1、Designation: D689 17Standard Test Method forInternal Tearing Resistance of Paper1This standard is issued under the fixed designation D689; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in paren
2、theses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope1.1 This test method measures the force perpendicular to theplane of
3、 the paper required to tear multiple sheets of paperthrough a specified distance after the tear has been started,using an Elmendorf-type tearing tester. The measured resultscan be used to calculate the approximate tearing resistance ofa single sheet. In the case of tearing a single sheet of paper, t
4、hetearing resistance is measured directly.NOTE 1Similar procedures for making Elmendorf-type tear measure-ments are found in ISO 1974 and TAPPI T414.1.2 This test method is not suitable for determining thecross-directional tearing resistance of highly directional boardsand papers.1.3 This standard d
5、oes 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, health and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This internatio
6、nal standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade (TBT) Commit
7、tee.2. Referenced Documents2.1 ASTM Standards:2D646 Test Method for Mass Per Unit Area of Paper andPaperboard of Aramid Papers (Basis Weight)D685 Practice for Conditioning Paper and Paper Productsfor TestingD1749 Practice for Interlaboratory Evaluation of Test Meth-ods Used with Paper and Paper Prod
8、ucts (Withdrawn2010)3E178 Practice for Dealing With Outlying Observations2.2 ISO Standard:4ISO 1974 PaperDetermination of Tearing Resistance (El-mendorf method)2.3 TAPPI Standard:5TAPPI T414 Internal Tearing Resistance of Paper3. Summary of Test Method3.1 One or more sheets of the sample material ar
9、e torntogether through a fixed distance by means of the pendulum ofan Elmendorf-type tearing tester. The work done in tearing ismeasured by the loss in potential energy of the pendulum. Theinstrument scale is calibrated to indicate the average forceexerted when a certain number of plies are torn tog
10、ether (workdone divided by the total distance torn).4. Significance and Use4.1 This test method is widely used within the paperindustry, in conjunction with other tests of strength, as apredictor of end-use performance of a wide range of grades ofpapers.5. Apparatus5.1 Elmendorf-type Tearing TesterS
11、everal types are avail-able and in use throughout the world, principally those ofAustralian, British, German, Swedish, and United States manu-facture. In addition, testing practices also vary.5.2 Instrumental and Procedural VariablesInstrumentsand practices in use vary in at least two major respects
12、:5.2.1 The Design of the Specimen ClampsTogether withthe structural characteristics of the paper governing the natureof the tear with respect to its splitting tendencies during thetest, this has an appreciable influence on the mode of tearing1This test method is under the jurisdiction of ASTM Commit
13、tee D09 onElectrical and Electronic Insulating Materials and is the direct responsibility ofSubcommittee D09.01 on Electrical Insulating Products.Current edition approved Sept. 1, 2017. Published September 2017. Originallycreated by ASTM Committee D06.92 Paper and Paper Products and approved in1942.
14、 Last previous edition approved in 2003 as as D4363 03 which waswithdrawn December 2009 and reinstated September 2017. DOI: 10.1520/D0689-17.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volu
15、me information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.4Available from American National Standards Institute, 25 W. 43rd St., 4thFloor, New York, NY 10036.5Available from the TechnicalAssocia
16、tion of the Pulp and Paper Industrial, P.O.Box 105113, Atlanta, GA 30348.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis international standard was developed in accordance with internationally recognized principles on standardizat
17、ion established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.1and can result in significant differences (1)6. The proceduredescribed in 5.3.7 reduces this eff
18、ect. The clamp designs usedby some manufacturers can vary even for their own models.Instruments are available with pneumatically activated grips aswell, which minimizes variations due to differences in clamp-ing pressures exerted by manually tightened grips.5.2.2 A Combined Variation in Testers and
19、TestingPracticesAs measured tearing resistance increases or de-creases for different types of paper, the measurement canbecome so large or so small as to be outside the practical rangeof the instrument. This problem can be overcome in one of twoways; change the number of sample sheets tested at one
