FLUIDIZED-BED COATING OF COPPER CYLINDERS

Powder coating technology for paint applications has become more attra ctive in recent years due to its advantages in saving paint powder aci d reducing pollution. The fluidized bed technique is a tried and teste d method of applying plastic coatings on small objects such as electri cal and automotive components, pipes, fittings, valves and wire produc ts. This paper presents the experimental findings for fluidized bed co ating of solid copper cylinders with diameters ranging from 4.8 mm to 12.7 mm with a commercially available thermoplastic paint powder, ''Le vasint S 31'' manufactured by Payer AG, Germany. Temperature profiles with time for various sets of coating conditions were compared with a theoretical lumped capacitance model for transient heat transfer in a fluidized bed. The effects of process parameters such as specimen size , preheat temperature, superficial velocity of air and immersion time on both coating thickness and porosity were investigated.