1、Designation: D 5650 97 (Reapproved 2002)An American National StandardStandard Test Method forResistance to Bending of Paper of Low Bending Stiffness(Taber-Type Tester in 0 to 10 Taber Stiffness UnitConfiguration)1This standard is issued under the fixed designation D 5650; the number immediately foll
2、owing the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test metho
3、d covers a procedure used to measure theresistance to bending of papers which are of low grammage orhigh flexibility, or both, and which exhibit bending stiffness inthe range from 0 to 10 Taber stiffness units.1.2 The bending moment required to deflect the free end ofa 38-mm (1.5-in.) wide verticall
4、y clamped specimen 15 fromits center line when the load is applied 10 mm (0.39 in.) awayfrom the clamp is determined. The resistance to bending iscalculated from the bending moment.1.3 The instrument used in this test method is identical tothat described in Test Method D 5342, used in the modifiedco
5、nfiguration described in Section 9.1.4 Test results obtained using the Taber-Type tester asdescribed in this test method have been reported to be as muchas 40 % different from those obtained using Test MethodD 5342, and this test method shall not be used where TestMethod D 5342 is specified.1.5 This
6、 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 determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents
7、2.1 ASTM Standards:D 585 Practice for Sampling and Accepting a Single Lot ofPaper, Paperboard, Fiberboard, or Related Products2D 685 Practice for Conditioning Paper and Paper Productsfor Testing2D 1968 Terminology Relating to Paper and Paper Products2D 5342 Test Method for Resistance to Bending of P
8、aper andPaperboard (Taber-Type Tester in Basic Configuration)2E 122 Practice for Calculating Sample Size to Estimate,With a Specified Tolerable Error, the Average for Charac-teristic of a Lot or Process33. Terminology3.1 DefinitionsDefinitions shall be in accordance withTerminology D 1968 and the Di
9、ctionary of Paper.44. Summary of Test Method4.1 A test specimen of defined dimensions is bent through aspecified angle using a specific testing instrument. The result-ing bending moment is read from the instrument scale.4.2 The resistance to bending can be calculated from thebending moment.5. Signif
10、icance and Use5.1 Bending resistance of paper relates to a number of enduse applications including wrapping, printing, copy machineperformance, high speed mechanical handling of documents,and other applications.6. Apparatus6.1 Description:6.1.1 The basic instrument that has been used for the testdes
11、cribed in this test method for nearly fifty years is a manuallyoperated (crank-driven) instrument. Over the years, variousimprovements in the basic instrument have been made forimproved ease of use or greater reproducibility of data, or both.These improvements include replacement of the manual(crank
12、) drive system with a constant speed motor, addition ofautomatic data determination, and automated instrument (mo-tor sequencing) operation. Fig. 1 shows the motor-drivenversion of the instrument (see 6.1.2). It is the motor-drivenmodel of the basic instrument that is the basis for this testmethod.
13、However, any of the instrument variations describedin this section, when properly calibrated and operated, shouldyield the same result. The components of the basic instrumentcan be seen in Fig. 1 as follows:6.1.1.1 A pendulum (A) supported in antifriction in bear-ings, carrying a vise (C) that has t
14、wo clamping screws for1This 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 1995. Last previous edition
15、 approved in 1995 as D 565095.2Annual Book of ASTM Standards, Vol 15.09.3Annual Book of ASTM Standards, Vol 14.02.4Available from the Technical Association of the Pulp and Paper Industry, P.O.Box 105113, Atlanta, GA 30348.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Consho
16、hocken, PA 19428-2959, United States.holding and centering the test specimen, the lower edge of thevise coinciding with the center of the pendulum bearing. Thependulum is balanced, and at its lower end is a stud (D) towhich weights may be attached and that loads the pendulum ata distance of 100 6 0.
