Laser joining of aluminum film coated with vinylic resin and plastic/bioplastic films for applications in food packaging

The present work studies the joining process by high power diode laser of aluminum films coated with vinylic resins with films in plastic and bioplastic materials. This study is part of the development of new technological solutions for the packaging of food products. In particular, the first part of the work was dedicated to the study of the process of coating aluminum films with vinylic resins, using an automatic applicator. The second part of the work, on the other hand, was dedicated to the study of the laser joining process of coated aluminum films with plastic counterparts from fossil sources, such as polyethylene terephthalate (PET) and polystyrene (PS), and counterparts in bioplastic, such as MaterBi (a bioplastic blend of thermoplastic starch, TPS, and polybutylene adipate-co-terephthalate, PBAT). The experimental study included the analysis of the influence of the laser process parameters, specifically the scanning speed and beam power, on the joining process. The welded joints between aluminum and plastic films were subsequently tested by means of tensile and peel-off tests. The results allowed identifying the best processing conditions of the materials examined, demonstrating the high potential of laser systems in conducting the joining process of aluminum and plastic films for food applications.