ASTM_D_4912_-_D_4912M_-_14.pdf

Designation:D4912/D4912M14Standard Test Method forFabric Stability of Vinyl-Coated Glass Yarn Insect Screeningand Louver Cloth1This standard is issued under the fixed designation D4912/D4912M;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 provides a procedure for evaluatingfabric stability by measuring the resistance to yarn slippage offilling yarns over warp yarns,or warp yarns over filling yarnsin vinyl-coated glass yarn insect screening and louver cloth.1.2 The values stated in either SI units or inch-pound unitsare to be regarded separately as standard.The values stated ineach system may not be exact equivalents;therefore,eachsystem shall be used independently of the other.Combiningvalues from the two systems may result in non-conformancewith the standard.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:2D76 Specification for Tensile Testing Machines for TextilesD123 Terminology Relating to TextilesD4028 Specification for Solar Screening Woven from Vinyl-Coated Fiber Glass YarnD7018 Terminology Relating to Glass Fiber and Its Products3.Terminology3.1 For all terminology relating to D13.18,Glass Fiber andIts Products,refer to Terminology D7018.3.1.1 The following terms are relevant to this standard:atmosphere for testing textiles,fabric stability.3.2 For all other terms related to textiles,refer to Terminol-ogy D1234.Summary of Test Method4.1 Samples of the vinyl-coated glass yarn insect screeningor louver cloth are subjected to a breaking force test whereyarns have been severed within the gage length area.The forcerequired to break the fused bond between yarn components andslip yarn segments in one direction over yarn segments in theopposite direction is reported as the fabric stability.5.Significance and Use5.1 This test method is considered satisfactory for accep-tance testing of commerical shipments since the method hasbeen used extensively in the trade for acceptance testing.5.1.1 In cases 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 comparative tests 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 which are as homogeneous as possible and whichare from a lot of material of the type in question.The testspecimens should then be randomly assigned in equal numbersto each laboratory for testing.The average results from the twolaboratories should be compared using Students t-test forunpaired data and an acceptable probability level chosen by thetwo parties before the testing begins.If a bias is found,eitherits cause must be found and corrected or the purchaser and thesupplier must agree to interpret future test results in the light ofthe known bias.5.2 Vinyl-coated glass yarn insect screening and louvercloth are subjected to a heating process to fuse the warp yarnsto the filling yarns of the woven structure.The force at whichyarns in one direction move over yarns in the oppositedirection is a measure of the bond of fusion.The degree of thebond of fusion on the vinyl-coated glass yarn insect screeningand louver cloth is used for process control.Fabric stabilitywas formerly called resistance to yarn slippage.6.Apparatus6.1 Tensile Testing MachineIn case of dispute a constant-rate-of-extension,CRE,tensile testing machine as described inSpecification D76 will be used.When agreed upon between the1This test method is under the jurisdiction ofASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.18 on Glass Fiber and itsProducts.Current edition approved Feb.1,2014.Published March 2014.Originallyapproved in 1989.Last previous edition approved in 2007 as D491207.DOI:10.1520/D4912-14.2For 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.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 purchaser and the supplier,a constant-rate-of-traverse tensile,CRT,testing machine can be used.6.1.1 The clamp faces shall be rubber or smooth metallicfaced at least 10 mm 0.4 in.wider than the specimen widthand with a minimum of 25