1、0759510 0545075 212 Designation:D 4911-94 4Crb AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 Race St.Phiiadelphia,Pa 19103 Reprinted from the Annual Book o f ACTM Standards Copyrlght ASTM!f not listed in the current combined index,will appear in the next edition Standard Tolerances for Yarns Made
2、of Man-Made Fibers and Spun on the Parallel Worsted or Modified Worsted System This standard is issued under the fixed designation D 491 I;the number immediately following the designation indicates the year of original adoption or,in the case of revision,the year of last revision.A number in parenth
3、eses indicates the year of last reapproval.A superscript epsilon(t)indicates an editorial change since the last revision or reapproval.1.Scope 1.1 These tolerances are applicable to all yams 59 tex(10.00/1 cotton count)or coarser spun of man-made fiber(s),4.5 to 30.0 dtex/filament,(4 to 25 denier/fi
4、lament)and spun on the parallel worsted or modified worsted system.These tolerances do not apply to novelty or fancy yams spun on the parallel worsted or modified worsted system.NOTE I-For tolerances for other spun yams,see Tolerances D 2644,Tolerances D 2645,Specification D 541,and Specification D
5、681.1.2 The values stated in SI units are to be regarded as standard;the values in inch-pound units are provided as information only.1.3 This standard does not purport to address all o f the safety concerns,i f any,associated with its use.It i s the responsibility o f the user o f this standard to e
6、stablish appro-priate sajty and health practices and determine the applica-bility o f regulatory limitations prior to use.2.Referenced Documents 2.1 ASTM Standards:D 123 Terminology Relating to Textiles2 D 54 1 Specification for Single Jute Yarn2 D681 Specification for Jute Rove and Plied Yarn for D
7、 1422 Test Method for Twist in Single Spun Yarns by D 1423 Test Method for Twist in Yarns by the Direct-D 1425 Test Method for Unevenness of Textile Strands D 1578 Test Method for Breaking Load of Skeins2 D 1907 Test Method for Yam Number by the Skein D2256 Test Method for Tensile Properties of Yarn
8、s by D 2257 Test Method for Extractable Matter in Textiles2 D 2258 Practice for Sampling Yam for Testing2 D 2494 Test Method for Commercial Mass of a Shipment of Yam or Man-Made Staple Fiber or Tow2 D2644 Tolerances for Yams Spun on the Woolen System2 Electrical and Packing Purposes2 the Untwist-Ret
9、wist Method2 Counting Method2 Using Capacitance Testing Equipment2 Method2 the Single-Strand Method2 I These tolerances are under the jurisdiction of ASTM Committee D-13 on Textiles and are the direct responsibility of Subcommittee D13.58 on Yarn Test Methods,General.Current edition approved June 15
10、,1994.Published August 1994.Originally published as D 491 1-89.Last previous edition D 49 I I-89.Annual Book o/ASTM Sfandurds,Vol 07.01.D2645 Tolerances for Yams Spun on the Cotton or Worsted Systems2 3.Terminology 3.1 Definitions:3.1.1 mod$ed worsted system,n-a worsted system for spinning man-made
11、fibers which relies on pin control of fibers during sliver weight reduction,but which bypasses the system of combing required with wool to remove noil.(Syn.parallel worsted system.)3.I.I.1 Discussion-The modified worsted system em-ploys roller-top cards with metallic wire,pin-drafters,bal-loon draft
12、ers,or gills,and widely spaced roller drafting assemblies in roving and spinning.3.I.2 parallel worsted system,n-see modijed worsted system.3.1.3 tolerances,n-when included in a contract,the limits to which the average(or other specified)value ob-served for a specific characteristic of a lot of mate
13、rial must conform to constitute a valid delivery.3.1.3.1 Discussion-The observed values must be ob-tained by specified test methods on randomly selected samples from a sample of the material to be tested.See Section 4 for details.3.1.4 worsted system,n-a spinning system adapted to fibers 50 to 250 m
14、m(2 to 9 in.)in length.3.1.5 For definitions of other textile terms,refer to Termi-nology D 123.4.Sampling 4.1 Division into Lots-Each shipment or consignment of a single lot of yam shall be considered a separate acceptance testing lot.4.2 Lot Sample-As a lot sample for acceptance testing,take at ra
15、ndom the number of shipping cases directed in an applicable material specification or other agreement between the purchaser and the supplier,such as an agreement to use Practice D 2258.Consider shipping cases to be the primary sampling units.NOTE 2-An adequate specification or other agreement betwee
16、n the purchaser and the supplier requires taking into account variability between shipping units,between packages or ends within a shipping unit,and between specimens from a single package so as to provide a sampling plan with a meaningful producers risk,consumers risk,acceptable quality level,and limited quality levei.4.3 Laboratory Samples and Test Specimens-Take labo-ratory samples and test specimens from each primary sampling unit of the lot sample for acceptance testing as directed in each
