SIST EN ISO 2431:1997
(Main)Paints and varnishes - Determination of flow time by use of flow cups (ISO 2431:1993, including Technical Corrigendum 1:1994)
Paints and varnishes - Determination of flow time by use of flow cups (ISO 2431:1993, including Technical Corrigendum 1:1994)
Replaces figure 1 by a figure, in which the mouth of the jet is 0,1 mm below the cup body in order to minimize eddy-current effects.
Lacke und Anstrichstoffe - Bestimmung der Auslaufzeit mit Auslaufbechern (ISO 2431:1993, einschließlich Technische Korrektur 1:1994)
Diese Internationale Norm gehört zu einer Reihe von Normen, welche die Probenahme und Prüfung von Lacken, Anstrichstoffen und ähnlichen Produkten behandelt. Diese Internationale Norm beschreibt ein Verfahren zur Bestimmung der Auslaufzeit von Lacken, Anstrichstoffen und ähnlichen Produkten, das zum Prüfen der Konsistenz angewendet werden kann. Ein Verfahren zum Einstellen auf die richtige Verarbeitungskonsistenz bei der Verarbeitungstemperatur wird im Anhang A beschrieben.
Peintures et vernis - Détermination du temps d'écoulement au moyen de coupes d'écoulement (ISO 2431:1993, Rectificatif Technique 1:1994 inclus)
1.1 La présente Norme internationale fait partie d'une série de normes traitant de l'échantillonnage et des essais des peintures, vernis et produits assimilés. 1.2 La présente Norme internationale prescrit une méthode pour la détermination du temps d'écoulement des peintures, vernis et produits assimilés qui peut être utilisée pour contrôler la consistance. Une méthode destinée à ajuster, à la température d'application, la consistance à une valeur correcte est décrite dans l'annexe A. 1.3 Quatre coupes d'écoulement, de dimensions semblables, mais ayant des diamètres d'orifice de 3 mm, 4 mm, 5 mm et 6 mm, sont prescrites. La méthode pour leur étalonnage est donnée. 1.4 La méthode est limitée aux produits dont la rupture d'écoulement de l'orifice de la coupe peut être déterminée avec certitude. Il est difficile de déterminer et de reproduire ce point de rupture dans le cas des matériaux présentant un temps d'écoulement supérieur à 100 s, en raison d'effets de ralentissement.
Barve in laki - Določanje iztočnega časa z uporabo iztočnih čaš (ISO 2431:1993, vključno s tehničnim popravkom 1:1994)
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN ISO 2431:1997
01-december-1997
%DUYHLQODNL'RORþDQMHL]WRþQHJDþDVD]XSRUDERL]WRþQLKþDã ,62
YNOMXþQRVWHKQLþQLPSRSUDYNRP
Paints and varnishes - Determination of flow time by use of flow cups (ISO 2431:1993,
including Technical Corrigendum 1:1994)
Lacke und Anstrichstoffe - Bestimmung der Auslaufzeit mit Auslaufbechern (ISO
2431:1993, einschließlich Technische Korrektur 1:1994)
Peintures et vernis - Détermination du temps d'écoulement au moyen de coupes
d'écoulement (ISO 2431:1993, Rectificatif Technique 1:1994 inclus)
Ta slovenski standard je istoveten z: EN ISO 2431:1996
ICS:
87.040 Barve in laki Paints and varnishes
SIST EN ISO 2431:1997 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN ISO 2431:1997
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SIST EN ISO 2431:1997
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SIST EN ISO 2431:1997
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SIST EN ISO 2431:1997
INTERNATIONAL
IS0
STANDARD 2431
Fourth edition
1993-02-I 5
Paints and varnishes - Determination of
flow time by use of flow cups
Pein tures et vernis - Dbtermination du temps d ’koulement au moyen
de coupes d ’bcoulement
Reference number
IS0 2431 :1993(E)
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SIST EN ISO 2431:1997
IS0 2431:1993(E)
Foreword
IS0 (the International Organization for Standardization) is a worldwide
federation of national standards bodies (IS0 member bodies). The work
of preparing International Standards is normally carried out through IS0
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. IS0
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 IS0 2431 was prepared by Technical Committee
lSO/TC 35, Paints and varnishes, Sub-Committee SC 9, General test
methods for paints and varnishes.
This fourth edition cancels and replaces the third edition
(IS0 2431:1984), of which it constitutes a technical revision.
Annex A of this International Standard is for information only.
0 IS0 1993
All rights reserved. No part of this publication may be reproduced or utilized in any form or
by any means, electronic or mechanical, including photocopying and microfilm, without per-
mission in writing from the publisher.
