Potencial de utilização de resíduos de filmes poliméricos e de fibras de vidro provenientes do processo de fabricação de pás eólicas

Abstract

The investments made in wind energy have been growing globally over the years, aiming at sustainable alternatives for the segment. However, this growth carries with it an increase in the consumption of production materials and wastes from its processes, which if not properly treated cause negative impacts to the environment. In a society increasingly attentive to ecological issues, concepts of reuse and recycling have been widely disseminated as ways of mitigating the aggression caused by the incorrect disposal of materials in the environment. Thus, in order to contribute to the sustainability of wind turbine manufacturing processes, this study investigates opportunities to reuse two types of waste from these industries: vacuum infusion polymer films and stitched and random glass fiber fabrics. Due to unsatisfactory initial results presented when using these materials together in the hot compression molding process, it was necessary to use them separately and in different molding processes. The first part of the study investigates alternative recycling of polymeric vacuum bag films that are discarded after the manufacturing process of wind turbine blades. The work involved the reuse of this type of polymer film by means of a hot molding process in a hydraulic press. After molding, the plates were cut into specimens for mechanical evaluation in flexural and impact tests and for Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). The results indicated that the waste analyzed is polyamide (nylon) and its mechanical properties are close to the properties mentioned in the literature for this type of polymer, being indicated for use in molding and/or machining of objects such as bearings, gears, rollers, guides and various pieces of industrial equipment. In the second part, the study proposes an alternative method for the reuse of glass fiber wastes (stitched and random) in the manufacture of new thermosetting polymer composites. Here, stitched fabrics from manufacturing processes were used, as well as material refused for technical non-compliance. Ten composites with different layers and fabric arrangements were prepared, which were mechanically evaluated in flexural and tensile and thermally by thermogravimetric analysis (TGA). The preparation process used was the resin transfer molding (RTM) whereby the polymer resin is suctioned into the fiber reinforcements, giving rise to the composites. The resin used in the moldings was the unsaturated polyester type of trade name Arazyn 13.0. Finally, the statistical analysis of mechanical results, performed according to Tukey's methodology, revealed that the number of glass fiber layers is determinant for mechanical properties of the composite, whereas the orientation of the fabrics inside the composites does not present significant differences. Depending on the application of the composites, if higher or lower mechanical resistance is required, other arrangements can be analyzed in order to obtain the desired properties. The composites developed can be applied as materials to obtain products such as doors, floors, walls, office partitions and other furniture with flat surface.