1、Designation: D 774/D 774M 97 ( Reapproved 2002)An American National StandardStandard Test Method forBursting Strength of Paper1This standard is issued under the fixed designation D 774/D 774M; the number immediately following the designation indicates the yearof original adoption or, in the case of
2、revision, the year of last revision. A number in parentheses indicates the year of last reapproval.A superscript epsilon (e) indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1. Scope1.1 This test meth
3、od covers measurements of the burstingstrength of paper and paper products occurring as single orlaminated flat sheets not over 0.6 mm 0.025 in. in thicknesshaving a bursting strength of 30 kPa up to 1400 kPa 4 psi upto 200 psi.1.2 This test method is not intended for use in testingcorrugated boxboa
4、rd, liner board, or hardboards that tend to cutthe thin rubber diaphragm.NOTE 1Similar procedures for making bursting strength measure-ments are found in ISO 2758 and TAPPI 403.1.3 The values stated in either SI units or in other units shallbe regarded separately as standard. The values stated in ea
5、chsystem may not be exact equivalents; therefore, each systemmust be used independently of the other, without combiningvalues in any way.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 e
6、stablish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:D 585 Practice for Sampling and Accepting a Single Lot ofPaper, Paperboard, Fiberboard, or Related Products2D 646 Test Method for Gramma
7、ge of Paper and Paperboard(Weight per Unit Area)2D 685 Practice for Conditioning Paper and Paper Productsfor Testing2D 1968 Terminology Relating to Paper and Paper Products22.2 ISO Standard:ISO 2758 PaperDetermination of bursting strength32.3 TAPPI Standard:TAPPI T 403 Bursting strength of paper43.
8、Terminology3.1 Definitions: Definitions shall be in accordance withTerminology D 1968 and the Dictionary of Paper.44. Significance and Use4.1 Bursting strength is widely used as a measure of theresistance to rupture in many kinds of paper. The test isrelatively easy and inexpensive to make and appea
9、rs tosimulate some use requirements.5. Apparatus5.1 Bursting Tester, having the following features andauxiliary equipment:5.1.1 Clamp, for firmly and uniformly securing the testspecimen without slippage during the test (recommendedclamping load 2700 N 600 lb) between two annular, plane,parallel, and
10、 preferably stainless steel surfaces.5.1.1.1 The upper clamping surface (the clamping ring) hasa circular opening 30.50 6 0.05 mm 1.200 6 0.002 in. indiameter. The surface which is in contact with the paper duringtesting has a continuous, spiral, 60 V-groove, at least 0.25 mm0.010 in. deep and of 0.
11、8 mm 132 in. pitch, the groovestarting at 3.2 mm 18in. from the edge of the opening. Thecircular edge of the opening that is in contact with the paperduring testing is relieved of sharpness with a very fine abrasivecloth (such as crocus cloth) but not rounded off enough to alterthe diameter of the o
12、pening.5.1.1.2 The lower clamping surface (the diaphragm plate)has an opening 33.1 6 0.1 mm 1.302 6 0.003 in. in diameter.Its surface has a series of concentric 60 V-grooves 0.30 mm0.012 in. deep, 0.8 mm 132in. apart, the center of the firstgroove being 3.2 mm 18in. from the edge of the opening. The
13、thickness of the plate at the opening is 0.66 mm 0.026 in.The lower edge which is in contact with the rubber diaphragmis rounded to an arc of 6.4 mm 0.25 in. radius to preventcutting of the diaphragm when pressure is applied.5.1.1.3 The clamping ring is connected to a clampingmechanism through a swi
14、vel-type joint or other means to1This test method is under the jurisdiction of ASTM Committee D06 on Paperand Paper Products and is the direct responsibility of Subcommittee D06.92 on TestMethods.Current edition approved Dec. 10, 1997. Published November 1998. Originallyapproved in 1944. Last previo
15、us edition approved in 1996 as D 774 96a.2Annual Book of ASTM Standards, Vol 15.09.3Available from American National Standards Institute, 11 W. 42nd St., 13thFloor, New York, NY 10036.4Available from the Technical Association of the Pulp and Paper Industry,Technology Park/Atlanta P.O. Box 105113, At
16、lanta, GA 30348.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.ensure an even clamping pressure. During tests, the circularedges of the openings in the two clamping plates are requiredto be concentric to within 0.25 mm 0.01 in.NOTE
17、2Because the clamping mechanism and clamping surfaces aresubject to considerable wear or distortion, they should be examinedperiodically and repaired or replaced when necessary.5.1.2 Circular Diaphragm, of pure gum rubber, 0.85 6 0.05mm 0.034 6 0.002 in. thick. This is clamped between thelower clamp
18、ing plate and the rest of the apparatus, so thatbefore the diaphragm is stretched by pressure underneath, thecenter of its upper surface is below the plane of the clampingsurface. The pressure required to raise the free surface of thediaphragm 9 mm 38in. above the top surface of the diaphragmplate i
19、s required to be 306 5 kPa 4.3 6 0.8 psi. In testing, abridge gage may be used, the test being carried out with theclamping ring removed. The diaphragm should be inspectedfrequently for permanent distortion and, if distorted, replaced.5.1.3 Means of applying controlled, increasing, hydrostaticpressu
20、re by a fluid, at the rate of 95 6 5 mL/min to theunderside of the diaphragm until the specimen bursts. Therecommended fluid is USP (96 %) glycerin. Purified ethyleneglycol (the permanent types of radiator antifreeze with addi-tives are not satisfactory) may be substituted if desired.NOTE 3The hydra
