ASTM_D_5736_-_95_2001.pdf

Designation:D 5736 95(Reapproved 2001)Standard Test Method forThickness of Highloft Nonwoven Fabrics1This standard is issued under the fixed designation D 5736;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year 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 describes the measurement of thick-ness of highloft nonwoven fabrics.For thickness of nonwovenfabrics other than highloft,see Test Method D 5729.1.2 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses may beapproximate.1.3 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 and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:D 123 Terminology Relating to Textiles2D 1776 Practice for Conditioning Textiles for Testing2D 1777 Test Method for Measuring Thickness of TextileMaterials2D 2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed Data3D 5729 Test Method for Thickness of Nonwoven Fabrics33.Terminology3.1 Definitions:3.1.1 highloft nonwoven fabric,na low-density fiber net-work structure characterized by a high ratio of thickness tomass per unit area.(Syn.highloft).3.1.2 nonwoven fabric,na textile structure produced bybonding or interlocking of fibers,or both,accomplished bymechanical,chemical,thermal,or solvent means,or combina-tion thereof.3.1.3 pressure,nthe force per unit area.3.1.3.1 DiscussionPressure may be expressed in any ap-propriate or specified units,such as pascals(Pa),newtons persquare metre(N/m2),or pound-force per square inch(psi).3.1.4 thickness,nthe distance between one surface and itsopposite.3.1.4.1 DiscussionIn textiles,the distance between theupper and lower surfaces of the material;measured under aspecified pressure.Thickness is usually determined as thedistance between an anvil,or base,and a presser foot used toapply the specified pressure.3.1.5 For definitions of other textile terms used in this testmethod,refer to Terminology D 123.4.Summary of Test Method4.1 The thickness of a highloft nonwoven fabric is deter-mined by observing the linear distance that a movable plane isdisplaced from a parallel surface by the specimen while undera specified pressure.5.Significance and Use5.1 This test method is used in the trade for acceptancetesting of commercial shipments;however,comparative testsas directed in 5.1.1 may be advisable.5.1.1 In case of a dispute arising from differences inreported test results when using this test method for acceptancetesting of commercial shipments of nonwoven fabrics,thepurchaser and the supplier should conduct comparative tests todetermine if there is a statistical bias between their laborato-ries.Competent statistical assistance is recommended for theinvestigation of bias.As a minimum,the two parties shouldtake a group of test specimens that are as homogeneous aspossible and that are from a lot of material of the type inquestion.Test specimens should then be randomly assigned inequal numbers to each laboratory for testing.The averageresults from the two laboratories should be compared using theappropriate students t-test and an acceptable probability levelchosen by the two parties before testing is begun.If a bias isfound,either its cause must be found and corrected or thepurchaser and the supplier must agree to interpret future testresults with consideration to the known bias.5.2 Thickness is one of the basic physical properties ofhighloft nonwoven fabrics.In certain industrial applications,the thickness may require rigid control within specified limits.Bulk and warmth properties of highloft nonwoven fabrics areoften estimated from their thickness values,and thickness isalso useful in measuring performance characteristics,such asbefore and after abrasion or shrinkage.1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.64 on Nonwoven Fabric.Current edition approved June 15,1995.Published September 1995.2Annual Book of ASTM Standards,Vol 07.01.3Annual Book of ASTM Standards,Vol 07.02.1Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959,United States.5.3 The thickness value of highloft nonwoven fabrics willvary considerably depending on the pressure applied to thespecimen at the time the thickness measurement is taken.In allcases,the apparent thickness varies inversely with the pressureapplied.For this reason,it is essential that the pressure bespecified when discussing or listing any thickness value.6.Apparatus6.1 Thickness Testing Gage4Having dimensions appr