1、Designation: D 4912 07Standard Test Method forFabric Stability of Vinyl-Coated Glass Yarn Insect Screeningand Louver Cloth1This standard is issued under the fixed designation D 4912; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、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 provides a procedure for evaluatingfabric stability by measuring the resistance to yarn
3、slippage offilling yarns over warp yarns, or warp yarns over filling yarnsin vinyl-coated glass yarn insect screening and louver cloth.1.2 This test method shows the values in both SI units andinch-pound units. “SI units” is the technically correct name fora system of metric units known as the Inter
4、national System ofUnits. “Inch-pound units” is the technically correct name forthe customary units used in the United States. The valuesexpressed in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may resu
5、lt in non-conformance with this 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
6、 limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D76 Specification for Tensile Testing Machines for TextilesD 123 Terminology Relating to TextilesD 4028 Specification for Solar Screening Woven fromVinyl-Coated Fiber Glass YarnD 7018 Terminology Relating to Glass Fiber and Its Pro
7、d-ucts3. Terminology3.1 For all terminology relating to D13.18, Glass Fiber andIts Products, refer to Terminology D 7018.3.1.1 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 D 1234
8、. 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
9、 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 di
10、spute 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
11、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
12、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 mus
13、t agree to interpret future test results in the light ofthe known bias.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.18 on Glass Fiber and itsProducts.Current edition approved Dec. 1, 2007. Published January 2008. Or
14、iginallyapproved in 1989. Last previous edition approved in 2002 as D 4912022For 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 onth
15、e ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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 for
16、ce 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.
17、6. Apparatus6.1 Tensile Testing MachineIn case of dispute a constant-rate-of-extension, CRE, tensile testing machine as described inSpecification D76will be used. When agreed upon betweenthe purchaser and the supplier, a constant-rate-of-traversetensile, CRT, testing machine can be used.6.1.1 The cl
18、amp 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 of force.NOTE 1The covering of the metallic faces with approximately a3-mm (0.11-in.) thick cardboard or other suitable material
19、has been founduseful for 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 textile. A lot may constitute all or part of asingle customer order.7.2 Lot SampleAs a lot sample for acceptance testing,take the
20、 number of rolls of insect screening or louver clothdirected in an applicable material specification or other agree-ment between the purchaser and the supplier. Consider rolls ofinsect screening or louver cloth to be the primary samplingunit. In the absence of such an agreement, take the number ofro
21、lls specified in Table 1.NOTE 2An adequate specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween rolls of insect screening or louver cloth and between testspecimens from a swatch or roll of insect screening or louver cloth toproduc
22、e a sampling plan with meaningful producers risk, consumersrisk, acceptable quality level, and limiting quality level.7.3 Laboratory SampleAs a laboratory sample for accep-tance testing, proceed as directed in an applicable materialspecification or other agreement between the purchaser and thesuppli
23、er. In the absence of such an agreement, use the lotsampling units for the laboratory sampling units. Take a fullwidth swatch,2m(2yd)long, from each selected lot samplingunit of screening or louver cloth. Take swatches after firstdiscarding a minimum of1m(1yd)from the very outside ofthe roll.7.4 Tes
24、t 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 to the warp and filling yarns. Cut alternatelengthwise yarns as shown in Fig. 1. Cut yarns equidistant fromthe center
25、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 B). Ensure each lengthwise yarn has only one cut.The short direction is the direction of test. Take test specimensfrom
26、 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 containing the same set of warp ends or if cut parallel tothe filling, containing the same set of filling picks, and thes
27、pecimens 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 period of at least 5 h in the atmosphere for testing glasstextiles, unless otherwise specified.NOTE 3In any event, 24 h is c
28、onsidered 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 specimenoccurs between 10 and 90 % of the full-scale force range.Secure the specimen centrally in the clamps of the tensi
29、letesting 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 uniform acrossthe clamped width.TABLE 1 Number of Rolls of Fabric in the Lot SampleTotal Length of Fabric in Lot Number of L
30、otSampling Unitsmft245 or less 800 or less 2246 to 6700, inclusive 801 to 22 000, inclusive 36701 and over 22 001 and over 5FIG. 1 Screening, Nonmetallic, Insert; Cut Pattern of SpecimenD49120728.3 When using air-actuated clamps set the air pressure to275 6 15 kPa (40 6 2 psi). When using manual cla
31、mps, 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 1mm(36 0.05 in.) from nip 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 (
32、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 fabric stability show no statistical difference at95 % confidence limit when using the tensile testers and rates of operations
33、pecified in 8.4. Refer to Specification D 4028 for comparison.8.6 Activate the tensile testing machine and record themaximum force required to separate the specimen into twosections as indicated by slippage of the yarns out of the wovenpattern or out of the vinyl casing at the location between the c
34、utlines. 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 the set ofspecimen, discard the result and take another specimen. Con-tinue this procedure until the required number of a
35、cceptablespecimens have been tested for each, the warp and fillingdirection.9. Report9.1 Report that the specimens were tested as directed in TestMethod D 4912. Include the product description and the typetensile testing machine used.9.2 Report, for each laboratory sampling unit of insectscreening o
36、r louver cloth, the average newtons (pounds-force)for each, the warp, and filling direction.9.3 Report, for the lot average, the average newtons(pounds-force) for each, the warp, and filling direction for alltested laboratory sampling units.10. Precision and Bias10.1 SummaryIn 95 out of 100 cases wh
37、en comparingtwo averages of five determinations each, the differencesshould not exceed the following amounts when all of thedeterminations are taken by the same well trained operatorusing the same piece of test equipment and specimens ran-domly drawn from the same sample of material but tested atdif
38、ferent 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 since the true value of fabricstability can only be defined in a specific test method. The basisfor this summary and for e
39、valuations 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-coated glass yarn insect screening were tested in each offour laboratories. Each laboratory used two operators, each ofwhom
40、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 2.NOTE 5The square roots of the components of variance are beingreported to express the variability as a percent of the
41、 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 be consideredsignificantly different at the 95 % probability level if thedifference equals or exceeds the critical differ
42、ences listed inTable 3.NOTE 6Since the interlaboratory test included only four laboratories,estimates of between-laboratory precision should be used with specialcaution.NOTE 7The tabulated values of the critical differences should beconsidered to be a general statement particularly with respect to b
43、etween-laboratory precision. Before a meaningful statement can be made aboutany two specific laboratories, the amount of statistical bias if any, between3Supporting data have been filed at ASTM International Headquarters and maybe obtained by requesting Research Report RR: D131077.TABLE 2 Coefficien
44、ts of Variation, Vinyl Coated Glass YarnInsect Screening, 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
45、3 Critical Differences 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
46、24.32 15.3 18.9 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
47、.6 24.15 8.8 16.3 21.510 6.2 15.1 20.6ATo convert the values of the critical differences to fabric stability, pounds,multiply the critical difference by the average of the two specific sets of data beingcompared and then divide by 100.D4912073them must be established, with each comparison based on r
48、ecent 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 fabric stability can be defined onl
49、y interms of a test method.11. Keywords11.1 fabric stability; vinyl-coated glass; insect screening;louver clothASTM International takes no position respecting the validity 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 yea
