Viscosity result

The Viscosity result shows the viscosity of the polymer at the time the results file was written.

The viscosity of a material is described as a measure of its ability to flow under pressure. This result is generated for the following mesh types:
and for analysis sequences that include:
Note: For thermoset processes, viscosity results are available for reactive molding and microchip encapsulation processes, for compressible analysis sequences only. The results are not available for Underfill or RTM.

The viscosity result is a profiled result, written at different times and on different layers. The maximum value for this result is 1.0e7.

Important: To create this result, ensure that you have set the number of profiled results to a value larger than zero. To check your settings, click (Home tab > Molding Process Setup panel > Process Settings), and click Advanced options. Click Edit associated with Solver parameters, select the Intermediate Output tab and confirm the profiled results for both the filling phase and the packing phase are greater than 0.
Note: For compression-type molding processes, this result is plotted displayed on the deformed mesh as the default setting. With this default setting, if you click through the time steps you can watch the polymer as it is compressed into the part shape. To turn it off, so that all you see is the result on the part, right-click the result, select Properties and uncheck Display on deformed mesh.

Using this result

The viscosity of polymers is dependant on temperature and shear rate. In general, as the temperature and shear rate that the polymer experiences both increase, the viscosity will decrease, indicating a greater ability to flow under a given applied pressure. The results are calculated from the viscosity distribution across the molten (above transition) part of the cavity.

For a Fill analysis using 3D analysis technology, viscosity is calculated for each tetrahedral element or node throughout the model. The values calculated by the program are the actual viscosity values for the tetrahedral elements, or nodes and represent a real case injection molding scenario. The 3D viscosity result is more accurate than the fast algorithm or the finite difference algorithm because actual values are being determined at each node of the solid model.

For microcellular analyses, the presence of gas bubbles changes the viscosity of the polymer. After the gas is injected, the viscosity decreases. Since the gas concentration changes over time, the viscosity of the polymer will change. This result can be used to show the effect of gas concentration and bubble growth on the viscosity of the polymer.

Note: Use the cutting plane tool to view Viscosity results through the solid model.

Things to look for

Parent topic: Flow results