ASTM_D_5732_-_95_2001.pdf

Designation:D 5732 95(Reapproved 2001)Standard Test Method forStiffness of Nonwoven Fabrics Using the Cantilever Test1This standard is issued under the fixed designation D 5732;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 covers stiffness properties of non-woven fabrics by employing the principle of cantilever bendingof the fabric under its own weight.Bending length is measuredand flexural rigidity calculated.1.2 This test method applies to most nonwoven fabrics thatare treated or untreated,including those heavily sized,coated,or resin-treated.1.3 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses may beapproximate.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 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 2904 Practice for Interlaboratory Testing of a Textile TestMethod That Produces Normally Distributed Data23.Terminology3.1 Definitions:3.1.1 bending length,nin textiles,a measure of theinteraction between fabric weight and fabric stiffness as shownby the way in which a fabric bends under its own weight.3.1.1.1 DiscussionBending length reflects the stiffness ofa fabric when bent in one plane under the force of gravity andis one component of drape.3.1.2 cross-machine direction,CD,nthe direction in theplane of the fabric perpendicular to the direction of manufac-ture.3.1.2.1 DiscussionIn nonwoven fabrics,the term cross-machine direction is used to refer to the direction analogous tocrosswise or filling direction in a woven fabric.3.1.3 flexural rigidity,na measure of stiffness,the coupleon either end of a strip or unit width bent into unit curvature,in the absence of any tension.3.1.4 machine direction,MD,nthe direction in the planeof the fabric parallel to the direction of manufacture.3.1.4.1 DiscussionIn nonwoven fabrics,the term machinedirection is used to refer to the direction analogous to length-wise or warp direction in a woven fabric.3.1.5 nonwoven fabric,na textile structure produced bybonding or interlocking of fibers,or both,accomplished bymechanical,chemical,thermal,or solvent means,or combina-tion thereof.3.1.6 stiffness,nresistance to bending.3.2 For definitions of other terms used in this test method,refer to Terminology D 123.4.Summary of Test Method4.1 A specimen is slid at a specified rate in a directionparallel to its long dimension,so that its leading edge projectsfrom the edge of a horizontal surface.The length of theoverhang is measured when the tip of the specimen is de-pressed under its own weight to the point where the line joiningthe top to the edge of the platform makes a 0.785 rad(41.5)angle with the horizontal.The stiffer the fabric,the longer ittakes to bend,thus,the higher numbers indicate a stiffer fabric.5.Significance and Use5.1 This test method may be used for acceptance testing ofcommercial shipments of nonwoven fabrics,however,cautionis advised since information about between-laboratory preci-sion is incomplete.A comparative test as directed in 5.1.1 maybe 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,the purchaser and the sup-plier should conduct a comparative test to determine if there isa statistical bias between their laboratories.Competent statis-tical assistance is recommended for the investigation of bias.As a minimum,the two parties should take a group of testspecimens that are as homogeneous as possible and that arefrom a lot of material of the type in question.Test specimensshould then be randomly assigned in equal numbers to eachlaboratory for testing.The average results from the twolaboratories should be compared using the appropriate Stu-dents t-test and an acceptable probability level chosen by thetwo parties before testing is begun.If a bias is found,either itscause must be found and corrected or the purchaser and the1This 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 07.01.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.supplier must agree to interpret future test results in the view ofthe known bias.5.2 This test method measures the drape stiffness of thenonwoven fabric.