1、Designation: D 1770 94 (Reapproved 2006)Standard Test Method forNeps, Vegetable Matter, and Colored Fiber in Wool Top1This standard is issued under the fixed designation D 1770; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear 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 the numberof neps and pieces of vegetable matter by size classes,
3、 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 D 1446.1.3 This standard does not purport to address all of thesafety conc
4、erns, 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 Standards:3D 123 Terminology Relating to TextilesD
5、 1776 Practice for Conditioning and Testing TextilesD 1446 Discontinued 1978; Method of Test for Number ofNeps in Cotton Samples42.2 ASTM Adjuncts:5Nep Scale Standard (1 Photo), Vegetable Matter Standard (1Photo)3. Terminology3.1 Definitions:3.1.1 colored fiber, n in wool top, any fiber the color or
6、shade of which differs from the normal color or shade of thefiber mass of the sample.3.1.2 laboratory sample, na portion of material taken torepresent the lot sample, or the original material, and used inthe laboratory as a source of test specimens.3.1.3 lot, nin acceptance sampling, that part of a
7、consign-ment or shipment consisting of material from one productionlot.3.1.4 nep, none or more fibers occurring in a tangled andunorganized mass.3.1.4.1 DiscussionFor the purpose of this test method, themass of unorganized fibers retains its identity upon removalfrom a fibrous strand.3.1.5 test spec
8、imen, n for wool top, a length of specifiedmass taken at random from a length of wool top selected as alaboratory sample.3.1.6 top, nin wool, a continuous untwisted strand ofwool fibers from which the shorter fibers or noils have beenremoved by combing.3.1.7 vegetable matter, n in wool top, the piec
9、es of burrs,seeds, shive, leaves, twigs, and grasses which have escapedremoval in processing, also foreign vegetable fibers such ashemp, sisal, etc., if present.3.1.8 For definitions of other textile terms used in this testmethod, refer to Terminology D 123.4. Summary of Test Method4.1 Four test spe
10、cimens 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 numbers of each classof neps and class of vegetable matter pieces, and the number ofcolored fiber
11、s, are recorded for each specimen. From these datathe average counts per specimen of 15 g are calculated.5. Significance and Use5.1 Test Method D 1770 for the determination of neps,vegetable matter, and colored fiber may be used for theacceptance testing of commercial shipments of wool top butcautio
12、n 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 using Test Method D 1770 foracceptance testing of commercial shipments, the purchaser andt
13、he 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 two parties should take a group of test1This test method is under the jurisdiction of AST
14、M Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.13 on Wool and Wool Felt.Current edition approved Aug. 15, 2006. Published October 2006. Originallyapproved in 1960. Last previous edition approved in 2000 as D1770 88 (2000)e1.2For additional information, reference may
15、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 Book of ASTMStandards volume information, refer to the standards Document Summary
16、 page onthe ASTM website.4Withdrawn.5Original prints of these illustrations are available from ASTM InternationalHeadquarters. Order Adjunct No. ADJD1770 for Nep Scale Standard and VegetableMatter Standard.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428
17、-2959, United States.specimens 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 compared using Stud
18、ents 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 known bias.6. Apparat
19、us6.1 Nep Scale Standard, see Fig. 1 and ADJD1770.56.2 Vegetable Matter Standard, see Fig. 2 and ADJD1770.56.3 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
20、 white translucent surface with under-lighting may be used for all tests. When a translucent surfaceis used, 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 w
21、ith a sensitivityof 0.01 g.7. Sampling7.1 Lot SampleAs a lot sample for acceptance testing,take at random the 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 sampli
22、ng units.NOTE 2An adequate specification or other agreement between thepurchaser and the supplier requires 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 sampli
23、ng plan with a meaningful producers risk, consumersrisk, acceptable quality level, and limiting quality level.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 h
24、as a clean, uniform appearance. If the shippingcontainers in the lot sample contain multiple packages, take 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 startin
25、g at arandom location along the length of the sample and cuttingwith scissors a section long enough to weigh 15.00 6 0.10 g,NOTE 1Figs. 1 and 2 should preferably not be used as substitutes for the original prints obtainable from ASTM.5FIG. 1 Visual StandardD 1770 94 (2006)2Vegetable Matter SpecksNot
26、 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 preferably not be used as substitutes for the original prints obtainable from ASTM.5FIG. 2 Vegetable Matter ClassesD 1770 94 (2006)3adjusting t
27、he length as needed to obtain the required mass.Record the mass of the conditioned specimen to the nearest0.01 g.8. Conditioning8.1 Bring the laboratory samples to moisture equilibrium forobtaining test specimens in the standard atmosphere for testingtextiles as directed in Practice D 1776. Precondi
28、tioning is notnecessary.9. Procedure9.1 Test each weighed specimen, in the prevailing atmo-sphere if preferred, as follows:9.1.1 Draw a portion not exceeding one-tenth of the speci-men and spread it over the prescribed examination surface.9.1.2 Remove with tweezers each colored fiber and reservefor
29、counting.9.1.3 Also remove with tweezers each nep (except thoseobviously smaller than size 1 on the nep scale, 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 descr
30、ibed in 9.1.1-9.1.3 onadditional portions of the specimen until the entire specimenhas been treated.9.1.5 Count 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), discardtho
31、se classified as smaller than size 1, and count and record thenumber in each nep size class.9.1.7 Classify each 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 recor
32、d the number in each vegetablematter size class.NOTE 3The original prints of the pictures on which Figs. 1 and 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
33、 mass of the four specimens tested.10.2 Calculate the total number of colored fibers in the fourspecimens, and 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 fib
34、ers 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 wool 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 eac
35、h 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 size 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 near
36、est 0.1 unit-the average number of vegetable matter pieces of each sizeclass per 15 g of wool top, using Eq 3: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
37、 = combined mass of four specimens, in grams.10.6 Combined “Defects” If the term “defects” is used tomean colored 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 m
38、ay be calculated by using Eq 4:D 5 d 3 15/w (4)where:D = average number of specified defects per 15 g of wooltop,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 to
39、p 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 oz 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 D 1770. Descri
40、be the lot of wool top and the methodof sampling used.11.2 Report the following information:11.2.1 Number of specimens 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, if
41、required, per 0.5 oz.11.2.3 Average number of combined specified defects per15 g (or 0.5 oz), if required.12. 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 th
42、e total countof a specified defect for all specimens included in each testD 1770 94 (2006)4result since such total counts have 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 t
43、esting errors, the critical differences in Table 1will be overly optimistic and the confidence limits in Table 2will be widened 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 ea
44、ch of five laboratories. Eachlaboratory used two operators, each of whom tested fourspecimens 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 between l
45、aboratories 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 specimens
46、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 D 1770 for test-ing the number of neps, vegetable matter pieces, and coloredfibers in wool top until the amount of b
47、ias, if any, between thetwo specific 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
48、 or group ofdefects in a single test result obtained as directed in TestMethod D 1770.12.5 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 D 1770 have
49、 no 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; wool6ASTM Research Report No. RR:D13-1038. A copy is available on loan fromASTM Headquarters, 100 Barr Harbor Drive, West Conshohocken, PA 19428.TABLE 1 Value of 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 b
