Use of the robust design methodology for identification of factors that contribute to the intensity of the “orange peel” aspect on painted bumper surfaces

The experiment tested various combinations of levels of the clear coat application factors (speed, flow, revolution per minute, operation voltage, atomizing air pressure) in the bumper samples. The intensity of the orange peel on coated surfaces samples was measured by a Wave Scan device that provides the wavelength reading as a function of two measures: Long Wave and Short Wave. The main results obtained by variance analysis of noise signal ratio showed that the factors that have significant effects on the value of the Short Wave response wavelength are: revolution per minute, operation voltage and the interactions flow*operation voltage and speed*operation voltage.

The factors that significantly affected the response value of the Long Wave wavelength are: flow, atomizing air pressure, revolution per minute, operation voltage and the interaction speed*operation voltage. As a result of analysis of the noise signal mean, it is presented the factors optimum design: speed = 920 m / s; flow = 160 ml/min; atomizing air pressure = 180 bar; revolution per minute = 90 revolutions / minute; operation voltage = 180 kilovolts.