21、ulic system, including the gages or transducers,must be mounted so as to be free from externally induced vibration.NOTE 4Because the bursting resistance of paper increases withincreased rate of loading, the rate of strain must be maintained effectivelyconstant to obtain reproducible results. Any air
22、 present in the hydraulicsystem of the tester will lower the rate of distortion of the specimen andmust be substantially removed. Air is most commonly trapped under therubber diaphragm and in the tubes of the gages. A simple method oftesting for the presence of excessive quantities of air is given i
23、n 8.3.5.1.4 Pressure Gage A maximum-reading pressure gageof the bourdon type, of appropriate capacity and with agraduated circular scale 95 mm 334 in. or more in diameter.5.1.4.1 The choice and characteristics of the gage are givenin Table 1. The 0 to 840 kPa 0 to 120 psi range gage may beused for a
24、ny test within its capacity, if so noted in the report.5.1.4.2 The expansibility of a gage is in the volume of liquidentering the gage tube per unit increase in pressure when air isabsent. It can be determined most conveniently by means of adilatometer device described by Tuck and Mason (1)5. Thegag
25、e expansibility must be within 15 % of the specified value.NOTE 5An appreciable flow of liquid into the gage occurs from thestart of the test to the instant of burst. A gage, therefore, reduces the rateof distension of the specimen by an amount depending upon its expansi-bility. When a number of gag
26、es are mounted on a single apparatus, caremust be taken that only the gage on which the measurement is being madeis open to the hydraulic system; otherwise an erroneously low burstpressure will be recorded.5.1.4.3 To avoid overloading and possible damage to thegage, a preliminary bursting test shoul
27、d be made with ahigh-capacity gage.5.1.5 As an alternative, a pressure transducer which con-nects to the tester in the same manner as the gage along withits necessary signal processing circuitry may be used. Thistransducer displays the results in a digital form, and in addition,may provide an output
28、 for communication with various dataprocessing devices (and can be substituted for the pressuregage in 5.1.4).5.1.5.1 Typical transducer ranges are shown in Table 2.5.1.5.2 To avoid overloading and possibly damaging thetransducer, a preliminary bursting test should be made with ahigh-capacity transd
29、ucer.6. Sampling6.1 Obtain the sample for testing in accordance with Prac-tice D 585.7. Test Specimens7.1 Not less than 20 specimens, each at least 64 by 64 mm(2.5 by 2.5 in.), shall be obtained from each test unit of thesample, so as to be representative of the test unit.8. Calibration and Maintena
30、nce8.1 Calibrate the pressure-indicating device by means of adead-weight tester of the piston type. If the device is aBourdon-type gage, it must be calibrated while inclined at thesame angle at which it is to be used. Preferably, calibrate withthe gage in its normal position. For an instrument error
31、 of lessthan 3 %, calibrate the pressure-indicating device in such amanner that known pressures are applied dynamically atapproximately the same rate as in testing of paper. Maximumreading pressure devices are subject to dynamic errors as wellas ordinary static calibration errors. A suitable method
32、ofdynamic calibration for greater precision is described in Tucket al. (2).8.1.1 Calibrate gages in frequent use at least once a month.If a gage is accidentally used beyond its capacity, recalibratebefore it is used again.8.2 Calibration of Transducer/Readout SystemCalibratethe transducer can be cal
33、ibrated on the same device as is usedto calibrate gages.8.2.1 Calibrate transducers in frequent use should be cali-brated at least once a month.5The boldface numbers in parentheses refer to the list of references at the end ofthis test method.TABLE 1 Gage CharacteristicsRange of bursting pressure Ra
34、nge of gage Scale graduation intervals Expansibility of gagekPa psi kPa psi kPa psi mL/kPa mL/psi2877 411 0105 015 0.7 0.156161 823 0210 030 1.5 0.2 0.080 0.011105135 1545 0420 060 3.5 0.5 0.050 0.007210630 3090 0840 0120 3.5 0.5 0.030 0.0045251575 75225 02100 0300 14.0 2.0 0.007 0.001D 774/D 774M 9
35、7 ( Reapproved 2002)28.3 Check for air in system. Any time that maintenance iscarried out on the apparatus that could allow air to enter thehydraulic system, take steps to ensure that all of the air hasbeen removed.8.3.1 To determine if there is air in the system, first applypressure as described in
36、 5.1.2 to raise the diaphragm 9 mm (38in.) above the top of the diaphragm plate and hold for 1 min.Any air trapped between the diaphragm and the fluid will showup as a white spot under the surface of the diaphragm. If thisoccurs, reinstall the diaphragm.8.3.2 Observe the pressure developed. Pressure
37、s less thanthe following indicate the presence of excessive quantities ofair in the system (or erroneous gage expansibilities in aninstrument equipped with a gage).Gage Range Pressure Developed, kPa psi0 to 30 83 120 to 60 138 200 to 120 241 350 to 300 621 908.3.3 A gradual loss in the pressure obta
38、ined indicates a leakin the system; correct this.8.3.4 After changing the diaphragm, if it is necessary topurge air from the rest of the hydraulic system, clamp a pieceof sheet metal over the diaphragm so that it cannot distend.Remove the cap from the bleeder valve adjacent to the gage ortransducer.
