SIST EN 14371:2005

Surface active agents - Determination of foamability and degree of foamability - Circulation test method

This document specifies a method for the determination of foamability and degree of foamability of surface active agents by means of a circulation equipment, whereby the solution of the surface active agent is under fast circulation.
The method is applicable to many surface active agents, especially for low and medium foaming surface active agents and products containing surface active agents.

Grenzflächenaktive Stoffe - Bestimmung der Schäumfähigkeit und des Verschäumungsgrades - Zirkulations-Prüfverfahren

Dieses Dokument legt ein Verfahren zur Bestimmung der Schäumfähigkeit und des Verschäumungsgrades von grenzflächenaktiven Stoffen mit Hilfe einer Umwälzeinrichtung fest, wobei die Lösung des grenzflächenaktiven Stoffes schnell umgewälzt wird.
Das Verfahren gilt für viele grenzflächenaktive Stoffe, besonders für schwach und mittelmäßig schäumende grenzflächenaktive Stoffe und für Produkte, die grenzflächenaktive Stoffe enthalten.

Agents de surface - Détection de l'aptitude au moussage et du taux de moussage - Méthode par circulation

Le présent document spécifie une méthode de détermination de l'aptitude au moussage et du taux de moussage des agents de surface au moyen d'un systeme de circulation permettant de soumettre la solution d'agent de surface a une circulation rapide.
La méthode est applicable a beaucoup d'agents de surface, et tout particulierement aux agents de surface faiblement ou moyennement moussants et aux formulations contenant des agents de surface.

Površinsko aktivne snovi - Ugotavljanje penjenja in stopnje penjenja - Metoda preskušanja s kroženjem

General Information

• Status: Published
• Publication Date: 31-Mar-2005
• ICS: 71.100.40 - Surface active agents
• Technical Committee: KDS - Cosmetics, chemical disinfectants and surface active agents
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 01-Apr-2005
• Due Date: 01-Apr-2005
• Completion Date: 01-Apr-2005
• Ref Project: EN 14371:2004 - Surface active agents - Determination of foamability and degree of foamability - Circulation test method

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 14371:2005
01-april-2005
Površinsko aktivne snovi - Ugotavljanje penjenja in stopnje penjenja - Metoda
preskušanja s kroženjem
Surface active agents - Determination of foamability and degree of foamability -
Circulation test method
Grenzflächenaktive Stoffe - Bestimmung der Schäumfähigkeit und des
Verschäumungsgrades - Zirkulations-Prüfverfahren
Agents de surface - Détection de l'aptitude au moussage et du taux de moussage -
Méthode par circulation
Ta slovenski standard je istoveten z: EN 14371:2004
ICS:
71.100.40 Površinsko aktivna sredstva Surface active agents
SIST EN 14371:2005 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 14371:2005

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SIST EN 14371:2005
EUROPEAN STANDARD
EN 14371
NORME EUROPÉENNE
EUROPÄISCHE NORM
September 2004
ICS 71.100.40

English version
Surface active agents - Determination of foamability and degree
of foamability - Circulation test method
Agents de surface - Détection de l'aptitude au moussage et Grenzflächenaktive Stoffe - Bestimmung der
du taux de moussage - Méthode par circulation Schäumfähigkeit und des Verschäumungsgrades -
Zirkulations-Prüfverfahren
This European Standard was approved by CEN on 1 July 2004.
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
© 2004 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14371:2004: E
worldwide for CEN national Members.

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SIST EN 14371:2005
EN 14371:2004 (E)
Contents
page
Foreword.3
Introduction .4
1 Scope.5
2 Normative references.5
3 Principle.5
4 Reagents.6
5 Apparatus.6
6 Test equipment.7
7 Sampling and preparation of the test sample.8
8 Procedure.9
9 Expression of results.13
10 Precision.13
11 Test report.13
Annex A (informative) Test equipment.14
Annex B (informative)  Results of sample A obtained in four laboratories according to M 1 and in three
laboratories according to M 2.16
Annex C (informative)  Ring test results.17
Annex D (informative)  Statistical data of the determination of foamability of reference surface active
agent RS 1 (0,01 %).18
Annex E (informative) Example of foam profiles of surface active agents and detergents .19



