ISO 3219:1993 pdf download – Plastics – Polymers/resins in the liquid state or as emulsions or dispersions – Determination of viscosity using a rotational viscometer with defined shear rate
1 Scope
This International Standard specifies the general prin- ciples of a method for determining the viscosity of polymers and resins in the liquid, emulsified or dis- persed state, including polymer dispersions, at a de- fined shear rate by means of rotational viscometers with standard geometry. Viscosity determinations made in accordance with this standard consist of establishing the relationship between the shear stress and the shear rate. The re- sults obtained with different instruments in accord- ance with this standard are comparable and apply to controlled shear as well as controlled stress instru- ments.
2 Normative reference
The following standard contains provisions which, through reference in this text, constitute provisions of this International Standard. At the time of publi- cation, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most re- cent edition of the standard indicated below. Mem- bers of IEC and IS0 maintain registers of currently valid International Standards.
ISO 291:1977, Plastics – Standard atmospheres for conditioning and testing.
A torque-measuring device shall be connected to one of the surfaces, thus permitting determination of the torque required to overcome the viscous resistance of the fluid. Suitable measuring systems are coaxial-cylinder sys- terns and cone-and-plate systems, among others. The accuracy of the thermometer shall be f 0,05 “C. 5 Sampling The sampling method, including any special methods of sample -preparation and introduction into the viscometer, shall be as specified in the test standard for the product in question. The dimensions of the measuring system shall be so specified as to satisfy the conditions specified in an- nexes A and 8, which are designed to ensure a ge- ometrically similar flow field for all types of measurement and all common types of basic instru- ment.
4.1.2 Basic instrument
Test conditions The basic instrument shall be designed to permit al- ternative rotors and stators to be fitted, for the gen- eration of a range of defined rotational frequencies (stepwise or continuously variable), and for measuring the resulting torque, or vice versa (i.e. generation of a defined torque and measurement of the resulting rotational frequency). The apparatus shall have a torque-measurement ac- curacy within 2 % of the full-scale reading. Within the regular working range of the instrument, the accuracy of rotational-frequency measurement shall be within 2 % of the measured value. The repeatability of vis- cosity measurement shall be + 2 %. 6.1 Calibration Viscometers shall be calibrated periodically, e.g. by measuring the torque characteristics or using refer- ence liquids of known viscosity (Newtonian fluids). If the best-fit straight line drawn through the measured points for the reference fluid does not pass through the origin of the coordinate system, within the limits of the accuracy of the method, the procedure and the apparatus shall be checked more extensively in ac- cordance with the manufacturer’s instructions. The viscosity of reference liquids used for calibration shall lie in the same range as that of the sample(s) to be measured. NOTE 3 By using different measuring systems and rota- tional frequencies, most commercial instruments cover a viscosity range from at least 1 0m2 Pas to IO3 Pas. The range of shear rates varies greatly with different equipment. The choice of a particular basic instrument and appropriate measuring system shall be made by considering the range of viscosities and shear rates to be measured.