The similarity theory and the scale‐up procedure developed from it make it possible to convert a technical‐physical process from one scale to another – generally in the upwards direction. In the design of extrusion dies with an annular die gap, the die is broken down into basic geometric elements, and scale‐up rules are then drawn up for the individual elements. In this project, scale‐up rules were found that satisfy both full and partial similarity. The pseudoplasticity and elasticity of the melt were also taken into consideration. A comparison of the model laws obtained with the results of finite element calculations showed good conformity between the models and the production versions.
Deviation in pressure difference between the model and the production version assuming flow behavior in accordance with the power law (Di = const. and L = const.).