2

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SIST EN 14371:2005
EN 14371:2004 (E)
Foreword
This document (EN 14371:2004) has been prepared by Technical Committee CEN/TC 276 “Surface active agents”,
the secretariat of which is held by AFNOR.
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 March 2005, and conflicting national standards shall be withdrawn at the latest by
March 2005.
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.
3

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SIST EN 14371:2005
EN 14371:2004 (E)
Introduction
The foamability and foamability degree are specified by means of a circulation equipment, whereby the solution of
the surface active agent is under fast circulation for 10 min. During this circulation a definite volume of foam is
generated which is a typical characteristic for the surface active agent at a certain concentration and temperature.
This volume is called "foamability“ and is recorded on a 0 ml to 1 500 ml scale and expressed in millilitres.
Additionally the degree of foamability is recorded in parallel on a 0 % to 300 % scale or calculated from the
foamability.
A basic objective is to test within a time, a defined circulation speed and a concentration range in which the foam
formation comes to a saturation volume. This saturation foam volume nearly represents maximum foamability and
is characteristic for any surface active agent.
After the circulation has been stopped, the destabilisation of the foam and the time in which half volume of foam is
collapsed are recorded. The half volume collapsing time t indicates the foam stability of the surface active agent.
v/2
A foamability profile versus temperature can be achieved by using single isothermal measurements (Method M 1)
or by using a new continuous method (Method M 2), where the temperature is changed (increased) during the test.
It was been found that the saturated volume quickly follows the temperature changes during circulation.
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SIST EN 14371:2005
EN 14371:2004 (E)
1 Scope
This document specifies a method for the determination of foamability and degree of foamability of surface active
agents by means of a circulation equipment, whereby the solution of the surface active agent is under fast
circulation.
The method is applicable to many surface active agents, especially for low and medium foaming surface active
agents and products containing surface active agents.
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.
EN ISO 3696, Water for analytical laboratory use — Specification and test methods (ISO 3696:1987)
EN ISO 4788, Laboratory glassware – Graduated measuring cylinders(ISO/DIS 4788:2003)
3 Principle
A gear pump recycles 500 g of the test solution, which is carefully controlled concerning the temperature, in a
2 000 ml jacked cylinder and sprays it in a bypass system through a nozzle onto the surface of the liquid. During
the test under high flow rate (200 l/h) a characteristic constant ”saturated“ volume is formed which cannot
significantly be increased by any increase of the circulation rate.
The volumes are measured either by visual recording or other equivalent recording auxiliaries like electronic foam
height recording systems.
The additionally created foam, starting from a 500 g (ml) volume, is recorded each 30 s. In the time interval
between 5,5 min and 10 min where a stable foam phase is observed, the average volume is determined. The
foamability at the concentration c and the temperature T, F , results from it as follows:
(c, T)
F = ΣV / 10 = 0 ml . 1 500 ml
s (5,5 min.10 min)
(c, T)
where
ΣV is the sum of the recorded, saturated volumes at 5,5 min; 6 min; 6,5 min; 7 min; 10 min.
s (5,5 min.10 min)
Finally the generated volume (= foam) can be compared with the starting volume and is expressed or recorded at a
scale as degree of foamability at the concentration c and the temperature T, F :
D(c, T)
F := F / 5 = 0 % . 300 %
D(c, T) (c, T)
Finally, having stopped the circulation the collapsing phase is recorded as the half volume of foam collapsing time
t expressed in seconds.
v/2
This indicates the stability of the foam and is an optional parameter, which can be measured. This value can be
determined by extrapolating from a graph or the collected data values or measured directly.
First such a concentration is chosen, that at 25 °C a volume of foam of about 700 ml to 1 200 ml can be reached
under above conditions, so that good foam characteristics with good resolutions of the values can be achieved.
