1、Designation: D6619 00 (Reapproved 2012)D6619 00 (Reapproved 2016)Standard Practice forIncorporating Pigments by High Speed Dispersion1This standard is issued under the fixed designation D6619; the number immediately following the designation indicates the year oforiginal adoption or, in the case of
2、revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This practice covers the dispersion of pigments using a laboratory size high-speed impeller mill
3、 It is similar in technicalcontent to ISO 8780-3.NOTE 1This practice is restricted to mill bases of moderately high viscosity due to either high vehicle concentration or high pigment concentration,or both, which can produce high shear force. It is not intended to provide a means of formulating eith
4、er pilot plant or full-scale mill base compositions(scaling up the process from laboratory equipment to factory mills is not simple).1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to esta
5、blish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ISO Standards:ISO 8780-3 Pigments and ExtendersMethods of Dispersion for Assessment of Dispersion CharacteristicsDispersion Usinga High Speed Impeller Mill23
6、 Significance and Use3.1 High speed dispersion is a commonly used dispersion method in the coatings industry. For the purpose of this practice, “highspeed” would normally be understood to be a range of RPM between 3 000 and 10 000. This practice provides a reference for itsuse, so that a producer a
7、nd user can standardize on an incorporation technique. This will minimize differences in the millbase, andallow the interested parties to concentrate on the physical, chemical, or optical methods to be run.4. Apparatus4.1 High-speed Impeller Mill, consisting of a cylindrical vessel and a horizontal
8、disk stirrer blade driven by a motor.Adisk witha serrated edge is commonly used.4.1.1 Drive UnitThe power rating of the drive unit shall be sufficient to maintain the peripheral speed of the disk at an agreedvalue. A reduced rotational speed shall be available for pre-mixing in accordance with 6.2.
9、The motor of the drive unit shall bemounted on a stand together with the impeller shaft so that its height can be adjusted. There shall be a clamping device for thevessel at the foot of the stand, such that the impeller shaft is concentric with the vessel.4.1.2 Disk and Vessel:4.1.2.1 The diameters
10、of the vessel and the disk shall be such that there is adequate clearance between the disk periphery andthe walls of the vessel (see Fig. 1). If the disk is serrated, it shall be mounted so that the direction of movement of the serrationsis such that the mill base flows in the directions shown in Fi
11、g. 1.4.1.2.2 The degree of dispersion achieved will depend on the type of disk used. Fig. 1 shows only one type.4.1.2.3 The type and diameter of the disk, the geometry of the vessel, and the speed of the disk shall be agreed upon andrecorded in the test report.NOTE 2A vessel with a double wall to al
12、low circulation of a liquid to control the temperature should be employed, if necessary. A lid with a centralaperture may also be provided.NOTE 3The diameter of a vessel used in an industrial scale mill is normally two to three times the diameter of the impeller, or sometimes even greater.The vessel
13、/disk geometry and the disk speed specified make allowance for the small diameter of a laboratory disk.1 This practice is under the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.24 on Physical Properties of Liquid Paints or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 00 (2016)3
