One of the main applications for the use of impact-modified polycarbonate is for the production of instrument panels (IP) for motor vehicles. The Department of Transportation has issued FMVSS #208 and NHTSA Standard #201 covering the safety requirements for IP. Impact-modified polycarbonate resins have been especially developed for IP applications (e.g. References 1 and 2).
Focused efforts have been undertaken with raw material suppliers in order to improve the efficacy of additives. Designed experiments (DOE), statistical quality control (SQC) via electronic data interchange, statistical process control (SPC), and product audits have been utilized in these improvement efforts.
Major resin suppliers extensively utilize SPC throughout production facilities. Hundreds of control charts are maintained by both production personnel and laboratory personnel in their attempt to maintain their respective processes in a state of statistical control (e.g. Reference 3).
Consistent resin reduces molder variability with the result being lower reject rates, uniform processing, and high quality parts at a lower cost. Statistically designed experiments have been performed to assist in product design and to determine optimum molding conditions.
Application of statistical techniques generally results in cost savings when applied over the entire process from manufacturing the resin to producing the finished part.