Flexible packaging has been widely employed in retail products such as biscuits, chocolates, candies etc. The packaging is normally printed on sheets around 1 m wide, which can have several packages printed side by side, covering all its width. This packaging is supplied to the packaging company in individual spools and parted longitudinally, to separate the strips that compose them. The project and the development of a photoelectric transducer to help the longitudinal cut of the flexible packaging are here presented. This paper reports the development of a product with a totally innovative concept, which does not use classic components of optical geometry (lenses, prisms and filters), characterized by constructive simplicity, low cost and high performance. Different technologies of optical sensors are analyzed and compared; then, the photoelectric sensor is defined as the best option for this application, not only from the technical point of view, but also from the economical one. Next, the technical characteristics of this sensor are described. Finally, the assembly of a photoelectric transducer with the selected sensor and its mathematical modeling is performed. The tests show that the developed transducer is fully able to operate in slitter-rewinder machines of last generation, whose speed can reach 800 m/min.
optical sensor; photoelectric transducer; flexible packaging; slitter-rewinder machines
