Designation: D2196 - 15 INTERNATIONAL Standard Test Methods for Rheological Properties of Non-Newtonian Materials by Rotational Viscometerl This standard is issued under the fixed designation D2196; the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. Anumber in parentheses indicates the year of last reapproval. A superscript epsilon (e) indicates an editorial change since the last revision or reapproval. This standard has been approved for use by agencies of the U.S. Department of Defense. 1. Scope or more speeds give better characterization of a non-Newtonian 1.1 These test methods cover the determination of the material than does a single viscosity measurement. apparent viscosity and the shear thinning and thixotropic 3.2 With Test Methods B and C, the extent of shear thinning properties of non-Newtonian materials in the shear rate range is indicated by the drop in viscosity with increasing rotational from 0.1 to 50 s-1 using a rotational viscometer operating in a speed. The degree of thixotropy is indicated by comparison of fluid of “infinite" dimensions. viscosities at increasing and decreasing rotational speeds (Test 1.2Thevalues stated in SI units areto beregarded asthe MethodB),viscosityrecovery(TestMethodB),orviscosities standard. The values given in parentheses are for information before and afterhighshear(combinationofTest Methods B only. and C).The high-shear treatment in Test Method C approxi mates shearing during paint application. The viscosity behavior 1.3 This standard does not purport to address the safety measured after high shear is indicative of the characteristics of concerns, if any, associated with its use. It is the responsibility the paint soon after application. of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory 4.Apparatus limitations prior to use. 4.1 Rotational Viscometer-The essential instrumentation 2. Summary of Test Method required providing the minimum rotational viscometer analyti- 2.1 Test Method A consists of determining the apparent cal capabilities for this method include: 4.1.1 A drive motor, to apply a unidirectional rotational viscosity of coatings and related materials by measuring the torque on a spindle rotating at a constant speed in the material. displacementto the specimenatatleastforrotational speeds between0.05and6rad/s(0.5and60r/min)constanttowithin 2.2 Test Methods B and C consist of determining the shear 1 % thinning and thixotropic (time-dependent) rheological proper- 4.1.2 Aforce sensor to measure the torque developed by the ties of the materials. The viscosities of these materials are specimen to the rotational displacement of the rotational determined at a series of prescribed speeds of a rotational-type element to within 1 %. viscometer operating in a fluid of “"infinite" dimensions. The 4.1.3 A coupling shaft, or other means, to transmit the agitation of the material immediately preceding the viscosity rotational displacement from the motor to the rotational ele- measurements is carefully controlled. ment. 4.1.4 A rotational element, spindle, or tool, such as the 3. Significance and Use cylindrical shape shown in Fig. 1, to fix the specimen between 3.1 Test Method A is used for determining the apparent the drive shaft and a stationary position. viscosity at a given rotational speed, although viscosities at two Nore 1—Each rotational element covers a range of about 1.5 decades of viscosity. The rotational element is selected so that the measured viscosity (or torque) is between 10 and 90 % of the range of the rotational These test methods are under the jurisdiction of ASTM Committee DO1 on element. Paint and Related Coatings, Materials, and Applications and are the direct responsibility of Subcommittee D01.24 on Physical Properties of Liquid Paints & 4.1.5 A data collection device, to provide a means o