From SIGMA version 11.1, it is possible to model a strand cooling. The temperature distribution within a polymer strand can be determined related to specific times. With the help of the strand cooling, the dimensioning of the cooling length can be significantly simplified and conclusions can be drawn on the necessary cooling times.

The temperature distribution is determined via the Finite Difference Method (FDM). Complex thermal conductions can be represented by the Fourier differential equation (see Equation 3). In the case of FDM, the partial derivatives are simplified as a difference quotient and so an approximate solution of the problem can be calculated. For the modelling, the present geometry is discretized and temperatures can be calculated for the interpolation points. [FP08]; [Mart11]