EN ISO 6721-2:1996

Plastics - Determination of dynamic mechanical properties - Part 2: Torsion-pendulum method (ISO 6721-2:1994, including Technical Corrigendum 1:1995)

Kunststoffe - Bestimmung dynamisch-mechanischer Eigenschaften - Teil 2: Torsionspendel-Verfahren (ISO 6721-2:1994, einschließlich Technische Korrektur 1:1995)

Dieser Teil von ISO 6721 legt zwei Verfahren fest (A und B) zur Bestimmung der linearen-dynamisch-mechanischen Eigenschaften von Kunststoffen, und zwar der Speicher- und Verlustkomponenten des Torsionsmoduls als Funktionen der Temperatur im Frequenzbereich von 0.1 Hz bis 10 Hz.

Plastiques - Détermination des propriétés mécaniques dynamiques - Partie 2: Méthode au pendule de torsion (ISO 6721-2:1994, Rectificatif Technique 1:1995 inclus)

Polimerni materiali – Določevanje dinamičnih mehanskih lastnosti – 2. del: Metoda s torzijskim nihalom (ISO 6721-2:1994, vključno s tehničnim popravkom 1:1995)

General Information

• Status: Withdrawn
• Publication Date: 20-Feb-1996
• Withdrawal Date: 31-May-2008
• ICS: 83.080.01 - Plastics in general
• Technical Committee: CEN/TC 249 - Plastics
• Drafting Committee: CEN/TC 249/SC 1/WG 3 - Mechanical properties and preparation of test specimens
• Current Stage: 9960 - Withdrawal effective - Withdrawal
• Start Date: 01-Jun-2008
• Completion Date: 01-Jun-2008
• Ref Project: SIST EN ISO 6721-2:1999 - Plastics - Determination of dynamic mechanical properties - Part 2: Torsion-pendulum method (ISO 6721-2:1994, including Technical Corrigendum 1:1995)

Relations

• Replaced By: EN ISO 6721-2:2008 - Plastics - Determination of dynamic mechanical properties - Part 2: Torsion-pendulum method (ISO 6721-2:2008)
• Effective Date: 22-Dec-2008

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN ISO 6721-2:1999
01-maj-1999
3ROLPHUQLPDWHULDOL±'RORþHYDQMHGLQDPLþQLKPHKDQVNLKODVWQRVWL±GHO0HWRGD
VWRU]LMVNLPQLKDORP,62YNOMXþQRVWHKQLþQLPSRSUDYNRP
Plastics - Determination of dynamic mechanical properties - Part 2: Torsion-pendulum
method (ISO 6721-2:1994, including Technical Corrigendum 1:1995)
Kunststoffe - Bestimmung dynamisch-mechanischer Eigenschaften - Teil 2:
Torsionspendel-Verfahren (ISO 6721-2:1994, einschließlich Technische Korrektur
1:1995)
Plastiques - Détermination des propriétés mécaniques dynamiques - Partie 2: Méthode
au pendule de torsion (ISO 6721-2:1994, Rectificatif Technique 1:1995 inclus)
Ta slovenski standard je istoveten z: EN ISO 6721-2:1996
ICS:
83.080.01 Polimerni materiali na Plastics in general
splošno
SIST EN ISO 6721-2:1999 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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INTERNATIONAL
ISO
STANDARD
6721-2
First edition
1994-11-01
Plastics - Determination of dynamic
mechanical properties -
Part 2:
Torsion-pendulum method
Plas tiques - Determination des propriktks mbcaniques dynamiques -
Partie 2: Methode au pendule de torsion
Reference number
ISO 6721-2:1994(E)

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ISO 6721=2:1994(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. Esch 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 patt in the work. ISO
collaborates closely with the International Electrotechnical Commission
(IEC) on all matters of electrotechnical standardization.
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.
International Standard ISO 6721-2 was prepared by Technical Committee
lSO/TC 61, Plastics, Subcommittee SC 2, Mechanical properties.
Together with ISO 6721-1, it cancels and replaces ISO 537:1989, which
has been technically revised.
ISO 6721 consists of the following Parts, under the general title
- Determination of dynamic mechanical properties:
Plas tics
- Part 1: General principles
- Part 2: Torsion-pendulum method
- Part 3: Flexural Vibration - ßesonance-curve method
- Part 4: Tensile Vibration - Non-resonance method
- Part 5: Flexural Vibration - Non-resonance method
- Part 6: Shear Vibration - Non-resonance method
- Part 7: Torsional Vibration - Non-resonance me thod
Annex A forms an integral part of this part of ISO 6721. Annexes B, C and
D are for information only.
0 ISO 1994
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced
or utilized in any form or by any means, electronie or mechanical, including photocopying and
microfilm, without Permission in writing from the publisher.
International Organization for Standardization
Gase Postale 56 l CH-l 211 Geneve 20 l Switzerland
Printed in Switzerland
ii

