ISO 16365-1:2025

International
Standard
ISO 16365-1
Second edition
Plastics — Thermoplastic
2025-02
polyurethanes for moulding and
extrusion —
Part 1:
Designation system and basis for
specifications
Plastiques — Polyuréthannes thermoplastiques pour moulage et
extrusion —
Partie 1: Système de désignation et base de spécifications
Reference number
© ISO 2025
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ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Designation system . 2
4.1 General .2
4.2 Data block 1 .3
4.3 Data block 2 .3
4.4 Data block 3 .4
4.5 Data Block 4 .5
4.5.1 General .5
4.5.2 Hardness .5
4.5.3 Tensile modulus of elasticity .6
4.6 Data block 5 .6
5 Examples of designations . 7
Bibliography . 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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The procedures used to develop this document and those intended for its further maintenance are described
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of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
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This document was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic
materials.
This second edition cancels and replaces the first edition (ISO 16365-1:2014), which has been technically
revised.
The main changes are as follows:
— the range of hardness Shore A in Table 4 has been modified.
A list of all parts in the ISO 16365 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
This document is based on the ISO 1043 series and ISO 11469.
The types of thermoplastic polyurethane are differentiated from each other by a classification system based
on appropriate levels of the designatory properties:
a) hardness;
b) tensile modulus of elasticity (optional);
and on information about the alternating hard and soft segments in the main chain, the intended application
and/or method of processing, important properties, additives, colour, fillers and reinforcing materials.
In order to specify a thermoplastic elastomer for a particular application or reproducible processing,
additional requirements are given in data block 5 (see 4.1 and 4.6).

v
International Standard ISO 16365-1:2025(en)
Plastics — Thermoplastic polyurethanes for moulding and
extrusion —
Part 1:
Designation system and basis for specifications
1 Scope
This document establishes a system of designation for thermoplastic polyurethane elastomers.
The designation system can be used as the basis for specifications.
The designation system is applicable to all thermoplastic polyurethane elastomers. It applies to materials
ready for normal use in the form of powder, granules or pellets, unmodified or modified by colourants, fillers
or other additives, etc.
This document does not intend to imply that materials having the same designation give necessarily the
same performance. This document does not provide engineering data, performance data, or data on
processing conditions which might be required to specify a material for a particular application and/or
method of processing.
NOTE If such additional properties are required, they can be determined according to the test methods specified
in ISO 16365-2, if suitable.
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 527 (all parts), Plastics — Determination of tensile properties
ISO 868, Plastics and ebonite — Determination of indentation hardness by means of a durometer (Shore
hardness)
ISO 1043-4, Plastics — Symbols and abbreviated terms — Part 4: Flame retardants
ISO 18064, Thermoplastic elastomers — Nomenclature and abbreviated terms
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 Designation system
4.1 General
The designation system for polyurethanes is based on the following standardized pattern (see Table 1).
Table 1 — Data block designation system
Designation
Identity Block
Description Internation- Individual Item Block
block (option- al Standard
Data Block 1 Data Block 2 Data Block 3 Data Block 4 Data Block 5
al) Block
The designation consists of an optional description block, reading “Thermoplastics”, and an identity block
comprising the International Standard number and an individual item block. For unambiguous designation,
the individual item block shall be subdivided into five data blocks comprising the following information.
— Data block 1: Identification of the thermoplastic polyurethane by its abbreviated symbol (TPU), in
accordance with ISO 18064, and optional information on the alternating hard and soft segments in the
main chain (see 4.2).
— Data block 2: Fillers or reinforcing materials including summarized nominal content (see 4.3):
— important properties, modifier, and flame retardant (see 4.3);
— declaration of recyclate: R followed by a number representing the percentage by mass of recyclate
(see 4.3).
— Data block 3: Application and processing:
— Position 1: method of processing (see 4.4);
— Positions 2 and further: additives, supplementary information and other characteristics (see 4.4).
— Data block 4: Designatory properties (see 4.5):
— hardness;
— modulus.
— Data block 5: For the purpose of specifications, a fifth data block containing additional information may
be used (see 4.6). The kind of information and the code-letters used are not the subject of this document.
The first character of the individual item block shall be a hyphen.
The five data bl
...