ASTM D226113 2017 Standard Test Method for Tearing Strength of Fabrics by the Tongue Single Rip Procedure ConstantRateofExtension Tensile Testing Machine Tearing Standard tear methods usually require the tear to be started before testing ID: 1033852
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1. ASTM D1424-09 (2019)Standard Test Method for Tearing Strength of Fabrics by Falling-Pendulum (Elmendorf-Type) Apparatus
2. ASTM D2261-13 (2017)Standard Test Method for Tearing Strength of Fabrics by the Tongue (Single Rip) Procedure (Constant-Rate-of-Extension Tensile Testing Machine)
3. TearingStandard tear methods usually require the tear to be started before testingImproves reproducibility of results Provides clamping areaTear continues in the same directionReported value is not directly related to the force required to start a tearStarting usually requires more force than continuingASTM D1424 & D2261
4. TearingPendulum tear occurs quickly, records maximum force onlyCRE machine tears more slowly, may record one or multiple peaksASTM D1424 & D2261
5. DefinitionsTearing forceforce required either (1) to start or (2) to continue or propagate a tear in a fabric under specified conditions. Tearing strengthcapacity of a material to withstand the ultimate tearing force required to propagate a tear after its initiation ASTM D1424 & D2261Report tearing force for individual specimensReport average force for each condition/direction as tearing strength
6. ScopeApplicable to most woven fabrics Air bag fabricsLayeredNappedPileUntreatedHeavily sizedCoatedResin-treatedOtherwise treatedASTM D1424 & D2261
7. ScopeASTM D1424Warp direction only of warp-knit fabricsNot suited for most other knitted fabricsNot applicable to woven elastic fabricsNot suitable for highly anisotropic fabrics Not for loose fabrics where tear transfer from one direction to another is likelyASTM D2261Method states it is also applicable to knit fabricsASTM D1424 & D2261
8. Scope (ASTM D1424)Warp direction only of warp-knit fabricsNot suited for most other knitted fabricsNot applicable to woven elastic fabricsNot suitable for highly anisotropic fabrics Not for loose fabrics where tear transfer from one direction to another is likelyASTM D1424
9. Laboratory Sample1 yard of full width fabric from each roll/piece in lot sampleAvoid inner or outer wrap from fabric rollsASTM D1424 & D2261
10. Specimens5 in each directionDistribute across length and width of sample10% of width from selvageASTM D1424 & D2261
11. DirectionMachine directionparallel to the direction of manufacturewale wise; warp directionCross-machine directionperpendicular to the direction of manufacturecourse wise; filling directionASTM D1424 & D2261
12. More About DirectionASTM D1424Short edge parallel to machine or cross-machine direction of the fabricFor specimens with short side parallel to warp (wales), tear is “across weft”For specimens with short side parallel to fill (courses), tear is “across warp”ASTM D2261Cut long sides parallel to machine or cross-machine directionLong side parallel to warp tears “across weft”Long sides parallel to fill tears “across warp”ASTM D1424 & D2261Sides parallel to slit must be on grainYarns perpendicular to slit will be torn
13. More About Direction (ASTM D1424)Short edge parallel to machine or cross-machine direction of the fabricFor specimens with short side parallel to warp (wales), tear is “across weft”For specimens with short side parallel to fill (courses), tear is “across warp”ASTM D1424Sides parallel to slit must be on grainYarns perpendicular to slit will be torn
14. Direction: ASTM D1424ASTM D1424Warp/machine directionfill/cross-machine yarns
15. Direction: ASTM D2261ASTM D1424 & D2261Warp/machine directionfill/cross-machine yarns
16. ConditioningPrecondition and condition specimens ASTM D1776Perform test at standard conditions21°C/70°F65% RHFor stretch fabrics, relax for 24 hASTM D1424 & D2261
17. Wet SpecimensWhen applicable, use desizing treatments that will not affect the normal physical property of the fabricSubmerge specimens in distilled or deionized water at ambient temperature until thoroughly soakedFor fabrics not easily wet, add 0.1% solution of nonionic wetting agent to the water bathSufficient wetting indicated by no significant change in tearing force after longer periods of immersion~1 hour for most fabrics Test within 2 min after removal from waterASTM D1424 & D2261
18. Specimens: ASTM D1424Original die modelASTM D1424
19. Specimens: ASTM D1424Fig. 1 from ASTM D1424Specimens cut by die or templateASTM D1424
20. Apparatus: ASTM D1424Stationary clampClamp on a swinging pendulum Means for levelingMeans for holding the pendulum in a raised positionMeans for instantly releasing the pendulumMeans for measuring the force to tear the test specimenASTM D1424
21. Apparatus: Older model: physical pointer; no electronics ASTM D1424
22. Apparatus: Digital models ASTM D1424
23. Apparatus: ASTM D1424Knife mounted on stationary post for initial specimen slitting (optional)Manual or pneumatic clamps Multiple full-scale force rangesASTM D1424
24. Set Up: ASTM D1424Select force range so tear occurs between 20% and 80% of capacity20% to 60% for high-capacity instrumentASTM D1424
25. Set Up: ASTM D1424For pneumatic clamps, use ~550 kPa (80 psi) pressure620 kPa (90 psi) maximum410 kPa (60 psi) minimumFor digital systems, follow manufacturer’s instructions for setting parameters pendulum selection# pliesunitsASTM D1424
