oSIST prEN ISO 535:2022

Paper and board - Determination of water absorptiveness - Cobb method (ISO/DIS 535:2022)

Papier und Pappe – Bestimmung des Wasserabsorptionsvermögens – Cobb-Verfahren (ISO/DIS 535:2022)

Papier et carton - Détermination de l'absorption d'eau - Méthode de Cobb (ISO/DIS 535:2022)

Papir, karton in lepenka - Določevanje absorpcije vode - Cobbova metoda (ISO/DIS 535:2022)

General Information

• Status: Not Published
• Public Enquiry End Date: 24-Mar-2022
• ICS: 85.060 - Paper and board
• Technical Committee: VPK - Pulp, paper, board and products
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 26-Jan-2022
• Due Date: 15-Jun-2022
• Ref Project: prEN ISO 535 - Paper and board - Determination of water absorptiveness - Cobb method (ISO/DIS 535:2022)

RELATIONS

• Revised: SIST EN ISO 535:2014 - Paper and board - Determination of water absorptiveness - Cobb method (ISO 535:2014)
• Effective Date: 15-Jan-2020

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN ISO 535:2022
01-marec-2022
Papir, karton in lepenka - Določevanje absorpcije vode - Cobbova metoda (ISO/DIS
535:2022)
Paper and board - Determination of water absorptiveness - Cobb method (ISO/DIS
535:2022)
Papier und Pappe – Bestimmung des Wasserabsorptionsvermögens – Cobb-Verfahren
(ISO/DIS 535:2022)

Papier et carton - Détermination de l'absorption d'eau - Méthode de Cobb (ISO/DIS

535:2022)
Ta slovenski standard je istoveten z: prEN ISO 535
ICS:
85.060 Papir, karton in lepenka Paper and board
oSIST prEN ISO 535:2022 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 535:2022
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oSIST prEN ISO 535:2022
DRAFT INTERNATIONAL STANDARD
ISO/DIS 535
ISO/TC 6/SC 2 Secretariat: SIS
Voting begins on: Voting terminates on:
2022-01-03 2022-03-28
Paper and board — Determination of water absorptiveness
— Cobb method
Papier et carton — Détermination de l'absorption d'eau — Méthode de Cobb
ICS: 85.060
This document is circulated as received from the committee secretariat.
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENT AND APPROVAL. IT IS
ISO/CEN PARALLEL PROCESSING
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/DIS 535:2022(E)
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION. © ISO 2022
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oSIST prEN ISO 535:2022
ISO/DIS 535:2022(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2022

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may

be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on

the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below

or ISO’s member body in the country of the requester.
ISO copyright office
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Website: www.iso.org
Published in Switzerland
© ISO 2022 – All rights reserved
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oSIST prEN ISO 535:2022
ISO/DIS 535:2022(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ..................................................................................................................................................................................... 1

3 Terms and definitions .................................................................................................................................................................................... 1

4 Principle ........................................................................................................................................................................................................................ 1

5 Reagents and materials ................................................................................................................................................................................ 2

6 Apparatus .................................................................................................................................................................................................................... 2

7 Sampling ....................................................................................................................................................................................................................... 3

8 Conditioning ............................................................................................................................................................................................................. 3

9 Preparation of test pieces ..........................................................................................................................................................................3

10 Procedure ....................................................................................................................................................................................................................3

10.1 General ........................................................................................................................................................................................................... 3

10.2 Mounting of the test pieces ........................................................................................................................................... ............... 3

10.3 Exposure to water and blotting .............................................................................................................................................. 4

10.4 Times of test .............................................................................................................................................................................................. 4

10.5 Rejection of test pieces .................................................................................................................................................................... 5

11 Expression of results ....................................................................................................................................................................................... 5

12 Test report .................................................................................................................................................................................................................. 6

Annex A (informative) Precision ............................................................................................................................................................................. 7

Annex B (informative) Blotting Paper................................................................................................................................................................ 9

Bibliography .............................................................................................................................................................................................................................10

iii
© ISO 2022 – All rights reserved
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oSIST prEN ISO 535:2022
ISO/DIS 535:2022(E)
Foreword

ISO (the International Organization 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 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 standardization.

