prEN ISO/ASTM 52924

Additive manufacturing - Qualification principles - Classification of part properties for additive manufacturing of polymer parts (ISO/ASTM/DIS 52924:2020)

This standard is aimed at providers of manufacturing services for polymer parts who use additive manufacturing machines and at the customers for these services. Designers of parts as well as buyers and providers of manufacturing services can specify, in a traceable manner, the required or the achievable level of quality with the aid of this standard. This standard applies to parts that have been manufactured from a thermoplastic polymer by means of laser sintering (LS) or material extrusion (MEX). Its applicability to other processes for polymers shall be checked in the specific case. The quality grades apply to parts that have not been post-processed after unpacking from the build space and the removal of possible support structures.

Additive Fertigung - Qualifizierungsgrundsätze - Güteklassen für additiv gefertigte Kunststoffbauteile (ISO/ASTM/DIS 52924:2020)

Fabrication additive - Principes de qualification - Classification des propriétés de la pièce pour la fabrication additive de pièces en polymère (ISO/ASTM/DIS 52924:2020)

Aditivna proizvodnja - Kvalifikacija - Razvrščanje lastnosti delov za aditivno proizvodnjo polimernih delov (ISO/ASTM/DIS 52924:2020)

General Information

• Status: Not Published
• Publication Date: 01-Feb-2022
• Withdrawal Date: 01-May-2022
• ICS: 25.030 - Additive manufacturing
• Technical Committee: CEN/TC 438 - Additive Manufacturing
• Drafting Committee: CEN/TC 438 - Additive Manufacturing
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 16-Feb-2023
• Completion Date: 16-Feb-2023
• Ref Project: oSIST prEN ISO/ASTM 52924:2020 - Additive manufacturing - Qualification principles - Classification of part properties for additive manufacturing of polymer parts (ISO/ASTM/DIS 52924:2020)

Standards Content (Sample)

SLOVENSKI STANDARD
oSIST prEN ISO/ASTM 52924:2020
01-junij-2020
Aditivna proizvodnja - Kvalifikacijska načela - Klasifikacija lastnosti delov za
aditivno proizvodnjo polimernih delov (ISO/ASTM/DIS 52924:2020)

Additive manufacturing - Qualification principles - Classification of part properties for

additive manufacturing of polymer parts (ISO/ASTM/DIS 52924:2020)

Additive Fertigung - Qualifizierungsgrundsätze - Güteklassen für additiv gefertigte

Kunststoffbauteile (ISO/ASTM/DIS 52924:2020)

Fabrication additive - Principes de qualification - Classification des propriétés de la pièce

pour la fabrication additive de pièces en polymère (ISO/ASTM/DIS 52924:2020)
Ta slovenski standard je istoveten z: prEN ISO/ASTM 52924
ICS:
25.030 3D-tiskanje Additive manufacturing
oSIST prEN ISO/ASTM 52924:2020 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO/ASTM 52924:2020
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oSIST prEN ISO/ASTM 52924:2020
DRAFT INTERNATIONAL STANDARD
ISO/ASTM DIS 52924
ISO/TC 261 Secretariat: DIN
Voting begins on: Voting terminates on:
2020-04-07 2020-06-30
Additive manufacturing — Qualification principles —
Classification of part properties for additive manufacturing
of polymer parts
ICS: 25.030
THIS DOCUMENT IS A DRAFT CIRCULATED
This document is circulated as received from the committee secretariat.
FOR COMMENT AND APPROVAL. IT IS
THEREFORE SUBJECT TO CHANGE AND MAY
NOT BE REFERRED TO AS AN INTERNATIONAL
STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS
ISO/CEN PARALLEL PROCESSING
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
Reference number
NATIONAL REGULATIONS.
ISO/ASTM DIS 52924:2020(E)
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. ISO 2020
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oSIST prEN ISO/ASTM 52924:2020
ISO/ASTM DIS 52924:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO/ASTM International 2020

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

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or ISO’s member body in the country of the requester. In the United States, such requests should be sent to ASTM International.

