1、BRITISH STANDARD BS ISO 5626:1993 Implementation of ISO 5626:1993 Paper Determination of folding endurance UDC 676.2.017.42:620.177BSISO5626:1993 This British Standard, having been prepared under the directionof the Paper and PrintingStandards Policy Committee, was published underthe authority of th
2、e Standards Board and comes intoeffect on 15 March 1994 BSI 11-1999 First published as BS 4419 March1969 Second edition February 1980 First published as BS ISO 5626 March 1994 The following BSI references relate to the work on this standard: Committee reference PAM/11 Draft for comment 92/44367 DC I
3、SBN 0 580 22979 3 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Paper and Printing Standards Policy Committee (PAM/-) to Technical Committee PAM/11, upon which the following bodies were represented: British Carton Association British F
4、ibreboard Packaging Association British Paper and Board Industry Federation British Printing Industries Federation British Textile Confederation Envelope Makers and Manufacturing Stationers Association Her Majestys Stationery Office Institute of Paper Conservation Pira International Post Office Univ
5、ersity of Manchester (Institute of Science and Technology) Coopted member Amendments issued since publication Amd. No. Date CommentsBSISO5626:1993 BSI 11-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword iii Text of ISO 5626 1BSISO5626:1993 ii BSI 11-1999 N
6、ational foreword This British Standard reproduces verbatim ISO5626:1993 and implements it as the UK national standard. This British Standard is published under the direction of the Paper and Printing Standards Policy Committee whose Technical Committee PAM/11 has the responsibility to: aid enquirers
7、 to understand the text; present to the responsible international committee any enquiries on interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. BS ISO5626:1993 supersedes BS4419:1980, which i
8、s withdrawn. NOTEInternational and European Standards, as well as overseas standards, are available from Customer Services, Publications, BSI, Linford Wood, Milton Keynes, MK146LE. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards a
9、re responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, theISO title page, pagesii toiv, pages1 to8 and abackcover. This st
10、andard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.ISO5626:1993(E) ii BSI 11-1999 Contents Page Foreword iii Introduction 1 1 Scope 1 2 Normative references 1 3 Definitions 1 4 Principle of th
11、e methods 1 5 Apparatus 2 6 Sampling 2 7 Conditioning 2 8 Preparation of test pieces 2 9 Procedure 2 10 Precision of the method 3 11 Test report 3 Annex A (normative) Descriptions of folding testers 5 Annex B (normative) Maintenance and calibration of the instruments 6 Annex C (informative) Temperat
12、ure rise limitations 8 Descriptors: Paper, tests, reverse bend tests, determination, folding strength, test equipment, calibration.ISO5626:1993(E) BSI 11-1999 iii Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodi
13、es). 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 has the right to be represented on that committee. International organizations, governmental and
14、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. Draft International Standards adopted by the technical committees are circulated to the member bodi
15、es for voting. Publication as an International Standard requires approval by at least75% of the member bodies casting a vote. International Standard ISO5626 was prepared by Technical Committee ISO/TC6, Paper, board and pulps, Sub-Committee SC2, Test methods and quality specifications for paper and b
16、oard. This second edition cancels and replaces the first edition (ISO5626:1978), of which it constitutes a technical revision (see introduction). Annex A andAnnex B form an integral part of this International Standard. Annex C is for information only.iv blankISO5626:1993(E) BSI 11-1999 1 Introductio
17、n A number of instruments for determining the folding endurance of paper are in existence, the most commonly used being the Khler Molin, Lhomargy, the MIT and the Schopper instruments. This International Standard is therefore based upon these four types of instrument. It should be noted, however, th
18、at the instruments do not give identical results. The first edition of this International Standard (ISO5626:1978) specified that the result be reported as the logarithm (to the base10) of the number of double folds before fracture. The reason for this was the widely held opinion that the relative fo
19、lding endurances of different papers are best indicated when the test values are expressed logarithmically. This procedure is still valid. However, experience during the life of the1978 edition has shown that the interpretation of logarithmic results has caused confusion and consequently results are
20、 frequently quoted as the number of double folds. In view of this, this International Standard allows the results to be reported as either folding endurance the logarithm (to the base10) of the number of double folds or the fold number (the antilogarithm of the folding endurance). It should be noted
21、 that the fold number as defined in this International Standard is not the mean of the observed number of double folds and is therefore different to the understanding of fold number which existed prior to1978 and which still persists in some countries. 1 Scope This International Standard specifies t
22、he methods for the determination of folding endurance of paper using Khler Molin, Lhomargy, MIT and Schopper testers. It sets out the conditions to be observed when using these instruments, and gives the precautions to be taken in using each instrument. Interpretation of the results is complicated b
23、y the fact that the different types of instrument included in this International Standard will give different numerical results for the same test material and they can produce dissimilar rankings for different test materials. Annex A,Annex B andAnnex C give information on the instruments and their m
24、aintenance and calibration. NOTE 1The results obtained with the instruments described are very sensitive to atmospheric conditions under which the test is carried out, particularly humidity. When operated with the standard loads, the Khler-Molin, Lhomargy and Schopper methods are applicable to paper
25、 up to0,25mm thick and having a tensile strength greater than1,33kN/m. The MIT tester has interchangeable folding heads allowing a range of thicknesses up to1,25mm to be accommodated. This International Standard does not state any preferences for any particular method. 2 Normative references The fol
26、lowing standards contain provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are en
27、couraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 186:1985, Paper and board Sampling to determine average quality. ISO 187:1990, Paper, board and pul