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INTERNATIONAL STANDARD * ISO ISO 6721=2:1994(E)
Plastics - Determination of dynamic mechanical
properties -
Part 2:
Torsion-pendulum method
edition indicated was valid. All Standards are subject
1 Scope
to revision, and Parties to agreements based on this
patt of ISO 6721 are encouraged to investigate the
This part of ISO 6721 specifies two methods (A and
possibility of applying the most recent edition of the
B) for determining the linear dynamic mechanical
Standard indicated below. Members of IEC and ISO
properties of plastics, i.e. the storage and loss com-
maintain registers of currently valid International
ponents of the torsional modulus, as a function of
Standards.
temperature, for small deformations within the fre-
quency range from 0,l Hz to IO Hz.
ISO 6721-1:1994, Plastics - Determination of dy-
namic mechanical properties - Part 7: General prin-
The temperature dependence of these properties,
ciples.
measured over a sufficiently broad range of tempera-
tures (for example from - 50 “C to + 150 “C for the
majority of commercially available plastics), gives in-
3 Definitions
formation on the transition regions (for example the
glass transition and the melting transition) of the
See ISO 6721-1 :1994, clause 3.
polymer. lt also provides information concerning the
onset of plastic flow. The two methods described are
4 Principle
not applicable to non-symmetrical laminates (see
ISO 6721-3:1994, Plastics - Determination of dy-
A test specimen of uniform Cross-section is gripped
namic mechanical properties - Part 3: Flexural vi-
by two clamps, one of them fixed and the other con-
bration - ßesonance-curve method). The methods
nected to a disc, which acts as an inertial member,
are not suitable for testing rubbers, for which the user
by a rod. The end of the specimen connected to the
is referred to ISO 4663:1986, Rubber - Determi-
disc is excited, together with the disc, to execute
nation of dynamic behaviour of vulcanizates at /OW
freely decaying torsional oscillations. The oscillation
Torsion pendulum method.
frequencies -
mode is that designated IV in ISO 6721-1 :1994, table
2, and the type of modulus is GtO as defined in
ISO 6721-1:1994, table 3.
2 Normative reference
The inertial member is suspended either from the
The following Standard contains provisions which, specimen (method A, see figure l), or from a wire
through reference in this text, constitute provisions (method B, s ee figure2). In the latter case, the wire
of this part of ISO 6721. At the time of publication, the is also part of the elastically oscillating System.
1

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ISO 6721=2:1994(E)
y Upper (fixed) clamp
y Temperature-controlled chamber
‘--.-Test specimen
L Lower (movable) clamp
y Inertial member
Figure 1 - Apparatus for method A
4
Counterweight
r Inertial member
Rod
w
--- Upper (movable) clamp
L -
y Test specimen
c
e
- Temperature-controlled chamber
Lower (fixedl clamp
Figure 2 - Apparatus for method B

