ISO 5637:2024

Paper and board - Determination of water absorption after immersion in water

This document specifies a method for the determination of the water absorption of paper and board after total immersion in water for a specified time. The method is applicable to all types of paper and board which have a degree of water resistance. It is not applicable to very absorbent papers such as tissue papers and tissue products.

Papier et carton — Détermination de l'absorption d'eau après immersion dans l'eau

General Information

• Status: Published
• Publication Date: 01-Oct-2024
• ICS: 85.060 - Paper and board
• Technical Committee: ISO/TC 6/SC 2 - Test methods and quality specifications for paper and board
• Drafting Committee: ISO/TC 6/SC 2 - Test methods and quality specifications for paper and board
• Current Stage: 6060 - International Standard published
• Start Date: 02-Oct-2024
• Due Date: 25-Mar-2025
• Completion Date: 02-Oct-2024

Relations

• Revises: ISO 5637:1989 - Paper and board - Determination of water absorption after immersion in water
• Effective Date: 06-Jun-2022

Overview

ISO 5637:2024 - "Paper and board - Determination of water absorption after immersion in water" specifies a standardized laboratory method to measure how much water paper and board absorb when totally immersed for a defined period. The method applies to papers and boards that have some degree of water resistance (it is not intended for very absorbent products such as tissues). Results are reported as water absorption (g/m²) and relative water absorption (percentage mass increase) based on precise mass measurements taken before and after immersion.

Key Topics and Requirements

• Scope: Total immersion test for paper and board with water resistance; excludes very absorbent tissue products.
• Sampling & conditioning: Samples should be representative (ISO 186) and conditioned in a standard atmosphere (ISO 187) throughout the test.
• Test pieces: Standard size 200 mm × 250 mm (longer side in machine direction); prepare enough specimens to obtain 10 valid results.
• Apparatus & materials:
  • Precision balance (readability to 1 mg)
  • Soak tank maintained per ISO 187 and free from surfactants
  • Metal roller (approx. 200 mm wide, ~10 kg mass) for excess-water removal
  • Blotting paper (≈250 g/m² grammage) larger than the test piece
  • Tared containers and thermometer (±0.1 °C)
  • Water complying with ISO 14487 (deionized/distilled) at laboratory conditioning temperature
• Immersion times: Select by expected water resistance:
  • Low resistance: 5 min ± 5 s
  • Medium: 30 min ± 1 min
  • High: 24 h ± 15 min
    Alternative immersion times may be used if justified and documented to achieve complete saturation.
• Procedure highlights: Immerse pieces vertically, ensure separation and no trapped air, blot and roll once forward and backward without applied pressure, weigh immediately after blotting. Maintain consistent blotting/weighing timing.
• Calculations: Water uptake is computed from the mass difference before and after immersion and expressed per unit area (g/m²) or as a relative percentage increase in mass.

Applications and Users

ISO 5637:2024 is used by:

• Paper and board manufacturers for product development and quality control
• Packaging engineers assessing water resistance of corrugated and other boards
• Third-party testing and certification laboratories
• Converters and printers checking substrate behavior during wet-process handling
• R&D teams evaluating coatings, additives, and barrier treatments

Practical uses include validating water-resistant grades, comparing treatments or coatings, and specifying performance for packaging exposed to wet environments.

Related Standards

• ISO 186 - Sampling to determine average quality
• ISO 187 - Standard atmosphere for conditioning and testing
• ISO 14487 - Standard water for physical testing

Keywords: ISO 5637:2024, water absorption test, paper and board testing, immersion test, water resistance, paper testing standard.

Standards Content (Sample)

International
Standard
ISO 5637
Third edition
Paper and board — Determination
2024-10
of water absorption after
immersion in water
Papier et carton — Détermination de l'absorption d'eau après
immersion dans l'eau
Reference number
© ISO 2024
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
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: [phone]
Email: [e-mail]
Website: www.iso.org
Published in Switzerland
ii
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 1
5 Apparatus, reagents and materials . 1
6 Sampling . 3
7 Test pieces . 4
7.1 Preparation .4
7.2 Conditioning.4
8 Procedure . 4
8.1 Preparation .4
8.2 Immersion time .4
8.3 Immersion of the test piece .4
8.4 Excess water removal . .5
8.5 Mass determination .5
9 Calculation of results . 6
9.1 General .6
9.2 Individual water absorption.6
9.3 Average water absorption .6
9.4 Relative water absorption .6
10 Test report . 6
Annex A (informative) Examples for support systems . 8

iii
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
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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 document 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).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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Any trade name used in this document is information given for the convenience of users and does not
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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 third edition cancels and replaces the second edition (ISO 5637:1989), which has been technically
revised.
The main changes are as follows:
— Clause 2 Normative references has been updated;
— Former Clause 5 Reagent and Clause 6 Apparatus incorporated into new Clause 5 Apparatus, reagents
and materials and revised;
— Clause 6 Sampling is revised;
— Clause 8 Procedure has been revised, especially immersion time and excess water removal;
— 8.5 "mass determination" has been added;
— Former Clause 9 Expression of results has been updated and the average water absorption has been added;
— Clause 11 Test report has been revised;
— Annex A with examples of possible support systems has been added;
— editorially revised.
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.

iv
International Standard ISO 5637:2024(en)
Paper and board — Determination of water absorption after
immersion in water
1 Scope
This document specifies a method for the determination of the water absorption of paper and board after
total immersion in water for a specified time.
The method is applicable to all types of paper and board which have a degree of water resistance. It is not
applicable to very absorbent papers such as tissue papers and tissue products.
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 terminology 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 absorption
mass of water absorbed per unit area under the specified cond
...