ISO copyright office ASTM International
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Published in Switzerland
ii © ISO/ASTM International 2020 – All rights reserved
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oSIST prEN ISO/ASTM 52924:2020
ISO/ASTM DIS 52924:2020(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Symbols and abbreviations ....................................................................................................................................................................... 2

4.1 Symbols ......................................................................................................................................................................................................... 2

4.2 Abbreviations ........................................................................................................................................................................................... 3

5 Classification system ........................................................................................................................................................................................ 3

5.1 Definition of the classes of part property ........................................................................................................................ 3

5.2 Typical classification of important material classes and usage of the classification

system for part properties ............................................................................................................................................................ 4

6 Test specimens for determining the characteristic values for the classification system .........6

6.1 General ........................................................................................................................................................................................................... 6

6.2 Tensile properties ................................................................................................................................................................................. 6

6.3 Dimensional accuracy ....................................................................................................................................................................... 6

6.4 Density ........................................................................................................................................................................................................... 7

6.5 Labelling ....................................................................................................................................................................................................... 7

6.6 Orientation, grid arrangement, and distribution in the build space ........................................................ 7

6.6.1 General...................................................................................................................................................................................... 7

6.6.2 Orientation and grid arrangement to be used ........................................................................................ 7

6.6.3 Distribution in the build space ............................................................................................................................ 7

6.7 Manufacturing ......................................................................................................................................................................................11

7 Determination of characteristic values and classification in the classification system ..........11

7.1 General ........................................................................................................................................................................................................11

7.2 Mechanical properties ...................................................................................................................................................................11

7.2.1 General...................................................................................................................................................................................11

7.2.2 Determination of characteristic values .....................................................................................................12

7.2.3 Classification in the classifcation system .................................................................................................12

7.3 Dimensional accuracy ....................................................................................................................................................................12

7.3.1 General...................................................................................................................................................................................12

7.3.2 Determination of characteristic values .....................................................................................................12

7.3.3 Classification in the classification system ...............................................................................................13

7.4 Relative part density .......................................................................................................................................................................13

7.4.1 General...................................................................................................................................................................................13

7.4.2 Determination of characteristic values .....................................................................................................13

7.4.3 Classification in the classification system ...............................................................................................13

7.5 Classification in classes of part properties ..................................................................................................................13

8 Initial classification and regular checking of the classifications ....................................................................14

8.1 Standard classification procedure .......................................................................................................................................14

8.2 Initial classification ..........................................................................................................................................................................14

8.3 Regular checking ................................................................................................................................................................................14

8.4 Renewed determination of the classifications in case of replacement of relevant

machine components .....................................................................................................................................................................14

Annex A (informative) Form for part property classification according to ISO/ASTM 52924 ..............16

Bibliography .............................................................................................................................................................................................................................17

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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.

The committee responsible for this document is ISO/TC 261, Additive manufacturing, in cooperation

with ASTM Committee F42, Additive Manufacturing Technologies, on the basis of a partnership

agreement between ISO and ASTM International with the aim to create a common set of ISO/ASTM

standards on Additive Manufacturing.
This is the first edition of this document.
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Introduction

The goal of this document is to improve the communication between providers and users of additive

manufactured polymer parts in relation to the part quality to be supplied. For this purpose, quality

criteria and part properties are categorised into a system of quality classes.

In the additive manufacturing processes relevant for polymers, the part properties depend very heavily

on the machine systems, the material and the process control used. Typically, the process control can

be optimised for productivity or quality. These goals are in principle contradictory in the context of the

performance of a specific machine.

The property classes listed in this standard help to make clear the differences in quality. The property

classes enable the user to define part specifications for manufacturing.

Along with the specification of the property classes, this standard states which property classes can be

achieved with typical materials. Test specimens and their arrangement in the build space are specified

(The related CAD data are included with this document as positioned STL data.). The determination

of the mechanical tensile properties, the dimensional accuracy and the part density with the aid of

these test specimens is described to make possible the assignment to property classes for the related

characteristic values.
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oSIST prEN ISO/ASTM 52924:2020
DRAFT INTERNATIONAL STANDARD ISO/ASTM DIS 52924:2020(E)
Additive manufacturing — Qualification principles —
Classification of part properties for additive manufacturing
of polymer parts
1 Scope

This document establishes the required or the achievable classes of part properties for additive

manufactured polymer parts in order to get a common understanding on part quality. It is aimed at

providers of manufacturing services for polymer parts who use additive manufacturing machines and

at the customers for these services. Designers of parts as well as buyers and providers of manufacturing

services can specify, in a traceable manner, the required or the achievable level of part properties with

the aid of this standard.