39、 By means of a special device for forcing hydraulicfluid into the system or by manually operating the hydraulicsystem, force the hydraulic fluid through the system until itemerges from the bleeder valve with an even flow and noevidence of free air bubbles are observed. Replace the cap onthe bleeder
40、valve before the fluid stops flowing. Remove sheetmetal from clamping device and check diaphragm height,adjusting if necessary.9. Conditioning9.1 Condition the sample in accordance with PracticeD 685, and make all tests in the same standard atmosphere.10. Procedure10.1 Unless the approximate strengt
41、h of the paper undertesting is known, make a preliminary test to determine therequired capacity of the measuring device (gage or transducer)being used. See Table 1 and Table 2. To avoid overload andpossible damage to a measuring device, begin the preliminarybursting tests with a high-capacity gage.
42、See 5.1.10.2 Clamp the specimen securely in position, apply thehydrostatic pressure as specified in 5.1.3 until the specimenruptures, and record the maximum registered by the pressuregage. Watch carefully for any movement (buckling) of theunclamped margin of the specimen. If slippage is indicated,di
43、scard the test and increase the clamping pressure for subse-quent tests.10.3 Make at least ten acceptable tests, applying an equalnumber to each side of the paper. Make no tests on areascontaining watermarks, creases, imperfections, or visible dam-age.10.4 After each test, return the measuring devic
44、e to zero.For the gage unit, this involves gently returning the indicatorneedle to the zero point.11. Calculation11.1 Calculate bursting strength as the arithmetic mean ofthe test results (corrected for any gage error) on each sample.11.2 To convert burst in psi (or points) to burst in kPa, usethe f
45、ollowing conversion: burst (psi) 3 6.8948 = burst (kPa).11.3 The following additional calculations are sometimesrequested on burst test data. Determine grammage (basisweight) as described in Test Method D 646.Burst index 5burst, kPagrammage, g/m2Burst factor 5burst, g/cm2grammage, g/m2usually oven d
46、ry!Burst ratio 5burst, psibasis weight, lb/reamBurst ratio is sometimes called “points per pound.”11.4 The mathematical relationship between burst factorand burst index (see 11.3) is as follows:Burst factorSg/cm2g/m2D3 9.8067 3 10225 Burst indexSkPag/m2D12. Report12.1 Report the following informatio
47、n:12.1.1 Bursting strength in kilopascals (or pounds persquare inch) as the arithmetical mean, corrected for any gageerror, to three significant figures.12.1.1.1 Upon agreement of parties involved in the testing,results may be reported with units of “points.” See 3.1.2.12.1.2 Number of tests made.12
48、.1.3 Maximum and minimum values of acceptable re-sults.12.1.4 Type of instrument used, including whether equippedwith a gage or pressure transducer.13. Precision and Bias13.1 Precision:13.1.1 Repeatability (within a laboratory) = 5.4 %.13.1.2 Comparability (between materials) = 9.5 %.13.1.3 Reproduc
49、ibility (between laboratories) = 14.3 %.13.1.4 These values are based on data obtained in aninterlaboratory study (3) among 50 laboratories, on 34 mate-rials using Perkins Model C instruments.13.2 BiasThe procedure in this test method has no biasbecause the value of bursting strength is defined only in termsof the test method.TABLE 2 Transducer/Digital Readout CharacteristicsRange of bursting pressure Range of transducer AccuracykPa psi kPa psi kPa psi5300 250 0300 050 1.0 0.255500 2100 0500
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