Experimental investigation of dry powder coating processing parameters on the polystyrene particle's distribution on the surface of carbon fibers

Abstract

Powder technology has been used to coat fibers with polymeric particles to manufacture composites. The material parameters such as particle size and fiber diameter and process parameters such as the particle charge and the particle velocity will influence the powder coating process. In this work, we present an experimental setup in which we characterize the coating of micron size particles on a fiber and examine the role of process parameters on the coating density. Monodispersed Polystyrene (PS) particles (2.8 ± 0.4 μm in diameter) were used to coat a carbon fiber (CF) 7 μm in diameter. A model setup was designed and fabricated in which the PS particles were charged with an ozone charging system, while the CF was maintained at the grounded state at all times. The setup consisted of two parts namely, a cyclone and a coating chamber. The distance between the PS particles was measured and the density of coating was examined using a microscope as a function of the processing parameters used in the setup. The measured average distance between the PS particles on the CF was used in our developed numerical model to estimate the friction coefficient between the charged PS particle and the grounded CF and the fiber volume fraction. The proposed methodology can be extended to any particle size, particle charge, and fiber diameter to estimate the friction coefficient and the fiber volume fraction at the microscale level.