1、BRITISH STANDARD BS EN ISO 787-18:1995 General methods of test for pigments and extenders Part 18: Determination of residue on sieve Mechanical flushing procedure ICS: 87.060.10; 87.060.30BSEN ISO 787-18:1995 This British Standard, having been prepared under the directionof the Sector Board forMater
2、ials and Chemicals, waspublished under the authorityof the Standards Boardand comes into effect on 15 December 1995 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference STI/1 Draft announced in BSI News November 1995 ISBN 0 580 24118 1 Committees responsi
3、ble for this British Standard The preparation of this British Standard was entrusted to Technical Committee STI/1, Pigments, upon which the following bodies were represented: British Cement Association British Coatings Federation Ltd. British Colour Makers Association British Precast Concrete Federa
4、tion Ltd. Cement and Concrete Pigment Suppliers Association China Clay Association Oil and Colour Chemists Association Titanium Pigment Manufacturers Technical Committee Zinc Development Association Amendments issued since publication Amd. No. Date CommentsBSEN ISO 787-18:1995 BSI 12-1999 i Contents
5、 Page Committees responsible Inside front cover National foreword ii Foreword 2 0 Introduction 3 1 Scope and field of application 3 2 References 3 3 Definition 3 4 Principle 3 5 Materials 3 6 Apparatus 3 7 Sampling 4 8 Procedure 4 9 Expression of results 4 10 Test report 5 Figure Mechanical flushing
6、 apparatus 5 List of references Inside back coverBSEN ISO 787-18:1995 ii BSI 12-1999 National foreword This Part of BS EN ISO787 has been prepared by Technical Committee STI/1. Itis identical with ISO787-18:1983 General methods of test for pigments and extenders Part 18: Determination of residue on
7、sieve Mechanical flushing procedure published by the International Organization for Standardization (ISO). In 1995 the European Committee for Standardization (CEN) accepted ISO787-18:1983 as European Standard EN ISO787-18:1995. As a consequence of implementing the European Standard this British Stan
8、dard is dual-numbered as BS EN ISO787-18:1995, BS3483-B12:1995. 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 British Standard does not of itself confer immunity f
9、rom legal obligations. Cross-references Publication referred to Corresponding British Standard ISO 787-7:1981 BS 3483 Methods for testing pigments for paints Part B3:1982 Determination of residue on sieve (water method, using a manual procedure) ISO 842:1984 BS 4726:1986 Methods for sampling raw mat
10、erials for paints and varnishes Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, theEN ISO title page, pages 2 to 6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This
11、 will be indicated in the amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 787-18 August 1995 ICS 87.060.10; 87.060.30 Descriptors: Paints, pigments, determination, sieve residues English version General methods of test for pigments and extenders Par
12、t18: Determination of residue on sieve Mechanicalflushing procedure (ISO 787-18:1983) Mthodes gnrales dessai des pigments et matires de charge Partie 18: Dtermination du refus sur tamis Mthode mcanique avec liquide dentranement (ISO 787-18:1983) Allgemeine Prfverfahren fr Pigmente und Fllstoffe Teil
13、 18: Bestimmung des Siebrckstandes Mechanisches Splverfahren (ISO 787-18:1983) This European Standard was approved by CEN on 1995-03-23. 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
14、 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 ot
15、her 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, Denmark, Finland, France, Germany, Greece, Iceland,
16、 Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels All rights of reproduction and
17、communication in any form and by any means reserved in all countries to CEN and its members. Ref. NO. EN ISO 787-18:1995 EEN ISO 787-18:1995 BSI 12-1999 2 Foreword The text of the International Standard from ISO/TC35, Paints and varnishes, of the International Organization for Standardization (ISO)
18、has been taken over as a European Standard by the Technical Committee CEN/TC298, Pigments and extenders. 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 February1996, and conflicting national stan
19、dards shall be withdrawn at the latest by February1996. According to CEN/CENELEC International Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Po
20、rtugal, Spain, Sweden, Switzerland and the United Kingdom.EN ISO 787-18:1995 BSI 12-1999 3 0 Introduction This document is a part of ISO787, General methods of test for pigments and extenders. 1 Scope and field of application 1.1 This part of ISO787 specifies a general method for determining the res
21、idue on a sieve from a sample of pigment or extender dispersed in water, using a mechanical flushing procedure. This method can also be applied to the examination of other powders or granules which are insoluble in water. It is neither applicable to hydrophobic nor pelletized pigments and extenders.
