、f 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 19428-2959,United States. Indivi
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