ISO 9895-2008 Paper and board - Compressive strength - Short-span test《纸和纸板 抗压强度 短距试验》.pdf

1、 Reference number ISO 9895:2008(E) ISO 2008INTERNATIONAL STANDARD ISO 9895 Second edition 2008-10-15 Paper and board Compressive strength Short-span test Papier et carton Rsistance la compression Essai faible cartement ISO 9895:2008(E) PDF disclaimer This PDF file may contain embedded typefaces. In

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4、printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below. COPYRIGHT PROTECTED DOCUMENT ISO 2008 All rights reserved. Unless othe

5、rwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyrigh

6、t office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland ii ISO 2008 All rights reservedISO 9895:2008(E) ISO 2008 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative r

7、eferences . 1 3 Terms and definitions. 1 4 Principle. 2 5 Apparatus 2 6 Calibration . 3 7 Sampling 3 8 Conditioning 3 9 Preparation of test pieces 3 10 Procedure 3 11 Calculation and expression of results 4 11.1 General. 4 11.2 Compressive strength 4 11.3 Compressive index. 4 12 Precision 5 12.1 Gen

8、eral. 5 12.2 Repeatability 5 12.3 Reproducibility 5 13 Test report . 5 Annex A (normative) Specifications for the clamps. 6 Annex B (informative) The reason for not measuring strain at break 7 Bibliography . 8 ISO 9895:2008(E) iv ISO 2008 All rights reservedForeword ISO (the International Organizati

9、on for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established ha

10、s the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Inte

11、rnational Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publica

12、tion as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rig

13、hts. ISO 9895 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps, Subcommittee SC 2, Test methods and quality specifications for paper and board. This second edition cancels and replaces the first edition (ISO 9895:1989), which has been revised to insert a grammage range in the sco

14、pe of this International Standard. Compared to the first edition, some editorial changes have also been made. ISO 9895:2008(E) ISO 2008 All rights reserved v Introduction This International Standard has been developed in order to specify the conditions for determining the compressive strength of pap

15、er and board used for the manufacture of containers and boxes. In this International Standard, the same terminology and symbols are used as in general literature concerning materials physics and mechanics. INTERNATIONAL STANDARD ISO 9895:2008(E) ISO 2008 All rights reserved 1 Paper and board Compres

16、sive strength Short-span test 1 Scope This International Standard specifies a method for determining the compressive strength in the machine and cross-directions of paper and board using a short-span compressive tester. It is intended for papers and boards used for the manufacture of containers and

17、boxes. This International Standard is recommended for papers and boards with a grammage from 100 g/m 2to 400 g/m 2 . NOTE 1 The procedure specified in this International Standard should not be used for the determination of strain at break (see Annex B). NOTE 2 For the determination of compressive st

18、rength of laboratory sheets, see instructions in ISO 5270 1 . 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document

19、(including any amendments) applies. ISO 186, Paper and board Sampling to determine average quality ISO 187, Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples ISO 536, Paper and board Determination of gramma

20、ge 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 compressive strength maximum compressive force per unit width that a test piece of paper or board can withstand until the onset of failure NOTE The compressive strength is expressed in kilone

21、wtons per metre. 3.2 compressive index compressive strength divided by the grammage NOTE The compressive index is expressed in kilonewton metres per kilogram. ISO 9895:2008(E) 2 ISO 2008 All rights reserved4 Principle A test piece, 15 mm wide, is clamped between two clamps, spaced 0,70 mm apart, whi

22、ch are forced towards each other until a compressive failure occurs. The maximum force is measured and the compressive strength is calculated. 5 Apparatus 5.1 Compressive tester, with two clamps (see Figure 1), for holding a test piece 15 mm wide. Each clamp includes a stationary jaw (S 1 , S 2 ) an

23、d a movable jaw (M 1 , M 2 ). The clamps (C 1and C 2 ) shall be 30 mm long and have a high-friction surface. The clamps shall be able to hold the test piece (T) in position with a constant clamping force of 2 300 500 N. The clamps shall be designed so that they grip the test piece firmly over its fu

24、ll width (see also Annex A). The stationary jaws shall be in the same plane and on the same side of the test piece. The clamping surfaces of the movable jaws shall be in the same plane and parallel to those of the stationary jaws. For specifications, see Annex A. At the start of the test, the free s

25、pan between the clamps shall be 0,70 mm 0,05 mm. Once the test is started, the clamps shall move towards each other at a speed of 3 mm/min 1 mm/min. The tester shall have a measuring and display system so that the maximum compressive force can be determined with an error of less than 1 % of the read

26、ing when this is within 10 % to 100 % of the full-scale range. The tester shall be designed so that a device for calibrating the load cell using weights of known mass can be attached. Alternatively, calibrated strain gauges can be used. The tester shall have a device showing the clamping force exert

27、ed by the jaws, expressed in newtons. Dimensions in millimetres Key C 1and C 2clamps M 1and M 2movable jaws S 1and S 2stationary jaws T test piece Figure 1 Clamping arrangement ISO 9895:2008(E) ISO 2008 All rights reserved 3 5.2 Cutting device, designed to produce test pieces of the required dimensi

28、ons with clean and parallel edges. 6 Calibration Check the calibration of the compressive tester regularly using calibrated weights or strain gauges. Select calibration weights or strain gauges so that the entire measuring range is covered with checks at evenly spaced points. The error at any point