20、time tobe changed, or the mass of the instrument pendulum can bechanged either by adding augmenting weights or by replacingthe entire pendulum with one of a different known mass. Thetearing length must never be varied in an effort to alter thependulum capacity.5.2.3 These differences, together with
21、other lesser differ-ences in design details between instruments or testing prac-tices, preclude specifying a tearing instrument and method thatwould give essentially the same test results when usingElmendorf instruments of different design and manufacture.Even for one specific model, some procedural
22、 variables such asthe number of plies torn can alter the test values calculated ona single sheet basis substantially. By necessity, this referencemethod must be arbitrary and is limited to the describedprocedure used with instruments conforming to all of therequirements specified under 5.3.5.3 Requi
23、red Instrument for this Test Method:5.3.1 Elmendorf Tearing Tester (2, 3, 4), with a cutout asshown in Fig. 1, which prevents the specimen from coming incontact with the pendulum sector during the test, and havingthe following elements:5.3.2 Stationary and Movable ClampThe movable clampis carried on
24、 a pendulum formed by a sector of a circle free toswing on a ball bearing.5.3.3 Knife, mounted on a stationary post for starting thetear.5.3.4 Means for Leveling the Instrument.5.3.5 Pendulum HolderMeans for holding the pendulumin a raised position and for releasing it instantaneously.5.3.6 Means fo
25、r Registering the Maximum Arc throughwhich the pendulum swings when released. The registeringmeans can consist of a graduated scale mounted on thependulum, a pointer mounted on the same axis as the pendulumwith constant friction just sufficient to stop the pointer at thehighest point reached by the
26、swing of the sector, and anadjustable pointer stop for setting the zero of the instrument.5.3.6.1 The pointer and scale can be replaced by a digitalreadout unit which gives readings of equivalent accuracy andprecision (5).5.3.7 With the pendulum in its initial position ready for atest, the clamps ar
27、e separated by an interval of 2.8 6 0.3 mmand are so aligned that the specimen clamped in them lies in aplane parallel to the axis of the pendulum, the plane making anangle of 27.5 6 0.5 with the perpendicular line joining theaxis and the horizontal line formed by the top edges of theclamping jaws.T
28、he distance between the axis and the top edgesof the clamping jaws is 103.0 6 0.1 mm. The clamping surfacein each jaw is at least 25 mm wide and 15.9 6 0.1 mm deep.NOTE 2In the past, it has been the practice for instruments commonlyavailable in the United States to be equipped with 36 6 1 mm wide ja
29、ws.It is possible for instruments currently available to be equipped with jawsas narrow as 25 mm. Testing has shown that the effect of jaw width on testresults is statistically insignificant. It is recommended, however, that thetest specimen length be adjusted to match jaw width. See Note 3.5.3.8 Th
30、e instrument measures the energy (work done) usedby the pendulum in tearing the test specimen. In order toconvert to average tearing force, the energy must be divided bythe total distance through which the force is applied. Thisdivision can be accomplished by the electronics in digitalreadout instru
31、ments so that the readout is directly in grams-force or in millinewtons (SI unit of force). For pointer andscale instruments, the scale could be in millinewtons or ingrams-force for a specified number of plies; for example, whenthe specified number of plies are torn together, the scalereading gives
32、the average tearing resistance (force) of a singleply.5.3.9 Instruments of several capacities (2000, 4000, 8000,16 000 32 000 mN (200, 400, 800, 1600, 3200 gf) and perhapsothers are available, with the several capacities being achievedby individual instruments, interchangeable pendulum sectors,or au
33、gmenting weights. The instrument recognized as “stan-dard” for this test method has a capacity of 1600 gf (15.7 N),6The boldface numbers in parentheses refer to the list of references at the end ofthis standard.FIG. 1 Newer Testing Model with Deep CutoutD689 172having a pendulum sector of such mass
34、and mass distributionthat its 0 to 100 scale is direct reading in grams-force per plywhen 16 plies are torn together. For a 16-ply test specimen, thetearing distance K = 16 4.3 cm (tearing distance per ply) 2= 137.6 cm. The factor 2 is included since in tearing a givenlength the force is applied twi
35、ce the distance. Likewise, for a16-ply test specimen, the tearing energy per ply for a scalereading of 100 would then be 100 gf 137.6 cm or 13 760gfcm (1349.4 mJ). For some of the instruments of differentcapacities where different numbers of plies are required, orwhen the number of plies tested usin
