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1、INTERNATIONAL STANDARD IS0 878045 First edition 1990-l 1-15 ANSI Internat Doe Set Pigments and extenders - Methods of dispersion for assessment of dispersion characteristics - Part 5: Dispersion using an automatic muller Pigments et mati b) pigments of medium binder demand - pigment concentration 40
2、 % (m/m); c) pigments of high binder demand - pigment con- centration 25 % (m/n. 8 Procedure If there are no water-cooled plates, take care that the temperature during the dispersion operation does not rise by more than 10C. Pre-condition new muller plates by milling a pigment in a suitable binder (
3、system) for 1000 revolutions with a load applied to the plates. Remove and dis- card the paste. Before use, check that the surfaces of each plate have an even, opaque appearance and are free from score marks and polished areas. 8.1 Dispersion Weigh out agreed amounts of the binder system (clause 5)
4、and pigment. The amounts weighed depend on the size of the muller plates. If the paste exudes from the edges of the plates during dispersion, the amount of the mill base shall be reduced appropriately. If the criterion for assessing the dispersion charac- teristics is to be the evaluation of the dev
5、elopment of tinting strength (see IS0 8781-l), the masses of the pigment and of the binder system shall be de- termined to within 0,5%. For other methods of as- sessment (for example fineness of grind, see IS0 8781-2, and change of gloss, see IS0 87813), wider tolerance ranges may be agreed on. Plac
6、e the binder system in the centre of the lower plate of the automatic muller (4.1). Sprinkle the pigment into the binder and mix together, using the minimum effort, with the aid of the spatula (4.2). Distribute the paste at several points at a distance of about 35 mm from the centre of the lower pla
7、te or spread it in the form of a ring with an internal di- ameter of 40 mm and an external diameter of 100 mm. NOTE 2 It is advisable to lay a paper ring of the requi- site shape as a pattern beneath the lower plate. Clean the spatula as much as possible by wiping it on the face of the upper plate o
8、f the mullet-. Close the plates of the muller and grind the mixture under an agreed load at an agreed rotational fre- quency and for an agreed number of revolutions in several successive stages (for example 50, 100, 200 and 400 revolutions, as shown in figure 1). Mid-way through each stage (for exam
9、ple after 25, 75, 150 or 300 revolutions), and at the end of each stage, homogenize the mill base by scraping together with the spatula, mixing (using minimum effort) and re- distributing it as described above. Take a test por- tion at the end of each stage as agreed. 2 Copyright International Organ
10、ization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 04:32:52 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8780-5:1990(E) Key 0 X homogenize and take a test portion as agreed. 1st
11、 stage 2nd stage 3rd stage 4th stage ii it X X 0 I I 0 0 0 I I I I I I 0 25 50 75 100 150 200 300 400 Number of revolutions homogenize Figure 1 - Example of grinding schedule When more than two test portions, or a test portion amounting to 15% of the paste, have been taken, repeat the procedure on f
12、resh mill base mixtures for each grinding stage. 8.2 Stabilization If necessary, for example if the mill base is not sta- ble enough, stabilize each test portion after its re- moval from the mill base by adding, for example, more binder and/or special additives. The procedure shall be agreed on betw
13、een the interested parties. 9 Test report The test report shall contain at least the following information: a) all details necessary to identify the product tested; b) a reference to this part of IS0 8780; c) the items of supplementary information referred to in annex A; d) any deviation from the pr
14、ocedure specified; e) the date(s) of the test. 3 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 04:32:52 MDTNo reproduction or networking permitted without license from IHS -,-,
15、- IS0 87804:1990(E) Annex A (normative) Required supplementary information The items of supplementary information listed in this annex shall be supplied as appropriate to enable the method to be carried out. The information required should preferably be agreed between the interested parties and may
16、be derived, in part or totally, from an international or national standard or other document related to the b) Binder system (see clause 5). c) Composition of the mill base (see clause 7) and its temperature (see clause 8). d) Dispersion conditions (load on the muller plates, and rotational frequenc
17、y and number of revol- utions of the plates) (see 8.1). product under test. a) Type and complete details of the automatic muller (see 4.1). e) Stabilization procedure (see 8.2). 4 Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical
18、Standards 1/9972545001 Not for Resale, 04/27/2007 04:32:52 MDTNo reproduction or networking permitted without license from IHS -,-,- IS0 8780-5:1990(E) UDC 667.622:541.18.052:542.22 Descriptors: paints, pigments, extenders, dispersibility, dispersing. Price based on 4 pages Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/27/2007 04:32:52 MDTNo reproduction or networking permitted without license from IHS -,-,-