ASTM_D_781_-_68_1973_scan.pdf

J Designation:D 781-68(Reapproved 1973)Technical Association of Pulp and Paper Industry Standard Method T 803 m-50 AMERICAN SOCIETY FOR TESTING AND MATERIALS 1916 Race St.,Philadelphia,Pa.19103 Reprinted from the Annual Book of ASTM Standards,Copyright ASTM If not listed in the current combined index,will appear in the next edition.Standard Test Methods for PUNCTURE AND STIFFNESS OF PAPERBOARD,AND CORRUGATED AND SOLID FIBERBOARD1 This Standard is issued under the fixed designation D 781;the number immediately following the designation indicates the year of original adoption or.in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.l.Scope 1.1 These methods cover the determination of puncture and stiffness of paperboard and corrugated and solid fiberboard.1.2 The methods appear in the following order:Puncture Test Stiffness Test PUNCTURE TEST 2.Significance Sections 2 to 7 8 to 12 2.1 The puncture test(also known as the Beach or G.E.Puncture test)measures the resistance of board in either single sheets(that is,components)or in combined form to punc-ture.Such puncture may result from contact with solid objects such as a corner of a box,or the like.The unit measured by the instrument is the energy required to puncture the contain-erboard in the designated manner(one unit equals 0.265 in-lb(0.305 cm kg).These units are actually made up of several components,the principal ones being the energy required to tear the material and the energy required to bend it out of the way of the point.By conducting both puncture and stiffness tests(see Section 8)on the same lot of material,the relative contribution of the tearing and the stiffness may be evaluated.2.2 The test evaluates in a composite fash-ion some fabrication factors and material values,although it is not possible to isolate the two specifically,3.Apparatus(Fig.I)3.1 Pendulum,incorporating an arm in the 207 form of an arc of 90 deg.3.2 Puncture Point,affixed to the end of the arm and having the shape of a right angle triangular pyramid I in.(25 mm)in height with rounded leading edges of 0.062 0.002-in.(1.57 0.05-mm)radius.The point shall be honed to a 0.062-in.radius and base edges left sharp,3.3 Puncture Point Collar,loose fitting around the base of the puncture point to avoid friction that would result if the punctured material rubbed against the puncture arm.3.4 Trigger or Latch,to hold the pendulum in the horizontal position.3.5 Clamping Jaws,spring-actuated,for holding the specimen to be tested.3.6 Pointer and Scale,to indicate the arc through which the pendulum travels after penetrating through the specimen.3.7 Weights,which when attached,give a maximum scale value of at least 1300 units of energy when the pendulum is in the horizontal position,and scale graduations to correspond to the weights used,NOTE-Modified machines having greater range are available.3.8 Loose Plate,inserted between the clamping jaws for the purpose of defining the test area.Means shall be provided for securing the removable plate once it has been properly positioned(see 4,I.7).The loose plate shall be removed when checking the zero reading of the apparatus.These methods are under the jurisdiction of ASTM Committee D-6 on Paper and Paper Products.Current edition accepted Sept.13,1968.Originally issued I 944.Replaces D 78 I-65 T.NOTICE:This standard has either been superseded and replaced by a new version or discontinued.Contact ASTM International(www.astm.org)for the latest information.3.9 Adjustable Screws,bearing against the pointer assembly during the measuring half of the pendulum swing,permitting adjustment of the full-scale position of the pointer.3.10 Release Attachments-For testing lighter materials,the apparatus can be sup-plied with an attachment that allows the re-lease of the pendulum at a 45-deg angle.An auxiliary low scale is also supplied which,when attached to the standard scale plate,provides additional calibration from Oto 30 and allows reading to half a unit.4.Adjustment of Apparatus 4.1 Install the apparatus on a rigid,heavy foundation of convenient height,bolt it in place,and level it in both horizontal directions.To eliminate the influence of extraneous move-ment during the swing of the pendulum,the mount should be a separate concrete base.Make adjustments of the apparatus with the entire clamping assembly unbolted and swung on a hinge away from the path of the pen-dulum.On older instruments the assembly must be removed completely from the ma-chine.4.1.1 Pendulum Friction-Remove the weights and weight support stud,put the puncture point collar in place on the point,rotate the pointer to a position below the zero mark,and then latch and release the pen-dulum.The pendulum should swing for a minimum of 8 min before coming to rest.4.1.2 Zero Reading-To check zero,re-move the weights and weight support stud;fix the puncture point collar on the base of the puncture point.Allow the pendulum to hang vertically on