29、shall not exceed 1 % of the reading within 10 % to 100 % of the full- scale range. If the instrument is out of calibration, make adjustments as instructed by the manufacturer. 7 Sampling If the tests are being performed to evaluate a lot, select the sample in accordance with ISO 186. If the tests ar

30、e made on another type of sample, make sure that the test pieces used are representative of the sample received. 8 Conditioning Condition the sample in accordance with ISO 187. 9 Preparation of test pieces Prepare the test pieces in the same atmospheric conditions as used to condition the sample. Fr

31、om undamaged areas of the sample, cut test pieces in the form of strips of at least 70 mm in length and with a width of 15 mm 0,1 mm. Cut test pieces with the longer side parallel to the machine direction in order to determine the compressive strength in the machine direction. Cut test pieces with t

32、he longer side parallel to the cross-direction in order to determine the compressive strength in the cross-direction. Cut a sufficient number of test pieces to allow at least 20 determinations in each required direction. This test, like all other tests depending on resistance to compression, is very

33、 sensitive to change in the moisture content of the test piece. Handle the test pieces carefully and never touch the compressive zone with bare hands. Keep the test pieces away from moisture, heat, direct illumination, expiration air and other conditions that may change their moisture content. Ensur

34、e that the clamps are not exposed to heat from lamps, motors, etc. The compressive strength is measured on a small area of 0,7 mm 15 mm. In order to minimize the influence of local variations in the paper, at least 20 determinations are prescribed. 10 Procedure Clamp the test piece in position in th

35、e jaws. Set the jaws in motion and read the maximum compressive force indicated. Test at least 20 test pieces in each required direction (machine direction and/or cross-direction). If multiple tests are to be made on a single test piece, ensure that the test area is not a part of the test piece that

36、 has been in the clamping area during the previous test. If required, determine the grammage of the conditioned sample (see Clause 8) in accordance with ISO 536. ISO 9895:2008(E) 4 ISO 2008 All rights reserved11 Calculation and expression of results 11.1 General Calculate and report results separate

37、ly for each required direction (machine direction and/or cross-direction). 11.2 Compressive strength Calculate the mean maximum compressive force and then calculate the compressive strength from Equation (1): C C b F b = (1) where C F is the mean maximum compressive force, in newtons; b is the initi

38、al width of the test piece, in millimetres (normally 15 mm); C b is the compressive strength, in kilonewtons per metre. Report the compressive strength, C b , to three significant figures. If required, also calculate the standard deviation of the compressive strength. 11.3 Compressive index If requi

39、red, calculate the compressive index from Equation (2): C C 1000 b g g = (2) where C g is the compressive index, in kilonewton metres per kilogram; C b is the compressive strength, in kilonewtons per metre; g is the grammage, in grams per square metre. Report the compressive index, C g , to three si

40、gnificant figures. ISO 9895:2008(E) ISO 2008 All rights reserved 5 12 Precision 12.1 General The variation between single tests using the same paper depends mainly on the structure of the paper. 12.2 Repeatability One laboratory tested flutings (grammage from 112 g/m 2to 180 g/m 2 ) and kraft liners

41、 (grammage from 125 g/m 2to 400 g/m 2 ) in four different apparatuses, side by side. The results (4 means of 20 determinations) normally had a coefficient of variation of less than 3 %. 12.3 Reproducibility In an interlaboratory comparison trial, 10 laboratories tested the same flutings (grammage fr

42、om 112 g/m 2to 180 g/m 2 ) and kraft liners (grammage from 125 g/m 2to 400 g/m 2 ). The coefficient of variation ranged between 3 % and 7 %. 13 Test report The test report shall include the following information: a) reference to this International Standard; b) date and place of testing; c) descripti

43、on and identification of the material tested; d) conditioning atmosphere used; e) grammage, if determined; f) direction of the test; g) number of replicates carried out, if not 20, in each tested direction; h) for each direction tested, the compressive strength and, if required, the coefficient of v

44、ariation; i) if required, for each direction tested, the compressive index; j) any departure from the procedure described in this International Standard or any other circumstances which may have affected the test results. ISO 9895:2008(E) 6 ISO 2008 All rights reservedAnnex A (normative) Specificati

45、ons for the clamps The four jaw edges in contact with the test piece in the 0,70 mm span shall not be blunted. The difference in the free span measured at the top and bottom of the jaws shall be less than 0,03 mm. Those parts of the two surfaces of the stationary jaws that grip the test piece in the

46、 area close to the free span shall lie between two parallel planes spaced 0,01 mm apart or less. Furthermore, all points of the two surfaces, extending 30 mm in each direction from the free span, shall lie between two parallel planes spaced 0,2 mm apart or less (see Figure A.1). All points of the bo

47、ttom surfaces of the jaws shall lie between two parallel planes spaced 0,1 mm apart or less (see Figure A.2). Dimensions in millimetres Figure A.1 Specifications for the maximum permissible departure from parallelism of the clamping surfaces Dimensions in millimetres Figure A.2 Specification for the

48、 maximum permissible departure from vertical alignment of the clamps ISO 9895:2008(E) ISO 2008 All rights reserved 7 Annex B (informative) The reason for not measuring strain at break The clamps of the compressive tester are constructed to clamp the test piece firmly without damaging it. The clampin

49、g force is therefore distributed over a large clamping area. This, however, has the consequence that the test piece slips or slides slightly during the test. The strain in different parts of the test piece during a test is shown schematically in Figure B.1. It is highest in the free span section and gradually decreases in the clamped parts of the test piece. The strain at break in compressive tests is of the order of 1 %, which means that the deformation to break in the 0,70 mm