The viscosity of epoxy resin is an important indicator of its fluidity and handleability, so accurately measuring its viscosity is crucial for product quality control. The following describes a method for measuring the viscosity of epoxy resin using a coaxial double-circle Rotational Viscometer with a specified shear rate. It is suitable for the determination of viscosity of liquid epoxy resin according to GB/T 22314-2008.
principle
The viscosity of a liquid sample is measured based on the shear rate used by the Rotational Viscometer and the resulting shear stress. The calculation formula of viscosity η is: η = Ï / γ, where eta is the viscosity, Ï is the shear force, and γ is the shear rate.
instrument
Rotational viscometer: including measurement system and basic instrument.
Temperature control device: maintain the measured temperature within a constant range.
Thermometer: measure the test temperature with an accuracy of 0.05°C.
sampling
Sampling is carried out in accordance with the method specified in the test standard of the product being tested to ensure that the sample does not contain any visible impurities and bubbles.
Test conditions
Calibration: Calibrate the viscometer regularly using a reference fluid of known viscosity.
Test temperature: The measurement should be carried out at the same temperature, usually (23.0 ± 0.2)°C.
Selection of shear rate: One shear rate is specified for Newtonian products, and multiple shear rates are used for non-Newtonian products.
step
Select fixed speed, rotation speed and rotation speed as needed.
Take a certain volume of sample, carefully pour it into the outer cylinder, and let it stand to release the bubbles.
Connect the instrument to the thermostat and activate the thermostat to maintain a constant temperature.
Turn on the power, start the motor to rotate the drum, wait for the pointer to stabilize and take a reading.
Result expression
Calculate the viscosity according to the operation manual or calculation chart attached to the instrument, and take the arithmetic mean of the three measurement results. The viscosity value can be expressed by the temperature and shear rate in brackets, for example: (23°C, 1600 s-1) = 4.25 Pa.s.
This epoxy resin viscosity measurement method is simple and easy to implement, can be used to accurately measure epoxy resin viscosity, and provides an important basis for product quality control.
