1、Designation: D 3991 94 (Reapproved 2006)Standard Specifications forFineness of Wool or Mohair and Assignment of Grade1This standard is issued under the fixed designation D 3991; 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 These specifications cover the classification, by finenessgrade, of wool or mohair that is in the grease, pull
3、ed, washed,or scoured state, or in the form of card sliver.1.2 These specifications are applicable also to assignment ofgrade for wool or mohair in spun materials or productsprocessed beyond carding on the woolen system but not on theworsted system which involves a combing process.NOTE 1For fineness
4、 specifications for wool top, mohair top, andalpaca, refer to Specifications D 3992 and D 2252.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 2130 Test Method for Diameter of Wool and OtherAnimal Fibers by MicroprojectionD 2252 Specification for Fineness of Types
5、of AlpacaD 3992 Specifications for Fineness of Wool Top or MohairTop and Assignment of Grade2.2 Federal Standards:Official Standards of the United States for Grades of Wool,Section 31.03Measurement Method for Determining Grade of Wool,Section 31.2043Official Standards of the United States for Grades
6、 of GreaseMohair, Section 32.14Measurement Method for Determining Grade of GreaseMohair, Section 32.2044NOTE 2A discussion on the development of grease mohair standardscan be found in the literature.5,63. Terminology3.1 Definitions:3.1.1 average fiber, diameter, n in wool and other animalfibers, the
7、 average width of a group of fibers when measured ona projected image.3.1.2 fineness, nof textile fibers, a relative measure ofsize, diameter, linear density or mass per unit length expressedin a variety of units.3.1.2.1 DiscussionThe fineness of wool and other animalfibers is expressed as the avera
8、ge fiber width or average fiberdiameter in micrometres (m).3.1.3 grade, nin wool and mohair, a numerical designa-tion used in classifying wool and mohair in their raw, semi-processed, and processed forms based on average fiber diam-eter and variation of fiber diameter.3.1.3.1 DiscussionThis specific
9、ation expresses the varia-tion in fiber diameter by means of the standard deviation of thefiber diameter measurements.3.1.3.2 The term “grade” should not be confused with theterms “quality” and “type.” “Quality” is a term that includesnot only fineness but also characteristics such as length, crimp,
10、strength, elasticity, luster, tactile hand, and color, all of whichaffect the spinnability of the fiber and the properties of theresulting yarn and fabric. The Bradford designations, for whichno standards exist, use a scale similar to that for gradedesignations (for example: 64s, 56s, and so forth)
11、and refer toquality and not solely to fineness. “Type” is a term designatinga particular combination of characteristics applicable to aspecific use or descriptive of geographical origin, breed ofsheep, or preparation for market.3.1.4 mohair, nthe hair of the Angora goat, Capra spe-cies.1These specif
12、ications are under the jurisdiction of ASTM Committee D13 onTextiles and are the direct responsibility of Subcommittee D13.13 on Wool andWool Felt.Current edition approved Aug. 15, 2006. Published October 2006. Originallyapproved in 1981. Last previous edition approved in 2000 as D 399194 (2000).Rep
13、laces D 419 and D 3109.2For 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.3Federal Register, Vol 30, No. 161, Au
14、g. 20, 1965, pp 1082910833.4Federal Register, Vol 36, No. 129, July 3, 1971, pp 1268112685.5Keller, H. R., Ray, H. D., Lineberry, C. T., and Pohle, E. M., “FinenessRelationship of Grease Mohair, Card Sliver, and Top,” Textile Research Journal,Vol42, No. 2, February 1971.6ASTM Research Report No. D13
15、 1012. A copy is available from ASTMHeadquarters, 100 Barr Harbor Drive, West Conshohocken, PA 19428.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.5 wool, nthe fibrous covering of the sheep, Ovisspecies.3.1.6 For definitions of
16、 other textile terms used in thisspecification, refer to Terminology D 123.4. Requirements4.1 The grade of wool shall conform to the requirements ofTable 1.4.2 The grade of mohair shall conform to the requirementsof Table 2.5. Significance and Use5.1 These specifications are considered satisfactory
17、for clas-sifying wool or mohair by grade and provide a basis foracceptance of commercial shipments.5.2 Grade determined by visual examination is a commontrade practice. In case of doubt or dispute, comparison of themeasured average fiber diameter and fiber diameter standarddeviation with the respect
18、ive specification shall be used as thereferee procedure for assigning grade.5.3 This specification is not intended for application tomixed lots, that is, lots of wool or mohair consisting of fleecesof different grades that are to be segregated into smaller morehomogeneous lots before use.6. Test Met
