EN ISO 293:2005
(Main)Plastics - Compression moulding of test specimens of thermoplastic materials (ISO 293:2004)
Plastics - Compression moulding of test specimens of thermoplastic materials (ISO 293:2004)
ISO 293:2004 specifies the general principles and the procedures to be followed with thermoplastics in the preparation of compression-moulded test specimens, and sheets from which test specimens may be machined or stamped.
Kunststoffe - Formgepresste Probekörper aus Thermoplasten (ISO 293:2004)
Diese Internationale Norm legt die allgemeinen Prinzipien und Verfahren fest, die für Thermoplaste bei der Herstellung von formgepressten Probekörpern und Platten zu befolgen sind, aus denen durch maschinelles Bearbeiten oder Stanzen Probekörper hergestellt werden können.
Um einen vergleichbaren Zustand bei den Formpressteilen zu erzielen, sind die Hauptschritte des Verfahrens, einschließlich vier unterschiedlicher Abkühlverfahren, genormt. Die erforderliche Presstemperatur und die Abkühlverfahren sind für jedes Material so, wie es in der entsprechenden Internationalen Norm für das Material festgelegt ist oder zwischen den beteiligten Partnern vereinbart wurde.
Das Verfahren wird nicht für verstärkte thermoplastische Kunststoffe empfohlen
Plastiques - Moulage par compression des éprouvettes en matières thermoplastiques (ISO 293:2004)
L'ISO 293:2004 spécifie les principes généraux et les modes opératoires à suivre, dans le cas de matières thermoplastiques, pour la préparation d'éprouvettes moulées par compression et de plaques nécessaires pour l'usinage ou la découpe d'éprouvettes.
Polimerni materiali - Preskušanci plastomerov, oblikovani s stiskanjem (ISO 293:2004)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-oktober-2005
1DGRPHãþD
SIST EN ISO 293:2003
Polimerni materiali - Preskušanci plastomerov, oblikovani s stiskanjem (ISO
293:2004)
Plastics - Compression moulding of test specimens of thermoplastic materials (ISO
293:2004)
Kunststoffe - Formgepresste Probekörper aus Thermoplasten (ISO 293:2004)
Plastiques - Moulage par compression des éprouvettes en matieres thermoplastiques
(ISO 293:2004)
Ta slovenski standard je istoveten z: EN ISO 293:2005
ICS:
83.080.20 Plastomeri Thermoplastic materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EUROPEAN STANDARD
EN ISO 293
NORME EUROPÉENNE
EUROPÄISCHE NORM
July 2005
ICS 83.080.20 Supersedes EN ISO 293:2003
English Version
Plastics - Compression moulding of test specimens of
thermoplastic materials (ISO 293:2004)
Plastiques - Moulage par compression des éprouvettes en Kunststoffe - Formgepresste Probekörper aus
matières thermoplastiques (ISO 293:2004) Thermoplasten (ISO 293:2004)
This European Standard was approved by CEN on 7 July 2005.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia,
Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36 B-1050 Brussels
© 2005 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 293:2005: E
worldwide for CEN national Members.
Foreword
The text of ISO 293:2004 has been prepared by Technical Committee ISO/TC 61 "Plastics” of
the International Organization for Standardization (ISO) and has been taken over as EN ISO
293:2005 by Technical Committee CEN/TC 249 "Plastics", the secretariat of which is held by
IBN.
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 January 2006, and conflicting national
standards shall be withdrawn at the latest by January 2006.
This document supersedes EN ISO 293:2003.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Endorsement notice
The text of ISO 293:2004 has been approved by CEN as EN ISO 293:2005 without any
modifications.
INTERNATIONAL ISO
STANDARD 293
Third edition
2004-05-01
Plastics — Compression moulding of test
specimens of thermoplastic materials
Plastiques — Moulage par compression des éprouvettes en matières
thermoplastiques
Reference number
ISO 293:2004(E)
©
ISO 2004
ISO 293:2004(E)
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©
ii ISO 2004 – All rights reserved
ISO 293:2004(E)
Contents Page
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Apparatus . 2
5 Procedure . 4
6 Inspection of the moulded specimens or sheets . 6
7 Specimen preparation report . 6
©
ISO 2004 – All rights reserved iii
ISO 293:2004(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 293 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 9, Thermoplastic
materials.
This third edition cancels and replaces the second edition (ISO 293:1986), of which it constitutes a minor
revision intended, above all, to update the normative references (Clause 2).
©
iv ISO 2004 – All rights reserved
ISO 293:2004(E)
Introduction
For reproducible test results, specimens with a defined state are required. In contrast to injection moulding, the
aim of compression moulding is to produce test specimens and sheets for machining or stamping of test
specimens that are homogeneous and isotropic.
