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…..
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Scientific Molding is a phrase that followers of John Bozzelli’s teaching and readers of his Plastics Technology columns should be familiar with by now. But what is Scientific Molding?And why do molders seem to have such a difficult time embracing its concepts?
The answer to the first question is straightforward: Scientific Molding is a practice for achieving optimal control of the injection molding process to deliver faster molding cycles, higher yields, and a more robust molding process. This optimal control of the molding process is realized by focusing mainly on the behavior of the material in the mold, rather than on the machine….
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