Extrusion International 2-2020

44 Extrusion International 2/2020 FILM TECHNOLOGY, QUALITY CONTROL ALEKO – the largest Russian manufacturer of equipment for polymer processing – has presented to themarket a product, which is unique in its technical characteristics, and whichmakes it possible to decrease thickness variations to 70% Automatic Thickness Control System tion for the global market, as even foreign analogues carry out the cor- rection only sequentially. Such an integrated approach of the system from ALEKO allows to reduce the in- dicator of the thickness variation up to 70%. Structure Due to the number of actuators evenly spaced around the perim- eter of the ring, the adjustment oc- curs pointwise, directly in the zone of occurrence of the thickness vari- ation. So, for example, with a die head diameter of 250 to 400 mm, Thickness variation is a frequent phenomenon in the production of film, which has a significant impact on both the quality and the actual cost of a unit of the final product (packaging). In addition, thickness variations of film may affect the sta- bility and performance of packaging equipment. The Russian company ALEKO is one of 9 companies in the world that has designed and offered the market a system for monitoring and control of thickness variations of film. The device is intended for continuous measurement and operational cor- rection of the profile thickness of tubular films during the extrusion process in real time. This is an excel- lent solution to achieve optimal film thickness and minimize the thick- ness variations. Operation principle An annular system of continuous measurement of film thickness based on a capacitive sensor from company Hch. Kündig & Cie. AG (Switzerland) detects deviations from a given value. The received data is transmitted by the sensor to the control system, where the soft- ware calculates the necessary ad- justment algorithm and corrects the corresponding film segment. The thickness variation is controlled by simultaneously correcting both the temperature and the volume of the airflow. This is a unique solu-