22、 1.2 ISO787-7 specifies a general method of test for determining the residue on a sieve from a sample of pigment or extender dispersed in water, using a manual procedure. 1.3 For most pigments and extenders, these two test methods will give different results, and it is therefore essential to state c
23、learly in a specification which method is to be used, and in the test report, which method has been used. NOTEWhen either of these general methods is applicable to a given pigment or extender, only a cross-reference to it should be included in the International Standard relating to that pigment or e
24、xtender, with a note of any detailed modification which may be needed in view of the special properties of the material under consideration. Only when neither of these general methods is applicable to a particular material a special method for determination of residue on sieve should be specified. 2
25、 References ISO 565, Test sieves Woven metal wire cloth, perforated plate and electroformed sheet Nominal sizes of openings 1) . ISO 787-7, General methods of test for pigments and extenders Part 7: Determination of residue on sieve Water method Manual procedure. ISO 842, Raw materials for paints an
26、d varnishes Sampling. 3 Definition residue on sieve (R) the coarse particles which remain on a sieve of a specified nominal aperture when a test is performed in accordance with this International Standard 4 Principle In the test apparatus, the pigment or extender under test, dispersed in water, is b
27、rought into centrifugal motion by a system of rotating jets of water. The water flushes the fine particles through the sieve, the coarse particles being retained on the sieve. The residue on the sieve is dried and weighed. 5 Materials 5.1 Filtered tap water, at a pressure of300 20kPa above atmospher
28、ic. 5.2 Wetting agents, such as ethanol95% (V/V) or sulphonates,etc., for pigments and extenders that are difficult to wet with water. The selection of an appropriate wetting agent shall be agreed between the parties, and the wetting agent used shall be stated in the test report. 6 Apparatus Ordinar
29、y laboratory apparatus and 6.1 Mechanical flushing apparatus (see theFigure) consisting of the following items. 6.1.1 Container 6.1.2 Cover, with protective hood, driving motor, hollow shaft with two nozzles with an internal diameter of1 0,2mm, head with three nozzles of diameter1 0,2mm, water suppl
30、y connection, filling funnel, handle and overflow. NOTEWith the specified pressure and internal diameter of the nozzles the water flow will be about5l/min. It is recommended that the internal diameter of the nozzles should be periodically examined. Calcareous deposits should be dissolved by chemical
31、 substances which do not attack the material of the nozzles. The cleaning should not be performed by mechanical means. 6.1.3 Sieve, consisting of a frame of metal or plastics material with a wire gauze of phosphor-bronze or stainless steel. The nominal mesh aperture shall be selected from the princi
32、pal sizes specified in ISO565 and shall be stated in the test report. NOTE 1Sieves may also be used in which three breaker lugs for dispersal of agglomerates project into the plane of the sieve. NOTE 2Sieves of nominal mesh aperture of454m are frequently used. It is recommended that the mesh apertur
33、es of the sieve should be periodically examined to check whether the mesh aperture of the sieve has been damaged, for example by the water jet or by heat. The sieve should be discarded if the mesh apertures have been affected. NOTE 3If a sieve with a plastics frame is used, care should be taken that
34、 the softening point of the plastics material is well above the temperature used for drying the residue. Sieves with a plastics frame should be heated at105 C to constant mass before being used for the first time. 1) At present at the stage of draft. (Revision of ISO565:1972.)EN ISO 787-18:1995 4 BS
35、I 12-1999 6.1.4 Sieve holder 6.2 Oven, capable of being maintained at105 2 C. 6.3 Balance, accurate to at least0,1mg. 6.4 Desiccator, containing an efficient desiccant. 7 Sampling Take a representative sample of the material to be tested as described in ISO842. 8 Procedure Carry out the determinatio
