1、BRITISH STANDARD BSEN ISO 8780-4:1995 Incorporating Amendment No.1 Pigments and extenders Methodsofdispersion for assessment of dispersion characteristics Part4: Dispersion using a bead mill The European Standard EN ISO8780-4:1995 has the status of a BritishStandardBSENISO8780-4:1995 This BritishSta
2、ndard, having been prepared under the directionof the Pigments, Paintsand Varnishes StandardsPolicy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 30April 1991 BSI 04-2000 The following BSI references relate to the work on this standard: Committee reference
3、 PVC/1 Draft for comment 86/52356 DC ISBN 0 580 19537 6 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by the Pigments, Paints and Varnishes Standards Policy Committee (PVC/-) to Technical Committee PVC/1, upon which the following bodies were re
4、presented: Aluminium Powder and Paste Association British Cement Association British Railways Board Chemical Industries Association Oil and Colour Chemists Association Paintmakers Association of Great Britain Ltd. Titanium Pigment Manufacturers Technical Committee Zinc Development Association Amendm
5、ents issued since publication Amd. No. Date Comments 8527 August 1995 Indicated by a sideline in the marginBSENISO8780-4:1995 BSI 04-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN ISO8780-4 3 Publication(s) referred to Inside back coverBSENI
6、SO8780-4:1995 ii BSI 04-2000 National foreword This Part of BS3483 has been prepared under the direction of the Pigments, Paints and Varnishes Standards Policy Committee. It is identical with ISO8780-4:1990 “Pigments and extenders Methods of dispersion for assessment of dispersion characteristics Pa
7、rt4: Dispersion using a bead mill”, published by the International Organization for Standardization (ISO). In 1994 the European Committee for Standardization (CEN) accepted ISO8780-4:1990 as European Standard EN ISO8780-4:1995. As a consequence of implementing the European Standard this BritishStand
8、ard is renumbered BSEN ISO8780-4 and any reference to BS3483-D4 should be read as a reference to BS EN ISO8780-4. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a Bri
9、tish Standard does not of itself confer immunity from legal obligations. Cross-references International Standard Corresponding BritishStandard ISO842:1984 BS4726:1986 Methods for sampling raw materials for paints and varnishes (Identical) ISO2431:1984 BS3900 Methods of test for paint Part A6:1986 De
10、termination of flow time by use of flowcups (Identical) BS3483 Methods of testing pigments for paints ISO8780-1:1990 Part D1:1991 Methods of dispersion for assessment of dispersion characteristics (Introduction) (Identical) ISO8781-1:1990 Part E1:1991 Assessment of dispersion characteristics from th
11、e change in tinting strength of coloured pigments (Identical) ISO8781-2:1990 Part E2:1991 Assessment of dispersion characteristics from the change in fineness of grind (Identical) ISO8781-3:1990 Part E3:1991 Assessment of dispersion characteristics from the change in gloss (Identical) Summary of pag
12、es This document comprises a front cover, an inside front cover, pagesi andii, theEN ISO title page, pages2 to8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the i
13、nside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO8780-4 March 1995 ICS 87.060.10 Descriptors: Paints, pigments, extenders, dispersibility, dispersing English version Pigments and extenders Methods of dispersion for assessment of dispersion characteristics Part4:Dispersion us
14、ing a bead mill (ISO8780-4:1990) Pigments et matires de charge Mthodes de dispersion pour valuer la dispersibilit Partie4: Dispersion laide dun disperseur billes (ISO8780-4:1990) Pigmente und Fllstoffe Dispergierverfahren zur Beurteilung des Dispergierverhaltens Teil4:Dispergierenmit einer Perlmhle
15、(ISO8780-4:1990) This European Standard was approved by CEN on 1994-10-17. 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 bibliog
16、raphical 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
17、 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, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Sp
18、ain, Sweden, Switzerland andUnited Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels 1995 All rights of reproduction and communication in any form and by any means reserved in all