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0 ISO ISO 6721=2:1994(E)
During a temperature run, the same inertial member (see 6.1) at a frequency of about 1 Hz, a maximum
tan be used throughout the whole run, which results moment of inertia of about 3 x 1 OW3 kg=m2 is rec-
ommended.
in a frequency decreasing naturally with increasing
temperature, or the inertial member tan be replaced
at intervals by a member of different moment of in-
5.2.1 Method A (see figure 1)
ertia in Order to keep the frequency approximately
The total mass of the inertial member, the lower
constant.
clamp, and the connecting rod shall be such that the
During the test, the frequency and the decaying am-
weight W carried by the specimen is not too high
plitude are measured. From these quantities, the
[see annex A, equation (A.2)].
storage component G ’tO and loss component G ”to of
the torsional complex modulus G& tan be calculated.
5.2.2 Method B (see figure 2)
The total mass of the inertial member, the upper
5 Test apparatus
clamp and the rod must be balanced by a suitable
counterweight, so that the longitudinal forte W acting
5.1 Pendulum
on the specimen is minimized [sec annex A, equation
(A.2)]. The wire supporting these Parts is part of the
Two types of torsion pendulum are specified for use
elastically oscillating System.
with this part of ISO 6721:
the inertial member is suspended from the test
a)
5.3 Clamps
specimen and the lower end of the specimen is
excited (method A, figure 1);
The clamps shall be designed to prevent movement
of the Portion of the specimens gripped within them.
the inertial member is suspended from a wire at-
b)
They shall be self-aligning in Order to ensure that the
tached to a counterweight and the upper end of
specimen axis remains aligned with the axis of rota-
the specimen is excited (method B, figure2).
tion and the test specimen remains adequately se-
cured over the whole temperature range without
Both types of pendulum consists of an intertial mem-
distortion occurring, thus allowing the free length of
ber, two clamps for gripping the specimen (one of
the specimen to be accurately determined.
which is connected to the inertial member by a rod)
and a temperature-controlled chamber enclosing the
The movable clamp shall be of low mass.
specimen and the clamps. For method B, a counter-
weight and connecting wire are also required. The moment of inertia of the whole System (consist-
ing of the movable clamp, the inertial member and the
connecting rod) shall be determined experimentally.
5.2 Inertial member
To prevent heat passing from the specimen out of the
The moment of inertia I of the inertial member, which
temperature-controlled chamber and in the opposite
may be made of aluminium, for instance, shall be
direction, the rod connecting the movable clamp and
selected as a function of the torsional stiffness of the
the inertial member shall be thermally non-
specimen, so that the temperature-dependent natura1
conducting.
frequency of the System lies between approximately
0,l Hz and 10 Hz.
5.4 Oscillation-inducing device
When testing Standard specimens (see 6.1) a mo-
ment of inertia Z of about 3 x 10B5 kg-m2 is rec-
The oscillation-inducing device shall be capable of ap-
ommended if the Same inertial member is to be used
plying to the pendulum a torsional impulse such that
throughout a run.
the pendulum oscillates initially through an angle of
not more than 1,5” in each direction for normal ma-
NOTE 1 For certain materials, e.g. filled polymers, a value
terials, or not more than 3” in each direction for low-
kg*m* may be necessary.
ofIofabout5x10-5
modulus materials (such as elastomers).
If a constant frequency is desired over a broad tem-
perature range, interchangeable inertial members with 5.5 Oscillation-frequency and
different values of I may be used, thereby permitting
oscillation-amplitude recording equipment
the moment of inertia to be varied in Steps of less
than 20 %, i.e. the frequency to be corrected in Steps Optical, electrical or other recording Systems may be
used provided they have no significant influence on
of less than IO %. When testing Standard specimens
3

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ISO 6721=2:1994(E)
The entire equipment for
the oscillating System.
7 Number of specimens
measuring frequency and amplitude shall be accurate
to + 1 % (within the transition region + 5 %). See ISO 6721-1:1994, clause 7.
-
5.6 Temperature-controlled chamber
8 Conditioning
See ISO 6721-3:1994, subclause 5.3. See ISO 6721-1 :1994, clause 8.
If mechanical conditioning of the specimen is re-
5.7 Gas supply
quired, the specimen shall be twisted through an an-
gle greater than 5” but less than 90” in both directions
Air or inert-gas supply for purging purposes.
about the torsional-test axis and returned to its normal
Position.
5.8 Temperature-measurement device
9 Procedure
See ISO 6721-1 :1994, subclause 5.5.
9.1 Test atmosphere
5.9 Devices for measuring test-specimen
dimensions
See ISO 6721-1:1994, subclause 9.1.
See ISO 6721-1 :1994, subclause 5.6.
9.2 Measurement of specimen cross-section
6 Test specimens
See ISO 6721-1 :1994, subclause 9.2.
See ISO 6721-1:1994, clause 6.
9.3 Mounting the test specimens
6.1 Shape and dimensions Clamp the test specimen between the upper and
lower clamps. The longitudinal axis of the test speci-
Rectangular test specimens having the following di-
men shall coincide with the axis of rotation of the os-
mensions are recommended:
cillating System. Any misalignment of the specimen
will Cause lateral oscillations that will interfere with
40 mm to 120 mm, preferably
free length, L:
the normal oscillation process.
50 mm
After clamping the test specimen, measure the dis-
width, b: 5 mm to 11 mm, preferably
tance between the clamps (the free length L) to
IO mm
+ 0,5 %. When setting up the oscillating System in
-
0,15 mm to 2 mm, preferably
thickness, h:
the chamber, check to make Sure that the test speci-
1 mm
men is not stressed.
Spetimens which are rectangular in Cross-section but
After assembling the oscillating System complete
whose thickness and/or width varies along the main
with test specimen, and checking its alignment, Start
axis of the specimen by more than 3 % of the mean
the heating or cooling (see 9.4).
value shall not be used. When comparing different
materials, the dimensions of the specimens shall be
9.4 Varying the temperature
identical. Specimen dimensions differing from the
preferred ones (50 mm x IO mm x 1 mm) should
See ISO 6721-1 :1994, subclause 9.4.
be Chosen to conserve geometric similarity with the
preferred specimen shape.
9.5 Performing the test
Alternative specimen shapes may be used (e.g. cylin-
Start the free oscillations by setting the pendulum in
drical or tubular); in such cases, dimensions and tol-
motion using the oscillation-inducing device (
...