A Fluidized Bed Polymer Coating Experiment and Practical Aspects of Design in Chemical Engineering and Pharma Industry

This experiment, first developed for a NSF Novel Process Workshop, is a highly visual experiment in chemical engineering processes and experimentation. In addition, it the coating process is environmentally benign because it has essentially no volatile emissions. The object of the experiment is to place a protective coating on a pellets, tablets, and metal object. The metal object is coated by first heating in a hot air stream and then dipping the object into a fluidized bed of thermoplastic powder. This experiment can be used throughout the curriculum.  For recruitment at the precollege and freshman level the fluid motion of the gas and particles can be observed through the clear plastic walls of the fluidized bed.  Using brightly colored particles gives the fluid bed the look of an executive desk amusement.  Prospective students and freshman can also feel the water like quality of the bed using a rod or ruler.  Freshmen use the fluidized bed as an example of the engineering measurements of flow rate, temperature, pressure and coating thickness.  They design an experiment to determine the desired coating thickness by varying the dipping time and temperature of the object.