EN ISO 844:2021

SLOVENSKI STANDARD
01-junij-2021
Nadomešča:
SIST EN ISO 844:2014
Penjeni polimerni materiali - Trde pene - Ugotavljanje lastnosti stiskanja (ISO
844:2021)
Rigid cellular plastics - Determination of compression properties (ISO 844:2021)
Harte Schaumstoffe - Bestimmung der Druckeigenschaften (ISO 844:2021)
Plastiques alvéolaires rigides - Détermination des caractéristiques de compression (ISO
844:2021)
Ta slovenski standard je istoveten z: EN ISO 844:2021
ICS:
83.100 Penjeni polimeri Cellular materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 844
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2021
EUROPÄISCHE NORM
ICS 83.100 Supersedes EN ISO 844:2014
English Version
Rigid cellular plastics - Determination of compression
properties (ISO 844:2021)
Plastiques alvéolaires rigides - Détermination des Harte Schaumstoffe - Bestimmung der
caractéristiques de compression (ISO 844:2021) Druckeigenschaften (ISO 844:2021)
This European Standard was approved by CEN on 31 January 2021.

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. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre 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 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, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 844:2021 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 844:2021) has been prepared by Technical Committee ISO/TC 61 "Plastics" in
collaboration with Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by NBN.
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 October 2021, and conflicting national standards shall
be withdrawn at the latest by October 2021.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN ISO 844:2014.
According 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, 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, Turkey and the
United Kingdom.
Endorsement notice
The text of ISO 844:2021 has been approved by CEN as EN ISO 844:2021 without any modification.

INTERNATIONAL ISO
STANDARD 844
Seventh edition
2021-03
Rigid cellular plastics —
Determination of compression
properties
Plastiques alvéolaires rigides — Détermination des caractéristiques
de compression
Reference number
ISO 844:2021(E)
©
ISO 2021
ISO 844:2021(E)
© ISO 2021
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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ii © ISO 2021 – All rights reserved

ISO 844:2021(E)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Symbols . 2
5 Principle . 3
6 Apparatus . 3
6.1 Compression-testing machine . 3
6.2 Devices for measuring displacement and force . 3
6.2.1 Measurement of displacement . 3
6.2.2 Measurement of force . 4
6.2.3 Calibration . 4
6.3 Instruments for measuring the dimensions of the test specimens . 4
7 Test specimens. 4
7.1 Dimensions . 4
7.2 Preparation . 5
7.3 Number . 5
7.4 Conditioning . 5
8 Procedure. 5
9 Expression of results . 6
9.1 General . 6
9.2 Compressive strength and corresponding relative deformation . 7
9.2.1 Compressive strength . 7
9.2.2 Nominal relative deformation (procedure A) . 7
9.2.3 Relative deformation (procedure B) . 8
9.3 Compressive stress at 10 % nominal relative deformation (procedure A) . 8
9.4 Nominal compressive modulus of elasticity (procedure A) . 8
9.5 Compressive modulus of elasticity (procedure B) . 9
10 Precision . 9
10.1 Procedure A . 9
10.2 Procedure B .10
11 Test report .11
Annex A (informative) Remarks about the determination of the compressive modulus .12
Bibliography .15
ISO 844:2021(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 61, Plastics, Subcommittee SC 10, Cellular
plastics, in collaboration with the European Committee for Standardization (CEN) Technical Committee
CEN/TC 249, Plastics, in accordance with the Agreement on technical cooperation between ISO and CEN
(Vienna Agreement).
This seventh edition cancels and replaces the sixth edition (ISO 844:2014), which has been technically
revised. The main changes compared to the previous edition are as follows:
— different extensometer gage lengths have been given for use with different specimen thicknesses;
— repeatability and reproducibility results from the interlaboratory test o
...