1、Designation: D1770 94 (Reapproved 2012)1Standard Test Method forNeps, Vegetable Matter, and Colored Fiber in Wool Top1This standard is issued under the fixed designation D1770; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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.1NOTEThe terminology section was updated in July 2012.1. Scope1.1 This test method covers the determination of the numberof
3、neps and pieces of vegetable matter by size classes, and thenumber of colored fibers, in 15 g samples of wool top.21.2 This test method is applicable to wool top in any form.NOTE 1For the determination of number of neps per specified mass ofcotton samples, refer to Test Method D1446.1.3 This standar
4、d 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. Referenced Documents2.1 ASTM
5、 Standards:3D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD1446 Method of Test for Number of Neps in CottonSamples4D4845 Terminology Relating to Wool2.2 ASTM Adjuncts:5Nep Scale Standard (1 Photo), Vegetable Matter Standard (1Photo)3. Terminology3.1 For all
6、 terminology related to D13.13, refer to Termi-nology D4845.3.1.1 The following terms are relevant to this standard:colored fiber, in wool top; laboratory sample; lot, in acceptancetesting; nep; test specimen, for wool top; top, in wool;vegetable matter.3.1.2 For definitions of other textile terms u
7、sed in this testmethod, refer to Terminology D123.4. Summary of Test Method4.1 Four test specimens are taken and examined in accor-dance with specified procedures. Each observed nep or piece ofvegetable matter is classified by size, by visual comparisonwith a specified standard size chart. The numbe
8、rs of each classof neps and class of vegetable matter pieces, and the number ofcolored fibers, are recorded for each specimen. From these datathe average counts per specimen of 15 g are calculated.5. Significance and Use5.1 Test Method D1770 for the determination of neps,vegetable matter, and colore
9、d fiber may be used for theacceptance testing of commercial shipments of wool top butcaution is advised because the between-laboratory precision isknown to be poor. Comparative tests as directed in 5.1.1 maybe advisable.5.1.1 In case of a dispute arising from differences inreported test results when
10、 using Test Method D1770 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 minimum, the
11、 two parties should take a group of testspecimens that are as homogeneous as possible and that arefrom 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 twolaboratories should be
12、compared using Students t-test forunpaired data and an acceptable probability level chosen by thetwo parties before the testing is begun. If a bias is found, eitherits cause must be found and corrected or the purchaser and thesupplier must agree to interpret future test results in the light ofthe kn
13、own bias.1This 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 July 1, 2012. Published August 2012. Originallyapproved in 1960. Last previous edition approved in 2006 as D1770 94
14、(2006).DOI: 10.1520/D1770-94R12E01.2For additional information, reference may be made to “Neps in Worsted Sliver,”Wool Science Review, Vol 22, March 1963, pp. 2838.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Boo
15、k of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.4Withdrawn. The last approved version of this historical standard is referencedon www.astm.org.5Original prints of these illustrations are available from ASTM InternationalHeadquarters. Order Adjun
16、ct No. ADJD1770 for Nep Scale Standard and VegetableMatter Standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6. Apparatus6.1 Nep Scale Standard, see Fig. 1 and ADJD1770.56.2 Vegetable Matter Standard, see Fig. 2 and ADJD1770.5
17、6.3 Examination Surfaces, consisting of a dark surfaceilluminated from above for nep test and a white surfaceilluminated from above for vegetable matter and colored fibertests. Alternatively, a white translucent surface with under-lighting may be used for all tests. When a translucent surfaceis used
18、, colored fibers must be reexamined on an over-lightedwhite surface to avoid inclusion of medullated fibers.6.4 Tweezers, with pointed ground ends.6.5 Balance or Scale, capacity at least 25 g with a sensitivityof 0.01 g.7. Sampling7.1 Lot SampleAs a lot sample for acceptance testing,take at random t
19、he number of shipping containers directed inan applicable material specification or other agreement be-tween the purchaser and the supplier. Consider shippingcontainers to be the primary sampling units.NOTE 2An adequate specification or other agreement between thepurchaser and the supplier requires
20、taking into account the variabilitybetween shipping containers, between laboratory samples within a ship-ping container, and between test specimens within a laboratory sample toprovide a sampling plan with a meaningful producers risk, consumersrisk, acceptable quality level, and limiting quality lev
21、el.7.2 Laboratory SampleAs a laboratory sample for accep-tance testing, take from each shipping container in the lotsample the first 3 yd (3 m) of material from the lead end of thestrand that has a clean, uniform appearance. If the shippingcontainers in the lot sample contain multiple packages, take
