Evaluation of the Plastic Film Thermoforming Process and the Operation of the Forming Tool with a Thermal Camera

In creation of three-dimensional shapes, such as tray packages, from plastic film with thermoforming process, the operation of the forming tool and the heating arrangement play a key role. The previous research information related to the monitoring of thermoforming of plastic film materials needs to be supplemented to enable more sophisticated process evaluation. During the commissioning of the new mould tool, its operation was ensured by monitoring the work cycle with a thermal camera and by making dimensional measurements for the end-products. In trial runs, tray packages were produced from two sample materials: monolayer PET-film and multilayer PP-film. Operation of mould design from the processing perspective, reproducibility of shapes and thickness distribution were observed as part of the package quality evaluation. The objective of the study was to understand the operation of the manufacturing process and the behaviour of the formed material more comprehensively by monitoring the system features related to heating. Respectively, utilization possibilities of the thermal camera were studied in terms of production speed increase. The versatile measurement data obtained with the properly adjusted thermal camera monitoring setup proved to be useful for adjusting the thermoforming process and in the evaluation of the forming tool operation.