BS EN ISO 2431-2011 Paints and varnishes Determination of flow time by use of flow cups《色漆和清漆 用流量杯测定流量时间》.pdf

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1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 2431:2011Paints and varnishes Determination of flow timeby use of flow cups (ISO2431:2011)BS EN ISO 2431:2011 BRITISH STANDARDNational forewordThis British Standard is

2、the UK implementation of EN ISO 2431:2011. It supersedes BS EN ISO 2431:1996 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee STI/10, Test methods for paints.A list of organizations represented on this committee can be obtained on request to its secreta

3、ry.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. BSI 2011 ISBN 978 0 580 68546 0 ICS 87.040 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was publish

4、ed under the authority of the Standards Policy and Strategy Committee on 31 December 2011.Amendments issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 2431 November 2011 ICS 87.040 Supersedes EN ISO 2431:1996English Version Paints and varnis

5、hes - Determination of flow time by use of flow cups (ISO 2431:2011) Peintures et vernis - Dtermination du temps dcoulement au moyen de coupes dcoulement (ISO 2431:2011) Beschichtungsstoffe - Bestimmung der Auslaufzeit mit Auslaufbechern (ISO 2431:2011) This European Standard was approved by CEN on

6、26 November 2011. 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 ma

7、y be obtained on application to the CEN-CENELEC Management Centre 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

8、to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lu

9、xembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All r

10、ights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 2431:2011: EBS EN ISO 2431:2011EN ISO 2431:2011 (E) 3 Foreword This document (EN ISO 2431:2011) has been prepared by Technical Committee ISO/TC 35 “Paints and varnishes“ in collaboration w

11、ith Technical Committee CEN/TC 139 “Paints and varnishes” the secretariat of which is held by DIN. 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 May 2012, and conflicting national standards shal

12、l be withdrawn at the latest by May 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 2431:1996. A

13、ccording to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,

14、 Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 2431:2011 has been approved by CEN as a EN ISO 2431:2011 without any modification. BS EN ISO 2431:20

15、11ISO 2431:2011(E) ISO 2011 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope 12 Normative references .13 Terms and definitions .14 Temperature considerations 25 Apparatus 25.1 Flow cups 25.2 Supplementary apparatus .56 Sampling 67 Procedure 67.1 Preliminary check for Newtonian fl

16、ow .67.2 Determination of flow time 68 Marking of products tested .79 Precision 79.1 General .79.2 Repeatability limit null .89.3 Reproducibility limit null 810 Test report .8Annex A (normative) Checking flow cups for wear and tear 10Annex B (informative) Conversion of flow times from one temperatur

17、e to another 12Bibliography .15BS EN ISO 2431:2011ForewordISO (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

18、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

19、 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 ad

20、opted 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 pat

21、ent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 2431 was prepared by Technical Committee ISO/TC 35, Paints and varnishes, Subcommittee SC 9, General test methods for paints and varnishes.This fifth edition cancels and replaces the fourth edition (ISO 2

22、431:1993), which has been technically revised. It also incorporates the Technical Corrigenda ISO 2431:1993/Cor.1:1994 and ISO 2431:1993/Cor.2:1999.The main technical changes are as follows:a) the curves in Figures 2 to 5 have been placed in a single figure (Figure 2) and the equations for the conver

23、sion of flow time to kinematic viscosity and vice versa represented by the curves in these figures have been moved from the figures to a table (Table 1);b) the accuracy of the stopwatch used is no longer specified;c) a clause has been added describing the marking of products tested to indicate the r

24、esults of the test;d) the procedure for checking the flow cups for wear and tear has been revised to include two alternative methods (one using a certified reference material or secondary working standard, the other using a certified flow cup) and has been moved to an informative annex;e) the former

25、 Annex A on the use of flow cups for the adjustment of paint consistency has been deleted;f) a new annex describing the conversion of flow times from one temperature to another has been added.ISO 2431:2011(E)iv ISO 2011 All rights reservedBS EN ISO 2431:2011IntroductionThe first edition of this Inte

26、rnational 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. The fourth edition specified f

27、our flow cups of orifice diameter 3 mm, 4 mm, 5 mm and 6 mm. The main changes made in this fifth edition are given in the foreword.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 confus

28、ion 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 the flow time of paints, varnishes and related products.It is recognized that flow times are re

29、producible 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.Pai

30、nts often contain flow-arresting agents to confer increased viscosity. Such paints exhibit non-Newtonian flow properties. Their viscosity during application can only be properly assessed using viscometers such as that described in ISO 3219.Resins and varnishes can exhibit Newtonian or near-Newtonian

31、 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 mm2/s.With thixotropic materials, stirring

