1、Designation: D 3786 08aStandard Test Method forBursting Strength of Textile FabricsDiaphragm BurstingStrength Tester Method1This standard is issued under the fixed designation D 3786; 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 () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method describes the measurement of theresistance of textile fabrics to bursting using a hydrau
3、lic orpneumatic diaphragm bursting tester. This test method isgenerally applicable to a wide variety of textile products.1.2 This test method may also be applicable for stretchwoven and woven industrial fabrics such as inflatable re-straints.1.3 The values stated in SI units are to be regarded assta
4、ndard.NOTE 1For the measurement of the bursting strength by means of aball burst mechanism, refer to Test Method D 3787.1.4 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-pr
5、iate safety and health practices and determine the applica-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 3787 Test Method for Bursting Strength of TextilesConstant-
6、Rate-of-Traverse (CRT) Ball Burst TestD 4850 Terminology Relating to Fabric2.2 Other Standard:TAPPI T 403, OM.91 Bursting Strength of Paper33. Terminology3.1 For all terminology related to D13.59, Fabric TestMethods, see Terminology D 4850.3.1.1 The following terms are relevant to this standard:burs
7、ting strength, knitted fabric, nonwoven fabric. stretchwoven fabric, woven fabric.3.2 For all other terminology related to textiles, see Termi-nology D 123.4. Summary of Test Method4.1 A specimen is clamped over an expandable diaphragm.The diaphragm is expanded by fluid pressure to the point ofspeci
8、men rupture. The difference between the total pressurerequired to rupture the specimen and the pressure required toinflate the diaphragm is reported as the bursting strength.5. Significance and Use5.1 This method for the determination of diaphragm burst-ing strength of knitted, nonwoven and woven fa
9、brics is beingused by the textile industry for the evaluation of a wide varietyof end uses.5.2 In cases where test results obtained using the proceduresin Test Method D 3786 have not been correlated with actualperformance, Test Method D 3786 is considered satisfactoryfor acceptance testing of commer
10、cial shipments of textilefabrics for bursting strength since the method has been usedextensively in the trade for acceptance testing. In cases wheredisagreement arising from differences in values reported by thepurchaser and the supplier when using Test Method D 3786 foracceptance testing, the stati
11、stical bias, if any, between thelaboratory of the purchaser and the laboratory of the suppliershould be determined with comparison based on testing speci-mens randomly drawn from one sample of material of the typebeing evaluated.NOTE 2The kind of load transfer and stretch that occur when knittedgood
12、s and nonwoven fabrics are worn are prevented by clamping them asdescribed in this method.6. Apparatus and Materials6.1 Inflated Diaphragm Bursting Tester4 A testing ma-chine that meets the requirements of 6.1.1-6.1.4. Mounted so asto be free of externally induced vibrations.1This test method is und
13、er the jurisdiction of ASTM Committee D13on Textilesand is the direct responsibility of Subcommittee D13.59 on Fabric Test Methods,General. General.Current edition approved July 1, 2008. Published August 2008. Originallyapproved in 1979. Last previous edition approved in 2008 as D 378608.2For refere
14、nced 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.3Available from Technical Association of the Pulp and Paper Industry, 1D
15、unwoody Park, Atlanta, GA 30341.4Hydraulic and pneumatic bursting strength testers and accessories arecommercially available.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.6.1.1 Clamps, for firmly and uniformly securing the testspec
16、imen between two annular, parallel, and durable surfaces,without slippage during the test. Use sufficient pressure toeffect the practicable minimization of slippage The upper andlower clamping surfaces shall have a circular coaxial apertureof 31 6 0.75 mm (1.22 6 0.03 in.) in diameter: The surfaceso
17、f the clamps shall be durable and any edge which might causea cutting action shall be rounded to a radius of not more than0.4 mm. The lower clamp shall be integral with the chamber inwhich a pressure medium inflates the rubber diaphragm.NOTE 3Since the clamping mechanism and clamping surfaces aresub
18、ject to considerable wear and distortion, they should be examinedperiodically and repaired or replaced when necessary. The effectiveness ofgrooving the clamping surfaces in the manner specified has not beendetermined.6.1.2 DiaphragmA diaphragm of molded synthetic ornatural rubber, clamped between th
