ISO 813-2:2024

Rubber, vulcanized or thermoplastic - Determination of adhesion to a rigid substrate - Part 2: Adhesion of a soft thermoplastic elastomer layer

This document specifies a test method for assessing the peel strength of a thermoplastic elastomer (TPE) to a rigid substrate. It is mainly applicable to soft components in the Shore A hardness range. This document specifies a test piece but not the injection moulding tool for its manufacture. Hence, it is possible that different results are obtained for test pieces produced using different injection moulding tools.

Caoutchouc vulcanisé ou thermoplastique — Détermination de l'adhérence à un substrat rigide — Partie 2: Adhérence d'une couche d'élastomère thermoplastique souple

General Information

• Status: Published
• Publication Date: 22-Feb-2024
• ICS: 83.060 - Rubber
• Technical Committee: ISO/TC 45/SC 2 - Testing and analysis
• Drafting Committee: ISO/TC 45/SC 2 - Testing and analysis
• Current Stage: 6060 - International Standard published
• Start Date: 23-Feb-2024
• Due Date: 24-Mar-2025
• Completion Date: 23-Feb-2024

Overview

ISO 813-2:2024 specifies a repeatable laboratory test method for measuring the adhesion (peel strength) of a soft thermoplastic elastomer (TPE) layer bonded to a rigid substrate. The standard is targeted mainly at soft components in the Shore A hardness range and defines the test piece geometry, conditioning, test apparatus and procedure for a 90° peel test. Note: ISO 813-2:2024 defines the test piece but does not prescribe the injection‑moulding tool, so results can vary with different mould designs.

Keywords: ISO 813-2:2024, thermoplastic elastomer, TPE adhesion, peel strength, adhesion to rigid substrate

Key topics and technical requirements

• Principle: Measure force required to peel a fixed-width TPE strip from a rigid substrate at a 90° angle.
• Apparatus:
  • Tensile testing machine (class 1 per ISO 5893).
  • Test trolley and guide pulley (recommended pulley Ø 8–9 mm); trolley horizontal start friction ≤ 4 N.
• Test pieces:
  • Standard soft component wall thickness (2 ± 0.2) mm; for very low hardness TPEs, (3 ± 0.2) mm allowed.
  • Preferably produced by two‑component injection moulding (core‑back technique recommended).
  • Moulded hard component surface roughness at bond area: RA 2.20 µm–3.20 µm (ISO 21920‑1).
  • Avoid visible defects (flow marks, sink marks, air inclusions, overmoulding) that affect bonding.
  • Minimum of five test pieces per test series.
• Conditioning and test conditions:
  • Condition specimens ≥16 h at (23 ± 2) °C / (50 ± 10) % RH (ISO 23529).
  • Peel at 100 mm/min; use trolley displacement to measure peeled length.
• Results and classification:
  • Peel strength W (N/mm) = F (N) / b (mm), where F is adhesion force evaluated per ISO 6133.
  • Fracture pattern classification (A, B, C, D, mixed patterns, or E) describes residue of TPE on substrate and failure mode.

Applications and who uses it

ISO 813-2:2024 is used by:

• TPE material suppliers and compounders for product characterization and specification.
• Injection moulders and tool designers assessing overmoulding and joint integrity.
• OEMs and product engineers in automotive, consumer goods, medical devices, electronics and industrial components where TPEs are bonded to rigid parts for functional, visual or haptic reasons.
• Testing and QA laboratories performing routine adhesion/peel testing and supplier qualification.

Practical benefits: provides a standardized, comparable way to evaluate TPE-to-substrate adhesion, guide material selection, validate moulding processes and support failure analysis.

Related standards

• ISO 5893 - Tensile test equipment specification
• ISO 6133 - Analysis of multi‑peak traces for tear and adhesion
• ISO 23529 - Conditioning of test pieces
• ISO 18899 - Calibration guide for test equipment
• ISO 21920‑1 - Surface roughness measurement

For implementation details, refer to the full ISO 813-2:2024 document and related normative references.