22、 alaboratory sample from one package drawn at random fromeach shipping container.7.3 Test SpecimensAfter conditioning, take one test speci-men from each unit in the laboratory sample by starting at arandom location along the length of the sample and cuttingwith scissors a section long enough to weig
23、h 15.00 6 0.10 g,adjusting the length as needed to obtain the required mass.Record the mass of the conditioned specimen to the nearest0.01 g.NOTE 1Figs. 1 and 2 should preferably not be used as substitutes for the original prints obtainable from ASTM.5FIG. 1 Visual StandardD1770 94 (2012)128. Condit
24、ioning8.1 Bring the laboratory samples to moisture equilibrium forobtaining test specimens in the standard atmosphere for testingtextiles as directed in Practice D1776. Preconditioning is notnecessary.9. Procedure9.1 Test each weighed specimen, in the prevailing atmo-sphere if preferred, as follows:
25、9.1.1 Draw a portion not exceeding one-tenth of the speci-men and spread it over the prescribed examination surface.Vegetable Matter SpecksNot to be Counted18 to12 in. (3.2 to 12.7 mm)12 to34 in. (12.7 to19.1 mm)34 to 1 in. (19.1 to 25.4 mm) 1 to 112 in. (25.4 to 38.1 mm)NOTE 1Figs. 1 and 2 should p
26、referably not be used as substitutes for the original prints obtainable from ASTM.5FIG. 2 Vegetable Matter ClassesD1770 94 (2012)139.1.2 Remove with tweezers each colored fiber and reservefor counting.9.1.3 Also remove with tweezers each nep (except thoseobviously smaller than size 1 on the nep scal
27、e, Fig. 1), and eachpiece of vegetable matter (except those obviously smaller thanthe “specks” class, Fig. 2), and reserve for size classificationand counting.9.1.4 Repeat the operations described in 9.1.1-9.1.3 onadditional portions of the specimen until the entire specimenhas been treated.9.1.5 Co
28、unt and record the number of colored fibers re-moved from the specimen.9.1.6 Classify each removed nep as to size by comparing itwith the nep scale standard (see Note under Fig. 1), discardthose classified as smaller than size 1, and count and record thenumber in each nep size class.9.1.7 Classify e
29、ach removed piece of vegetable matter as tosize by comparing it with the vegetable matter standard (seeNote under Fig. 2), discard those classified as smaller than“specks,” and count and record the number in each vegetablematter size class.NOTE 3The original prints of the pictures on which Figs. 1 a
30、nd 2 arebased are available from ASTM and should be used in classifying neps orvegetable matter.9.2 Calculate the test results as directed in Section 10.10. Calculation10.1 Calculate the total mass of the four specimens tested.10.2 Calculate the total number of colored fibers in the fourspecimens, a
31、nd the total number of observed neps in each sizeclass and of pieces of vegetable matter in each size class.10.3 Colored FiberCalculate to the nearest 0.1 unit theaverage number of colored fibers per 15 g of wool top using Eq1:F 5 f 3 15/w (1)where:F = average number of colored fibers per 15 g of wo
32、ol top.f = total number of colored fibers in the four specimens,andw = combined mass of the four specimens, in grams.10.4 NepsCalculate to the nearest 0.1 unit the averagenumber of neps of each nep size class per 15 g of wool top,using Eq 2:Ni5 ni3 15/w (2)where:Ni= average number of neps of nep siz
33、e class i per 15 g ofwool top,ni= total number of neps of nep size class i in the fourspecimens, andw = combined mass of the four specimens, in grams.10.5 Vegetable MatterCalculate to the nearest 0.1unit the average number of vegetable matter pieces of eachsize class per 15 g of wool top, using Eq 3
34、:Vj5 vj3 15/w (3)where:Vj= average number of vegetable matter pieces of sizeclass j per 15 g of wool top,vj= total number of vegetable matter pieces of size classj in the four specimens, andw = combined mass of four specimens, in grams.10.6 Combined “Defects” If the term “defects” is used tomean col
35、ored fibers, neps of stated size classes, and vegetablematter pieces of stated size, classes, then for any specifiedcombination of defects, the average number of defects per 15g of wool top may be calculated by using Eq 4:D 5 d 3 15/w (4)where:D = average number of specified defects per 15 g of wool
36、top,d = total number of specified defects in the four speci-mens, andw = combined mass of four specimens, in grams.10.7 Conversion to 0.5-oz Sample Basis The averagecounts per 15 g of wool top may be converted to averagecounts per 0.5 oz by using Eq 5:A 5 0.945 M (5)where:A = average count per 0.5 o
37、z of wool top,M = average count per 15 g of wool top, and0.945 = factor obtained from 15/(28.35/2).11. Report11.1 State that the specimens were tested as directed in TestMethod D1770. Describe the lot of wool top and the method ofsampling used.11.2 Report the following information:11.2.1 Number of s
38、pecimens tested.11.2.2 Average number of neps of each size class, averagenumber of vegetable matter pieces of each size class, andaverage number of colored fibers per 15 g of wool top or, ifrequired, per 0.5 oz.11.2.3 Average number of combined specified defects per15 g (or 0.5 oz), if required.12.
