ASTM_D_4974_-_D_4974M_-_22.pdf

Designation:D4974/D4974M22Standard Test Method forHot Air Thermal Shrinkage of Yarn and Cord Using aThermal Shrinkage Oven1This standard is issued under the fixed designation D4974/D4974M;the number immediately following the designation indicates theyear of original adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of lastreapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This test method covers the measurement of shrinkageof yarns and cords when exposed in a thermal shrinkage oven.1.2 This test method is applicable to yarns and cords madeof nylon,polyester,and other polymers not detrimentallyaffected by the temperature used and with linear densities in therange from 20 to 700 tex 180 to 6300 denier.1.2.1 Yarns or cords for testing may be taken from yarn orcord packages or from fabrics.1.3 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system are not necessarily exact equivalents;therefore,toensure conformance with the standard,each system shall beused independently of the other,and values from the twosystems shall not be combined.Referee decisions are to use SIunits.1.4 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 practices and deter-mine the applicability of regulatory limitations prior to use.Specific hazard statements are given in Section 8.1.5 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,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD885/D885M Test Methods for Tire Cords,Tire CordFabrics,and Industrial Filament Yarns Made from Manu-factured Organic-Base FibersD1776/D1776M Practice for Conditioning and Testing Tex-tilesD6477 Terminology Relating to Tire Cord,Bead Wire,HoseReinforcing Wire,and Fabrics(Withdrawn 2022)33.Terminology3.1 Definitions:3.2 For definitions of terms relating to tire cord,bead wire,hose wire,and tire cord fabrics,refer to Terminology D6477.3.2.1 The following terms are relevant to this standard:greige cord,in tire cords;standard atmosphere for testingtextiles;thermal shrinkage;tire cord.3.3 For definitions of other terms related to textiles,refer toTerminology D123.3.3.1 The following terms are relevant to this standard:yarn.4.Summary of Test Method4.1 A relaxed,conditioned specimen of yarn or cord issubjected to dry heat for a specified time while under aspecified tension.The percent shrinkage is read directly from ascale or display on the instrument while the specimen is stillunder tension and exposed to heat.5.Significance and Use5.1 This test method may be used for the acceptance testingof commercial shipments of yarns and cords.Caution isadvised because yarn and cord may contract in length over aperiod of time due to room temperature retraction.Thermalshrinkage values are reduced proportionately by the amount ofroom temperature retraction.NOTE1Experience,especially with nylon,shows that yarn retraction,which may be observed directly as shortening of length(or indirectly asdenier increase),will occur in unrestrained yarn or cord that is not atequilibrium(equilibrium in this case being defined as essentially zerothermal shrinkage yarn or fully relaxed yarn).Normally,retractive forces1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.19 on Industrial Fibers andMetallic Reinforcements.Current edition approved June 1,2022.Published June 2022.Originallyapproved in 1999.Last previous edition approved in 2016 as D497404(2016).DOI:10.1520/D4974_D4974M-22.2For 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.3The last approved version of this historical standard is referenced onwww.astm.org.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 Technical Barriers to Trade(TBT)Committee.1are present in most wound packages of yarn and cord;thus,unrestrainedyarn near the surface is likely,with time,to undergo some retraction.Afterretraction,such yarns exhibit lower th