1、BSI Standards PublicationBS EN ISO 535:2014Paper and board Determination of waterabsorptiveness CobbmethodBS EN ISO 535:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 535:2014. Itsupersedes BS EN 20535:1994 which is withdrawn.The UK participation in it
2、s preparation was entrusted to TechnicalCommittee PAI/11, Methods of test for paper, board and pulps.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are resp
3、onsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 78153 7ICS 85.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Po
4、licy and Strategy Committee on 28 February 2014.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 535 February 2014 ICS 85.060 Supersedes EN 20535:1994English Version Paper and board - Determination of water absorptiveness - Cobb method (IS
5、O 535:2014) Papier et carton - Dtermination de labsorption deau - Mthode de Cobb (ISO 535:2014) Papier und Pappe - Bestimmung des Wasserabsorptionsvermgens - Cobb-Verfahren (ISO 535:2014) This European Standard was approved by CEN on 23 December 2013. CEN members are bound to comply with the CEN/CEN
6、ELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre
7、or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the of
8、ficial versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherland
9、s, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights o
10、f exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 535:2014 EBS EN ISO 535:2014EN ISO 535:2014 (E) 3 Foreword This document (EN ISO 535:2014) has been prepared by Technical Committee ISO/TC 6 “Paper, board and pulps” in collaboration with Technic
11、al Committee CEN/TC 172 “Pulp, paper and board” the secretariat of which is held by DIN. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2014, and conflicting national standards shall be wi
12、thdrawn at the latest by August 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 20535:1994. Accordin
13、g to the CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Gr
14、eece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 535:2014 has been approved by CEN as EN ISO 535:2014 without
15、 any modification. BS EN ISO 535:2014ISO 535:2014(E) ISO 2014 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Reagents and materials . 16 Apparatus . 27 Sampling 28 Conditioning 29 Preparation of test pieces .
16、210 Procedure. 310.1 Mounting of the test piece . 310.2 Exposure to water and blotting 310.3 Times of test 310.4 Rejection of test pieces . 411 Expression of results 412 Test report . 5Annex A (informative) Precision . 6Bibliography 8BS EN ISO 535:2014ISO 535:2014(E)ForewordISO (the International Or
17、ganization 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 establ
18、ished has 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 standardizati
19、on.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with
20、the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).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 rights. Details of any pat
21、ent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For
22、an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for th
23、is document is ISO/TC 6, Paper, board and pulps, Subcommittee SC 2, Test methods and quality specifications for paper and board.This third edition cancels and replaces the second edition (ISO 535:1991), which has been technically revised to include precision data.iv ISO 2014 All rights reservedBS EN
24、 ISO 535:2014ISO 535:2014(E)IntroductionThe test described in this International Standard permits the determination of the quantity of water that can be absorbed by the surface of paper or board in a given time. Water absorptiveness is a function of various paper and board characteristics such as si
25、zing, porosity, etc. ISO 2014 All rights reserved vBS EN ISO 535:2014BS EN ISO 535:2014Paper and board Determination of water absorptiveness Cobb method1 ScopeThis International Standard specifies a method of determining the water absorptiveness of sized paper and board, including corrugated fibrebo
26、ard, under standard conditions. It may not be suitable for paper of grammage less than 50 g/m2or embossed paper. It is not suitable for porous papers such as newsprint or unsized papers such as blotting paper or other papers having a relatively high water absorptiveness for which ISO 87872is more su
27、itable.This method is not intended to be used for precise evaluation of the writing properties of paper although it does give a general indication of suitability for use with aqueous inks.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document
28、and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 186, Paper and board Sampling to determine average qualityISO 187, Paper, board and pulps Stan
29、dard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samplesISO 5269-1, Pulps Preparation of laboratory sheets for physical testing Part 1: Conventional sheet-former method3 Terms and definitionsFor the purposes of this document, the following
30、terms and definitions apply.3.1water absorptiveness (Cobb value)calculated mass of water absorbed in a specified time by 1 m2of paper or board under specified conditionsNote 1 to entry: The test area is normally 100 cm2.4 PrincipleA test piece is weighed immediately before and immediately after expo
31、sure for a specified time of one surface to water, followed by blotting. The result of the increase in mass is expressed in grams per square metre (g/m2).5 Reagents and materials5.1 Water, distilled or deionized. The temperature of the water is important and should be maintained during the test at t