39、Precision and Bias12.1 IntroductionTest results are reported as the averagecounts of specified defects per 15-g specimen of wool top. Theprecision of test results is evaluated in terms of the total countof a specified defect for all specimens included in each testresult since such total counts have
40、a Poisson distribution whilethe average defect counts do not have such a distribution. If thetotal counts for actual test results include bias due to systematicsampling or testing errors, the critical differences in Table 1will be overly optimistic and the confidence limits in Table 2will be widened
41、 by the existence of such bias.12.2 Interlaboratory Test Data6An interlaboratory testwas run in 1976 in which randomly drawn samples of one ballof wool top were tested in each of five laboratories. Eachlaboratory used two operators, each of whom tested four6Supporting data have been filed at ASTM In
42、ternational Headquarters and maybe obtained by requesting RR:D13-1038.D1770 94 (2012)14specimens of the material. The average count per 14-g speci-men were found to be: total neps, 40.5; total vegetable matterpieces, 9.5; colored fibers, 20.5. The test results indicatedsignificant differences betwee
43、n laboratories and between op-erators within laboratories for neps and colored fibers, andbetween laboratories for vegetable matter pieces.12.3 Critical DifferencesTable 1 contains criteria for de-termining whether the total defect counts for two test results,each based on the same number of specime
44、ns of a stated size,should be considered significantly different at the 95 % prob-ability level. No justifiable statement can be made about thebetween-laboratory precision of Test Method D1770 for testingthe number of neps, vegetable matter pieces, and colored fibersin wool top until the amount of b
45、ias, if any, between the twospecific laboratories has been established by comparisonsbased on recent data obtained on specimens randomly drawnfrom one sample of wool top of the type to be tested.12.4 Confidence LimitsTable 2 shows the 95 % confi-dence limits for the total count of a specified defect
46、 or group ofdefects in a single test result obtained as directed in TestMethod D1770.12.5 BiasThe true values for the count of neps, vegetablematter, and colored fiber in wool top can be defined only interms of a specific test method. Within this limitation, theprocedures in Test Method D1770 have n
47、o bias.12.5.1 Although the average results obtained by manyoperators in many laboratories should contain no bias, theresults of the interlaboratory test suggest that differencessometimes exist between operators or between laboratories.13. Keywords13.1 impurity; vegetable matter; woolTABLE 1 Value of
48、 b for Critical Differences in Defect Counts, a and b, for Two Test ResultsAr=a+b b r=a+b b r=a+b b r=a+b b1 0 26 7511876282 7 21 7293 8 8 31 824 0 29 541979305 30 9 5198036 0 1 562081317 32 9 72 238 0 33 10 58 21 83 329 1 34 10 59 21 84 3210 351 602185321 6 122863312 2 3712622 733 8 32388344 9 42 9
49、315 3 4013652490356 1 62 1317 4 4214672592368 3 82 339 5 92 43720 5 451 70269531 6 5 12 6372 5 4716722797383 6 8 32 834 9 7 428993925 7 50 17 75 28 100 39AThe probability level for the critical difference is 95 % for two-sided limits. If the observed value of b 100, use the following:b 5 c 2 1 2 k=cwhere:b = calculated value of b, rounded to the nearest whole number,c = r/2, andk = 1.386 for the 95 % probability level.D1770 94 (2012)15ASTM International takes no position respecting the validity of any patent rights asserted in connection with