19、 countries to CEN and its members Ref.No.ENISO8780-4:1995EENISO8780-4:1995 BSI 04-2000 2 Foreword This European Standard has been taken over by the Technical Committee CEN/TC298, Pigments and extenders, from the work of ISO/TC35, Paints and varnishes, of the International Organization for Standardiz
20、ation (ISO). This European Standard shall be given the status ofa national standard, either by publication of an identical text or by endorsement, at the latest by September 1995, and conflicting national standards shall be withdrawn at the latest by September 1995. According to the CEN/CENELEC Inte
21、rnal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. NOTENormative references to interna
22、tional publications are given in Annex ZA (normative). Contents Page Foreword 2 1 Scope 3 2 Normative references 3 3 Required supplementary information 3 4 Apparatus 3 5 Binder system 4 6 Sampling 4 7 Mill base composition 4 8 Volume of grinding spheres 4 9 Procedure 5 10 Test report 5 Annex A (norm
23、ative) Required supplementary information 6 Annex ZA (normative) Normative references to international publications with their relevant European publications 7 Figure 1 Example of stirrer assembly 4 Figure 2 Effective diameter of discs 4 Table 1 Mill base volume and dimensions ofbeadmill vessel 4ENI
24、SO8780-4:1995 BSI 04-2000 3 1 Scope This part of ISO8780 specifies a method for the dispersion of pigments and extenders using a bead mill. It is for use in conjunction with the methods of assessment described in ISO8781, using an agreed binder system of low viscosity. It should be read in conjuncti
25、on with ISO8780-1. This method is restricted to low- and medium-viscosity mill bases allowing free movement of the grinding spheres (seeclause7). Therefore, it is suitable for mill bases having a viscosity higher than those for which the dispersion method described in ISO8780-2 is appropriate. 2 Nor
26、mative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO8780. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO
27、8780 are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO842:1984, Raw materials for paints and varnishes Sampling. ISO2431:1984, Paints and varni
28、shes Determination of flow time by use of flow cups. ISO8780-1:1990, Pigments and extenders Methods of dispersion for assessment of dispersion characteristics Part1: Introduction. ISO8781-1:1990, Pigments and extenders Methods of assessment of dispersion characteristics Part1: Assessment from the ch
29、ange in tinting strength of coloured pigments. ISO8781-2:1990, Pigments and extenders Methods of assessment of dispersion characteristics Part2: Assessment from the change in fineness of grind. ISO8781-3:1990, Pigments and extenders Methods of assessment of dispersion characteristics Part3: Assessme
30、nt from the change in gloss. 3 Required supplementary information For any particular application, the test method specified in this part of ISO8780 needs to be completed by supplementary information. The items of supplementary information are given inAnnex A. 4 Apparatus Ordinary laboratory apparatu
31、s and glassware, together with the following: 4.1 Bead mill, consisting of the following elements (seealso Figure 1). 4.1.1 Drive unit The power rating of the drive unit shall be sufficient to maintain the effective peripheral speed of the discs (seeFigure 2) at an agreed value. The motor of the dri
32、ve unit shall rotate the impeller shaft at between1000r/min and5000r/min. The drive unit shall be mounted on a stand so that the height of the impeller discs can be adjusted. There shall be a clamping device for the vessel at the foot of the stand, such that the impeller shaft is concentric with the
33、 vessel. 4.1.2 Stirrer assembly and vessel The stirrer assembly shall consist of a shaft on which solid discs, perforated discs or rings are arranged concentrically or eccentrically. The distance between the revolving stirrer and the wall shall be such that there is adequate clearance between the ef
34、fective disc periphery and the walls ofthe vessel (seebelow). The degree of dispersion achieved will depend on the type of stirrer assembly used. Figure 1 shows only one possible type. The geometry of the strirrer assembly and vessel shall be as follows: Minimum clearance between revolving stirrer a
35、sssembly and walls of vessel:10mm Minimum clearance between lowest disc and base of vessel:10mm The minimum effective peripherical speed , in metres per second of the disc, shall be adjustable between5m/s and7m/s, calculated as follows: The type, number and diameter of the discs, the geometry of the
