ASTM_D_5734_-_95_2001.pdf

Designation:D 5734 95(Reapproved 2001)Standard Test Method forTearing Strength of Nonwoven Fabrics by Falling-Pendulum(Elmendorf)Apparatus1This standard is issued under the fixed designation D 5734;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 the measurement of the averageforce required to propagate a single-rip tear starting from a cutin a nonwoven fabric using a falling-pendulum(Elmendorf)apparatus.1.2 This standard Elmendorf tear tester with interchange-able pendulums has become the preferred test apparatus fordetermining tearing strength up to 6400 grams-force.It isrecognized that some older test instruments with augmentingweights continue to be used.As a consequence,these older testinstruments may be used when agreed upon between thepurchaser and the supplier.The conditions for the older units asused with this test method are included in the appendix.Fortearing strength above 6400 grams-force,a high-capacity testinstrument is available equipped with augmenting weights toincrease the capacity.1.3 This test method is applicable to most nonwoven fabricsthat are treated or untreated,including heavily sized,coated,orresin-treated,provided the fabric does not tear in the directioncrosswise to the direction of the force applied during the test.If the tear does not occur in the direction of the test,the fabricis considered untearable in that direction by this test method.1.4 The values stated in SI units are to be regarded as thestandard.The inch-pound units given in parentheses may beapproximate.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 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 689 Test Method for Internal Tearing Resistance of Pa-per3D 1776 Practice for Conditioning Textiles for Testing2D 4848 Terminology of Force and Deformation Propertiesof Textiles43.Terminology3.1 Definitions:3.1.1 length of tear,nin tensile testing,the length offabric torn,as measured on the fabric before tearing.3.1.2 lengthwise direction,nin textiles,the direction in amachine-made fabric parallel to the direction of movement thefabric followed in the manufacturing machine.3.1.2.1 DiscussionFor nonwovens,an easily distinguish-able pattern for orientation may not be apparent,especially ifremoved from the roll.Care should be taken to maintain thedirectionality by clearly marking the direction.3.1.3 nonwoven fabric,na textile structure produced bybonding or interlocking of fibers,or both,accomplished bymechanical,chemical,thermal,or solvent means,or combina-tion thereof.3.1.4 tearing energy,nin tensile testing of fabrics,thework done in tearing the specimen.3.1.5 tearing force,nthe average force required to con-tinue a tear previously started in a fabric.3.1.5.1 DiscussionFor nonwovens,the tearing force isrecorded as the maximum force required to continue a tearpreviously started in a fabric.3.1.6 tearing strength,nthe force required either to startor to continue or propagate a tear in a fabric under specifiedconditions.3.1.7 widthwise direction,nin textiles,the direction in amachine-made fabric perpendicular to the direction of move-ment the fabric followed in the manufacturing machine.3.1.8 For definitions of other textile terms used in this testmethod,refer to Terminologies D 123 and D 4848.4.Summary of Test Method4.1 The force required to continue a slit previously cut in anonwoven fabric is determined by measuring the work done intearing it through a fixed distance.The tester consists of asector-shaped pendulum carrying a clamp which is in align-ment with a fixed clamp when the pendulum is in the raised,starting position with maximum potential energy.The speci-men is fastened in the clamps and the tear is started by cutting1This 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 15.09.4Annual Book of ASTM Standards,Vol 07.02.1Copyright ASTM,100 Barr Harbor Drive,West Conshohocken,PA 19428-2959,United States.a slit in the specimen between the clamps.The pendulum isthen released and the specimen is torn as the moving jawmoves away from the fixed one.The scale attached to thependulum is graduated to read the tearing force of thespecimen.5.Significance and Use5.1 This test method for the determination of tearingstrength by the pendulum method is used in th