19、hod6.1 Test the material as directed in Test Method D 2130.Measure at least the minimum number of fibers needed toattain confidence limits of the mean within 60.4 m at aprobability level of 95 % (see Annex A1 of Test MethodD 2130).6.1.1 In case of dispute the microprojector procedure, TestMethod D 2
20、130, is specified as the referee method.7. Assignment of Grade7.1 Compare the observed average fiber diameter and stan-dard deviation in fiber diameter, determined as directed inSection 6, with the specifications for the various grades for thematerial being tested.7.1.1 WoolAssign the grade that cor
21、responds to the aver-age fiber diameter and maximum standard deviation require-ments specified in Table 1. If the observed standard deviationexceeds the maximum specified for the grade to which theobserved average fiber diameter corresponds, assign to thewool the next coarser grade. Assignment of gr
22、ade is illustratedby the following examples:7.1.1.1 Example 1Average fiber diameter, 27.25 m; stan-dard deviation, 6.72 m; assigned grade, 56s.7.1.1.2 Example 2Average fiber diameter, 27.25 m; stan-dard deviation, 7.80 m; assigned grade, 54s.7.1.1.3 Example 3Average fiber diameter, 27.25 m; stan-dar
23、d deviation, 8.50 m; assigned grade, 54s.7.1.2 MohairAssign the grade that corresponds to theaverage fiber diameter and maximum standard deviation re-quirements specified in Table 2. If the observed standarddeviation exceeds the maximum specified for the grade towhich the observed average fiber diam
24、eter corresponds, assignto the mohair a dual grade designation, the second designationbeing one grade coarser than the grade to which the averagefiber diameter corresponds. Assignment of grade is illustratedby the following examples:7.1.2.1 Example 1Average fiber diameter, 28.50 m; stan-dard deviati
25、on, 8.1 m; grade designation, 32s.7.1.2.2 Example 2Average fiber diameter, 28.50 m; stan-dard deviation, 8.6 m; grade designation, 32/30s.7.2 Interpretation of ResultsThe true average fiber diam-eter of a lot of wool or mohair can be determined only bymeasurement of every fiber in the lot. Since thi
26、s is notpracticable, reliance is placed on the result obtained throughthe measurement of a sample. The likelihood that the observedaverage fiber diameter correctly identifies the grade increasesas the average approaches the midpoint of the fineness range ofthe grade concerned, and decreases as the a
27、verage approacheseither limit of such range. The probability of the correctness ofthe grade designation of a lot may be increased by increasingthe number of fibers measured.8. Conformance8.1 When the purchaser and the supplier have agreed uponspecific requirements for fineness, wool or mohair that f
28、ails tomeet those requirements may be rejected. Rejection should beTABLE 1 Specifications for Grades of WoolAGradeRange for Average FiberDiameter, mStandard Deviation,max, mFiner than 80s under 17.70 3.5980s 17.70 to 19.14 4.0970s 19.15 to 20.59 4.5964s 20.60 to 22.04 5.1962s 22.05 to 23.49 5.8960s
29、23.50 to 24.94 6.4958s 24.95 to 26.39 7.0956s 26.40 to 27.84 7.5954s 27.85 to 29.29 8.1950s 29.30 to 30.99 8.6948s 31.00 to 32.69 9.0946s 32.70 to 34.39 9.5944s 34.40 to 36.19 10.0940s 36.20 to 38.09 10.6936s 38.10 to 40.20 11.19Coarser than 36s over 40.20AThe specifications in this table conform to
30、 the Official Standards of the UnitedStates for Grades of Wool as promulgated by the U.S. Department of Agriculture,effective Jan. 1, 1966.TABLE 2 Specifications for Grades of MohairAGradeRange for Average FiberDiameter, mStandard Deviation,max, mFiner than 40s under 23.01 7.240s 23.01 to 25.00 7.63
31、6s 25.01 to 27.00 8.032s 27.01 to 29.00 8.430s 29.01 to 31.00 8.828s 31.01 to 33.00 9.226s 33.01 to 35.00 9.624s 35.01 to 37.00 10.022s 37.01 to 39.00 10.520s 39.01 to 41.00 11.018s 41.01 to 43.00 11.5Coarser than 18s over 43.01AThe specifications in this table conform to the Official Standards of t
32、he UnitedStates for Grades of Grease Mohair as promulgated by the U.S. Department ofAgriculture, effective Aug. 1, 1971.D 3991 94 (2006)2reported to the supplier in writing. In case of disagreement withthe results of the tests, the supplier may make claim for a retest.9. Keywords9.1 animal fibers (e
33、xcept wool); number grade; wool; yarnASTM 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 ri
34、skof 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 withdrawn. Your comments are invited either for revision of th
35、is 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 your comments have not received a fair hearing you shouldmake
36、 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 (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).D 3991 94 (2006)3