28、ps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples. 3 Definitions For the purposes of this International Standard, the following definitions apply. 3.1 double fold one complete oscillation of the test piece, during which it is
29、folded first backwards and then forwards about the same line 3.2 folding endurance logarithm (to the base10) of the number of double folds required to cause rupture of the test piece when tested under applied standard stress conditions 3.3 fold number antilogarithm of the mean folding endurance 4 Pr
30、inciple of the methods Folding backwards and forwards in a standardized manner of a narrow strip of paper subjected to a longitudinal stress, until it breaks.ISO5626:1993(E) 2 BSI 11-1999 5 Apparatus 5.1 Fold tester (seeAnnex A). Details for maintenance and calibration of instruments are given inAnn
31、ex B. 5.2 Means of measuring the temperature in the vicinity of the folding head NOTE 2Heating of the paper in the test area, which results either from the work done on the paper or from heat transferred from the instrument motor via the jaws, can lead to local embrittlement of the paper test strip
32、and thus to low folding endurance results. These effects can be minimized by insulation or isolation of the drive motor from the remainder of the apparatus and by adequate ventilation of the area surrounding the folding head (seeAnnex C). 5.3 If necessary, means of ventilating the space around the f
33、olding head, for example by mounting a fan next to the folding head to draw air across the test piece. 5.4 Device for cutting the test pieces 6 Sampling Take samples in accordance with ISO186. 7 Conditioning Condition the samples in accordance with ISO187. 8 Preparation of test pieces Prepare the te
34、st pieces in the same atmosphere used to condition the samples. Cut at least10pieces in each required principal direction of the paper. The test pieces shall be15mm 0,1mm wide and of sufficient length for the instrument being used. Each edge shall be clean-cut and parallel to the opposite edge. The
35、test pieces shall be initially free from folds, wrinkles or blemishes not inherent in the paper. The area where the flexing takes place shall not contain any portion of a watermark. Take care not to handle with bare hands any part of the test piece that will be exposed between the clamps. 9 Procedur
36、e 9.1 General Carry out the tests in the same atmosphere used to condition the samples. Throughout the test, monitor the air temperature in the vicinity of the folding head. The temperature shall not increase by more than1 C after4h of operation. If the temperature increases by more than1 C, stop th
37、e test and wait for the temperature to return to normal before restarting the test. Disregard the test in progress when the test was stopped. If the number of double folds is less than10or greater than10000, decrease or increase the tension, if this is possible. The use of a nonstandard tension, and
38、 its value, shall be stated in the test report. At least10readings for each required principal direction of the paper are required. The machine direction test is that in which the long axis of the test piece is in the machine direction of the paper and the stress is applied in the machine direction,
39、 the break being in the cross direction. Reject any individual result where the test piece has slipped in the clamps or broken away from the fold line. Determine the logarithm (to the base10) of each of the individual readings. Calculate separately the mean of the values for machine and cross direct
40、ions respectively. If required (see clause11), determine the antilogarithms of the means for machine and cross directions respectively. Calculate the standard deviation of individual folding endurance values, i.e. the individual readings in logarithmic form, or, if required, the antilogarithm of thi
41、s standard deviation. For details concerning the operation of each type of instrument, see9.2 to9.5. 9.2 Schopper instrument Level the instrument. Move the reciprocating blade so that its slot is in the neutral position and, in testers with a flywheel, lock the flywheel into position by the spring s
42、tud that engages in the recess in the flywheel. Release the clamps by raising the cylinder locks. Place the test piece in the clamps. Make sure that the test piece and clamps are aligned correctly. Tighten the screws of the clamps so that the test piece is held firmly and evenly without possibility
43、of slippage. Apply the tension to the test piece by drawing back the ends of the clamp cylinders until the cylinder locks engage. Release the flywheel from the stud lock. Engage or switch on the counter. Commence folding and continue until the test piece breaks, when the counter will automatically s
44、top. Record the number of double folds required to break the test piece. Return the counter reading to zero.ISO5626:1993(E) BSI 11-1999 3 9.3 Lhomargy instrument Level the instrument. Place the appropriate loading weights on the platform provided. Use a tension of9,81N, unless the number of double f
45、olds is very low, in which case loading weights equivalent to a tension of4,91N may be used. Insert the paper, in the form of a loop, in the two clamps above the loading weights, so that it is fully engaged. Lightly close the two knurled knobs. Ensure that the blade is in the vertical plane. Take th
46、e loading weights in one hand and, with the other, engage the paper in the two lower rollers and in the slot of the blade. This slot should be in a convenient position,i.e.between the upper pair and the lower pair of rollers. Centre the part of the test piece that passes through the slot of the blad
47、e well on the rollers. Release the loading weights without jolting. Set the engaging lever, commence folding and continue until the test piece breaks, when the counter will automatically stop. Record the number of double folds required to break the test piece. Return the counter reading to zero. 9.4
48、 Khler Molin instrument Level the instrument. Set the folding clamp so that the gap between the two jaws is approximately vertical. Lock the lower clamp in the raised position. Hold the test piece with its ends between the jaws of the folding and the lower clamps. Centre the test piece (guidelines a
49、re provided in the folding clamp and lower clamp) and tighten the clamps so that the test piece cannot slip during the test. Apply the load800g (7,85N) to the lower clamp and set the revolution counter to the zero position or record the reading. Release the lower clamp, commence folding and continue until the test piece breaks, when the counter will automatically stop. Record the number of double folds required to break the test piece. Return the folding clamp and the lower clamp to their starting positions. 9.5 MIT instrument Level the instrument. Turn