19、e lower clamping plate andthe rest of the apparatus so that before the diaphragm isstretched by pressure underneath it the center of its uppersurface is nominally level with the plane of the clampingsurface. The diaphragm should be inspected frequently forpermanent distortion and renewed as necessar
20、y.6.1.3 Pressure GageThe instrument must be fitted with apressure measuring system, accurate throughout the entirerange of its scale to within a value of1%ofitsmaximumcapacity. For those instruments with a Bourdon type gage thecapacity of the gage shall be such that the individual readingswill be no
21、t less than 25 % nor more than 75 % of the totalcapacity of the gage.6.1.4 Pressure SystemA means of applying controlledincreasing pressure to the underside of the diaphragm until thespecimen bursts. This can be achieved by two methods;hydraulic or pneumatic.6.1.4.1 Hydraulic Pressure is produced by
22、 a fluid displacedat the rate of 95 6 5 mL/min. The fluid is displaced by a pistonin the pressure chamber of the apparatus. The recommendedchamber fluid is USP chemically pure 96 % glycerin.NOTE 4Ethylene glycol may be substituted for the glycerine ifdesired.6.1.4.2 Pneumatic Pressure is produced by
23、 controlling theflow of clean dry air through a valve. The valve is configuredas per 11.4.16.1.5 Aluminum Foil For Calibration of Tester5Pieces ofpretested aluminum sheet having a known bursting strength inthe range of 70 to 790 kPa (10 to 115 psi) are used for checkingthe overall performance of the
24、 tester6.1.6 Pressure Recording.6.1.6.1 Hydraulic InstrumentsMeans shall be provided atthe instant of rupture of the specimen for stopping any furtherapplication of the loading pressure and for holding unchangedthe contents of the pressure chamber until the total burstingpressure and the pressure re
25、quired to inflate the diaphragmindicated on the gage have been recorded.6.1.6.2 Pneumatic InstrumentsMeans shall be providedfor recording the loading pressure at the point of rupture.Diaphragm correction (tare pressure) is achieved by inflatingthe diaphragm to the same distension recorded at burstin
26、g andrecording the amount of pressure to achieve this.7. Sampling7.1 Lot SampleAs a lot sample for acceptance testing,take at random the number of rolls of fabric directed in anapplicable material specification or other agreement betweenthe purchaser and the supplier. Consider rolls of fabric to be
27、theprimary sampling units.NOTE 5An adequate specification or other agreement between thepurchaser and the supplier requires taking into account the variabilitybetween rolls of fabric and between specimens from a swatch from a rollof fabric to provide a sampling plan with a meaningful producers risk,
28、consumers risk, acceptable quality level, and limiting quality level.7.2 Laboratory SampleAs a laboratory sample for accep-tance testing, take a full width swatch 1 m (1 yd) long from theend of each roll of fabric in the lot sample, after first discardinga minimum of1m(1yd)offabric from the very out
29、side of theroll. From each roll or piece of circular knit fabric selectedfrom the lot sample, cut a band at least 305 mm (1 ft) wide7.3 Test SpecimensCut ten test specimens from eachswatch in the laboratory sample with each specimen being 125mm (5 in.) square.8. Calibration8.1 Routine Verification o
30、f Testing MachineCheck theoperation of the testing machine at least once each month bybursting five specimens of standard aluminum sheet. Theaverage of the indicated bursting resistance for the fivespecimens of aluminum sheet should be between 65 % of thatmarked on the package of the pretested alumi
31、num sheetstandard.8.2 Calibration of Pressure Measuring System Calibratethe pressure measuring system, while inclined at the sameangle at which it is used, by means of a dead-weight tester ofthe piston type. Alternatively, a traceable electronic pressuregage may be used or other calibration instrume
32、ntation recom-mended by the equipment manufacturer. Such calibration ispreferably carried out with the gage in its normal position inthe tester.8.3 Where agreement is not attained, check the testeraccording to the instructions given in Tappi Method T-403OS-74.NOTE 6Possible causes of low readings ar
33、e gage error (bias ornonlinearity), gage expansivity too high, excessive gage pointer friction,air in hydraulic system or gage, diaphragm collapsed too far at zero, andlow pumping rate (hand-driven tester). Possible causes of high readingsare: gage error (bias nonlinearity), loose gage pointer (over
34、shoot), gagepointer bent by stop-pin, insufficient clamping force (slipping), nonuni-form clamping (partial slipping), stiff or inelastic diaphragm, diaphragmabove clamping plate at zero, multiple sheet testing, high pumping rate(hand-driven tester), and double bursts. If a gage is accidentally used
