1、Designation: D 2968 95 (Reapproved 2008)Standard Test Method forMed and Kemp Fibers in Wool and Other Animal Fibers byMicroprojection1This standard is issued under the fixed designation D 2968; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、 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 by micro-projection of the percentage of medullated f
3、ibers (med andkemp fibers) in wool or other animal fibers such as mohair,cashmere, alpaca, or camels hair in their various forms.1.2 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
4、 appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 2130 Test Method for Diameter of Wool and OtherAnimal Fibers by Microprojection3. Terminology3.1 Defini
5、tionsFor definitions of other textile terms usedin this test method, refer to Terminology D 123.3.2 Definitions of Terms Specific to This Standard:3.2.1 kemp fiber, na medullated animal fiber in which thediameter of the medulla is 60 %, or more, of the diameter of thefiber.3.2.2 med fiber, na medull
6、ated animal fiber in which thediameter of the medulla is less than 60% of the diameter of thefiber.3.2.3 medulla, nin mammalian hair fibers, the more orless continuous cellular marrow inside the cortical layer inmost medium and coarse fibers.3.2.4 medullated fiber, nan animal fiber that in its origi
7、nalstate includes a medulla.3.2.5 wool, nthe fibrous covering of the sheep, ovisspecies.4. Summary of Test Method4.1 The magnified images of a specimen of the animal fibersare examined. All medullated fibers are measured and classedas either med fibers or kemp fibers. The observed numbers ofmed and
8、kemp fibers are expressed as percentages of the totalnumber of fiber images examined.5. Significance and Use5.1 Test Method D 2968 for the determination of med andkemp fibers by microprojection may be used for the acceptancetesting of commercial shipments of wool and other animalfibers, but caution
9、is advised since only a few types of animalfibers have been subjected to interlaboratory tests to ascertainthe precision of tests for med and kemp fibers by this testmethod. Comparative tests as directed in 5.1.1 may be advis-able.5.1.1 In case of a dispute arising from differences inreported test r
10、esults when using Test Method D 2968 foracceptance testing of commercial shipments, the purchaser andthe supplier should conduct comparative tests to determine ifthere is a statistical bias between their laboratories. Competentstatistical assistance is recommended for the investigation ofbias. As a
11、minimum, the two parties should take a group of testspecimens which are as homogeneous as possible and whichare from a lot of material of the type in question. The testspecimens should then be randomly assigned in equal numbersto each laboratory for testing. The average results from the twolaborator
12、ies should be compared using Students t-test forunpaired data and an acceptable probability level chosen by thetwo parties before testing is begun. If a bias is found, either itscause must be found and corrected, or the purchaser and thesupplier must agree to interpret future test results in view of
13、 theknown bias.5.2 Knowledge of the incidence of med fibers and kempfibers in wool and other animal fibers is of importance tomanufacturers of woven or knitted fabrics because of theapparent dye resistance and light reflectance qualities of thesefibers. This is not to imply that all kemp fibers will
14、 resist dye1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.13 on Wool and Felt.Current edition approved Aug. 1, 2008. Published October 2008. Originallyapproved in 1971. Last previous edition approved in 2001 as D 2968
15、 95 (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 the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Dri
16、ve, PO Box C700, West Conshohocken, PA 19428-2959, United States.and all med fibers will accept dye normally. In practice, aproportion of kemp fibers will appear normal after dyeing anda proportion of med fibers will appear chalky white afterdyeing. From the perspective of visual and aesthetic probl
17、ems,medullated fibers having an abnormally large diameter and ahigh degree of medullation are probably the worst kind.6. Apparatus and Material6.1 The apparatus and material required in this test methodare identical to those specified in Test Method D 2130.7. Sampling7.1 Adequate sampling procedures
18、 for loose fibers (grease,pulled, and scoured), sliver, top, yarn, and fabric are describedin Test Method D 2130.8. Procedure8.1 Prepare the test specimens, calibrate the microprojector,condition the specimens, and prepare the slides by use of theheavy-duty cross-section device as directed in Test M
19、ethodD 2130. Have two operators independently prepare at least oneslide for each test specimen.8.2 Have each of the two operators make observations usingthe procedure specified in Test Method D 2130, except thatonly medullated fibers need be measured. For such fibers,measure the diameter of both the
20、 medulla and the fiber,calculate their ratio, and classify the fiber as either med orkemp as defined in 3.2.1 and 3.2.2. For every fiber examined,record whether it is unmedullated, med, or kemp. See Fig. 1.8.3 Count and record the number of med and kemp fibersand the total number of animal fibers ex
21、amined. Unlessotherwise directed in an applicable specification or by agree-ment, each operator should observe 500 fibers for a total of1000 fibers.9. Calculation9.1 Calculate, to the nearest 0.1 %, the med and kemp fiberscontent using (Eq 1) and (Eq 2):med fibers, % 5 100 m/n (1)kemp fibers, % 5 10