32、 or other such mechanical disturbance immediately before testing will reduce the flow time compared with that for an unstirred sample. With such materials, uncertain and variable flow time values are obtained with all the flow cups. The repeatability and reproducibility limits given in Clause 9 cann

33、ot be achieved in the determination of the flow time of such materials.ISO 2431:2011(E) ISO 2011 All rights reserved vBS EN ISO 2431:2011BS EN ISO 2431:2011INTERNATIONAL STANDARD ISO 2431:2011(E)Paints and varnishes Determination of flow time by use of flow cups1 Scope1.1 This International Standard

34、 specifies a method for determining the flow time of paints, varnishes and related products that can be used to control consistency.1.2 Four flow cups of similar dimensions, but having orifice diameters of 3 mm, 4 mm, 5 mm and 6 mm, are specified. Two methods for checking the flow cups for wear and

35、tear are given (see Annex A).Flow cups with a replaceable jet are not covered by this International Standard as the close tolerances on the supply of the material under test to the jet are not met.Commonly used dipping flow cups are also not covered by this International Standard. In general, the fa

36、brication tolerances for such flow cups are greater than those of the flow cups specified in this International Standard. Therefore flow time determinations with dipping flow cups give a precision which is lower than that obtained with the flow cups specified in this International Standard (see Clau

37、se 9).1.3 The method is limited to testing materials for which the breakpoint of the flow from the orifice of the flow cup can be determined with certainty. This point is difficult to determine and reproduce for materials with flow times near the upper limit of the measurement range (100 s) due to s

38、lowing-down effects.2 Normative referencesThe 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 1513

39、, Paints and varnishes Examination and preparation of test samplesISO 15528, Paints, varnishes and raw materials for paints and varnishes Sampling3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1flow timettime that elapses from the moment when th

40、e material under test starts to flow from the orifice of the filled flow cup to the moment when the flow stream of material first breaks off close to the orifice3.2Newtonian flowtype of flow exhibited by a material in which, at a constant temperature, the ratio of the shear stress to the shear rate

41、does not vary either with time or with the shear rateNOTE When variations in this ratio are small, the effect on viscosity of mechanical disturbance, such as stirring, is negligible and the material is said to have near-Newtonian flow. ISO 2011 All rights reserved 1BS EN ISO 2431:20113.3non-Newtonia

42、n flowtype of flow exhibited by a material in which, at a constant temperature, the ratio of the shear stress to the shear rate varies either with time or with shear rate3.4kinematic viscosityratio of the dynamic viscosity to the density of the liquidNOTE The SI base unit for kinematic viscosity is

43、metres squared per second (m2/s).4 Temperature considerationsThe effect of temperature on flow time is highly significant with respect to application properties and varies with the type of product.For reference purposes, (23,0 0,5) C is specified as the test temperature in this International Standar

44、d. However, it might be more convenient to carry out comparative testing at some other agreed temperature (for example, 25 C) because of prevailing temperature conditions (see also Annex B).For control by flow time, the test sample and flow cup shall be conditioned to an agreed or specified temperat

45、ure and it shall be ensured that the temperature variation does not exceed 0,5 C during testing. The flow cup shall be in a place which is free from draughts.5 Apparatus5.1 Flow cups5.1.1 DimensionsThe dimensions of the ISO flow cups and the tolerances allowed in manufacture shall be as shown in Fig

46、ure 1.NOTE The most critical tolerance is the internal diameter of the jet of the flow cup, because the flow time is inversely proportional to the fourth power of this dimension.5.1.2 MaterialThe jet of the flow cup shall be made of stainless steel or sintered carbide, and the body of the flow cup s

47、hall be made of a material which is corrosion-resistant and is not affected by the products to be tested.5.1.3 ConstructionThe dimensions not specified, such as wall thickness, shall be such that no distortion of the flow cup can occur in use. The external shape should preferably be as shown in Figu

48、re 1, but may be modified for convenience of use, or manufacture, provided that the protruding jet of the flow cup is protected from accidental damage as far as possible by an external protective sleeve. Such a protective sleeve shall not be immediately adjacent to the jet, so as to prevent any capi

49、llary action when the material under test flows out.Flow cups having an additional jacket for temperature control are preferred.5.1.4 FinishThe interior surfaces of the flow cups, including the orifice, shall be smooth and free from turning marks, crevices, ledges and burrs which might cause random flow or trap sample or cleaning material.NOTE The standard of finish required is equivalent to a maximum roughness nullnull (as defined in ISO 4287) of not more than 0,5 m.ISO 2431:2011(E)2 ISO 2011 All rights reservedBS EN ISO 2431:2011Dimensions in m