1、Designation: D6828 02 (Reapproved 2015)Standard Test Method forStiffness of Fabric by Blade/Slot Procedure1This standard is issued under the fixed designation D6828; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the stiff-ness of fabrics by measuring the force required to push aspecimen in
3、to a slot of predetermined width with a metal bladeworking at a predetermined capacity.NOTE 1For other methods for testing stiffness, refer to Test MethodsD1388, D4032, and D5732.1.2 This test method is applicable to fabrics of any fibercontent whose stiffness does not exceed the capacity of thePene
4、trator Beam apparatus. Specimens can be taken fromfabrics, rolls, or end products.1.3 The values stated in SI units are to be considered asstandard; the values inch-pound units are included for infor-mation only.1.4 This standard does not purport to address all of thesafety concerns, if any, associa
5、ted 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:2D123 Terminology Relating to TextilesD1388 Test Method for S
6、tiffness of FabricsD1776 Practice for Conditioning and Testing TextilesD2904 Practice for Interlaboratory Testing of a Textile TestMethod that Produces Normally Distributed Data (With-drawn 2008)3D2906 Practice for Statements on Precision and Bias forTextiles (Withdrawn 2008)3D4032 Test Method for S
7、tiffness of Fabric by the CircularBend ProcedureD4850 Terminology Relating to Fabrics and Fabric TestMethodsD5732 Test Method for Stiffness of Nonwoven FabricsUsing the Cantilever Test (Withdrawn 2008)32.2 Statistical Analysis Software:43. Terminology3.1 Definitions:3.1.1 For definitions of textile
8、terms used in this methodrefer to Terminology D4850. For other terms used in thismethod, refer to Terminology D123.4. Summary of Test Method4.1 A swatch of fabric rests on two flat plate supportsseparated by a fixed distance. A force is applied to the fabricswatch midway between the supports by mean
9、s of a bladeattached to a motor driven beam. The maximum force neededto push the fabric through the supports is measured as aresistance to bending of the fabric.5. Significance and Use5.1 This test method is considered satisfactory for qualitycontrol testing.5.2 If there are differences of practical
10、 significance betweenreported test results for two laboratories, comparative testsshould be performed to determine if there is a statistical biasbetween them, using competent statistical assistance. As aminimum, use test samples as homogeneous as possible, drawnfrom the material from which the dispa
11、rate test results wereobtained, and randomly assigned in equal number to eachlaboratory for testing. The test results from the two laboratoriesshould be compared using a statistical test for unpaired data, ata probability level chosen prior to the testing series. If a bias isfound, either its cause
12、must be found and corrected, or futureresults for the source material must be adjusted in consider-ation of the known bias.5.3 The stiffness of fabric relates to its resistance to bendingwith further processing and use. It measures the fiber and yarn1This test method is under the jurisdiction of AST
13、M Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,Specific.Current edition approved July 1, 2015. Published September 2015. Originallyapproved in 2002. Last previous edition approved in 2011 as D6828 02(2011).DOI: 10.1520/D6828-02R15.2For refer
14、enced 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.3The last approved version of this historical standard is referenced on
15、www.astm.org.4SAS Institute, Box 8000, Cary, NC 27511.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1bending capabilities, the cohesion of individual fibers andyarns relative to their displacement and binders or finishes thathold the
16、m in place.6. Apparatus6.1 Handle-O-Meter Tester,5(Fig. 1), having the followingparts:6.1.1 Specimen Platform, consisting of two adjustable platescapable of forming an opening between the two plates.6.1.2 Penetrating Blade, to force the fabric into the slotbetween the plates.6.1.3 Penetrator Beam, t
17、o move the Penetrator Blade.6.1.4 Force Measuring Device, operating at a predeterminedcapacity, to measure the force required to force the fabric intothe slot.6.1.5 Calibration Weight, for calibration of the force appro-priate for the Penetrator Blade.6.2 Specimen Marking Template, 102 by 100 6 5.0
18、mm (4.0by 4.0 6 0.2 in.).7. Sampling and Test Specimens7.1 Primary Sampling UnitConsider material as put-upfor shipment to be the primary sampling unit, such as rolls,bolts or pieces of fabric, or carton of garments or flat goods, asapplicable. (See Annex A1.)7.2 Laboratory Sampling UnitAs a laborat
