1、Designation:D1423/D1423M16(Reapproved 2022)Standard Test Method forTwist in Yarns by Direct-Counting1This standard is issued under the fixed designation D1423/D1423M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last re
2、vision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This test method covers the determination of
3、the amountand direction of twist at the completion of any stage of twistingin single(spun or filament),plied,cabled,or novelty(exclusiveof long-term repeat patterns)yarns.The procedures are de-signed primarily for yarns in packages,but,with specialprecautions,they are applicable to yarns taken from
4、fabrics.The procedure for spun yarn in 9.2 is also applicable torovings.1.2 For plied yarns,this test method covers the determina-tion of the twist of the plied yarns and the twist of the singleyarn before plying.For cabled yarns,the test method covers thedetermination of the cable or hawser twist;t
5、he twist of theplied yarn after plying,but prior to the last twisting operation;and the twist of the single yarn before plying.Procedures arealso included for the determination of the twists of the singleand plied yarn components as they lie in the final structure.Also,directions are included for th
6、e determination of twist inplied yarn made with direct cabling technology.1.3 This test method is not intended for yarns that extendmore than 5.0%when tension is increased from 2.5 to 7.5mN/tex 0.25 to 0.75 gf/tex.Following the procedures of thistest method for such yarns would be independent of the
7、 biasand precision determined for this test method.The report fromsuch testing should include the tension used for this testing.1.4 UnitsThe values stated in either SI units or inch-pound units are to be regarded separately as standard.Thevalues stated in each system are not necessarily exact equiva
8、-lents;therefore,to ensure conformance with the standard,eachsystem shall be used independently of the other,and valuesfrom the two systems shall not be combined.NOTE1For a more rapid but less accurate method of determiningtwist in single spun yarns,refer to Test Method D1422.NOTE2This test method h
9、as been evaluated for use in determiningtwist in open end yarns and is not recommended.1.5 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 appro-priate safety,health,and environmental
10、 practices and deter-mine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards,Guide
11、s and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1059 Test Method for Yarn Number Based on Short-Length SpecimensD1422 Test Method for Twist in Single Spun Yarns by t
12、heUntwist-Retwist MethodD1776 Practice for Conditioning and Testing TextilesD1907 Test Method for Linear Density of Yarn(Yarn Num-ber)by the Skein MethodD3888 Terminology for Yarn Spinning SystemsD4849 Terminology Related to Yarns and Fibers3.Terminology3.1 Refer to Terminology D4849 for definitions
13、 of thefollowing terms used in this standard:direction of twist,singleyarn,spun yarn,twist,twist factor,twist multiplier,and yarn.3.2 Refer to Terminology D123 and Terminology D3888 fordefinitions of other terms used in this standard.4.Summary of Test Method4.1 A specified length of specimen is moun
14、ted in a twistdevice.One end is rotated until all the elements are free oftwist.The number of turns is counted and the turns per unitlength are calculated.1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.58 on Yarns and
15、Fibers.Current edition approved Feb.1,2022.Published March 2022.Originallyapproved in 1956.Last previous edition approved in 2016 as D142302(2016).DOI:10.1520/D1423_D1423M-16R22.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For
16、Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technica
