kSIST FprEN 321:2025

Wood-based panels - Determination of moisture resistance under cyclic test conditions

This document specifies a test method for the determination of the moisture resistance of wood-based panels under cyclic test conditions.

Holzwerkstoffe - Bestimmung der Feuchtebeständigkeit durch Zyklustest

Dieses Dokument legt ein Prüfverfahren zur Bestimmung der Feuchtebeständigkeit von Holzwerkstoffen durch Zyklustest fest.

Panneaux à base de bois - Détermination de la résistance à l'humidité selon essais cycliques

Le présent document décrit une méthode d’essai en milieu humide pour la détermination du comportement des panneaux à base de bois dans les conditions d’un essai cyclique.

Lesne plošče - Ugotavljanje odpornosti proti vlagi pri cikličnih pogojih

General Information

• Status: Not Published
• Public Enquiry End Date: 29-Jun-2024
• ICS: 79.060.01 - Wood-based panels in general
• Technical Committee: LLZ - Les, lesni izdelki in zaščita lesa
• Current Stage: 5020 - Formal vote (FV) (Adopted Project)
• Start Date: 07-Nov-2025
• Due Date: 26-Dec-2025
• Completion Date: 07-Nov-2025
• Directive: 305/2011 - Regulation (eu) No 305/2011 of the European Parliament and of the Council of 9 march 2011 laying down harmonised conditions for the marketing of construction products and repealing council directive 89/106/eec
• Ref Project: FprEN 321 - Wood-based panels - Determination of moisture resistance under cyclic test conditions

Relations

• Revises: SIST EN 321:2004 - Wood-based panels - Determination of moisture resistance under cyclic test conditions
• Effective Date: 27-Dec-2023

Overview

kSIST FprEN 321:2025:2024 is a European standard developed by CEN/TC 112 that specifies a test method for evaluating the moisture resistance of wood-based panels under cyclic test conditions. This updated standard supersedes EN 321:2001 and introduces refined wording to eliminate misinterpretations, ensuring accurate and reliable testing procedures.

The standard focuses on simulating real-life moisture exposure by subjecting wood-based panels to repeated cycles of water immersion, freezing, and drying. The results provide critical information on the durability and structural integrity of these materials when exposed to varying moisture levels, which is essential for manufacturers, quality control labs, and product developers dealing with wood-based panels.

Key Topics

• Scope: Defines methods for determining the moisture resistance of wood-based panels through cyclic wetting, freezing, and drying cycles.
• Apparatus Requirements:
  • Water bath maintaining 20 ± 1 °C
  • Freezing cabinet with temperatures between −12 °C and −25 °C
  • Drying cabinet at 70 ± 2 °C with controlled air exchanges
• Test Pieces:
  • Sampling and sizing according to EN 326-1 and EN 310/317/319 respectively
  • Conditioning to a constant mass at 65 ± 5 % relative humidity and 20 ± 2 °C before testing
• Cyclic Test Procedure:
  • Three complete cycles each including immersion in neutral pH water, freezing, drying, and reconditioning
  • Immersion time per cycle: 70 ± 1 hours
  • Freezing time per cycle: 24 ± 1 hours
  • Drying time per cycle: 70 ± 1 hours
• Measurement Parameters:
  • Swelling in thickness post-treatment (according to EN 317)
  • Tensile strength perpendicular to the board plane (EN 319)
  • Bending strength (EN 310)
• Result Reporting: Includes detailed expression of swelling and strength changes, following EN 326-1 guidelines for test reports

Applications

kSIST FprEN 321:2025:2024 is crucial for assessing the performance and durability of various wood-based panels such as particleboards, fibreboards, and oriented strand boards (OSB) used in both internal and external environments. Its practical applications include:

• Product Development: Enables manufacturers to improve moisture-resistant properties of wood panels.
• Quality Assurance: Provides a reproducible testing method for verifying compliance with moisture performance specifications.
• Construction Industry: Assists specifiers and builders in selecting wood-based panels suitable for cyclic moisture exposure, reducing failure risks.
• Research and Innovation: Facilitates investigation of new adhesives, treatments, and panel compositions for enhanced moisture durability.

By simulating realistic environmental cycling, the standard provides actionable data to support material optimization and regulatory compliance in building, furniture, and packaging industries involving wood-based panels.

