(141c) CFD-Based Modeling of Nanopaint Application and Sustainability Assessment

Nanocoating is a material in which inorganic nano-size filler particles are incorporated in the coating matrix.  Over the past decade, nanocoatings have found significant application areas in the automotive, OEM, chemical, architectural and many other industries, as they may be able to provide advanced performance properties, such as significantly improved resistance to heat, chemical, scratch, corrosion, or to incorporate newer functionalities, such as self-cleaning, self-healing etc.  With the advancement in the coating systems, there is a growing concern over the issues related to material-product-manufacturing sustainability.  Among those, environmental and health impact of nanocoating manufacturing has caught a special attention.  In the automotive coating manufacturing process, thermoset nanocoating film is developed through paint spray and curing.  The emission of nanoparticles from the coating films in these operations can cause severe environmental and health problems, if the paint application processes are not designed and operated by following sustainability principles. 

In this work, a computational fluid dynamics (CFD)-based system modeling and simulation approach is introduced to investigate the emission and flow patterns of nanoparticles and paint material during the paint spray operation.  In addition, a set of carefully selected sustainability metrics are proposed to quantify the product and process sustainability.  The CFD spray model can characterize the dynamics of paint film formation on substrate, and the sustainability performance is evaluated based on nanopaint formulation data and rheological parameters, operational data about paint spray ejection speed, downdraft air velocity, positioning of spray guns, and the paint booth geometry and ventilation system design data.   These parameters are quantified and analyzed using the CFD models for air flow, species transport and energy consumption.  Model-based simulation facilitates the identification of optimal operation parameters for superior coating quality, minimum nanoparticles emission, and minimum energy consumption.  The design is further studied for improving its energy efficiency by modifying the geometry of the spray booth and positioning of spray guns.  A comprehensive case study will demonstrate its application potential for achieving a significant improvement of sustainability performance in nanopaint applications.