The Influence of Processing Variables on the Properties of Flocked Fabrics

The effect of 16 variables of the dc electrostatic flocking process has been investigated in a two-level factorial screening experiment. Properties examined include mass and number of fibers sifted, mass and number of fibers flocked, percent of available fibers flocked, percent of theoretical maximum packing density, and abrasion resistance of flocked fabric. The 16 independent variables included six machine variables (voltage, electrode separation, sifter speed and screen mesh, flocking time, and substrate vibration), three flock variables (fiber type, length, and denier), five adhesive variables (adhesive type, concentration, viscosity, thickness, and drying conditions), ambient humidity, and substrate (polyethylene film and aluminum foil). Only the three flock variables and the voltage were found to influence the properties of the flocked fabric. The quantity of fiber sifted was affected by the fiber denier and length and by the sifter speed, but the sifter speed did not influence the flocked fabric. The packing density of the flock on the fabrics ranged from 0.4 percent of the theoretical maximum (for low denier, long length nylon fiber flocked in a low electric field) to 13 percent (for high denier, short length nylon flocked in a high electric field). Of all the variables studied, fiber length had the greatest effect on the flocking properties; increasing the fiber length decreased the number of fibers sifted, number of fibers flocked, and percent of maximum flock density.