Related Standards

For comprehensive testing and specification, kSIST FprEN 321:2025:2024 references several interconnected standards:

• EN 310: Wood-based panels - Determination of modulus of elasticity and bending strength
• EN 317: Particleboards and fibreboards - Determination of swelling in thickness after water immersion
• EN 319: Particleboards and fibreboards - Determination of tensile strength perpendicular to the plane of the board
• EN 325: Wood-based panels - Determination of dimensions of test pieces
• EN 326-1: Wood-based panels - Sampling, cutting, inspection, and expression of test results
• EN 300, EN 312, EN 622-5, EN 634-2: Standards detailing product specifications and classifications for different wood-based panel types

Integration of these standards ensures a robust framework for evaluating mechanical and moisture resistance properties, facilitating consistent quality assessment throughout the wood panel industry.

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Keywords: kSIST FprEN 321:2025, wood-based panels moisture resistance, cyclic test conditions, moisture resistance test, wood panel durability, EN 321:2024, wood panel testing standards, moisture cycling test, timber panel moisture resistance, quality control wood panels, wood-based panel standards, CEN TC112.

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN 321:2024
01-junij-2024
Lesne plošče – Ugotavljanje odpornosti proti vlagi pri cikličnih pogojih
Wood-based panels - Determination of moisture resistance under cyclic test conditions
Holzwerkstoffe - Bestimmung der Feuchtebeständigkeit durch Zyklustest
Panneaux à base de bois - Détermination de la résistance à l'humidité selon essais
cycliques
Ta slovenski standard je istoveten z: prEN 321
ICS:
79.060.01 Lesne plošče na splošno Wood-based panels in
general
oSIST prEN 321:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 321:2024
oSIST prEN 321:2024
DRAFT
EUROPEAN STANDARD
prEN 321
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2024
ICS 79.060.01 Will supersede EN 321:2001
English Version
Wood-based panels - Determination of moisture resistance
under cyclic test conditions
Panneaux à base de bois - Détermination de la Holzwerkstoffe - Bestimmung der
résistance à l'humidité selon essais cycliques Feuchtebeständigkeit durch Zyklustest
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee
CEN/TC 112.
If this draft becomes a European Standard, CEN members are bound to comply with the CEN/CENELEC Internal Regulations
which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.

This draft European Standard was established by CEN 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 official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
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.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 321:2024 E
worldwide for CEN national Members.

oSIST prEN 321:2024
prEN 321:2024 (E)
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Principle . 4
5 Apparatus . 4
5.1 Water bath . 4
5.2 Freezing cabinet . 4
5.3 Drying cabinet . 4
6 Test pieces . 5
6.1 Sampling . 5
6.2 Dimensions of test pieces . 5
6.3 Conditioning . 5
7 Procedure . 5
7.1 Treatment of the test pieces . 5
7.1.1 General. 5
7.1.2 Initial conditioning and measurement . 5
7.1.3 Cyclic treatment . 5
7.1.4 Reconditioning . 7
7.2 Determination of swelling in thickness . 7
7.3 Determination of tensile strength perpendicular to the plane of the board . 7
7.4 Determination of bending strength . 7
8 Expression of results . 8
8.1 Swelling in thickness . 8
8.2 Tensile strength . 8
8.3 Bending strength . 8
9 Test report . 8
Bibliography . 9

oSIST prEN 321:2024
prEN 321:2024 (E)
European foreword
This document (prEN 321:2024) has been prepared by Technical Committee CEN/TC 112 “Wood-based
panels”, the secretariat of which is held by DIN.
This document is currently submitted to the CEN Enquiry.
This document will supersede EN 321:2001.
prEN 321:2024 includes the following significant technical changes with respect to EN 321:2001:
— the wording of 7.2 has been changed to avoid misinterpretations;
— The Bibliography has been updated.
This standard is one of a series specifying methods of test for determining the behaviour of wood-based
panels under the influence of moisture.
oSIST prEN 321:2024
prEN 321:2024 (E)
1 Scope
This document specifies a test method for the determination of the moisture resistance of wood-based
panels under cyclic test conditions.
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.
EN 310, Wood-based panels — Determination of modulus of elasticity in bending and of bending strength
EN 317, Particleboards and fibreboards — Determination of swelling in thickness after immersion in water
EN 319, Particleboards and fibreboards — Determination of tensile strength perpendicular to the plane of
the board
EN 325, Wood-based panels — Determination of dimensions of test pieces
EN 326-1, Wood-based panels — Sampling, cutting and inspection — Part 1: Sampling and cutting of test
pieces and expression of test results
3 Terms and definitions
No te
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