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In the present work, 100% cotton knitted fabrics were functionalized with ZnO nanoparticles, in order to enhance the hydrophobic properties of the fibers surface. The incorporation methods of ZnO NPs and different types of cotton samples (including polymer coated, and uncoated with and without a nonionic pretreatment) were evaluated, in order to understand the influence in the hydrophobicity values. Cotton fabrics with and without NPs were characterized by ground-state diffuse reflectance, field emission scanning electron microscopy and energy-dispersive spectroscopy, attenuated total reflectance-Fourier transform infrared spectroscopy and water contact angle (WCA). The best results were obtained when the polymer-coated fabric was functionalized using a precursor concentration of 0.2 M, exhibiting superhydrophobic behavior with static WACs of more than 150°. Although pretreated and untreated ZnO-functionalized cotton fabrics had a slightly lower wettability, they showed interesting results, with improvements in WCA from 116° to 143°. In summary, this work demonstrates that the ZnO NPs have a huge potential to be used as surface finishings for the development of easy cleaning fibrous structures.

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The pressure profile analysis for monitoring and diagnosis processing failures during an injection moulding process, such as burn marks and short shots, is a useful instrument for process and part quality control and production with zero defects and greater efficiency. Therefore, this work aims to demonstrate the in-cavity pressure monitoring feasibility for failure diagnosis and injection moulding process optimization. The methodology used to analyse the obtained pressure variation is presented. The results were correlated to the typical cavity pressure profile, which enables the acquisition of information about the process and the moulding tool. This way, it was possible to determine the origin of the defects present in the injected parts, focusing not only on the velocity to pressure switchover but also on the initial part of the curve, related to the filling phase. Moreover, the obtained results and the studied processing conditions were correlated with the injection moulding process simulation.