Dealing with so many variables can get confusing. One way to get a handle on them is to organize or categorize the processing variables into groups. To do this I use Don Paulson’s four plastic variables (Don founded Paulson Training Programs Inc.), but I change the word “variables” to “categories.” This helps separate plastic variables from machine variables. So I review the process problem relative to four categories of variables—from the point of view of the plastic: flow rate (encompassing shear rate and injection velocity); temperature; pressure; cooling rate and time…..
Click HERE to read John’s PTOnline article