1、Designation: D4912/D4912M 14Standard 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 o
2、f 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 resistan
3、ce 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 eq
4、uivalents; 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
5、 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 Specificati
6、on 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:atmospher
7、e 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 leng
8、th 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 commeric
9、al 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 comparativ
10、e 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
11、 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 tes
12、ting 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 yar
13、nsto 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 sta
14、bilitywas 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 of ASTM Co
15、mmittee 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 standard
16、s, 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 19
17、428-2959. United States1purchaser 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 mm 1 in. in the direction ofapplication
18、of force.NOTE 1The covering of the metallic faces with approximately a 3-mm0.11-in. thick cardboard or other suitable material has been found usefulfor preventing crushing of the specimen.7. Sampling and Number of Specimens7.1 Lot SizeA lot is defined as a single shipment of asingle type of glass te
19、xtile. A lot may constitute all or part of asingle customer order.7.2 Lot SampleAs a lot sample for acceptance testing, takethe number of rolls of insect screening or louver cloth directedin an applicable material specification or other agreementbetween the purchaser and the supplier. Consider rolls
20、 of insectscreening or louver cloth to be the primary sampling unit. Inthe absence of such an agreement, take the number of rollsspecified in Table 1.NOTE 2An adequate specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween rolls of
21、insect screening or louver cloth and between testspecimens from a swatch or roll of insect screening or louver cloth toproduce a sampling plan with meaningful producers risk, consumersrisk, acceptable quality level, and limiting quality level.7.3 Laboratory SampleAs a laboratory sample for accep-tan
22、ce testing, proceed as directed in an applicable materialspecification or other agreement between the purchaser and thesupplier. In the absence of such an agreement, use the lotsampling units for the laboratory sampling units. Take a fullwidth swatch,2m2ydlong, from each selected lot samplingunit of
23、 screening or louver cloth. Take swatches after firstdiscarding a minimum of1m1ydfrom the very outside ofthe roll.7.4 Test SpecimensFrom each swatch in the laboratorysample, cut five specimens in each the warp and fillingdirection, 50 by 125 mm 2 by 5 in. with the long dimensionrespectively parallel
24、 to the warp and filling yarns. Cut alternatelengthwise yarns as shown in Fig. 1. Cut yarns equidistant fromthe center of the specimen length having three widthwise yarnsbetween the yarns cut above the center of the specimen length(Cut A) and the yarns cut below the center of the specimenlength (cut
25、 B). Ensure each lengthwise yarn has only one cut.The short direction is the direction of test. Take test specimensfrom each swatch in the laboratory sample in such a way thatno specimen is closer than one tenth the width of the swatchfrom the selvage with no two specimens cut parallel to thewarp co
26、ntaining the same set of warp ends or if cut parallel tothe filling, containing the same set of filling picks, and thespecimens from different swatches are each taken from adifferent part of the width of the swatches.8. Procedure8.1 Condition the laboratory samples without precondition-ing for perio
27、d of at least 5 h in the atmosphere for testing glasstextiles, unless otherwise specified.NOTE 3In any event, 24 h is considered ample exposure to bring thesamples to moisture equilibrium.8.2 Select the force range of the tensile testing machine suchthat the maximum force required to separate the sp
28、ecimenoccurs between 10 and 90 % of the full-scale force range.Secure the specimen centrally in the clamps of the tensiletesting machine, taking care that the long dimension is asnearly as possible parallel to the direction of application of theforce. Ensure that the tension in the specimen is unifo
29、rm acrossthe clamped width.8.3 When using air-actuated clamps set the air pressure to275 6 15 kPa 40 6 2 psi. When using manual clamps, ensureno slippage of the specimen occurs in the clamps.8.4 Adjust the tensile testing machine in the starting posi-tion to a distance of 75 6 1mm36 0.05 in. from ni
30、p to nipof the clamps along the specimen axis.8.5 Operate the CRE tensile testing machine with a pullingspeed of 125 6 5 mm/min 5 6 0.2 in./min, and when agreedupon between the purchaser and the supplier, a CRT tensilemachine with a pulling speed of 300 6 10 mm/min 12 6 0.5in./min.NOTE 4Values for f
31、abric stability show no statistical difference at95 % confidence limit when using the tensile testers and rates of operationTABLE 1 Number of Rolls of Fabric in the Lot SampleTotal Length of Fabric in Lot Number of LotSampling Unitsm ft245 or less 800 or less 2246 to 6700, inclusive 801 to 22 000, i