19、ory samplingunit take from rolls at least one full-width piece of fabric thatis1m(1yd)inlength along the selvage (machine direction),after first removinga1m(1yd)length.7.3 Test SpecimensFrom each laboratory sampling unit,take five specimens 100 by 100 6 2.5 mm (4 by 4 6 0.1 in.).Take specimens repre
20、senting a broad distribution from differ-ent positions diagonally across the width of the laboratorysampling unit. Specimens should be staggered in such amanner that no specimens contain the same yarns. With theface of the specimen up, place a small locator mark in thelower right hand corner of the
21、specimen parallel to thewarp/machine direction (MD). (See Annex A2.) The mark willbe used to correctly position the specimen prior to testing sothat the stiffness of four different areas of the specimen can bedetermined. Label specimen to maintain identity.7.3.1 For fabric widths 100 mm (4 in.) or m
22、ore, take nospecimens closer than 25 mm (1 in) from the selvage edges ofthe laboratory sampling unit.7.3.2 For fabric widths less than 150 mm (4 in.), use theentire width of the laboratory sampling unit for specimens.7.3.3 Ensure specimens are free of folds, creases, orwrinkles.Avoid getting oil, wa
23、ter, grease, etc. on the specimenswhen handling.7.3.4 If the fabric has a pattern, ensure that the specimensare a representative sampling of the pattern.8. Preparation of Apparatus8.1 Place the tester on a flat surface and level according tomanufacturers instructions.5The sole source of supply of th
24、e apparatus known to the committee at this timeis Thwing-Albert Instrument Co., Philadelphia, PA. If you are aware of alternativesuppliers, please provide this information to ASTM International Headquarters.Your comments will receive careful consideration at a meeting of the responsibletechnical com
25、mittee1, which you may attend.FIG. 1 Handle-O-Meter TesterD6828 02 (2015)28.2 Install Penetrator Beam Assembly. Selection of beam isdetermined by thickness and weight of the fabric. Most fabricswill require a 1000 g beam.8.3 Engage the power control and allow 15 min for thecircuitry to stabilize.8.4
26、 Calibrate the instrument by placing the calibrationweight specified on the upper edge of the blade. The readingwill be a negative number. Make necessary adjustments asdirected in the instruction manual.8.5 Set the width of the slot by moving the plates to thedesired location as directed in the inst
27、ruction manual. Slotwidth is determined by the fabric to be tested. Most fabrics willrequire a 10 mm (0.40 in.) slot width.8.6 Select Quadruple mode using Mode button on controlpanel.8.7 Maintenance (see Annex A3).9. Conditioning9.1 Bring the test specimens to moisture equilibrium fortesting in the
28、standard atmosphere for testing textiles asdirected in Practice D1776 or, if applicable, in the specifiedatmosphere in which the testing is to be performed.10. Procedure10.1 Make all the tests in the standard atmosphere fortesting.10.2 Zero the instrument by pressing the zero/force buttonto obtain a
29、 zero reading on the force display.10.3 Place specimen face-up over the slot on the platform sothat the warp/machine direction mark on the specimen is in thelower left corner and perpendicular to the slot. About13 (30mm, 1.3 in.) of the specimen should be to the right of the slotand23 (65 mm, 2.6 in
30、.) to the left. (See Annex A2, Position 1.)10.4 Handle the test specimens carefully to avoid alteringthe natural state of the material.10.5 Depress the test switch and allow the blade to completeone cycle by pushing the specimen into the slot and returningto the start position. It is not necessary t
31、o close the lid of theinstrument during testing.10.6 Record the maximum reading in the warp/machinedirection face up.10.7 Remove the specimen from the slot, keeping face-sideup. Rotate the specimen 90 clockwise so that the warp/machine direction mark is parallel to the slot and the locatormark is po
32、sitioned in the vertical direction in the lower leftcorner of the specimen (see AnnexA2, Position 2).Arrange thespecimen so that about13 of the specimen is to the right of theslot and23 to the left. Re-zero the tester if the digital forcedisplay does not read zero.10.8 Activate the tester and record
33、 the maximum force inthe filling/cross direction face-up.10.9 Remove the specimen from the slot and turn it over sothat the back side is facing up and the warp/machine direction(MD) of the specimen is perpendicular to the slot. The locatormark on the underneath side of the specimen must be on theopp
34、osite side from its location in 10.3. (See Annex A2,Position 3). This procedure will expose a fresh area of thespecimen for testing.10.10 Activate the tester and record the maximum readingof the warp/machine direction face down.10.11 Remove the specimen from the slot, keeping backside of specimen fa
