Application of powder coating
As described in Nelson, Coffin and Copeland (2003), “The application of powder coating (a type of paint used on appliances and, in limited settings, cars) is done by spraying the material through a ‘gun’ that has an electrical charge on it. There are three factors to consider in setting up the application booth: the gun distance from the target item, the charge and the pressure (flow rate) of the material through the gun. This data set contains data from 18 runs.” Note that there is no data for the high flow rate, high charges, and low distance as these combinations were infeasible from an operations standpoint (they were such that too much paint would be applied to the target).
A data frame with 18 observations on the following 4 variables.
distance of the gun from the target (inches) - an ordered factor with levels
charge used (kvolts) - an ordered factor with levels
flow rate in gm/min. - an ordered factor with levels
a measure of the resulting gloss
Peter R. Nelson, Marie Coffin and Karen A. F. Copeland (2003), Introductory Statistics for Engineering Experimentation, Elsevier. (Appendix A)
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str(applicat) dotplot(distance ~ gloss|flowrate, applicat, groups = charge, type = c("p","a"), layout = c(1,2), ylab = "Gun distance from target (in.)", strip = FALSE, strip.left = TRUE, auto.key = list(columns = 3, lines = TRUE), xlab = "Gloss for two flow rates (gm/min) and three charges (kvolts)") dotplot(charge ~ gloss|flowrate, applicat, groups = distance, type = c("p","a"), layout = c(1,2), ylab = "Charge (kvolts)", strip = FALSE, strip.left = TRUE, auto.key = list(columns = 3, lines = TRUE), xlab = "Gloss for two flow rates (gm/min) and three distances from target (in)")