36、g the “standard” instru-ment differs from 16, different values of K or the tearing energyper ply, or both, can be calculated.5.3.10 n the “standard” instrument, the zero reading on thescale is at about 70 from the center line (that is, the verticalbalance line when the pendulum hangs freely), the 10
37、0 readingis at about 21 from the center line, and a vertical force of1057.3 6 2.0 gf (10.369 6 0.020 N) applied at 22.000 60.005 cm from the pendulum axis is required to hold thependulum sector at 90 from its freely hanging position. Othertearing instruments will require vertical forces that are fac
38、torsof 2 greater or smaller than 1057.3 gf and, if calibrated inmillin- ewtons, the zero reading would remain at 70 and the1000 reading would be at about 19 (or the 981 reading atabout 21).5.3.11 The cutting knife for the test specimen is centeredbetween the clamps and adjusted in height so that the
39、 tearingdistance is 43.0 6 0.2 mm; for example, the distance betweenthe end of the slit made by the knife and the upper edge of thespecimen is 43.0 6 0.2 mm when the lower edge of the63.0-mm wide specimen rests against the bottom of the clamp.5.4 Instruments are available for automated testing thati
40、ncorporates automatic sample insertion, automatic samplecutting, and so forth, in addition to electronic data readout asspecified in 5.3.4. These automated instruments can be used,provided the conditions specified in 5.3 are met.5.5 Specimen Cutter, to ensure parallel specimens 63 60.15 mm wide with
41、 sharp and clean edges. For this purpose, itis desirable to use the type having two hardened and groundbase shears, twin knives tensioned against the base shears, anda hold-down mechanism.6. Sampling and Test Specimens6.1 Obtain the sample to be tested in accordance withMethods D585.6.2 From each te
42、st unit of the sample, prepare ten represen-tative specimens in each principal direction of the paper, unlessa test in only one direction is required. For each specimen,arbitrarily designate one side of the material in some way, suchas “primary side”, “print side”, “wire side”, “side one”, and sofor
43、th. For each specimen, keep the designated sides of all theplies facing the same way.NOTE 3It has been found (6) that there is usually no advantage intesting more than ten specimens of a homogeneous test unit of the sample.6.3 Cut each ply for a test specimen so that its dimension onthe side placed
44、in the clamps is at least 53 mm and thedimension through which the tear will be propagated is 63.0 60.15 mm. Take all the plies to be torn together from a singlesheet. If sufficient material is not provided, take from adjacentsheets of a unit.NOTE 4The correct dimension for the side of the test spec
45、imen thatwill be placed in the clamps is equal to the distance between the outermostedges of each of the instruments jaws (62 mm). For the instrumentdescribed in 5.3, that distance is at least225mm(the minimum widthfor each jaw face) plus 2.8 mm (the distance between the clamps) or atleast 53 mm. In
46、 the United States, the majority of the instruments havejaws 36+1mmwide. A dimension of 76 6 2.0 mm for the side of thesample to be held in the clamps is correct.7. Calibration and Adjustment7.1 As noted in Section 5, several Elmendorf-type testersare available and in use at the present time. Minor
47、differencesin calibration or adjustment procedures, or both, can apply toinstruments obtained from different vendors that comply with5.3, thus it is questionable that specific calibration procedurescan be used for all instruments complying with 5.3. Theinformation contained in this section is to be
48、used as a guide inplacing an individual instrument into proper calibration for usein performing the test.7.2 Verification of ScaleOnce the scale has been verified,it is unnecessary to repeat this step, provided the tester is keptin adjustment and no parts become changed or perceptiblyworn. The scale
49、 can be verified either by the potential energymethod or by the method which uses the check weightsobtainable from the manufacturer. The potential energy methodis relatively time-consuming and complicated. The checkweight method is relatively simple.7.2.1 Potential Energy MethodThe procedure (7) for veri-fication is as follows: Anchor and level the tester. Clamp aknown weight (in grams), W, to the radial edge of the sectorbeneath the jaws, the center of gravity of the weight (includingmeans of attaching) having been previously marked by apunched dot on
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