35、cing up. Rotate the specimen 90 counter-clockwise so that the warp/machine direction of the specimenis parallel to the slot and the locator mark on the underneathside of the specimen is on the opposite side from its location in10.7. (See Annex A2, Position 4.)10.12 Activate the tester and record the
36、 maximum readingof the filling/cross direction face down.10.13 Continue as directed in 10.3 10.12 until all speci-mens have been tested.11. Calculation11.1 Determine Total Stiffness of each specimen (see AnnexA2).11.2 Average Total Stiffness measurements for each labora-tory sampling unit using valu
37、es from the individual specimens.Calculate the standard deviation of the specimens.12. Report12.1 State that the specimens were tested as directed in TestMethod D6828. Describe the material or product sampled andsampling method used.12.2 Report the following information:12.2.1 Total stiffness of eac
38、h specimen and the averagestiffness of the specimens from each laboratory sampling unit.12.2.2 Dimensions of the test specimens.12.2.3 Testing conditions used.12.2.4 Slot width and Penetrator Beam used and instrumentmodel.13. Precision and Bias13.1 SummaryThe following precision and bias state-ments
39、 have been prepared in accordance with Practice D2906.In comparing two single observations (single operator preci-sion) for the materials tested, the difference should not exceedthe values shown in Table 2 in 95 our of 100 cases when bothobservations are taken by the same well trained operator using
40、the same piece of test equipment and specimens randomlydrawn from the same sample of material. Larger differences areTABLE 1 Average Stiffness Values, gAFabric #1day #1 day #2operator 1 operator 2 operator 1 operator 2140.4 141.3 147.1 149.6Fabric #2day #1 day #2operator 1 operator 2 operator 1 oper
41、ator 2546.0 595.2 592.7 583.5AMean of Total Stiffness Measurements (MD face-up + CD face-up + MDface-down + CD face-down = Total Stiffness) obtained for five specimens.D6828 02 (2015)3likely to occur under all other circumstances. The true value ofstiffness can be defined only in terms of a specific
42、 test method.Within this limitation, this test method has no know bias.Paragraphs 13.2 13.4 explains the bias for this summary andfor evaluations made under other conditions.13.2 Interlaboratory Test DataAn interlaboratory test wasrun in 2001, in which randomly-drawn samples of two fabricswere teste
43、d in each of two laboratories. Two operators in eachlaboratory each tested ten specimens of each fabric using thistest method. Five of the ten specimens were tested on one dayand five specimens were tested on a second day.Analysis of thedata was conducted using Practice D2904, Practice D2906 andStat
44、istical Analysis Software (SAS). The components of vari-ance for stiffness expressed as standard deviations were calcu-lated to be the values listed in Table 3. The two fabric typeswere: (1) Woven mid weight and (2) Warp knit with weftinsertion.13.3 PrecisionFor the components of variance reported i
45、nTable 3, two averages of observed values should be consideredsignificantly different at the 95 % probability level if thedifference equals or exceeds the critical differences listed inTable 2. There were sufficient differences related to the fabrictype and structure to warrant listing the component
46、s ofvariance and the critical differences separately. Consequentlyno multi-material comparisons were made.NOTE 2Since this interlaboratory test included only two materials andtwo laboratories, estimates of between-laboratory precision should beused with special caution. Interlaboratory testing of ot
47、her fabric types is inprogress.NOTE 3The tabulated 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 abouttwo specific laboratories, the amount of statistical bias, if
48、 any, betweenthem must be established, with each comparison being based on recentdata obtained on specimens taken from a lot of material to the type beingevaluated so as to be as nearly homogeneous as possible and thenrandomly assigned in e equal numbers to each of the laboratories.13.4 BiasThe proc
49、edure in this test method for measuringstiffness has no bias because the value of this property can bedefined only in terms of a test method.14. Keywords14.1 bending; fabric; penetrator blade; stiffnessANNEXES(Mandatory Information)A1. SAMPLINGA1.1 Lot SampleAs a lot sample for acceptance testing,randomly select the number of rolls or pieces of fabric directedin an applicable material specification or other agreementbetween the purchaser and the supplier. Consider material asput-up for shipment to be the primary sampling unit, such asrolls, bolts or pieces of
