① Flow Curve Testing

In flow curve testing, the abscissa represents the shear rate, which characterizes the degree of shear imposed on the sample by certain processes or means. The ordinate represents the viscosity. As shown, the viscosity of the red, green, and blue samples decreases with the increase of the shear rate. This is consistent with the characteristics of most samples in practical processes because polymers generally have such properties.

② Yield Stress Testing

In yield stress testing, the abscissa of the graph is the shear stress, which can be regarded as the force applied to the sample, and the ordinate is the deformation. It shows the deformation process of the sample under a certain force. If the deformation suddenly increases, it indicates that the sample has yielded.
The concept of yield stress has many applications in our daily life. For example, for toothpaste, the force required to squeeze it out is the yield stress. When it comes to adhesives, like silicone adhesive, we can also consider the force needed to extrude it from the tube as the yield stress.

③ Thixotropy Testing

Thixotropy testing is crucial as thixotropy is an important property of adhesives. Generally, it is understood as a time - related behavior. The abscissa is time, and the ordinate is viscosity. During the experiment, first, a relatively low shear is applied to simulate the behavior in a static state. Then, a sudden acceleration is applied to simulate the behavior during use, and the viscosity usually decreases. After that, when returning to the low - shear state, we observe the change process of the viscosity.
Through this experiment, many actual situations in the production process can be simulated. These three stages respectively simulate the static state, the usage state, and the state after the force is removed and the recovery process. The recovery condition in the recovery state is related to leveling and sagging.
It is reported that this can also be quantitatively expressed. By comparing the viscosity at different times during the recovery to the initial state with the viscosity in the static state in the third (recovery) stage, the thixotropy can be quantitatively characterized. Currently, this is a very good method.

④ Viscosity - Temperature Characteristic Testing

In viscosity - temperature characteristic testing, the abscissa represents the temperature change, and the ordinate represents the viscosity. It shows the change process of viscosity with the change of temperature. Generally, the viscosity decreases as the temperature rises. For example, if a sample is stored in a refrigerator after being prepared, its viscosity will increase. Or if a sample is prepared in the south and then sent to the north for use, its viscosity will also increase.