32、nclusive 36701 and over 22 001 and over 5FIG. 1 Screening, Nonmetallic, Insert; Cut Pattern of SpecimenD4912/D4912M 142specified in 8.4. Refer to Specification D4028 for comparison.8.6 Activate the tensile testing machine and record themaximum force required to separate the specimen into twosections
33、 as indicated by slippage of the yarns out of the wovenpattern or out of the vinyl casing at the location between the cutlines. If a specimen slips in the jaws, breaks at the edge of, orin the jaws, or if for any reason attributed to faulty operationthe result falls markedly below the average for th
34、e set ofspecimen, discard the result and take another specimen. Con-tinue this procedure until the required number of acceptablespecimens have been tested for each, the warp and fillingdirection.9. Report9.1 Report that the specimens were tested as directed in TestMethod D4912/D4912M. Include the pr
35、oduct description andthe type tensile testing machine used.9.2 Report, for each laboratory sampling unit of insectscreening or louver cloth, the average newtons pounds-forcefor each, the warp, and filling direction.9.3 Report, for the lot average, the average newtonspounds-force for each, the warp,
36、and filling direction for alltested laboratory sampling units.10. Precision and Bias10.1 SummaryIn 95 out of 100 cases when comparing twoaverages of five determinations each, the differences should notexceed the following amounts when all of the determinationsare taken by the same well trained opera
37、tor using the samepiece of test equipment and specimens randomly drawn fromthe same sample of material but tested at different times.Warp Direction9.6 % of the averageFill Direction8.8 % of the averageLarger differences are likely to occur under all other condi-tions. This test method has no bias si
38、nce the true value of fabricstability can only be defined in a specific test method. The basisfor this summary and for evaluations made under otherconditions is explained in 10.2 10.4.10.2 Interlaboratory Test Data3An interlaboratory testwas run in 1986 in which randomly drawn specimens ofvinyl-coat
39、ed glass yarn insect screening were tested in each offour laboratories. Each laboratory used two operators, each ofwhom tested five specimens of each material in each the warpand filling direction at different times. The components ofvariance expressed as coefficients of variation are listed inTable
40、 2.NOTE 5The square roots of the components of variance are beingreported to express the variability as a percent of the average fabricstability rather than as the square of that unit of measure.10.3 PrecisionFor the components of variance reported inTable 2, two averages of observed values should b
41、e consideredsignificantly different at the 95 % probability level if thedifference equals or exceeds the critical differences listed inTable 3.NOTE 6Since the interlaboratory test included only four laboratories,estimates of between-laboratory precision should be used with specialcaution.NOTE 7The t
42、abulated values of the critical differences should beconsidered to be a general statement particularly with respect to between-laboratory precision. Before a meaningful statement can be made aboutany two specific laboratories, the amount of statistical bias if any, betweenthem must be established, w
43、ith each comparison based on recent dataobtained on specimens taken from a lot of material of the type beingevaluated and nearly homogeneous as possible and then randomlyassigned in equal numbers to the two laboratories.10.4 BiasThe procedure in this test method has no biasbecause the value of fabri
44、c stability can be defined only interms of a test method.11. Keywords11.1 fabric stability; vinyl-coated glass; insect screening;louver cloth3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR:D13-1077.TABLE 2 Coefficients of Variat
45、ion, Vinyl Coated Glass Yarn InsectScreening, Percent of AverageMaterial DirectionSingle-OperatorComponent, %Within-LaboratoryComponent, %Between-LaboratoryComponent, %WarpSingle-material 7.8 4.1 0.0Multi-material 9.8 4.1 6.0FillSingle-material 7.1 5.0 2.8Multi-material 7.1 5.0 5.1TABLE 3 Critical D
46、ifferences for the Conditions Noted, Vinyl-Coated Glass Yarn Insect Screening, 95 % Probability Level,Percent of AverageANumber ofObservations inEach AverageSingle-OperatorPrecision, %Within-LaboratoryPrecision, %Between-LaboratoryPrecision, %Warp, Single-Material Comparisons1 21.6 24.3 24.32 15.3 1
47、8.9 18.95 9.6 14.8 14.810 6.8 13.1 13.1Warp, Multi-Material Comparisons1 22.3 25.0 30.02 16.2 19.8 25.85 11.1 15.8 22.910 8.8 14.3 21.9Fill, Single-Material Comparisons1 19.7 24.0 25.32 13.9 19.6 21.15 8.8 16.3 18.110 6.2 15.1 17.0Fill, Multi-Material Comparisons1 19.7 24.0 27.82 13.9 19.6 24.15 8.8
48、 16.3 21.510 6.2 15.1 20.6ATo convert the values of the critical differences to fabric stability, pounds, multiplythe critical difference by the average of the two specific sets of data beingcompared and then divide by 100.D4912/D4912M 143ASTM International takes no position respecting the validity
49、of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional s
copyright@ 2008-2019 麦多课文库（www.mydoc123.com）网站版权所有
备案/许可证编号：苏ICP备17064731号-1