**5. Conclusions**

Through simulation, a 60-mm-long profile geometry model is obtained at the outlet of the head, thus minimizing the swelling of the melt and obtaining a deformation with dimensional differences that are within the recommended percentages, as described in Section 3.2.3.

The 60-mm length obtained from the simulation is recommended to use in the extrusion process to overlap the distance that must exist between the head and the caliper in order to avoid problems of clogging of the molten material that enters the caliper and apply vacuum.

From the results of the simulation, it is determined that the distribution of the velocity vectors in each of the cross sections is not homogeneous and also the shear deformations had very high values, which cause internal stresses to be generated in the profile that causes their failure in service.

Therefore, the geometry of the head flow channel should be redesigned to improve these parameters that influence the final properties of the profile, such as the generation of high internal stresses that affect the quality of the product.

An optimal parallel zone can also be defined, because its length influences the swelling effect of the melt; that is to say, by increasing it, a greater relaxation of internal stresses is obtained and consequently a less deformation of the material at the exit of the caliper [7]. It was possible to carry out the rheological test and obtain the k and n values of the Power Law for the rigid PVC compound of the present work using a special capillary rheometer connected in line with an extruder and they could be used in a simulation software that uses fluid dynamics. Computational and the direct extrusion method [9] is used to optimize the design of a head of a rectangular profile in rigid PVC.

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

Therefore, the predictive capacity of the ANSYS Polyflow simulation software is verified for this work and with it, it can be applied for the simulation of more complex profile geometries.

Finally, a specific calibrator is designed and built for this profile and in only three tests with the extruder equipment, the operation of the same and of the process is optimized, verifying that the flow used in the simulation is correct, obtaining a profile with the geometry and final dimensions required and with a dimensional error of less than 5%.
