1、BRITISH STANDARD BS EN ISO 8780-3:1995 Incorporating Amendment No.1 Pigments and extenders Methods of dispersion for assessment of dispersion characteristics Part 3: Dispersion using a high-speed impeller mill The European Standard EN ISO8780-3:1995 has the status of a BritishStandardBSENISO8780-3:1
2、995 This BritishStandard, having been prepared under the directionof the Pigments, Paintsand Varnishes StandardsPolicy Committee, waspublished under the authorityof the Standards Boardand comes into effect on 30 April1991 BSI04-2000 The following BSI references relate to the work on this standard: C
3、ommittee reference PVC/1 Draft for comment86/52355DC ISBN 0 580 19536 8 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 followin
4、g bodies were represented: 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 Ass
5、ociation Amendments issued since publication Amd. No. Date Comments 8528 August 1995 Indicated by a sideline in the marginBSENISO8780-3:1995 BSI 04-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN ISO8780-3 3 Publication(s) referred to Inside
6、back coverBSENISO8780-3:1995 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 ISO8780-3:1990 “Pigments and extenders Methods of dispersion for assessment of dispersion cha
7、racteristics Part 3: Dispersion using a high-speed impeller mill”, published by the International Organization for Standardization (ISO). In 1994 the European Committee for Standardization (CEN) accepted ISO8780-3:1990 as European Standard EN ISO8780-3:1994. As a consequence of implementing the Euro
8、pean Standard this BritishStandard is renumbered as BS EN ISO8780-3 and any reference to BS3483-D3 should be read as a reference to BS EN ISO8780-3. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct
9、 application. Compliance with a British 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) BS3483 Methods of testing
10、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 the change in tinting strength of coloured pigments (Identical) ISO8781-2:1990 Part
11、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 pages This document comprises a front cover, an inside front cover, pagesi andii, the
12、EN ISOtitle 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 inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO8780-3 Ma
13、rch1995 ICS 87.060.10 Descriptors: Paints, pigments, extenders,dispersibility, dispersing English version Pigments and extenders Methods of dispersion for assessment of dispersion characteristics Part 3: Dispersion using a high-speed impeller mill (ISO8780-3:1990) Pigments et matires de charge Mthod
14、es de dispersion pour valeur la dispersibilit Partie3: Dispersion laide dune turbine disperseuse grande vitesse (ISO8780-3:1990) Pigmente und Fllstoffe Dispergierverfahren zur Beurteilung des Dispergierverhaltens Teil3: Dispersgieren mit einem Hochgeschwindigkeitsrhrer (ISO8780-3:1990) This European
15、 Standard was approved by CEN on1994-10-17. 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 bibliographical references concerning
16、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 langua
17、ge 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, Spain, Sweden, Switzerland and Un
18、itedKingdom. 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 or reproduction and communication in any form and by any means reserved in all countries to CEN and its membe
19、rs Ref. No. EN ISO8780-3:1995 EENISO8780-3:1995 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 Standardization (ISO). This European
20、Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September1995, and conflicting national standards shall be withdrawn at the latest by September1995. According to the CEN/CENELEC Internal Regulations, the follow
21、ing 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 UnitedKingdom. NOTENormative references to international publications are given
22、 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 Procedure 5 9 Test report 5 Annex A (normative) Required supplementaryinformation 6 Annex ZA (normativ
23、e) Normative references tointernational publications with their relevantEuropean publications 7 Figure 1 Schematic section of a serrated-disc impeller mill 4ENISO8780-3:1995 BSI 04-2000 3 1 Scope This part of ISO8780 specifies a method for the dispersion of pigments and extenders using a high-speed
24、impeller mill. It is for use in conjunction with the methods of assessment described in ISO8781, using an agreed binder system. It should be read in conjunction with ISO8780-1. NOTE 1A high-speed impeller mill may be used either to disperse a pigment fully or partially as a preliminary to further di
25、spersion using other equipment, for example sand or bead mills or attritors. This method is restricted to mill bases of moderately high viscosity due to either high binder concentration and/or high pigment concentration which produces high shear forces. It is not intended to provide a means of formu
26、lating full-scale mill base compositions (scaling up the process from laboratory equipment to factory mills is not simple). 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this part of ISO8780. At the time of publicati
27、on, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this part of ISO8780 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 curr
28、ently valid International Standards. ISO842:1984, Raw materials for paints and varnishes Sampling. ISO8780-1:1990, Pigments and extenders Methods of dispersion for assessment of dispersion characteristics Part 1: Introduction. ISO8781-1:1990, Pigments and extenders Methods of assessment of dispersio
29、n characteristics Part 1: Assessment from the change in tinting strength of coloured pigments. ISO8781-2:1990, Pigments and extenders Methods of assessment of dispersion characteristics Part 2: Assessment from the change in fineness of grind. ISO8781-3:1990, Pigments and extenders Methods of assessm
