PENETRATION OF INDUCTION-CHARGED PARTICLE S INTO AN ADHESIVE MATERIALLAYER AND THEIR FILM FORMATION

Penetration of induction-charged particles, through a field with horiz ontally set parallel plate electrodes, into an adhesion layer on the l ower surface of an upper electrode and their film formation are invest igated by an experimental approach, using polyurethane, alumna, and si lica powders. The results of the experiment on powder coated film thic kness are explained on the basis of ratio of thickness of adhesive mat erial layer to particle diameter. In a thin film of adhesive material, powder-coated film thickness equals particle diameter. In a medium fi lm thickness of adhesive material, powder-coated film thickness after drying is dominated linearly by initial wet film thickness of the adhe sive material. High electric fields give high particle penetration spe eds and fix them securaly in the adhesive material layer. The effect o f particle diameter on dry film thickness is not observed. Particles, having diamond-like shape, are vertical in the adhesive material surfa ce and horizontal on the bottom of the film. When first supplying high voltage, the amount of powder attaching on the adhesion surface incre ases exponentially. Thereafter, the amount of particle penetrating the film is proportionate to the square root of time. In a thick adhesive material layer, particles can not arrive at the electrode by a certai n time due to a high viscosity of adhesion.