In the process of compression moulding, mixing of material takes place on a negligible scale. Granules and
powders fuse only at their surfaces and preforms (milled sheets) are only partially softened.
Isotropic and homogeneous specimens can, therefore, only be obtained when the moulding material is itself
homogeneous and isotropic. This has to be considered when processing multiphase materials, such as ABS,
which retain their internal structure.
©
ISO 2004 – All rights reserved v
.
vi
INTERNATIONAL STANDARD ISO 293:2004(E)
Plastics — Compression moulding of test specimens of
thermoplastic materials
1Scope
This International Standard specifies the general principles and the procedures to be followed with
thermoplastics in the preparation of compression-moulded test specimens, and sheets from which test
specimens may be machined or stamped.
In order to obtain mouldings in a reproducible state, the main steps of the procedure, including four different
cooling methods, are standardized. For each material, the required moulding temperature and cooling methods
are as specified in the appropriate International Standard for the material or as agreed between the interested
parties.
The procedure is not recommended for reinforced thermoplastics.
2 Normative references
The following referenced documents are indispensable for the application 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 286-1, Geometrical product specifications (GPS) — ISO coding system for tolerances of linear sizes —
Part 1: Bases of tolerances and fits
ISO 4287, Geometrical Product Specifications (GPS) — Surface texture: Profile method — Terms, definitions
and surface texture parameters
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
moulding temperature
temperature of the mould or the press during the preheating and moulding time, measured in the nearest
vicinity to the moulded material
3.2
demoulding temperature
temperature of the mould or the press platens at the end of the cooling time, measured in the nearest vicinity to
the moulded material
NOTE For positive moulds, holes are normally drilled in the mould for measuring the temperatures defined in 3.1 and 3.2.
3.3
preheating time
time required to heat the material in the mould up to the moulding temperature while maintaining the contact
pressure
©
ISO 2004 – All rights reserved 1
ISO 293:2004(E)
3.4
moulding time
time during which full pressure is applied while maintaining the moulding temperature
3.5
average cooling rate (non-linear)
rate of cooling by a constant flow of the cooling fluid, calculated by dividing the difference between moulding and
demoulding temperatures by the time required to cool the mould to the demoulding temperature
NOTE The average cooling rate is usually expressed in degrees Celsius per minute.
3.6
cooling rate
constant rate of cooling in a defined temperature range obtained by controlling the flow of the cooling fluid in
such a way that over each 10 min interval the deviation from this specified cooling rate does not exceed the
specified tolerance
NOTE The cooling rate is usually expressed in degrees Celsius per hour.
4 Apparatus
4.1 Moulding press
The press shall have a clamping force capable of applying a pressure (conventionally given as the ratio of the
clamping force to the area of the mould cavity) of at least 10 MPa.
The pressure shall be maintained to within 10 % of the specified pressure during the moulding cycle.
The platens shall be capable of
◦
a) being heated to at least 240 C;
b) being cooled at a rate given in Table 1.
The difference between the temperatures of any points of the mould surfaces shall not vary by more than
◦ ◦
± 2 C during heating and ± 4 C during cooling.
When the heating and cooling system is incorporated in the mould, it shall comply with the same conditions.
The platens or mould shall be heated either by high-pressure steam, by a heat-conducting fluid in an
appropriate channel system, or by using electric heating elements. The platens or mould are cooled by a heat-
conducting fluid (usually cold water) in a channel system.
For quench cooling (see method C in Table 1), two presses shall be used, one for heating during moulding and
the other for cooling.
For a specified cooling method, the flow rate of the heat-conducting fluid shall be predetermined in a test
without any material in the mould.
The temperature may be continuously controlled in the centre between the upper and lower platen of the press.
4.2 Moulds
4.2.1 General
The characteristics of the test specimens prepared by using different types of moulds are not the same. In
particular, the mechanical properties depend on the pressure applied to the material during cooling.
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2 ISO 2004 – All rights reserved
ISO 293:2004(E)
In general, two types of moulds, “flash moulds” (see Figure 1) and “positive moulds” (see Figure 2), are used for
compression moulding test specimens of thermoplastics.
Figure 1 — Types of flash (“picture frame”) moulds
Figure 2 — Positive-type mould
Flash moulds permit excess moulding material to be squeezed out and do not exert moulding pressure on the
moulding material during cooling. They are particularly convenient for preparing test specimens or panels of
similar thickness or comparable levels of low internal stress.
With positive moulds, the full moulding pressure, neglecting friction, is exerted on the material during cooling.
The thickness, stress and density of the resulting mouldings depend on mould construction, size of material
charge and the moulding and cooling conditions. This type of mould produces consolidated test specimens with
moulded surfaces and is therefore particularly suitable for obtaining flat surfaces or suppressing the formation
of voids within test specimens.
4.2.2 Fabrication
The moulds shall be made of material
...
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