*3.2.3 Comparison of original profile contours vs. cast profile outlet head*

Another important result of this simulation is obtained: the contour of the profile in the molten state at the outlet of the head at a distance of 60 mm.

To do this, the orientation of the axes of the channel geometry is modified in the post-processing stage, eliminating all contours and surfaces except for the contours of the output profile of the head (original) and the profile of the molten material at the output, from the head at a distance of 60 mm.

By superimposing both contours, the geometric and dimensional differences that exist between them can be seen and therefore, this image is exported and said differences are dimensioned (**Figure 17**).

They are due to the aforementioned incidence of the swelling effect of the melt that causes an increase in the cross-sectional area of the flow of the melt at the outlet of the head.

In a previous simulation, a channel geometry model was used with an outer zone at the head outlet of 10 mm, with which the deformations were greater, there were important geometric and dimensional differences, and the profile could not have been calibrated or manufactured, because it would have stuck in the caliper, thus optimizing the design of the model by increasing the length of the area at the exit of the cast profile with a new simulation at a distance of 60 mm.

The dimensional variation at a distance of 60 mm from the head can be seen in **Table 3**.

**Figure 17.** *Comparison of original profile contours (black) and head outlet (blue).*

*Design, Simulation, and Analysis of the Extrusion Process of a PVC Thermoplastic Profile… DOI: http://dx.doi.org/10.5772/intechopen.100909*


**Table 3.**

*Dimensional variations between the original profile and the head outlet profile at a distance of 60 mm.*

Therefore, maximum deformation values were achieved due to the swelling effect of the melt within the recommended parameters, which are 3–6% for thicknesses of rigid PVC profiles between 3 and 4 mm thick [6].