36、 vessel and the effective peripheral speed of the revolving discs shall be agreed on and shall be recorded in the test report. NOTE 1A vessel with a double wall to allow circulation of a liquid to control the temperature is recommended, and a lid with a central aperture may also be provided. NOTE 2T
37、he nominal capacity of the vessel will depend on the volume of the mill base. Examples are given in Table 1. where D is the effective diameter, in metres, of the rotating discs (seeFigure 2); n is the rotational frequency, in revolutions perminute, of the shaft;ENISO8780-4:1995 4 BSI 04-2000 Table 1
38、 Mill base volume and dimensions ofbead mill vessel 4.2 Grinding spheres, of a suitable type. Spheres of the same size and type shall be used for all the mill bases under simultaneous test. The type, mean diameter and density shall be agreed on and shall be recorded in the test report. If the sphere
39、s have never been used, they shall be conditioned by stirring them in a mill base (seeclause7), for example for60min, and cleaned. NOTE 3The diameter, density and total mass of the grinding spheres have a significant effect on the dispersion obtained. Glass spheres of a mean diameter of1mm to2mm and
40、 a density of2,6g/cm 3 0,2g/cm 3have been found to be suitable. Steel balls with a diameter of2mm to3mm, a density of about7,8g/cm 3and a hardness on Mohs scale of7 to8 may also be used. 5 Binder system The binder system shall be agreed on between the interested parties. The test report shall state
41、the binder, the solvent and the concentration of the binder in the solvent, as well as giving information on the rheological properties (for example viscosity or flow time) of the binder system. The same batch of binder system shall be used for all tests in the same series. 6 Sampling Take a represe
42、ntative sample of the product to be tested, as described in ISO842. 7 Mill base composition The viscosity of a mill base depends on the binder demand of the pigment and its concentration in a given binder system. Preliminary experiments shall therefore be carried out to ascertain a suitable mill bas
43、e composition. The viscosity of the mill base during dispersion shall be such that the grinding spheres can move freely (seeclause1) while the bead mill is running. This can be checked by observation. For binder systems with flow times of20s to40s, determined with flow cup ISO2431 No.6, the followin
44、g pigment concentrations have been found to be suitable as starting points: a) pigments of low binder demand pigment concentration25% (m/m) to60% (m/m); b) pigments of medium binder demand pigment concentration10% (m/m) to25% (m/m); c) pigments of high binder demand pigment concentration lower than1
45、0% (m/m). 8 Volume of grinding spheres The apparent volume of the grinding spheres(4.2) shall be approximately40% of the total volume of the container. The same volume of grinding spheres shall be used in all tests in the same series. Figure 1 Example of stirrer assembly Figure 2 Effective diameter
46、of discs Mill base volume Diameter of vessel Height of vessel Nominal capacity of vessel ml mm mm ml 50 50 70 125 100 65 85 250 200 85 110 500ENISO8780-4:1995 BSI 04-2000 5 9 Procedure 9.1 Pre-mixing Weigh the agreed amounts of the binder system and pigment into the vessel (see4.1.2). If the criteri
47、on for assessing the dispersion characteristics is to be the evaluation of the development of tinting strength (seeISO8781-1), the masses of the pigment and of the binder system shall be determined to within0,5%. For other methods of assessment (for example fineness of grind, seeISO8781-2, and chang
48、e of gloss, seeISO8781-3), wider tolerance ranges may be agreed on. Stir with the appropriate stirrer assembly(4.1.2), without the grinding spheres, until the pigment is wetted. The pre-mixing time shall be agreed on and shall be recorded in the test report. NOTE 4The components may also be pre-disp
49、ersed with a high-speed impeller mill as described in ISO8780-3. 9.2 Dispersion Add the appropriate amount of grinding spheres (seeclause8). If appropriate, bring the mill base to the agreed temperature. Disperse at the agreed effective peripheral speed of the discs. Confirm that the grinding spheres are moving freely (seeclause7). If they are not, adjust the mill base composition (seeclause7) and repeat the procedure from9.1. Take test portions from the mill base after each of several (agreed) stirring times as follo