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SIST EN 14371:2005
EN 14371:2004 (E)
Two equivalent (recording) test methods are available:
 Method M 1: Isothermal measurement
The recording is done at a defined constant temperature, e.g. at 25 °C; other preferred temperatures for
recording are 20 °C, 30 °C, 40 °C . 80 °C. Finally a foamability profile is plotted using the foamability
(saturated volume) V versus temperature or the degrees of foamability [%] V versus temperature. Typically
s s
two recordings under identical conditions are made and the average values are taken.
 Method M 2: Continuous measurement
After an isothermal starting phase (5 min at 20 °C) a saturated foam volume is found. Afterward during a
continuous temperature increase of 1 °C/min between 20 °C to 80 °C, the foam volumes are recorded. The
saturated foam volume quickly follows the temperature changes and the foamability V versus temperature
s
can be graphically recorded.
The values shall be recorded at each degree.
4 Reagents
4.1 General
During the test use only reagents of recognized analytical grade and water complying with grade 1 in accordance
with EN ISO 3696.
4.2 Laboratory cleaner, e.g. phosphate based surface active agents, with low foaming, for glassware, capable
of removing surface active agents.
4.3 Reference surface active agent (RS 1), for calibration.
NOTE If doubts occur about the correct function with a foamability of F = (1 030 ± 100) ml, see 6.3.
(0,01 %, 25 °C)
5 Apparatus
5.1 Test equipment, consisting of:
5.1.1 2 l-jacked cylinder, with 3 scales:
Scale 1: 0 ml to 500 ml, for indicating the test volume; 500 ml start level = 0.
Scale 2: 0 ml to 1 500 ml for the generated foam.
Scale 3: 0 % to 300 % degrees of foamability.
Inside dimensions shall be in accordance with ISO 4788. Dimensions of the outlet valve at the bottom are optional.
5.1.2 Gear pump, with a pump head flow rate of 0 l/h to 280 l/h where a rate of 200 l/h shall be adjustable.
5.1.3 Gear pump regulation unit.
5.1.4 Bypass system: Suction tube (8 mm), manometer (0 kPa to 60 kPa), tubes, nozzle (50 mm length, 5 mm
diameter).
5.1.5 Electronic temperature sensor, arranged along and behind the suction tube, with a temperature
indication either in a digital display or on the display at the thermostatic bath.
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SIST EN 14371:2005
EN 14371:2004 (E)
5.1.6 Telescopic stand, e.g. H-basement.
5.1.7 Liftable pump suspension, consisting of a supporting lever, pump on swinging lever and clamps.
5.1.8 Thermostatic bath, consisting either of a common thermostatic bath or a programmable thermostatic bath
(preferably used for continuous recording).
5.2 Beaker glass, capacity 800 ml, for preparing the solutions.
5.3 Water jet vacuum pump, recommended for removing test solutions from the cylinder.
5.4 Balance, with an accuracy of 0,1 g.
5.5 Stop watch, with an accuracy of 0,1 s.
6 Test equipment
6.1 Installation of the test equipment
The individual parts (5.1.1 to 5.1.8) shall be assembled according to the supplier’s instructions.
Install the telescopic stand, fix the suspension lever with the screw on the telescopic stand, at a height of 688 mm
from the desk, fix the gear pump (5.1.2) on the swinging lever and fix the swinging lever above the supporting lever
with a clamp (≈ 732 mm); shift both to a position (slight corrections are possible) where the suction tube can be
installed on the pump head. The distance between suction tube and bottom of the cylinder shall finally be exactly
10 mm. Fix a clamp (≈ 445 mm) on the lower part of the telescopic stand, so that the whole upper part cannot be
shifted lower than to the clamp. Now adjust this 10 mm distance between the suction tube and the bottom. The
swinging lever can be moved upward together with the suction tube, if necessary, upward after a slight release at
its fixation clamp. Then it is possible to remove the cylinder by lifting and moving the suction tube with the pump
slightly to the operator.
Install the bypass with the manometer and the nozzle. The nozzle shall be in a position exactly central above the
cylinder. Fix the electronic temperature sensor along and behind the suction tube with small plastic clamps and
connect it to the thermostatic bath or to the device which indicates the internal temperature. Connect pump and
regulation unit.
The arrangement of the test equipment is shown in Figure A.1.
6.2 Calibration of the pump and circulation flow
To determine the n
...