The Use of a 12‐run Plackett–Burman Design in the Injection Moulding of a Technical Plastic Component

During injection moulding of technical plastic components it is often the case that 15–20 variables need to be set to operational conditions when the production of a new plastic components is started. In this case study, a 12‐run Plackett–Burman design is used in the experimentation with eight factors and nine responses to obtain better operational conditions for the production of a certain product. A 12‐run Plackett–Burman design belongs to the class of non‐geometric orthogonal arrays. Most of these designs have very good projection properties compared with their run sizes, but due to partial aliasing among effects, standard methods of analysing fractional factorial two‐level designs do not apply. In this paper, part of the planning of the experiment, the method of analysis used and the results achieved are presented. Substantial improvement in the operational conditions was obtained. Copyright © 2006 John Wiley & Sons, Ltd.