JAPANESEINDUSTRIAL
STANDARD
Translated and Published by
Japanese Standards Association

JIS K 6401: 2023

(JRMA/JSA)

Flexible cellular polymeric materials —Polyurethane foam for load-bearing
applications excluding carpet underlay —Specification

ICS 83.100
Reference number : JIS K 6401 : 2023 (E)
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15 S

K 6401 : 2023

Date of Establishment: 1965-05-01
Date of Revision:

2023-02-20

Date of Public Notice in Official Gazette: 2023-02-20
Investigated by: Japanese Industrial Standards CommitteeStandards Board for ISO area
Technical Committee on Chemical Products andAnalytical Methods
JIS K 6401 : 2023, First English edition published in 2024-05
Translated and published by: Japanese Standards Association
Mita Avanti, 3-11-28, Mita, Minato-ku, Tokyo, 108-0073 JAPANIn the event of any doubts arising as to the contents,
the original JIS is to be the final authority.
 JSA 2024
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized
in any form or by any means, electronic or mechanical, including photocopying and microfilm, without
permission in writing from the publisher.
Printed in JapanHN

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Contents
Page
Introduction ······························································································· 11

Scope ································································································ 12Normative references··········································································· 13Terms and definitions ·········································································· 244.1
4.24.3
4.4

Classification ····················································································· 3
General ····························································································· 3Type ································································································· 3Class ································································································ 3
Grade ······························································································· 75Form ································································································ 866.16.26.36.46.5

Quality ····························································································· 8Tolerance on mass ·············································································· 8Tolerance on apparent density ······························································ 8Tolerance on dimensions ······································································ 8
Physical properties·············································································· 9
Burning properties ·············································································· 977.17.27.37.47.57.67.77.87.97.107.11

Test methods ····················································································13
General test conditions ·······································································13
Mass ·······························································································13Apparent density ···············································································13
Dimensions ·······················································································13
Hardness··························································································13
Resilience ·························································································13
Compression set ················································································14Hardness loss ratio ············································································14
Tensile strength and elongation at break ···············································14
Tensile strength after humidity ageing ··················································14
Tensile strength after heat ageing ························································1488.18.28.3Inspection·························································································14
General ····························································································14Type inspection ·················································································14
Acceptance inspection ·········································································159Marking ···························································································15

Annex A (informative)
Annex B(informative)

Typical applications for each class of material·················16
Burning properties of flexible polyurethane foam(i)
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and recommendations regarding its use ······················ 17
Annex JA(informative)

Annex JB (informative)

Quality items desirable to be considered between
the interested parties············································· 19
Comparison table between JIS and corresponding
International Standard ············································ 22(ii)PROTECTED BY COPYRIGHTK 6401 : 2023

Foreword
This Japanese Industrial Standard has been revised by the Minister ofEconomy, Trade and Industry through deliberations at the Japanese Industrial Standards Committee as the result of proposal for revision ofJapanese Industrial Standard submitted by The Japan Rubber Manufacturers Association (JRMA)/Japanese Standards Association (JSA) witha draft being attached, based on the provision of Article 12, paragraph (1)of the Industrial Standardization Act applied mutatis mutandis pursuant
to the provision of Article 16 of the said Act. This edition replaces theprevious edition (JIS K 6401 : 2011), which has been technically revised.
This JIS document is protected by the Copyright Act.
Attention is drawn to the possibility that some parts of this Standard
may conflict with patent rights, published patent application or utility
model rights. The relevant Minister and the Japanese Industrial Standards Committee are not responsible for identifying any of such patentrights, published patent application or utility model rights.

(iii)
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BlankJAPANESE INDUSTRIAL STANDARD

JIS K 6401 : 2023

Flexible cellular polymeric materials — Polyurethane foam
for load-bearing applications excluding carpet underlay —Specification
Introduction
This Japanese Industrial Standard has been prepared based on ISO 5999 : 2013,
Edition 3, with some modifications of the technical contents.
The vertical lines on both sides and dotted underlines indicate changes from the corresponding International Standard. A list of modifications with the explanations isgiven in Annex JB.
1ScopeThis Standard specifies requirements for flexible load-bearing polyurethane foam ofthe polyether type, consisting of a network of cells which are essentially open and interconnecting (hereafter referred to as foams).
This Standard is not applicable to polyurethane foams foamed in place, to foams foruse in heat-welded systems unless for load-bearing purposes or foams for carpet backing and underlay or for cushioning for packaging.
The foam is classified according to the type of foam, the performance during a fatigue
test, and the indentation hardness index used as a means of grading materials.
Recommended applications for the range of flexible polyurethane foams covered bythis Standard are listed in Annex A.
NOTE

The International Standard corresponding to this Standard and thesymbol of degree of correspondence are as follows.

Flexible cellular polymeric materials — Polyurethane
foam for load-bearing applications excluding carpet underlay — Specification (MOD)ISO 5999 : 2013

In addition, symbols which denote the degree of correspondence in thecontents between the relevant International Standard and JIS are IDT(identical), MOD (modified), and NEQ (not equivalent) according toISO/IEC Guide 21-1.
WARNING

2

Persons using this Standard should be familiar with normal laboratory
practice. This Standard does not purport to address all of the safety
problems, if any, associated with its use. It is the responsibility of theuser of this Standard to establish appropriate safety and health practices.

Normative references
Part or all of the provisions of the following standards, through reference in this text,

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