The present work deals with the high-power diode laser joining process of aluminum films coated with a polyester resin with polypropylene (PP) films. The first part of the work focused on analyzing the coating process of aluminum films with a polyester resin, using an automatic applicator. The second part of the work was focused on the analysis of the laser joining process of coated aluminum films with plastic counterparts made of PP. Different thicknesses and colors of the PP parts were tested in order to analyze the joining process under a wide range of different conditions. The experimental plan involved the study of the influence of the laser joining parameters, in particular the scanning speed and beam power, on the joints. The joints between aluminum and PP films were subsequently tested by means of tensile and peel-off tests. All the joints between aluminum and PP are obtained through the so-called laser transmission welding (LTW) mechanism. Analysis of the mechanical response of the welded joints allowed to identify the optimal processing window, that is, the choice of the operational parameters that leads to satisfactory welded joints, stating the high potential of laser systems in the joining process of aluminum and PP films for food packaging applications.

Drag finishing of brass (Cu-30 wt.% Zn) rings using fluidized abrasives, which is a new finishing technology, is comparatively evaluated with centrifugal disk finishing. The comparison was performed by selecting the same abrasive granulates of two different sizes and operating the equipment for the same processing time or at their respective maximum speeds. The experimental analysis investigated the change in workpiece morphology, material removal during finishing and dimensional accuracy. The results showed that each of the types of equipment investigated in the study were capable of a high finishing performance with a relatively short processing time. However, fluidized bed assisted drag finishing was more effective than centrifugal disk finishing in both the achievable quality of the processed parts and reduced processing time. In contrast, centrifugal disk finishing was preferable whenever low erosion and stringent dimensional tolerances were demanded