32、he temperature used for conditioning and testing.5.2 Blotting paper, having a grammage of 250 g/m2 25 g/m2. Pulp evaluation blotters are acceptable for the purposes of this International Standard (see ISO 5269-1).INTERNATIONAL STANDARD ISO 535:2014(E) ISO 2014 All rights reserved 1BS EN ISO 535:2014
33、ISO 535:2014(E)6 Apparatus6.1 Absorptiveness tester for the determination of water absorptiveness.Any type of apparatus may be used which permits an immediate and uniform contact of the water with the part of the test piece submitted to the test; controlled rapid removal of the unabsorbed water from
34、 the test piece at the end of the contact period; and the rapid removal of the test piece without the risk of contact with water outside the test area.In its simplest form, the apparatus consists of a rigid base with a smooth, planar surface, and a rigid metal cylinder of 112,8 mm 0,2 mm internal di
35、ameter (corresponding to a test area approximately 100 cm2) and with a means of clamping it firmly to the base plate. The edge of the cylinder in contact with the test piece shall be flat and machined smooth with a thickness sufficient to prevent the cylinder cutting into the test piece. The height
36、of the cylinder is not important provided it is sufficient to contain a water depth of 10 mm.NOTE 1 For materials where leakage between the cylinder and the upper surface of the test piece may occur during the test, a soft, elastic, non-absorbent gasket may be interposed to prevent this. This gasket
37、 should have the same internal diameter as the cylinder after clamping.NOTE 2 To prevent damage to the machined edge of the cylinder caused by clamping it upside down it is advisable to mark the top in some way so that it can be identified readily.NOTE 3 If a cylinder of a small area is used it is r
38、ecommended that this should not be less than 50 cm2. The water depth must still be 10 mm.6.2 Metal roller, with a smooth face, 200 mm wide, a diameter of 90 mm 10 mm and a mass of 10 kg 0,5 kg.6.3 Balance, with an accuracy of 1 mg.6.4 Timer, reading in seconds and capable of timing up to at least 30
39、 min.6.5 Graduated cylinder, or other means of measuring appropriate aliquots.7 SamplingIf the tests are being made to evaluate a lot, the sample shall be selected in accordance with ISO 186. If the tests are made on another type of sample, make sure that the specimens taken are representative of th
40、e sample received.8 ConditioningCondition the specimens as specified in ISO 187. Keep them in the conditioning atmosphere throughout the test.9 Preparation of test piecesPrepare the test pieces in the same atmospheric conditions used to condition the specimens. Avoid contact of the test area with ha
41、nds or fingers, cut from the specimens at least 10 test pieces of sufficient 2 ISO 2014 All rights reservedBS EN ISO 535:2014ISO 535:2014(E)size to exceed the diameter of the cylinder by at least 10 mm from any edge, ensuring that the test area is free from visible folds, creases, cracks or other de
42、fects.NOTE For normal apparatus (see 6.1) a width of about 125 mm is suitable.If watermarks are present, these areas should be avoided if possible. When the specimens available are too small to allow the normal apparatus to be used, a smaller test area may be agreed upon between the interested parti
43、es and depending on the corresponding equipment availability.10 ProcedureCarry out the test in the same atmospheric conditions used to condition the specimens (see Clause 8).10.1 Mounting of the test pieceEnsure that the upper surface of the base plate and the edge of the cylinder which will come in
44、 contact with the test piece are dry before commencing each test.Weigh the test piece to the nearest 1 mg and place it with the surface to be tested uppermost on the base plate. Place the cylinder with the machined edge in contact with the test piece and clamp sufficiently firmly to prevent any leak
45、age of water between it and the test piece.10.2 Exposure to water and blottingFor the purposes of this International Standard, the time of test is defined as the time between the moment the water first contacts the test piece and the commencement of blotting.Pour 100 ml 5 ml of water (5.1) or propor
46、tionately less for a smaller test area, into the cylinder, thus providing a head of 10 mm and start the timer (6.4) immediately. Use new water for each determination.The test procedure for any selected exposure time should, where possible, conform to the conditions summarized in 10.3, the exposure t
47、ime being selected according to the water absorptiveness of the paper and board under consideration. If, for example, a test time of 60 s has been selected, pour off the excess water after 45 s (see Table 1), taking care that no water comes into contact with the surface of the test piece outside the
48、 test area. Quickly unclamp the cylinder and remove it. Remove the test piece and place it, test face uppermost, on a sheet of dry blotting paper (5.2) previously placed on a flat rigid surface. 60 s after commencement of the test, place a second sheet of blotting paper on top of the test piece and
49、remove the excess water, using the hand roller (6.2) with two rollings (once forward and once back) without exerting any pressure on the roller.NOTE 1 On corrugated fibreboard the roller should be applied with its axis parallel to the flutes.NOTE 2 Where corrugated fibreboard is indented by the cylinder edge or which exhibits “washboarding” it may not be possible for the blotting paper to contact the entire wet area of the test piece. In such cases it is recommended that instead of using the roller, the back of the blotting paper i