35、beyond its capacity, it must be recalibrated before it is used again.9. Conditioning9.1 Bring the specimens (or laboratory samples) from theprevailing atmosphere to moisture equilibrium for testing in thestandard atmosphere for textile testing as directed in PracticeD 1776.5Standardized aluminum she
36、ets are commercially available.D 3786 08a210. Selection and Number of Specimens10.1 Unless otherwise agreed upon, as when specified in anapplicable material specification, take ten specimens of thelaboratory sample(s) of fabric. Each specimen shall be at least125 mm (5 in.) square, or a circle 125 m
37、m (5 in.) in diameter.Specimens need not be cut for testing. No two specimens fromknitted fabric should contain the same wale or course yarns.Take no specimens nearer the selvage than one tenth the fabricwidth. This restriction does not apply to tubular knitted fabric.11. Procedure11.1 Make all test
38、s on specimens conditioned in the stan-dard atmosphere for testing textiles as directed in 9.1.11.2 Hand Driven Hydraulic Tester:11.2.1 Insert the conditioned specimen under the tripod,drawing the specimen taut across the plate, and clamp speci-men in place by bringing the clamping lever as far to t
39、he rightas possible.NOTE 7For specimens with considerable stretch, it may be necessaryto extend the fabric uniformly over the plate to remove some of the stretchbefore clamping.11.2.2 Rotate the hand wheel, clockwise at a uniform speedof 120 rpm until the specimen bursts.11.2.3 Stop turning the hand
40、 wheel at the instant of ruptureof the specimen (see Note 8).11.2.4 Immediately after rupture and in rapid succession,release the clamping lever over the specimen. Immediatelyrelease the strain on the diaphragm by turning the wheelcounterclockwise to its starting position and record the pres-sure re
41、quired to inflate the diaphragm (tare pressure). Recordthe total pressure required to rupture the specimen.NOTE 8If the pressure stops increasing, as indicated by the dial, andthe specimen has not broken, push the operating lever to remove thepressure. Record that the stretch of the fabric exceeds t
42、he dimensionallimitations of the tester. If slippage of the specimen is noted, discard theresult and use a new specimen.11.3 Motor-Driven Hydraulic Tester:11.3.1 Insert the specimen between the top and bottomclamp ensuring that the specimen is free from creases andfolds. Securely clamp the specimen
43、in place by following themanufacturers instructions appropriate to the machine. Applypressure to the specimen until it bursts.11.3.2 Diaphragm Correction (Tare Pressure)Using thesame settings as employed to burst the specimen, record thepressure required to distend only the diaphragm to the samepres
44、sure and height as used to burst the specimen. Record thisas the diaphragm correction (tare pressure).11.4 Pneumatic Tester:11.4.1 Adjust the control valve of the bursting tester so thatthe mean time to distend a specimen to burst falls within(20+/-5) s. Preliminary trials may be needed to fix the c
45、orrectsetting of the control valve. Time to burst is to be recordedbetween the beginning of vaulting and the bursting of the testspecimen.11.4.2 Clamp the specimen securely. Ensuring that thespecimen does not slip. Place the distension recording deviceinto the measuring position and adjust it to the
46、 zero position.Fasten the safety cover in position according to machinerequirements. Apply pressure to the test specimen until thefabric bursts.11.4.3 Diaphragm correction. With the same setting of thecontrol valve as that employed in the above tests, distend thediaphragm without the presence of a t
47、est specimen by anamount equal to the mean height at burst of the test specimen.Note the pressure at this distension of the diaphragm as the“diaphragm pressure”.12. Calculation12.1 Calculate the bursting pressure of each specimen bysubtracting the tare pressure required to inflate the diaphragmfrom
48、the total pressure required to rupture the specimen.12.2 Report the pressure reading of each individual speci-men and the average for each laboratory sampling unit and thelot.12.3 Report the type of bursting tester used.13. Report13.1 State that the specimens were tested as directed in TestMethod D
49、3786 using the Inflated Diaphragm Bursting Tester.Describe the material or product sampled and the method ofsampling used.13.2 Report the bursting strength of each individual speci-men and their average in kPa (psi).13.3 Report the type of bursting tester used.14. Precision and Bias14.1 SummaryIn comparing two averages of ten observa-tions each, the difference should not exceed the followingcritical differences in 95 out of 100 cases when both sets ofobservations are taken by the same well-trained operator usingthe same piece of test equipment and specimens