22、0 k/n (2)where:m = number of med fibers observed,k = number of kemp fibers observed, andn = total number of animal fibers observed.10. Report10.1 State that the specimens were tested as directed in TestMethod D 2968. Describe the material or product sampled andthe method used.10.2 Report the followi
23、ng information:10.2.1 The med fibers content,10.2.2 The kemp fibers content, and10.2.3 The total number of animal fibers observed.11. Precision and Bias11.1 Interlaboratory Test Data3An interlaboratory testwas conducted in 1970 in which three randomly drawn samplesfrom one lot of mohair top were tes
24、ted in each of fivelaboratories. Two operators in each laboratory each examined500 fibers per sample. The test results for med fibers and kempfibers were found to be free of bias due to sampling or testingerrors for nine of the ten operators involved.11.1.1 Interlaboratory test data are on file only
25、 for mohairtop. These test results were found to be free of bias due tosampling and testing errors for nine out of ten operators. Since3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D131036.NOTE 1The contrast between the solid
26、and the hollow portions of the medullated fibers is significantly reduced when the medulla becomes filled withmounting medium.FIG. 1 Types of Medulla in Wool and Mohair FibersD 2968 95 (2008)2similar data for med and kemp measured on other types ofanimal fibers or mohair samples removed from forms o
27、therthan top are not on file, no statements can be made concerningthe bias measurements made on such samples.11.1.2 Test results for med and kemp fibers are reported asa percent of the fibers examined. Such test results have abinomial distribution and for the small percentages of interestwould requi
28、re a transformation when analyzing the data. Forthis reason, the precision of test results is evaluated in terms ofthe count of med fibers observed and the count of kemp fibersobserved in the 1000 fibers examined for a single test result.Such counts have a Poisson distribution and may be compareddir
29、ectly without requiring a transformation.11.2 Critical DifferencesTwo counts of med fibers in testresults or two counts of kemp fibers in test results should beconsidered significantly different at the 95 % probability levelif the smaller of the two counts is equal to or less than the valuelisted in
30、 Table 1.NOTE 1In comparing observed counts for test results from each oftwo different laboratories, test results from two operators within the samelaboratory, or other similar cases, Table 1 may be used, only if acomparison based on recent data obtained on specimens randomly drawnfrom one sample of
31、 the material to be evaluated has verified the absenceof bias between the two specific laboratories or operators.11.3 Confidence LimitsSingle counts of med fibers orsingle counts of kemp fibers in a test result have the 95 %confidence limits listed in Table 2.11.4 BiasTest Method D 2968 for testing
32、the percentagesof med and kemp fibers in wool and other animal fibers has noknown bias and may be used as a referee method.12. Keywords12.1 animal fibers (except wool); microscopical examina-tion; woolTABLE 1 Values of b for Critical Differences in Number of Medor Kemp Fiber Counts, a and b, for Two
33、 Test ResultsAr=a+bbr=a+bbr=a+bbr=a+bb1026 75118762820 7 2 93028 8531878240 9 4 9 9305030 95 1 806031 95620813170 2 7 28 0 33 10 58 21 83 329 1 34 10 59 21 84 3210 1 35 11 60 21 85 3211 1 36 11 61 22 86 3312 2 7 2622 73 381 3238 3414 2 9 2642 95 3 40136524 03516 3 4113662491357 4 2 46725 2 618 431 8
34、2 9339 4 56925 4 720 5 4515702695321 5 4615712696377 67227 7 823 6 481 32 9834 9 77428 925 7 50 17 75 28 100 39AThe probability level for the critical difference is 95 %, for two-sided limits. If theobserved value of b 100, use the following:b 5 c 2 1 2 k=cwhere:b = calculated value of b, rounded to
35、 the nearest whole number,c = r/ 2, andk = 1.386 for the 95 % probability level.D 2968 95 (2008)3ASTM 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 determi
36、nation 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 years andif not revised, either reapproved or wi
37、thdrawn.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 committee, which you may attend. If you feel that yo
38、ur 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. Individual reprints (sin
39、gle 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).TABLE 2 95 % Confidence Limits for Number of Counts per TestResultsAObservedCountLowe
40、rLimitUpperLimitObservedCountLowerLimitUpperLimit0 0.0 3.71 0.0 5.6 26 17.0 38.12 0.2 7.2 27 17.8 39.33 0.6 8.8 28 18.6 40.54 1.1 10.2 29 19.4 41.65 1.6 11.7 30 20.2 42.86 2.2 13.1 31 21.1 44.07 2.8 14.4 32 21.9 45.28 3.4 15.8 33 22.7 46.49 4.1 17.1 34 23.5 47.510 4.8 18.4 35 24.4 48.711 5.5 19.7 36
41、 25.2 49.812 6.2 21.0 37 26.0 51.013 6.9 22.2 38 26.9 52.214 7.6 23.5 39 27.7 53.315 8.4 24.7 40 28.6 54.516 9.1 26.0 41 29.4 55.617 9.9 27.2 42 30.3 56.818 10.7 28.4 43 31.1 57.919 11.4 29.6 44 32.0 59.120 12.2 30.8 45 32.8 60.221 13.0 32.1 46 33.7 61.422 13.8 33.3 47 34.5 62.523 14.6 34.5 48 35.4
42、63.624 15.4 35.7 49 36.2 64.825 16.2 36.9 50 37.1 65.9ALower confidence limit for counts = c 1-(19 c) t (19 c)1/23Upper confidence limit for counts = d 1-(19 d)+t (19 d)1/23where:c = observed number of counts,d = c+1,andt = value of Students t for infinite degrees of freedom, two-sided limits, andthe specified probability level (t = 1.960 at the 95 % probability level).D 2968 95 (2008)4