Standards Content (Sample)

International
Standard
ISO 813-2
First edition
Rubber, vulcanized or
2024-02
thermoplastic — Determination of
adhesion to a rigid substrate —
Part 2:
Adhesion of a soft thermoplastic
elastomer layer
Caoutchouc vulcanisé ou thermoplastique — Détermination de
l'adhérence à un substrat rigide —
Partie 2: Adhérence d'une couche d'élastomère thermoplastique
souple
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
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Principle . 2
5 Apparatus . 2
5.1 Tensile testing machine .2
5.2 Test trolley .2
6 Calibration . 3
7 Test pieces . 3
7.1 Form and dimensions .3
7.2 Test piece fabrication using the injection moulding method .4
7.3 Test piece with inserted rigid substrate.5
7.4 Number of test pieces .5
8 Conditioning . 5
9 Test conditions . 6
10 Procedure . 6
11 Expression of results . 6
11.1 Peel strength .6
11.2 Fracture pattern .7
12 Test report . 8
Annex A (informative) Example of listing the test results . 10
Annex B (normative) Calibration schedule .12
Annex C (informative) Glossary . 14
Bibliography .15

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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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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this may not represent the latest information, which may be obtained from the patent database available at
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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 45, Rubber and rubber products, Subcommittee
SC 2, Testing and analysis.
A list of all parts in the ISO 813 series can be found on the ISO website.
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
Introduction
Nowadays it is common to use combinations of materials aimed at achieving special properties for parts
of a product. Thermoplastic elastomers (TPEs) are used in a large percentage of these applications for
functional, visual, acoustic, haptic and tactile reasons, with injection moulding used as the joining method in
[3,4]
the majority of cases. Due to their thermoplastic nature, TPE materials are gaining importance steadily
in this area relative to vulcanized rubber.
Due to the wide variety of TPE types encountered nowadays and the large number of manufacturers, it is
difficult to reach comparative conclusions regarding the bond strength between two materials. Accordingly,
the purpose of this document is to specify a peel test procedure specifically for measuring the adhesion of a
TPE to a rigid substrate.
v
International Standard ISO 813-2:2024(en)
Rubber, vulcanized or thermoplastic — Determination of
adhesion to a rigid substrate —
Part 2:
Adhesion of a soft thermoplastic elastomer layer
WARNING 1 — Persons using this document should be familiar with normal laboratory practice. This
document does not purport to address all of the safety problems, if any, associated with its use. It is
the responsibility of the user to establish appropriate safety and health practices and to determine
the applicability of any other restrictions.
WARNING 2 — Certain procedures specified in this document can involve the use or generation of
substances, or the generation of waste, that could constitute a local environmental hazard. Reference
should be made to appropriate documentation on safe handling and disposal after use.
1 Scope
This document specifies a test method for assessing the peel strength of a thermoplastic elastomer (TPE) to
a rigid substrate. It is mainly applicable to soft components in the Shore A hardness range.
This document specifies a test piece but not the injection moulding tool for its manufacture. Hence, it is
possible that different results are obtained for test pieces produced using different injection moulding tools.
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 5893, Rubber and plastics test equipment — Tensile, flexural and compression types (constant rate of
traverse) — Specification
ISO 6133, Rubber and plastics — Analysis of multi-peak traces obtained in determinations of tear strength and
adhesion strength
ISO 18899:2013, Rubber — Guide to the calibration of test equipment
ISO 23529, Rubber — General procedures for preparing and conditioning test pieces for physical test methods
3 Terms and definitions
No terms and definitions are listed in this document.
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/

4 Principle
The force required to cause separation of a strip of a TPE covering a rigid substrate is measured, the angle of
separation being 90° and the width and thickness of the TPE being fixed within specified limits.
Special TPE material descriptions are listed in Annex C for better understanding.
5 Apparatus
5.1 Tensile testing machine
A tensile testing machine in accordance with class 1 of ISO 5893 shall be used to perform the peel test.
5.2 Test trolley
An example of a suitable test trolley used for clamping the test piece is shown in Figure 1 and the clamping
arrangement in Figure 2. The trolley mounting shall be such that the force required to set the test trolley,
including the guide pulley, in motion in the horizontal direction does not exceed 4 N.
All dimensions are just a guide. The chosen dimension of the test specimen shall fit securely into the trolley.
Dimensions in millimetres
Key
1 clamped test specimen
2 mounting
3 clamping plates
4 guide pulley, free rotation shall be possible, a diameter of 8 mm to 9 mm is recommended
Figure 1 — Test trolley
Dimensions in millimetres
Key
1 tensile axis
2 free end of the soft component
3 guide pulley
F direction of the force the soft component is pulled from the rig
...