1、BRITISH STANDARD BS EN 14371:2004 Surface active agents Determination of foamability and degree of foamability Circulation test method The European Standard EN 14371:2004 has the status of a British Standard ICS 71.100.40 BS EN 14371:2004 This British Standard was published under the authority of th
2、e Standards Policy and Strategy Committee on 2 December 2004 BSI 2 December 2004 ISBN 0 580 44936 X National foreword This British Standard is the official English language version of EN 14371:2004. The UK participation in its preparation was entrusted to Technical Committee CII/34, Methods of test
3、for surface active agents, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in th
4、e BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a contract. Users are responsible
5、for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK i
6、nterests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 19 and a back cover. The BSI copyright notice displayed in this document indicates wh
7、en the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN14371 September2004 ICS71.100.40 Englishversion SurfaceactiveagentsDeterminationoffoamabilityanddegree offoamabilityCirculationtestmethod AgentsdesurfaceDtectio
8、ndelaptitudeaumoussageet dutauxdemoussageMthodeparcirculation GrenzflchenaktiveStoffeBestimmungder SchumfhigkeitunddesVerschumungsgrades ZirkulationsPrfverfahren ThisEuropeanStandardwasapprovedbyCENon1July2004. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatethecondition
9、sforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheCentralSecretariatortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Avers
10、ioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheCentralSecretariathasthesamestatusast heofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,Cyprus,CzechRepublic,Denmark,Estonia,Finland,France, Germany,Greece,Hungary,
11、Iceland,Ireland,Italy,Latvia,Lithuania,Luxembourg,Malta,Netherlands,Norway,Poland,Portugal, Slovakia, Slovenia,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2004CEN
12、Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN14371:2004:EEN 14371:2004 (E) 2 Contents page Foreword3 Introduction .4 1 Scope5 2 Normative references5 3 Principle5 4 Reagents.6 5 Apparatus.6 6 Test equipment7 7 Sampling and preparation of the test sam
13、ple.8 8 Procedure.9 9 Expression of results13 10 Precision.13 11 Test report13 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 Ann
14、ex 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 EN 14371:2004 (E) 3 Foreword This document (EN 14371:2004) has been prepared by Technica
15、l 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 w
16、ithdrawn 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, Hungar
17、y, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EN 14371:2004 (E) 4 Introduction The foamability and foamability degree are specified by means of a circulation equipment, where
18、by 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 recor
19、ded 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
20、 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.
21、The half volume collapsing time t v/2indicates the foam stability of the surface active agent. 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)
22、during the test. It was been found that the saturated volume quickly follows the temperature changes during circulation. EN 14371:2004 (E) 5 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 equi
23、pment, 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 docume
24、nts 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
25、(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 on
26、to 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 auxil
27、iaries 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
28、 c and the temperature T, F (c, T) , results from it as follows: F (c, T)= V s (5,5 min.10 min) / 10 = 0 ml . 1 500 ml where V s (5,5 min.10 min)is the sum of the recorded, saturated volumes at 5,5 min; 6 min; 6,5 min; 7 min; 10 min. Finally the generated volume (= foam) can be compared with the sta
29、rting 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 D(c, T) := F (c, T)/ 5 = 0 % . 300 % Finally, having stopped the circulation the collapsing phase is recorded as the half volume of foam collapsing time t v/2expr
30、essed in seconds. 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 7
31、00 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. EN 14371:2004 (E) 6 Two equivalent (recording) test methods are available: Method M 1: Isothermal measurement The recording is done at a defined constant te
32、mperature, 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 sversus temperature or the degrees of foamability % V sversus temperature. Typically two recordings under identical con
33、ditions 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
34、foam volume quickly follows the temperature changes and the foamability V sversus temperature 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 accordan
35、ce 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 (0,
36、01 %, 25 C)= (1 030 100) ml, see 6.3. 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 foamabili
37、ty. 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
38、), 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. EN 14371:2004 (E) 7 5.1.6 Telescopic sta
39、nd, 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, capacit
40、y 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
41、) shall be assembled according to the suppliers 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
42、 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 th
43、at 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
44、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
45、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 necessary flow rat
46、e of 200 l/h, it is helpful to measure the flow rate for at least three different pump settings, e.g. at 40, 60 and 80 intervals by regulating the pump control unit. Usually a setting of about 70 units gives a flow rate of 200 l/h. Pour approximately 2 l of water into a 2 l calibrated beaker and cir
47、culate it at the desired setting. Take the mass of calibrated beaker, fill in during circulation until an amount of approximately 900 g from the water jet is reached. Time with the stopwatch (5.5) to the nearest 0,1 s. Read the mass of water caught in the beaker on the balance (5.4) to the nearest 0
48、.1 g. Use the following short form of equation for the calculation of the flow rate, r f : t , m r f 6 3 = (1) where m is the mass of the water caught in the beaker, in grams; t is the time, in seconds. EN 14371:2004 (E) 8 Using at least three different values, plot the most accurate calibration graph possible for pump delivery l/h against scale intervals. Extrapolate this graph to obtain the scale interval necessary for 200 l/h. If required, check the calibration at suitable time intervals. Under standard conditions the manometer i