17、025 mm (3.94 in.) from its center;without added weights the loading is 10 6 0.001 g. A line (E)coinciding with the center line of the vise jaws and the weightstud (D), is engraved at the upper end of the pendulum.6.1.1.2 A vertical disk (F), driven on the same axis as thependulum by a driving mechan
18、ism, carries two driving armattachments (G) so located as to provide the specimen with acantilevered loading length of 50 6 0.025 mm (1.97 in.) whenit is deflected 15. Fig. 1 does not show the crankdrivingmechanism. The driving arms have rollers (H) that are adjust-able to accommodate specimens of d
19、ifferent thicknesses. Onthe periphery of the upper part of the disk is a marked line (J)coinciding with the center line between the driving rollers (H)and the axis, and two reference lines (K and L) are engraved onthe periphery of the disk at angular distances of 7.5 and 15 onboth sides of the cente
20、r mark (J).6.1.1.3 Located around the periphery of the disk (F) is afixed annular disk (M) with a load scale from 0 to 100 on bothsides of a zero point that is adjusted to coincide with the centerline mark (J), the scale indicating the bending moment requiredto flex the specimen to the right or to t
21、he left, the divisionsbeing in accordance with the sine of the angle through whichthe pendulum and weight are turned.6.1.1.4 Various loading weights (P) for the pendulum, togive a maximum bending moment of 5000 g-cm (490 mNm).6.1.1.5 A 10 Unit compensating weight (X) to be mountedon the stud (Y) nea
22、r the top of the pendulum when theinstrument is used as described in this test method.6.1.2 For operator convenience and improved testing repro-ducibility, the “driving mechanism” (crank) of the basic unitwas replaced by a motor to drive the vertical disk (F) at aconstant rate of 210 6 20 per minute
23、. Other than this change,the motor-driven instrument has the components of the “basicinstrument” in accordance with 6.1.1. The motor is reversibleusing the switch (N), that preferably also operates an electricbrake to stop the disk at any point on the scale. The motor-driven version of the instrumen
24、t shown in Fig. 1 is theinstrument in most wide use today, and is the basis of this testmethod.6.1.3 More recently, automated versions of the basic instru-ment have become available. These are two types: automaticreading of results (only), and automation of instrument opera-tion as well as reading o
25、f results.6.1.3.1 Devices are available that may be retrofitted to thebasic instrument for automatically determining and recordingthe scale readings (see section 10.2 ). Results are displayed ona digital readout device. In addition, the retrofitted unit mayprovide a signal output suitable for transm
26、ission to a stand-alone printer or an integrated acquisition system.6.1.3.2 Totally automated versions of the basic motor-driveninstrument (see 6.1.2), incorporating the components describedin 6.1.2.1 , and in addition automatically controlling the entiresequence of operations described in 10.2 , ar
27、e also available.7. Sampling7.1 Acceptance SamplingAcceptance sampling shall bedone in accordance with Practice D 585.7.2 Sampling for Other PurposesThe sampling and thenumber of test specimens depends upon the purpose of thetesting. Practice E 122 is recommended.7.3 In sampling, take care not to be
28、nd, roll, score, orotherwise damage the area to be tested.8. Test Specimens8.1 From each test unit, cut ten square test specimens38.1 6 0.3 mm (1.50 6 0.01 in.) in each dimension. At thevery edge of each test specimen, mark or in some other wayidentify the machine direction of each square specimen,
29、beingcareful not to damage the specimens in any way. All cutspecimens must be free from scores or blemishes. A specialcutter for cutting the samples may be available from thevendor, or a high-precision cutting board may be used.9. Preparation of Apparatus9.1 Place the instrument on a firm, level sur
30、face. A standardlaboratory bench is generally quite satisfactory and should bechecked with a carpenters level to verify that it is level(front-to-back, side-to-side) when the instrument is initiallyinstalled. Set the loading disk (F) at zero and place a chosenweight (P) on the pendulum stud. If poss
31、ible, choose a weightsuch that the resulting readings for the specimen to be testedare near the center of the measured test range. Close the twojaws of the vice (C) to meet on the center line of the pendulumand adjust the legs of the instrument so that the engraved mark(E) coincides with zero on the
32、 scale of M. Level the instrumentfront to back as well as side to side.9.2 Displace the pendulum 15 and release it to check thebearing friction. It should make at least 20 complete swingsbefore coming to rest. If it does not, check for obviouscontamination by dust particles. In the absence of any ob
33、viousproblem, contact the vendor to arrange service or maintenance.9.3 If the instrument has a brake, check that it functionsproperly. It should “freeze” (stop and securely hold) therotating disk (F) in place within less than a second of itsFIG. 1 Stiffness InstrumentD 5650 97 (2002)2application so
34、that the result can be easily determined. (Opera-tion of the brake on the automated instrument is automaticallycontrolled as part of the automatic reversal from clockwise tocounterclockwise (or vice versa) rotation.)9.4 Conversion of the Instrument to the 0 to 10 TaberStiffness Unit Range:9.4.1 Remo
35、ve and invert the roller assemblies (right andleft), in accordance with the manual for the instrument beingused, changing the effective test length of the from the 50 mmrequired in Test Method D 5342 to the 10 mm required in thistest method.9.4.2 Place the 10 Unit compensator weight on the stud near
36、the top of the pendulum.10. Calibration10.1 Calibrate the instrument and check the accuracy of theapparatus at regular intervals. The method of calibrationdepends on the type of instrument and done following themanufacturers instructions for the instrument used. Springsteel test pieces supplied by t
37、he manufacturer of the instrumentfor calibration purposes are generally used. If readings withinthe tolerance suggested by the manufacturer are not achieved,it may be necessary to return the instrument for servicing.11. Conditioning11.1 Condition the specimens and make the tests in anatmosphere in a
38、ccordance with Practice D 685.12. Procedure12.1 Place a conditioned test specimen in the vise (C) withone end approximately level with its top edge and the other endbetween the rollers (H).12.2 With the two clamping screws of the vise (C), align thespecimen with the center line of the pendulum.12.2.
