1. Introduction

   This paper discusses a methodology for increasing powder deposition efficiency in through the use of efficient gun-nozzles for powder coating guns. Figure 1 presents 3-piece tinplate aerosol cans being powder coated in pilot equipment using three corona spray guns. In the present system each of the three corona gun is used to powder coat different regions of the work piece. The first gun powder coat the bottom part of the cans, the middle gun powder coat the middle part of the cans while the third gun powder coat the top part of the cans. It was observed that the existing standard gun-nozzle design produces significant powder waste when used to spray the top, middle and bottom of the cans with height 132mm and diameter 40mm. This paper therefore investigates the existing process and presents a design methodology for designing and evaluating the efficiency of gun nozzles. It also presents experimental results and Computational Fluid Dynamic (CFD) validation of the gun nozzle designs. Figure 2 illustrates the design methodology implemented in this work.