30、ent of dispersion characteristics Part 3: Assessment 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 i
31、n Annex A. 4 Apparatus Ordinary laboratory apparatus and glassware, together with the following: 4.1 High-speed impeller mill, consisting of a cylindrical vessel and a horizontal disc stirrer blade driven by a motor. A disc with a serrated edge is commonly used. 4.1.1 Drive unit The power rating of
32、the drive unit shall be sufficient to maintain the peripheral speed of the disc at an agreed value. A reduced rotational frequency shall be available for pre-mixing in accordance with8.2. The motor of the drive unit shall be mounted on a stand together with the impeller shaft so that its height can
33、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 vessel. 4.1.2 Disc and vessel The diameters of the vessel and the disc shall be such that there is adequate clearance between the disc periphery and the walls of
34、 the vessel (seebelow). If the disc is serrated, it shall be mounted so that the direction of movement of the serrations is such that the mill base flows in the directions shown in Figure 1. The degree of dispersion achieved will depend on the type of disc used. Figure 1 shows only one possible type
35、. The geometry of the vessel/disc assembly shall be related to the diameter D of the disc as follows: Diameter of vessel:1,3D to3D Clearance between plane of disc and base of vessel:0,25D to0,5D Depth of mill base:0,5D to2D The peripheral speed , in metres per second, of the disc, shall be adjustabl
36、e between5m/s and20m/s, calculated as follows: The type and diameter of the disc, the geometry of the vessel and the speed of the disc shall be agreed on and recorded in the test report. NOTE 2A vessel with a double wall to allow circulation of a liquid to control the temperature is recommended, and
37、 a lid with a central aperture may also be provided. where D is the diameter, in metres, of the disc; n is the rotational frequency, in revolutions per minute, of the impeller shaft.ENISO8780-3:1995 4 BSI 04-2000 NOTE 3The diameter of a vessel used in an industrial-scale mill is normally two to thre
38、e times the diameter of the impeller, or sometimes even greater. The vessel/disc geometry and the disc speed specified in this part of ISO8780 make allowance for the small diameter of a laboratory disc. 4.2 Spatula 5 Binder system The binder system shall be agreed on between the interested parties.
39、The test report shall state 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 serie
40、s. 6 Sampling Take a representative sample of the product to be tested, as described in ISO842. 7 Mill base composition 7.1 General requirements It is essential that the mill base assumes a flow pattern in the form of a toroid (or doughnut). The concentrations of pigment and binder system required t
41、o give this pattern shall be determined by prior experiment. In order to develop high shear in the mill, a high-viscosity mill base is desirable. Thus, high pigment loadings and/or high binder-solids are usually recommended. The best combination depends on the wetting properties of the binder system
42、 for the pigment being tested. NOTE 4It may be preferable to operate the laboratory mill under non-ideal conditions so that differences between pigments are exaggerated. It has been found in practice that, with well-formulated mill bases, differences between easily dispersible pigments are minimized
43、 so that this test method is insensitive. Figure 1 Schematic section of a serrated-disc impeller millENISO8780-3:1995 BSI 04-2000 5 7.2 Determination of mill base composition Add sufficient binder system to cover the impeller. Start the motor at the lowest speed. Make small additions of pigment and
44、gradually increase the speed to that agreed. Observe the flow pattern throughout the whole operation and note how much pigment has been added when a toroid is first formed. Continue to add pigment until the toroid starts to collapse and again note the pigment mass added. Select a pigment concentrati
45、on between these two points. 8 Procedure 8.1 Preliminaries Weigh the pre-determined amount (see7.2) of the binder system into the vessel. Weigh the pre-determined amount (see7.2) of the pigment into a separate container. If the criterion for assessing the dispersion characteristics is to be the eval
46、uation 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 change of gloss, seeISO8781-3), wider tolerance ranges may be agreed o
47、n. 8.2 Pre-mixing If appropriate, bring the vessel and the binder system to the agreed temperature (see8.3). Immerse the impeller to the agreed depth (see4.1.2). With the impeller running at a low speed, gradually incorporate the pigment within a period of5min. Add the pigment at such a rate that a
48、small amount of unwetted pigment always remains visible on the surface. Stop the motor, raise the impeller and, using a spatula(4.2), scrape off any pigment adhering to the impeller shaft and walls of the vessel into the mill base. 8.3 Dispersion Lower the impeller into the vessel to the agreed dept
49、h. Adjust the speed of rotation to that agreed. Confirm, from the flow pattern, that the mill base composition is satisfactory (see7.2). If the flow pattern is unsatisfactory, adjust the amount of pigment or binder system in the vessel until the flow pattern is correct and then, using the revised proportions, repeat the procedure from8.1. Take test portions of the mill base after each of several (agreed) stirring times as follows: Stop the impeller after each of a number of agreed stirring times (for example 4min, 8min, 16min, 32min) a