39、1 Pressure of the clamping screws may impact testresults, and clamping pressure should be firm enough to holdthe specimen, but not so firm as to compress or deform it.NOTE 1At the present time, use of calibration spring steel orspecimens of samples of known stiffness as determined by this test metho
40、dare the only recommendations for determining if vise pressure is so greator so slight that test results are affected adversely.12.3 Turn each of the screws for adjusting the rollers (H) sothat they just contact the specimen. Then, after taking up thebacklash in one screw, back off one-quarter turn
41、to give adistance between rollers of 0.33 + 0.03 mm (0.013 + 0.001in.) greater than the thickness of the specimen.NOTE 2On instruments not equipped with adjustable rollers (H), usethe appropriate set of rollers for the thickness of the board to be tested.NOTE 3It is not necessary for the pendulum to
42、 balance at zero withthe undeflected specimen in place. Curvature of the specimen will resultin a difference between the two readings which are averaged to give thestiffness of the specimen. This difference has been used as a measure ofcurl, but this should be done with caution, as this difference m
43、ay alsoreflect a genuine difference in stiffness between the two orientations of thespecimen with respect to the deflecting force. If the specimen is so badlycurled that both readings fall on the same side of zero, take the lowerreading as negative when calculating the average, but include mention o
44、fthis occurrence in the report, as this much curl may make the materialuseless for its intended purpose.12.4 For the Basic Motor-Driven InstrumentSwitch onthe motor to rotate the loading disk (F) to the left and thusdeflect the specimen until the engraved mark (E) on thependulum is aligned with the
45、15 mark (L) on the loading disk.Stop the motor, record the scale reading on the fixed annulardisk (M) and immediately return the loading disk to zero (seeNote 3). Take a similar reading by deflecting the specimen tothe right. The stiffness of the specimen is taken as the averageof the two readings m
46、ultiplied by the factor required for theinstrument range weight used (see the manufacturers instruc-tions). Test five specimens cut in each direction.NOTE 4When the motor is “stopped,” an electric brake immediatelystops the disk and holds it in place so a reading can be taken. Oninstruments not equi
47、pped with an electric brake, take the reading as thedisk rotates over the end point.12.4.1 For the basic motor-driven instrument retrofitted withdigital readout, the scale readings are automatically “captured”and are recorded from a digital display. The motor is started,stopped, and reversed in acco
48、rdance with 12.4.12.5 For the Automated InstrumentThe operations de-scribed in 12.4 are automatically done in sequence after the testis initiated. Scale readings (left and right) are displayed on theinstrument readout.13. Calculation13.1 Bending Moment Calculate the bending moment asthe average of t
49、he two readings (left and right deflection)multiplied by 0.10, the factor required when the 10 Unitcompensator weight is used.13.2 Where SI results are desired, convert the value instiffness to millinewton metres by multiplying by 0.098066.13.3 Resistance to BendingDivide the bending moment(mNm) by the length (m). Result is force (mN) required todeflect the sample through the specified distance. (Length(m) = 0.010 metres)14. Report14.1 Report the following information:14.1.1 Bending Moment:14.1.1.1 The average value in stiffness units or millinewtonmetres of the s