26. Procedure: ASTM D1424Position pendulum in starting position; set force recording mechanism to zeroASTM D1424
27. Procedure: ASTM D1424Tester-Slit SpecimensPlace specimen in clamps (upper edge parallel to top of clamps)Close clampsUsing the built-in knife blade, cut a 20-mm (0.787-in.) slit from the bottom edge, leaving 43.0 ±0.15 mm (1.69 ± 0.005 in.) to be tornManually-Slit SpecimensCut a 20-mm (0.787-in.) slit in the center of one long edgeEnsure fabric remaining to be torn is 43 ± 0.15 mm (1.69 ± 0.005 in.)Place specimen in the clamps with slit centrally located between themClose clampsASTM D1424
28. ASTM D1424Procedure: ASTM D1424
29. Procedure: ASTM D1424Release pendulumCatch pendulum just after the threshold of its backward swing Return pendulum to locked starting positionIf applicable, do not disturb position of the pointerRecord readingASTM D1424
30. Procedure: ASTM D1424ASTM D1424
31. Procedure: ASTM D1424Observe specimens during tearingDiscard specimens with unusual behavior and test anotherspecimen slips in the jaw tear more than 6 mm (0.25 in.) from projection of original slittear across specimen (perpendicular to slit)incomplete tearNote puckering (do not reject)ASTM D1424
32. Calculations: ASTM D1424For manual (pointer) instruments onlyFt = Rs × Cs/100Ft is tearing forceRs is scale readingCs is full scale capacityFor heavy-duty instruments: Ft = Rs × 100Average each direction and condition (dry/wet)For each lab sampleFor each lotASTM D1424
33. Report: ASTM D1424Test method (ASTM D1424-09)Material testedElmendorf tearing strength for each test direction and testing conditionCondition of test (with or without wetting)Puckering, if it occurs during the testNumber of tests rejected because of crosswise tearingStandard deviation or coefficient of variation (if requested)For computer-processed data, note software usedMake, model, and capacity of testing machineType of clamps (manual or pneumatic)Clamp pressureAny modification of the test methodASTM D1424
34. Troubleshooting: ASTM D1424Place instrument on a sturdy, level surfaceEnsure no perceptible movement of base or bench during pendulum swingInstrument movement during swing is a significant source of errorRaise pendulum and visually check clamp alignmentExamine knife edge for sharpness, wear, and central alignmentRemove dust, especially from jawsASTM D1424
35. Calibration: ASTM D 1424Check zeroingUse calibrated weight to check 50% for each pendulumSee manufact-urer’s calibration instructionsASTM D1424pendulumCheck weight
36. Specimens: ASTM D2261Fig. 1 from ASTM D2261All tolerances ± 0.5%ASTM D2261
37. Apparatus: ASTM D2261CRE-type tensile testing machineConstant Rate of Extension: pulling clamp moves at a uniform rate and force-measuring mechanism moves a negligible distanceCRT-type acceptable if agreed uponConstant Rate of Traverse: pulling clamp moves at a uniform rate and the force is applied through the other clamp which moves noticeablyASTM D2261
38. Apparatus: ASTM D2261Minimum 25 × 75 mm (1 × 3 in) jaw facesMust be parallel and flat50 × 75 mm (2 × 3 in) recommendedSerrated or rubber face recommendedPneumatic clamping system13 kN (2,900 lbf) clamping forceManual clamping acceptable if no slippage occursASTM D2261
39. Set Up: ASTM D2261Initial clamp distance75 ±1 mm (3.0 ± 0.05 in)Crosshead speed50 ±2 mm/min (2 ±0.1 in/min)300 ±10 mm/min (12 ±0.5 in/min) if agreedASTM D2261
40. Procedure: ASTM D2261Secure specimen in jaws One tongue up, one tongue down, showing opposite facesASTM D2261FaceBack
41. Procedure: ASTM D2261Begin crosshead movementAfter a nominal take-up load of 0.5 N (0.1 lbf) has been reached, record the single-peak or multiple-peak tearing forces (see Calculation)ASTM D2261
42. Procedure: ASTM D2261Stop crosshead motion after tearing ~75 mm (3 in) or the entire specimenReturn crosshead to starting positionNote if tear occurs crosswise to the direction of applied forceRemove the tested specimen Repeat for five specimens of each testing direction and conditionASTM D2261
43. Calculation: ASTM D2261Option 1, Average of Five Highest Peaks(for fabrics exhibiting five peaks or more)After the initial peak, determine the five highest peak forces to the nearest 0.5 N (0.1 lbf).Calculate the average of these five peak forcesASTM D2261
44. Calculation: ASTM D2261Option 2, Single-Peak Force(for fabrics exhibiting less than five peaks)Record the highest peak force as the single-peak force to the nearest 0.5 N (0.1 lbf)ASTM D2261
45. Calculation: ASTM D2261Average each direction and condition (dry/wet)For each lab sampleFor each lotAverage tearing force of specimens = tearing strength of sampleASTM D2261
46. Report: ASTM D2261Test method (ASTM D2261-13)Material testedTongue tearing strength for each testing direction and testing condition (to nearest 0.5 N or 0.1 lbf)Calculation option used (single-peak or average of five highest peak forces after initial peak)Condition of test (with or without wetting)Standard deviation or coefficient of variation (if requested)For computer-processed data, note software usedMake, model, and capacity of testing machineClamp typeAny modification of the test methodASTM D2261
47. Troubleshooting: ASTM D2261Clamping modification may be necessary to prevent slipping or damage in clampsModify if a fabric slips in the jaws or if ≥ 25% of specimens break within 5 mm of the jaw.Pad jawsCoat or tape fabric under jaw facesMedium-grit emery cloth on jaw facesNote all modifications in the reportASTM D2261