1、Designation: D 6770 07Standard Test Method forAbrasion Resistance of Textile Webbing (Hex Bar Method)1This standard is issued under the fixed designation D 6770; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. 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 determination of abrasionresistance of textile webbing using a hex bar abrasion tester.1.1.1 The r
3、esistance is expressed as a percentage of retainedbreak strength.1.2 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 appl
4、ica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 123 Terminology Relating to TextilesD 1776 Practice for Conditioning and Testing TextilesD 4850 Terminology Relating to Fabric2.2 Other Standard:Federal Standard 191, Method 4108 “Strength and Elonga-tion,
5、 Breaking; Textile Webbing, Tape and BraidedItems”33. Terminology3.1 For all terminology relating to Fabrics, refer to Termi-nology D 4850.3.1.1 The following terms are relevant to this standard:abrasion, abrasion cycle, in abrasion testing, breaking force,standard atmosphere for preconditioning tex
6、tiles, standardatmosphere for testing textiles, stroke, in hex bar abrasiontesting, webbing, in textiles3.2 For all other terminology related to textiles, refer toTerminology D 123.4. Summary of Test Method4.1 Abrasion resistance is measured by subjecting the speci-men to unidirectional reciprocal r
7、ubbing over a specific barunder specified conditions of tension, stroke length and time.Resistance to abrasion is evaluated by determining the percentretention of breaking force of an abraded specimen comparedto an unabraded specimen.5. Significance and Use5.1 The measurement of the resistance to ab
8、rasion of textilewebbing is very complex. The resistance to abrasion is affectedby many factors that include the inherent mechanical propertiesof the fibers; the dimensions of the fibers; the structure of theyarns; the construction of the webbing; the type, kind, andamount of treatment added to the
9、fibers, yarns, or webbing; thenature of the abradant; the variable action of the abradant overthe specimen area abraded; the tension on the specimen; thepressure between the specimen and the abradant; and thedimensional changes in the specimen.5.2 The resistance of textile webbing to abrasion as mea
10、-sured by this test method does not include all the factors whichaccount for wear performance or durability in actual use. Whilethe abrasion resistance stated in terms of the number of cyclesand durability (defined as the ability to withstand deteriorationor wearing out in use, including the effects
11、 of abrasion) arefrequently related, the relationship varies with different enduses. Different factors may be necessary in any calculation ofpredicted durability from specific abrasion data.5.3 Laboratory tests may be reliable as an indication ofrelative end use in cases where the difference in abra
12、sionresistance of various materials is large, but they should not berelied upon where differences in laboratory test findings aresmall. In general, the results should not be relied upon forprediction of performance during actual wear life for specificend uses unless there are data showing the specif
13、ic relationshipbetween laboratory abrasion tests and actual wear in theintended end use.1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.60 on Fabric Test Methods,Specific.Current edition approved July 1, 2007. Publishe
14、d August 2007. Originallyapproved in 2002. Last previous edition approved in 2002 as D 677002e2.2For 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 Docume
15、nt Summary page onthe ASTM website.3Available from Superintendent of Documents, Government Printing Office,Washington, DC 20402.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5.4 While there has not been extensive interlaboratorytes
16、ting prior to development of this standard, there has beensome quality control testing by manufacturers. An intralabora-tory test was conducted to initiate this test method, using asingle product. This data will be used to determine a prelimi-nary statement on precision and bias. Subsequent to appro
17、valof this standard, a formalized interlaboratory procedure will beinitiated under the direction of a professional statistician andwill produce a research report. Samples used in this controlledtest will be representative of end use applications.5.5 These general observations apply to most webbings
18、thatare used in automotive, aerospace, industrial, and militaryapplications.5.6 This test method can be used for acceptance testing ofcommercial shipments but comparisons should be made withcaution because estimates of between-laboratory precision areincomplete.5.7 If there are differences of practi
