Research Article Wood-Reinforced Polyphthalamide Resins: MultiFunctional Composite Coating for Metal Substrates M. Barletta, 1 G. Rubino, 2 V. Tagliaferri, 1 F. Trovalusci, 3 and S. Vesco 1 1 Dipartimento di Ingegneria dell’Impresa, Universit` a degli Studi di Roma Tor Vergata, Via del Politecnico, 1-00133 Roma, Italy 2 Dipartimento di Economia e Impresa, Universit` a degli Studi della Tuscia, Via del Paradiso, 47-01100 Viterbo, Italy 3 Universit` a Niccol` o Cusano, Via Don Carlo Gnocchi, 3-00166-Roma, Italy Correspondence should be addressed to M. Barletta; barletta@ing.uniroma2.it Received 25 February 2014; Accepted 30 June 2014; Published 20 August 2014 Academic Editor: Jose Ramon Leiza Copyright © 2014 M. Barletta et al. his is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Protective layers were deposited on aluminum substrates by dipping them inside a luidized bed (FB) of wood and polyphthalamide powders. he experimental investigation looked into the inluence of the main process parameters (number and composition of superimposed layers, heating temperature, and dipping time) on the visual appearance, scratch adhesion, wear resistance, and thermal insulation of the resulting coatings. Micromechanical and tribological responses of the coatings were signiicantly improved by the efect of the wooden particles dispersed inside the polyphthalamide binder. An improvement of the thermal insulation was also achieved whatever the setting of the process parameters. Further, the coatings displayed good adhesion to the substrate and wear endurance. 1. Introduction In recent years, specialty powder paints have been continu- ously developed to face the increasing demands of high stan- dards in terms of aesthetic and functional performance of the industrial coatings. Powder coatings are widely used in difer- ent ields, from automotive to electrical industry, and repre- sent more than 10% of the market [1]. Among functional coat- ings, the interest in protective and thermal insulating ilms for metallic substrates is increased, since they can feature simultaneously long lasting and energy saving characteristics. he research main goal in this ield is to improve not only the material but also the coating technologies, with particu- lar regard to the process sustainability and costs (e.g., reduc- tion in pollutant solvent-borne primer and expensive surface activation processes). In this context, the interest in luidized bed (FB) coating process is increased, because of the advantages it allows: sig- nificant savings and environmental safety, feasibility on com- plex geometries, and the need for basic equipment, which can be easily scaled up and fully automated. he irst application of this technology was in the 1970s, when FB coating in the earliest studies of Richart [2, 3] and Pettigrew [4, 5] was proved to be a cost-efective and environmental friendly alternative to traditional painting processes. Since then, more sophisticated FB processes were developed to coat also large volumes of small and complex shaped parts. In the past decade, electrostatic FB was applied by Ali and Inculet [6, 7] to deposit thermosetting powder coatings onto rotors. In addition, Leong et al. [8, 9] developed a wide range of analytical and numerical models to simulate the deposition process inside a FB of thermoplastic powders. More recently, Barletta et al. looked into FB coating process using new generation of coatings materials and investigating the relationship among process parameters, FB hydrodynam- ic behaviour, and material properties [10, 11]. Understand- ing of the physical mechanisms involved in the deposition process and the development of operational maps which are very useful to the practitioners for automation and control were depicted in those analyses [12]. Despite the increasing scientiic interest in the FB, such technology is still poorly used in the industrial practice because of being troublesome in coating of complex shaped parts, expensive downtime during color change, and draw- backs in the abatement of the elutriated powders. hus, FB is so far devoted to speciic application where specialty Hindawi Publishing Corporation International Journal of Polymer Science Volume 2014, Article ID 494068, 11 pages http://dx.doi.org/10.1155/2014/494068