Abstract:

This study shows how the quality of low liniar density polyethylene (LLDPE) foil can be optimized by controlling the outlet temperature of the extrusion head, using infrared thermography. The first part of the paper presents the material and the description of the quality testing method used in the field of polyethylene film testing. The theoretical foundations of the thermography method used is also briefly shown. The hypothesis is that the variation of the mechanical properties of the foil along the extruder cylinder is caused by temperature differences at which the process takes place. To confirm these aspects, an experimental plan was designed with the help of an infrared thermography camera to highlight the connection between local temperature and mechanical characteristics. It was found that even at 5% temperature variations, the difference in mechanical properties is very important with a sharp decrease in the case of samples taken from the ends of the cylinder. Real-time temperature measurement, at any point on the extruder generator, made it possible to observe the values that appear in the manufacturing process as well as to design and validate an automated reaction loop system that maintains the temperature at the extremities in the area of the corresponding levels from the half of the cylinder where the best product quality is obtained.