19、cal significance betweenreported test results for two laboratories (or more), compara-tive tests should be performed to determine if there is astatistical bias between them, using competent statistical assis-tance. As a minimum, use samples for such comparative teststhat are as homogenous as possibl
20、e, drawn from the same lot ofmaterial as the samples that resulted in disparate results duringinitial testing, and randomly assigned in equal numbers to eachlaboratory. The test results from the laboratories involvedshould be compared using a statistical test for unpaired data, ata probability level
21、 chosen prior to the testing series. If bias isfound, either its cause must be found and corrected, or futuretest results must be adjusted in consideration of the knownbias.6. Apparatus6.1 Webbing Abrasion TesterThe webbing abrasion testerconsists of a suitable mechanism that will provide a recipro-
22、cating motion of the webbing over a standardized hex bar. Oneend of each specimen is attached to the mechanism and theother end passing over a hexagonal steel rod is attached to aweight. The hexagonal rod is so fixed as to subject the webbingspecimen to abrasion on two adjacent edges as the drum mov
23、esthe specimen across the rod. One example of such a mecha-nism is a reciprocating drum as illustrated in Fig. 1.6.1.1 Mass “B” shall be 900 6 60g(2lb6 2 oz) forwebbing with breaking strengths up to 4500 N (1000 lb), 18006 60g(4lb6 2 oz) for breaking strengths of 4500 to 13 500N (1000 to 3000 lb) an
24、d 2400 6 60 g (5.2 6 2 lb) for breakingstrengths over 13 500 N (3000 lb).6.1.2 Steel hexagonal rods “C” shall be 6.35 6 0.03 mm(0.250 6 0.001 in.) when measured across opposite flat sidesand the radius shall be 0.5 6 0.2 mm (0.020 6 0.008 in.). Thesteel shall have a cold drawn finish and a Rockwell
25、Hardnessof B-91 to B-101. The edges of the hexagonal rods shall nothave any burrs, nicks or scale.6.1.3 The mechanism “D” shall have a nominal outsidediameter of 400 mm (16 in.) or be some mechanism able toproduce a reciprocating motion of at least 300 mm (12 in.) overthe hex rod with a suitable mea
26、ns for attaching the specimen tobe tested without damage to the specimen.6.1.4 The crank-arm “F” shall be attached to the mechanism“D” and to the driver disk “E” in such a manner that when thespecimen is attached to the mechanism, the specimen duringthe test will oscillate over the hexagonal rod the
27、 requireddistance during each stroke and at the required rate (see 10.4).6.1.5 The hexagonal rod shall be so placed that specimen“A” with the weight attached to one end and the other endpassing over the hexagonal rod and attached to the drivemechanism will form an angle of 85 6 2 “H”.6.2 Tensile Tes
28、ting Machine4, CRE-Type equipped withsplit-drum webbing clamps as described in Federal TestMethod 191b, Method 4108.7. Sampling and Test Specimens7.1 Lot SampleTake a lot sample as directed in theapplicable material specification. In absence of such a specifi-cation randomly select five rolls or pie
29、ces to constitute the lotsample.4Apparatus and accessories are commercially available.FIG. 1 Webbing Abrasion TesterD67700727.2 Laboratory Sampling UnitAs a laboratory samplingunit take from each roll or piece one piece of webbing that is2.8 m (3.0 yd) in length.7.3 Test SpecimensFrom each laborator
30、y sampling unit,cut 2 test specimens 1.4 m (1.5 yd) in length. Mark onespecimen “A” for abraded and the other “U” for unabraded.7.3.1 When the lot or shipment consists of less than 5 rollsor pieces, randomly select 5 test specimens that represent allrolls or pieces in the lot or shipment.7.4 Ensure
31、specimens are free of folds, creases, or wrinkles.Avoid getting oil, water, grease, and so forth, on the specimenswhen handling.8. Conditioning8.1 Condition the test specimens to moisture equilibrium fortesting in the standard atmosphere for testing textiles inaccordance with Practice D 1776 or, if
32、applicable, in thespecified atmosphere in which the testing is to be performed.8.2 In the event of dispute concerning the results of teststhat may be affected by the moisture content, test specimensshall be preconditioned by bringing them to approximatemoisture equilibrium in the standard atmosphere
33、 for precondi-tioning textiles in accordance with Practice D 1776.9. Preparation and Calibration of Test Apparatus9.1 Ensure the test machine is on a level, sturdy surface andfree from vibration.9.2 For hexagonal rods a manufacturers certificate of com-pliance shall be acceptable as to the requireme
34、nts as describedin 6.1.2.10. Procedure10.1 Condition the “A” test specimens in the standardatmosphere for testing textiles, in accordance with Section 8.10.2 Attach the required mass (6.1.1) to one end of the testspecimen, pass the other end over the hexagonal rod and attachto the drum. The length o