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 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 patent 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 an explanation of the voluntary nature of standards, the meaning of ISO specific terms and

expressions related to conformity assessment, as well as information about ISO's adherence to

the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see

www.iso.org/iso/foreword.html.

This document 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 fourth edition cancels and replaces

the third edition (ISO 535:2014), which has been technically revised.
The main changes compared to the previous edition are as follows:
— Requirements in 5.1 “Water” and 5.2 “Blotting paper” added;
— Specification for the use of ink added in 5.3 “Ink”;
— Chapter 6 “Apparatus” and 6.2 “Metal roller” revised;
— Preparation of test pieces added in chapter 9;

— 10.3 “Exposure to water and blotting” and 10.4 “Times of test” revised and requirements added;

— Several additional explanations added in 10.5 “Rejection of test pieces”;
— Editorial changes.

Any feedback or questions on this document should be directed to the user’s national standards body. A

complete listing of these bodies can be found at www.iso.org/members.html.
© ISO 2022 – All rights reserved
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oSIST prEN ISO 535:2022
DRAFT INTERNATIONAL STANDARD ISO/DIS 535:2022(E)
Paper and board — Determination of water absorptiveness
— Cobb method
1 Scope

This document specifies a method of determining the water absorptiveness of paper and board,

including corrugated fibreboard, under standard conditions.

This document does not apply for paper of grammage less than 50 g/m or embossed paper. It is not

applicable for porous papers such as newsprint or papers such as blotting paper or other papers having

a relatively high water absorptiveness for which ISO 8787 is more suitable.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. 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 quality

ISO 187, Paper, board and pulps — Standard atmosphere for conditioning and testing and procedure for

monitoring the atmosphere and conditioning of samples
ISO 14487, Pulps — Standard water for physical testing
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1
water absorptiveness

Cobb valuecalculated mass of water absorbed in a specified time by 1 m of paper or board under

specified conditions
Note 1 to entry: The test area is normally 100 cm .
4 Principle

A test piece is weighed immediately before and immediately after exposure 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/m ).

Particular attention shall be paid if any water penetrates through the test piece or the test piece shows

signs of leakage.
© ISO 2022 – All rights reserved
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oSIST prEN ISO 535:2022
ISO/DIS 535:2022(E)
5 Reagents and materials

5.1 Water, distilled or deionized, having the temperature of laboratory conditioning i.e.

23 °C ± 1 °C or 27 °C ± 1 °C in tropical countries. The temperature of the water is important and should

be maintained during the test at the temperature used for conditioning and testing. The water should

fulfil the requirements of ISO 14487.
2 2
5.2 Blotting paper, having a grammage of 250 g/m ± 25 g/m .

Blotting papers as described in ISO 5269-1 are acceptable for the purposes of this document, see

Annex B.

The blotting paper shall have the dimensions of at least 140 mm × 140 mm either circular or rectangular.

5.3 Ink, 0,15 % ± 0,015 % of commercially available waterbased ink can be added to the water (5.1)

to support the visibility of penetrated water.

A differing pH-value of the ink can increase or decrease the pH-value of the water (5.1) and can have a

negative impact on some papers, especially on some coatings. The addition of ink shall not change the

pH-value of water more than +/- 0,5 units from the original pH-value.

The electrical conductivity of the water (5.1) shall not exceed 0,2625 mS/m at 25 °C when ink was added

(ISO 14487). The use of ink and the description of the latter shall be mentioned in the test report.

The addition of the ink shall not affect the surface tension of the water.
6 Apparatus
6.1 Absorptiveness tester for the determination of water absorptiveness (3.1).
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 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 diameter (corresponding to a test area of 100 cm ) 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 of the cylinder is not important provided it is sufficient to contain a water

depth of 10 mm.

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

should have the same internal diameter as the cylinder after clamping.
If a gasket is used, it shall be used for all test pieces.

NOTE The diameter of the gasket can be tested as follows: mount a piece of noncarbon paper into the

absorptiveness tester which has roughly the same dimensions as the test piece and close the cylinder as for the

test. If the pressure is not high enough for an adequate impression use a usual test piece and the noncarbon paper

to increase the thickness of the arrangement. In some cases, a compressible , blotter-like paper or other papers

might be more
...