This document applies to parts that have been manufactured from a thermoplastic polymer by means

of powder bed fusion with laser for polymers (PBF-LB/P), alternatively named laser sintering (LS)

or material extrusion (MEX). Its applicability to other processes for polymers shall be checked in the

specific case.
NOTE Laser sintering is also known as selective laser sintering (SLS ).

NOTE The process called material extrusion (MEX) in ISO/ASTM 52900 is also known as fused layer modelling

(FLM), fused layer manufacturing or fused deposition modelling (FDM) or fused filament fabrication (FFF).

The classification of part properties apply to parts that have not been post-processed after unpacking

from the build space and after removing possible support structures.
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 37:2017, Rubber, vulcanized or thermoplastic — Determination of tensile stress-strain properties

ISO 291:2008, Plastics — Standard atmospheres for conditioning and testing

ISO 527-1:2012, Plastics - Determination of tensile properties - Part 1: General principles

ISO 3167:2014, Plastics — Multipurpose test specimens

ISO 10350-1:2017, Plastics — Acquisition and presentation of comparable single-point data — Part 1:

Moulding materials
ISO 20457:2018, Plastics moulded parts — Tolerances and acceptance conditions
ISO/ASTM 52900:2018, Additive manufacturing; General principles — Terminology

ISO/ASTM 52921:2013-06, Standard terminology for additive manufacturing - Coordinate systems and

test methodologies
3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO/ASTM 52900 and the

following apply.
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ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http:// www .electropedia .org/
— ISO Online browsing platform: available at https:// www .iso .org/ obp
3.1
part density

ratio of part mass, m, and measured part volume, V, of a laser sintered or material extruded part

ρ= (1)
Note 1 to entry: The part is generally cubeshaped.
3.2
laser sintered as manufactured

state of a cooled part after the end of the laser sintering process immediately after unpacking

Note 1 to entry: Laser sintered parts as manufactured are generally dry.

Note 2 to entry: The laser sintered part as manufactured state exists for the materials PA12, PA11, PP, PE, PAEK,

TPE in the following conditions:

— The build job is cooled to room temperature in a nitrogen atmosphere, where the supply of air during cooling

until the parts are unpacked shall be avoided if possible or reduced to a minimum.

— The parts are unpacked within three days of the end of the build job.

— The parts have been subjected to the air for a maximum of 4 h since the start of part removal.

— The parts removed are stored with the exclusion of air, e.g., in air-tight and moisture-tight packaging.

3.3
nominal material density
solid density of the feedstock, measured on a specimen free of pores

Note 1 to entry: In data sheets, the nominal material density is mostly stated as material density of compounded,

injection molded or compression molded material.
3.4
relative part density
ratio of part density, ρ (3.1), and nominal material density, ρ (3.3)
D= (2)
4 Symbols and abbreviations
4.1 Symbols
The following symbols are used throughout this standard:
Symbol Designation Unit
D relative part density %
m part mass g, kg
V part volume cm
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Symbol Designation Unit
ρ part density g/cm
ρ nominal material density g/cm
4.2 Abbreviations
The following abbreviations are used throughout this standard:
ABS acrylonitrile butadiene styrene
LS laser sintering
MEX material extrusion
NW non-tool related dimensions
PA6 polyamide 6
PA11 polyamide 11
PA12 polyamide 12
PAEK polyaryletherketone
PC polycarbonate
PE polyethylene
PEI/PC polyetherimide/polycarbonate blend
PP polypropylene
TG tolerance group
TPE thermoplastic elastomer
TPA thermoplastic copolyamide
TPC thermoplastic polyester elastomer
TPU thermoplastic polyurethane
5 Classification system
5.1 Definition of the classes of part property

Classes of part properties shall be established based on mechanical tensile properties, density and

dimensional accuracy of manufactured parts.

To make the differences in quality during the additive manufacturing of polymer parts clearer and

easier to communicate, the classification system shown in Table 1 shall be used.

This system classifies typical value ranges for important part characteristics and assigns these ranges

to common materials for the laser sintering and material extrusion processes.

