1、Designation: D6770 07 (Reapproved 2011)Standard Test Method forAbrasion Resistance of Textile Webbing (Hex Bar Method)1This standard is issued under the fixed designation D6770; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the y
2、ear of last 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 abrasionresistance of textile webbing using a hex bar abrasion tes
3、ter.1.1.1 The resistance 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 det
4、ermine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D123 Terminology Relating to TextilesD1776 Practice for Conditioning and Testing TextilesD4850 Terminology Relating to Fabrics and Fabric TestMethods2.2 Other Standard:Federal Standard 191, Me
5、thod 4108 “Strength and Elonga-tion, Breaking; Textile Webbing, Tape and BraidedItems”33. Terminology3.1 For all terminology relating to Fabrics, refer to Termi-nology D4850.3.2 The following terms are relevant to this standard:abrasion, abrasion cycle, breaking force, standard atmospherefor precond
6、itioning textiles, standard atmosphere for testingtextiles, stroke, in hex bar abrasion testing, webbing.3.3 For all other terminology related to textiles, refer toTerminology D123.4. 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.5.4 While there has not been extensive interlaboratorytesting prior to development of this standard, there has beensome quality control testing by manufacturers. An intralabora-tory test was conducted to initiate
14、 this test method, using asingle product. This data will be used to determine a prelimi-nary statement on precision and bias. Subsequent to approval1This test method is under the jurisdiction of ASTM Committee D13 on Textilesand is the direct responsibility of Subcommittee D13.60 on Fabric Test Meth
15、ods,Specific.Current edition approved May 1, 2011. Published July 2011. Originally approvedin 2002. Last previous edition approved in 2007 as D677007. DOI: 10.1520/D6770-07R11.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. Fo
16、r Annual Book of ASTMStandards volume information, refer to the standards Document 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 194
17、28-2959, United States.of 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 app
18、ly to most webbings 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 d
19、ifferences of practical 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 h
20、omogenous as possible, 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, a
21、ta probability level 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 wil
22、l provide a recipro-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 e
23、dges as the drum movesthe 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
24、(1000 to 3000 lb) and 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 fi
25、nish and a Rockwell 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
26、 with a suitable means 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 t
27、he hexagonal rod the 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
28、 “H”.6.2 Tensile Testing 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 sele
29、ct five rolls or pieces to constitute the lotsample.7.2 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 laboratory sampling unit,cut 2 test specimens 1.4 m (1.5 yd) in length. Mark ones
30、pecimen “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.4Apparatus and accessories are commercially available.FIG. 1 Webbing Abrasion Teste
31、rD6770 07 (2011)27.4 Ensure 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
32、with Practice D1776 or, if 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
33、 in the standard atmosphere for precondi-tioning textiles in accordance with Practice D1776.9. 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 acce
34、ptable as to the requirements 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 attac
35、hto the drum. The length of 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
36、 be identi-fied as 1 through 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
37、 specimens aregiven a 300 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
38、the test specimens from the 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
39、lot to the nearest 1 % as 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
40、the average breaking force 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 breakin
41、g force tothe nearest 1 % 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
42、contained in the associated 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
43、sampled.12.2 Report the following 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 te
44、st specimens.12.2.4 For computer-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 tes
45、t included less than the recom-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 incl
46、uded whenavailable.13.3 BiasThe procedure of this test method provides atest value that can be defined only in terms of this test method.There is no independent, referee method by which bias may bedetermined. No known bias has been determined for this testmethod.14. Keywords14.1 hex-bar abrasion res
47、istance; webbingD6770 07 (2011)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
48、.600 4.620 22.980 46.4202 4.600 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 4.68
49、0 23.340 4.620 4.620 4.500 4.520 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 46.1203 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