35、f the test specimens shall be adjusted,without altering the original length, so that the test specimenswill oscillate across the hexagon rod and each end of theabraded area will be equidistant from the ends of the testspecimens.10.3 The edges of each new hexagonal rod shall be identi-fied as 1 throu
36、gh 6, and rotated after each use so that noabrading edges are used more than once. Use edge 1 and twofor one test specimen, edge 3 and 4 for a second test specimen,edges 5 and 6 for a third test specimen, and then discard therod.10.4 Oscillate the mechanism so that the test specimens aregiven a 300
37、6 25 mm (12 6 1 in.) traverse over the rod at therate of 1 6 .03 strokes (0.5 cycles) per second for 5000 strokes(2500 cycles). One single stroke is 300 6 25 mm (12 6 1 in.)in one direction only.10.5 After the machine has stopped at the predeterminednumber of cycles remove the test specimens from th
38、e abradingmachine.10.6 Continue as directed in 10.2-10.5 until all the requiredspecimens have been abraded for each laboratory samplingunit.10.7 Determine the breaking force of the abraded specimens(A) and the unabraded specimens (U) for each laboratorysampling unit in the lot to the nearest 1 % as
39、directed inFed-Std-191, Method 4108 set as follows:10.7.1 Attach the split drum webbing clamps in the tensiletester and set the distance between them to 250 mm (10 in.)center to center.10.7.2 Set the testing speed to 75 6 25 mm (3 6 1 in./min).11. Calculation11.1 Calculate the average breaking force
40、 for the lot of theabraded test specimens from the results of the laboratorysampling units.11.2 Calculate the average breaking force for the lot of theunabraded test specimens from the results of the laboratorysampling units.11.3 Calculate the percentage of retained breaking force tothe nearest 1 %
41、for the lot using Eq 1:AR 5100AU(1)where:AR = abrasion resistance, %,A = average breaking force of the abraded specimens, N(lb), andU = average breaking force of the unabraded specimens,N (lb).11.3.1 When data are automatically computer processed,calculations are generally contained in the associate
42、d software.It is recommended that computer-processed data be verifiedagainst known property values and its software described in thereport.12. Report12.1 Report that the abrasion resistance was determined inaccordance with Test Method D6770. Describe the material orproduct sampled.12.2 Report the fo
43、llowing information for the laboratorysampling unit and for the lot as applicable to a materialspecification or contract order:12.2.1 Abrasion resistance, percent retained in breakingforce.12.2.2 Breaking force of abraded test specimens.12.2.3 Breaking force of unabraded test specimens.12.2.4 For co
44、mputer-processed data, identify the program(software) used.13. Precision and Bias13.1 An intralaboratory test was conducted for the determi-nation of precision and bias of this test method. The results ofthe test are attached as Table 1.NOTE 1Because the intralaboratory test included less than the r
45、ecom-mended five laboratories, estimates of precision data may be eitherunderestimated or overestimated to a considerable extent and should beused with special caution.13.2 PrecisionA statement on the precision of this testmethod is being developed. The results will be included whenavailable.D677007
46、3TABLE 1 Raw Data from Intralaboratory TestMaterial 1Before Abrasion Material 2After AbrasionLab. Opr. Test 1 Test 2 Test 3 Test 4 Test 5 Opr. Sum Test 1 Test 2 Test 3 Test 4 Test 5 Opr. Sum Total Opr. SumSet 1 1 4.720 4.820 4.600 4.700 4.600 23.440 4.620 4.460 4.680 4.600 4.620 22.980 46.4202 4.600
47、 4.720 4.700 4.720 4.680 23.420 4.640 4.600 4.580 4.680 4.600 23.100 46.5203 4.580 4.720 4.720 4.560 4.720 23.300 4.620 4.480 4.400 4.520 4.480 22.500 45.8004 4.740 4.740 4.520 4.720 4.740 23.460 4.500 4.420 4.640 4.540 4.620 22.720 46.1805 4.700 4.660 4.600 4.700 4.680 23.340 4.620 4.620 4.500 4.52
48、0 4.380 22.640 45.9806 4.600 4.680 4.500 4.480 4.540 22.800 4.380 4.480 4.520 4.400 4.560 22.340 45.140Lab Sum 139.760 136.280 276.040Set 2 1 4.600 4.720 4.600 4.720 4.680 23.320 4.420 4.220 4.180 4.320 4.280 21.420 44.7402 4.680 4.700 4.660 4.700 4.640 23.380 4.520 4.500 4.560 4.520 4.640 22.740 46
49、.1203 4.660 4.720 4.660 4.660 4.640 23.340 4.460 4.540 4.640 4.500 4.580 22.720 46.0604 4.760 4.740 4.640 4.660 4.380 23.180 4.540 4.620 4.620 4.560 4.580 22.920 46.1005 4.680 4.700 4.740 4.620 4.680 23.420 4.500 4.440 4.480 4.480 4.440 22.340 45.7606 4.640 4.720 4.740 4.840 4.780 23.720 4.600 4.400 4.600 4.520 4.580 22.700 46.420Lab Sum 140.360 134.840 275.200Set 3 1 4.680 4.720 4.700 4.700 4.680 23.480 4.500 4.460 4.480 4.540 4.460 22.440 45.9202 4.620 4.600 4.680 4.680 4.620 23.200 4.500 4.560 4.600 4.580 4.640 22.880 46.0803 4.560 4.740 4.560 4.680 4.720 23.260 4.660 4.1