The classification system contains eleven different classes of part properties that are sequentially

numbered from 0 to 10.

Material characteristic values determined as per typical standards from the tensile test (ISO 527-1 or

for elastic materials ISO 37) and the density measurement in 7.4 are used as characteristic values. At

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the same time, the dimensional accuracy achievable with additive manufacturing is assigned to the

tolerance classes according to ISO 20457 for dimensions that are not tool related.

The part property classes in the classes 0 to 10 cover ranges that can typically be achieved on

consideration of all the material aspects of polymer-processing additive processes. Here each

characteristic value shall be considered independent from the others and dependent on the part

orientation. This means that each characteristic value can have a different class.

Table 1 — (1 of 3)— Classes of part properties for polymer parts from additive manufacturing

Characteristic Tensile modulus Strength/ Ten- Strain at break/ Relative part Dimensional

value sile strength Elongation at density accuracy
break
Unit MPa MPa % %

Test standard ISO 527-1/ ISO 527-1/ ISO 37 ISO 527-1/ ISO 37 acc. to 8.3 ISO 20457

Class 10 > 8 000 > 100 > 200 > 99,5 —
Class 9 > 6 000 ≤ 8 000 > 85 ≤ 100 > 100 ≤ 200 > 99 ≤ 99,5 —
Class 8 > 5 000 ≤ 6 000 > 70 ≤ 85 > 50 ≤ 100 > 98,5 ≤ 99 TG 1 NW
Class 7 > 4 000 ≤ 5 000 > 60 ≤ 70 > 35 ≤ 50 > 97,5 ≤ 98,5 TG 2 NW
Class 6 > 3 000 ≤ 4 000 > 50 ≤ 60 > 25 ≤ 35 > 95 ≤ 97,5 TG 3 NW
Proper-
Class 5 > 2 500 ≤ 3 000 > 45 ≤ 50 > 20 ≤ 25 > 92,5 ≤ 95 TG 4 NW
ty class
Class 4 > 2 000 ≤ 2 500 > 40 ≤ 45 > 15 ≤ 20 > 90 ≤ 92,5 TG 5 NW
Class 3 > 1 500 ≤ 2 000 > 30 ≤ 40 > 10 ≤ 15 > 85 ≤ 90 TG 6 NW
Class 2 > 1 000 ≤ 1 500 > 20 ≤ 30 > 5 ≤ 10 > 80 ≤ 85 TG 7 NW
Class 1 > 500 ≤ 1 000 > 10 ≤ 20 > 3 ≤ 5 > 70 ≤ 80 TG 8 NW
Class 0 0 ≤ 500 > 0 ≤ 10 0 ≤ 3 > 0 ≤ 70 TG 9

5.2 Typical classification of important material classes and usage of the classification

system for part properties

The intention is to make the range of typical part properties for a material type and an additive

manufacturing process distinguishable and comparable. To clarify this point, typical classifications for

important material classes for laser sintering and for material extrusion are summarised in Table 2

based on the state of the art and experts’ experience.

The compilation shows that characteristic values cannot always be classified exactly in one grade. Due

to differences between machines and variations in parameters, the related achievable characteristic

values can fall into different classes. On the basis of Table 2, the quality of parts from different providers

and parameter sets can be compared and requirements on the specific parts can be defined.

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Table 2 — (2 of 3)— Examples for classifications for typical laser sintering and material