International Organization for Standardization
Case Postale 56 l CH-1211 Geneve 20 l Switzerland
Printed in Switzerland
ii
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SIST EN ISO 2431:1997
IS0 2431:1993(E)
Introduction
The first edition of this International Standard, published in 1972, specified
only one flow cup of orifice diameter 4 mm. The second edition specified
three flow cups of orifice diameter 3 mm, 4 mm and 6 mm. The third
edition corrected errors in figures 2 and 4 and the equations for those
figures. This fourth edition specifies four flow cups of orifice diameter
3 mm, 4 mm, 5 mm and 6 mm.
As is well known, many countries over the years have developed their
own standard flow cups and the difficulty in correlation between them has
led to considerable confusion in comparing values. The standardization of
an improved design of flow cup has been recommended after careful
consideration, by an expert working group, of the role of flow cups for the
measurement of flow time of paints, varnishes and related products.
It is recognized that the flow times are reproducible only for products of
Newtonian or near-Newtonian flow properties. This effectively limits their
practical use. Nevertheless, for checking purposes, these flow cups do
serve a useful purpose. Furthermore, the measurement of flow time is
often used to confirm the application consistency.
Paints often contain flow-arresting agents to confer increased viscosity.
Such paints exhibit anomalous flow properties. Their viscosity during ap-
plication can only be properly assessed using viscometers operating at
high velocity gradients, such as that described in IS0 2884.
Resins and varnishes may exhibit Newtonian or near-Newtonian flow at
much higher viscosities than most paints and, where this applies, flow
cups can provide a useful means of controlling the consistency. To meet
this requirement, this International Standard provides flow cups suitable
for viscosities up to about 700 mm*/s.
Recommendations for the use of flow cups for the adjustment of paint
consistency are given in annex A.
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SIST EN ISO 2431:1997
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SIST EN ISO 2431:1997
IS0 2431:1993(E)
INTERNATIONAL STANDARD
- Determination of flow time by
Paints and varnishes
use of flow cups
IS0 1512:1991, Paints and varnishes - Sampling of
1 Scope
products in liquid or paste form.
1.1 This International Standard is one of a series of
IS0 1513:1992, Paints and varnishes - Examination
standards dealing with the sampling and testing of
and preparation of samples for testing.
paints, varnishes and related products.
IS0 2884:1974, Paints and varnishes - Determi-
nation of viscosity at a high rate of shear.
1.2 This International Standard specifies a method
for determining the flow time of paints, varnishes and
related products that may be used to control consist-
ency. A method for the adjustment of paints to the
correct application consistency at the application
3 Qefinitions
temperature is described in annex A.
For the purposes of this International Standard, the
following definitions apply.
1.3 Four flow cups of similar dimensions, but having
orifice diameters of 3 mm, 4 mm, 5 mm and 6 mm,
are specified. The method for their calibration is given. 3.1 flow time: Time that elapses from the moment
when the material under test starts to flow from the
orifice of the filled cup to the moment when the flow
1.4 The method is limited to testing materials for
stream of material first breaks close to the orifice.
which the breakpoint of the flow from the orifice of
the flow cup can be determined with certainty. This
3.2 Newtonian flow: Type of flow exhibited by a
point is difficult to determine and reproduce for ma-
material in which the ratio of the shear stress to the
terials with flow times in excess of 100 s due to
velocity gradient does not vary either with time or
slowing-down effects.
with the velocity gradient. When variations in this ratio
are small, the effect on viscosity of mechanical dis-
turbance, such as stirring, is negligible and the ma-
2 hbrmative references
terial is said to have near-Newtonian flow.
The following standards contain provisions which,
3.3 anomalous flow: Type of flow exhibited by a
through reference in this text, constitute provisions
material in which, at a constant temperature, the ratio
of this International Standard. At the time of publi-
of the shear stress to the velocity gradient varies ei-
cation, the editions indicated were valid. All standards
ther with time or with rate of shear. For example, with
are subject to revision, and parties to agreements
so-called thixotropic materials, stirring or other such
based on this International Standard are encouraged
mechanical disturbance immediately before test will
to investigate the possibility of applying the most re-
reduce the flow time below that for an unstirred
cent editions of the standards indicated below.
sample. With such materials, uncertain and variable
Members of IEC and IS0 maintain registers of cur-
values for flow time are obtained in all flow cups.
rently valid International Standards.
1
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SIST EN ISO 2431:1997
IS0 2431:1993(E)
5.1.2 Construction
3.4 dynamic viscosity: Ratio of the applied shear
stress to the velocity gradient.
