An optimization approach to practical problems in plasticating single screw extrusion

Setting the extruder operating conditions, or establishing the adequate geo metry of the screw, for a given group of specifications, is dealt with as a n optimization problem where the solution is searched in a nonconvex space. In practice, this is a conflicting multi-attribute optimization problem, w here various optima may coexist. The methodology developed involves the max imization of an objective function, quantifying the adequacy of the extrude r-die combination response to particular inputs, whose values are computed using an extrusion modeling package developed for this work. Genetic Algori thms (GAs) are used to generate better sets of inputs. In a second stage, m ulti-objective optimization through Pareto curves, coupled to GAs, is imple mented since, beyond optimization, it also provides a better understanding of the characteristics of the extrusion system under study.