extrusion materials
Char- Te Charac-teristic TPA/TPC/ PEI/PC PA 12
Class PA 12 (LS) PA 11 (LS) PAEK (LS) ABS (MEX)
ac- st st value range TPU (LS) (MEX) (MEX)
ter- Unit an
istic da
Alignment XY ZX XY ZX XY ZX XY ZX XY ZX XY ZX XY ZX
value rd
< 500 0 X X
500≤1000 1
1000≤1500 2 X X
1500≤2000 3 X X X X X X
2000≤2500 4 X X X
Ten-
ISO
sile
MPa 527- 2500≤3000 5 X
mod-
ulus
3000≤4000 6 X X
4000≤5000 7
5000≤6000 8
6000≤8000 9
> 8000 10
< 10 0 X X
10≤20 1 X X
20≤30 2 X X
Str
30≤40 3 X X
eng
ISO
th/
40≤45 4 X X X X
ns MPa 45≤50 5 X X X X X X
ile
ISO
50≤60 6 X X X X X X
str
eng
60≤70 7 X X
70≤85 8 X X
85≤100 9
> 100 10
< 3 0 X X X X
3≤5 1 X
Str 5≤10 2 X X X X
ain
10≤15 3 X X
ISO
bre
15≤20 4 X X X X
ak/
Elo % 20≤25 5 X X X
nga
ISO
25≤35 6 X X
tio
n at
35≤50 7 X X
bre
ak 50≤100 8 X X
100≤200 9 X X
> 200 10 X X
< 70 0
70≤80 1
80≤85 2
85≤90 3 X
Rel-
90≤92,5 4 X X X
ac-
ative
cord-
part % 92,5≤95 5 X X X X X
ing to
den-
8.3
95≤97,5 6 X X X X X X
sity
97,5≤98,5 7 X X X X X X
98,5≤99 8 X X X X X
99≤99,5 9 X
> 99,5 10
a The component density is specified independent of orientation.
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Table 2 (continued)
Char- Te Charac-teristic TPA/TPC/ PEI/PC PA 12
Class PA 12 (LS) PA 11 (LS) PAEK (LS) ABS (MEX)
ac- st st value range TPU (LS) (MEX) (MEX)
ter- Unit an
istic da
Alignment XY ZX XY ZX XY ZX XY ZX XY ZX XY ZX XY ZX
value rd
TG 9 0
TG 8 NW 1
TG 7 NW 2 X X X X X X
TG 6 NW 3 X X X X X X X X X X X X X X
Di-
TG 5 NW 4 X X X X X X X X X X X X X X
men-
ISO
sional TG 4 NW 5 X X X X X X X X X X
20457
accu-
TH 3 NW 6
racy
TG 2 NW 7
TG 1 NW 8
a The component density is specified independent of orientation.

It shall be noted that the upper classes of part properties listed usually define the maximum values

currently technically possible. The definition of a requirement for a specific material with a higher class

is therefore not appropriate in this context and can only be achieved by a few specialists in exceptional

cases. At the same time, it shall be noted that the information relates to the unfilled material types in

each case.
6 Test specimens for determining the characteristic values for the
classification system
6.1 General

To perform a classification in the established system in clause 5, a comparable pool of data shall be

created. These data can only be determined by measurements on a minimum number of at least 7 test

specimens.

Test specimen shall be manufactured under defined process conditions and in particular with defined

test specimen arrangements.
Requirements established in 6.2 to 6.7 apply.
6.2 Tensile properties

Tensile test specimens according to ISO 3167 type A with a total length of at least 150 mm and a test

cross-section of 4 mm × 10 mm shall be used. For elastic materials (TPE, TPA, TPC, TPU), a test specimen

according to ISO 37 type S2 shall be used.

An alternative type of test specimen may be used, in consultation between suppliers and customers and

deviating from this standard, only in machines with a smaller usable build space (longest build space

edge or build space height less than 150 mm) on which the dimensions of the test specimens cannot be

met. This deviation shall be stated with the information on the classification with the tensile bar used.

6.3 Dimensional accuracy

Bars with a cross-section of 5 mm × 10 mm and different test specimen lengths shall be manufactured.

The lengths to be manufactured are around 24 mm, 40 mm, 65 mm, 100 mm and 150 mm and are

therefore in the middle of the nominal dimension ranges to be checked according to ISO 20457. Before

manufacturing, the length dimensions shall be adjusted to an integer multiple of the layer thickness

used. This is done to exclude measurement deviations due to the layer thickness during classification.

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For this purpose the stated length dimensions are divided by the layer thickness, and the resulting

number shall be rounded to the next whole number. This rounded number is in turn multiplied by the

layer thickness. The resulting length is the test specimen length to be manufactured.

The larger lengths may be excluded, in consultation between suppliers and customers, only in machines

with a smaller usable build space (longest build space edge or build space height less than 150 mm)

on which the dimensions of the test specimens cannot be met. This deviation shall be stated with the

information on the classification with the modified validity range.
6.4 Density
Cubes with an edge length of 20 mm sh
...