36、n in duplicate. 8.1 Test portion Weigh, to the nearest0,1%, into a beaker of suitable capacity, a quantity of the sample, m 0 , such that a sufficient residue on the sieve (6.1.3) is obtained. Generally, a test portion of5to50g is necessary, but in the case of products yielding a very low residue on
37、 the sieve a greater test portion, up to300g, should be used. 8.2 Preparation of the dispersion Disperse the test portion (8.1) in a suitable quantity of water in a beaker by stirring with a glass rod to give a free-flowing suspension. If the test portion is not readily wetted by water, use a wettin
38、g agent(5.2). NOTEA slowly rotating paddle stirrer may be used, but do not use high power stirrers as these may cause the de-aggregation of pigment particles. 8.3 Determination 8.3.1 Adjust the flow of the water of the mechanical flushing apparatus (6.1) so that the water pressure is300 20kPa above
39、atmospheric, and switch on the motor. Transfer the suspension quantitatively, by way of the funnel (see theFigure), to the apparatus and rinse the beaker and funnel with water. Record the time when the fine particles have almost completely passed through the sieve as indicated by the noise of the wa
40、ter passing through the nozzles becoming louder, hissing sharply and then remaining constant, while at the same time the water running through the sieve appears to be clear. Continue flushing for a further10min (see note1) in order to break agglomerates by the now fully active water jet and to rinse
41、 the last fine particles through the sieve (see note2). NOTE 1For some pigments a flushing duration of10min is not necessary. With such pigments the required duration should be determined by preliminary experiments and if a period shorter than10min is used this should be stated in the test report. N
42、OTE 2If the flushing water is very hard, it is advisable to give the apparatus a final rinse with distilled water in order to prevent the formation of deposits of calcium salts on the sieve on drying. 8.3.2 Switch off the motor, and then stop the water flow. Remove the sieve from the test apparatus
43、and dry it in the oven (6.2) at105 2 C (see the note) for1h. Allow the sieve and residue to cool in the desiccator (6.4) and weigh to the nearest0,1mg (m 1 ). Remove the residue from the sieve using a finebrush and weigh the empty sieve to the nearest0,1mg (m 2 ). NOTEIf the melting point of the res
44、idue on the sieve is lower than110 C, a more suitable drying temperature should be used and this should be stated in the test report. 8.3.3 If the duplicate determinations differ by more than0,1% absolute, repeat the procedure. If the two further determinations still differ by more than0,1% absolute
45、, state all four values in the test report, and check the product for inhomogeneity. 8.4 Examination of the residue Inspect the residue for the presence of incompletely dispersed pigment or extender and, if present, repeat the whole procedure (clause8) using an alternative dispersing agent agreed be
46、tween the parties. If the residue contains extraneous matter, report its presence and nature. 9 Expression of results Calculate the residue on sieve (mechanical flushing procedure) by the equation where R is the residue on sieve, expressed as a percentage by mass; m 0 is the mass, in grams, of the t
47、est portion; m 1 is the mass, in grams, of the sieve with residue; m 2 is the mass, in grams, of the empty sieve. Report the mean of the duplicate determinations if they agree to within 0,1% absolute. If not, see8.3.3. If the result with the100g test portion is less than0,01% this should be stated i
48、n the test report as “less than 0,01%”.EN ISO 787-18:1995 BSI 12-1999 5 10 Test report The test report shall contain at least the following information: a) the type and identification of the product tested; b) a reference to this International Standard (ISO787-18); c) the result of the test as indic
49、ated in clause9; d) the nominal mesh aperture of the sieve used; e) the mass of the test portion; f) if used, the type and quantity of the wetting agent; g) a description of the type and condition of the residue on sieve (for example extraneous matter); h) any deviation, by agreement or otherwise, from the procedure specified (see note1 to 6.1.3, note1 to 8.3.1 and note to 8.3.2); j) the date of the test. Figure Mechanical flushing apparatus6 blankBSEN ISO 787-18:1995 BSI 12-1999 List of references See n