The dimensions not specified, such as wall thickness,
NOTE 1 The SI unit for dynamic viscosity is the Pascal
shall be such that no distortion of the cup can occur
second (Pas). The traditional unit is the centipoise (cP);
in use. The external shape shown in figure 1 is rec-
1 cP = 1 mPas.
ommended, but may be modified for convenience of
use, or manufacture, provided that the protruding jet
3.5 kinematic viscosity: Ratio of the dynamic vis- of the cup is protected from accidental damage as far
cosity to the density of the liquid.
as possible by an external protective sleeve. Such a
protective sleeve shall not be immediately adjacent to
NOTE 2 The SI unit for kinematic viscosity is the square
the jet, so as to prevent a capillary action when the
metre per second (m*/s). The traditional unit is the
material under test flows out.
centistokes (cSt); 1 cSt = 1 mm*/s.
Flow cups having a casing for temperature con-
NOTE 4
trol are preferred.
4 Temperature considerations
5.1.3 Finish
The effect of temperature on flow time is highly sig-
nificant with respect to application properties and The interior surfaces of the cups, including the orifice,
varies with the type of product. shall be smooth and free from turning marks,
crevices, ledges and burrs which may cause random
For international reference purposes, it is essential to
flow or trap sample or cleaning material.
standardize one test temperature and (23 + 0,s) “C is
specified in this International Standard. However, it NOTE 5 The standard of finish required is equivalent to
a maximum roughnessl) of not more than 0,5 pm.
may be more convenient to carry out comparative
testing at some other agreed temperature (for exam-
ple, 25 “C) because of prevailing temperature con-
ditions.
5.1.4 Calibration
For control by flow time, the test sample and flow cup
Dimensionally similar cups will give, with Newtonian
shall be conditioned to an agreed or specified tem-
liquids, similar flow times, provided that the tempera-
perature and it shall be ensured that the temperature
ture of testing is precisely the same. The use of such
variation does not exceed 0,5 “C during testing.
liquids to calibrate cups provides a useful means of
initially checking that dimensionally similar cups are
within the accepted tolerances of performance and
also for checking from time to time whether any wear
5 Apparatus
or damage has taken place sufficient to bring a cup
outside the accepted tolerances.
For calibration of any particular cup, use a standard
5.1 Flow cups
oil*) of known kinematic viscosity and draw a graph
of kinematic viscosity versus temperature from the
data given by the supplier for the oil.
5.1 .l Dimensions
Using the procedure described in clause 7, determine
The dimensions of the IS0 flow cups and the toler-
the flow time of the oil at a known temperature within
ances allowed in manufacture shall be as shown in
the range 20 “C to 30 “C, measured to the nearest
figure 1.
0,l “C.
NOTE 3 The most critical tolerance is the internal diam-
Record this flow time, which should be in the range
eter of the jet of the cup, because the flow time is inversely
30 s to 100 s and preferably near the mid-point of this
proportional to the fourth power of this dimension.
range, to an accuracy of 0,2 s.
The jet of the cup shall be made of stainless steel or
From the prepared graph, read the kinematic viscosity
sintered carbide, unless otherwise specified, and the
at the test temperature.
body of the cup shall be made of a material which is
Using the appropriate equation, calculate the flow
corrosion resistant and is not affected by the products
time corresponding to this kinematic viscosity.
to be tested.
Parameters, their values and general rules for specifying re-
I) In the sense defined in IS0 468:1982, Surface roughness -
quirements; i.e. the arithmetical mean deviation R, from the mean line of the profile.
2) Information on suppliers of suitable oils can be obtained from national standards organizations.
2
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SIST EN ISO 2431:1997
IS0 2431:1993(E)
NOTE 6 The calibration curves plotted in figures 2 to 5 for
These calibration equations are as follows:
these equations are given for information only.
v = 0,443t - (200/t)
3-mm cup
If the two values of flow time obtained do not differ
v = 1,37t - (200/t)
4-mm cup
by more than 3 %, the cup is deemed satisfactory for
5-mm cup v = 3,28t - (220/t)
use.
6-mm cup v = 6,90t - (570/t)
Dimensions in millimetres,
unless otherwise indicated
[No radius;,
R,= 0,s
poq
Jet
Valued) for the given flow cups
Dimension
3-mm 4-mm 6-mm
CUP
CUP CUP
I
62,7 62,4 62,l
A 63
3 4 5 6
B
6 7 8
c 5
I
I) For tolerances, see the enlarged
...
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