EVALUATION OF THE EFFECT OF PROCESSING PARAMETERS ON THE PROPERTIES OF ADVANCED STYRENIC RESINS - A DESIGN OF EXPERIMENTS APPROACH

The effect of processing conditions on the performance of advanced sty renic resins (ASR) is examined. ASR systems offer a combination of hig h gloss and high impact, which allows them to be considered as alterna tives in applications previously dominated by acrylonitrile / butadien e / styrene copolymers (ABS). Injection molding conditions were set ac cording to the principles of statistical design of experiments. The in formation provided by this statistical design of experiments (DOE) met hod is extensive and highly organized. For the current study, a 25 ful l factorial model was based on five parameters at two levels of variat ion. With this model, the effects of injection speed, melt temperature , mold temperature, hold pressure, and cooling time on part properties were investigated. The properties measured were tensile modulus, tens ile yield strength, tensile ultimate strength, and Gardner and Izod im pact strengths. This study represents an initial variable screening fo r the establishment of a process window for this particular material. At the same time, significant process knowledge, valuable for further future optimization, was gained and structure-morphology relationships were investigated. (C) 1997 John Wiley & Sons, Inc.