The product unifomity for a continuous polymer extrusion process directly depends on the stabilty of the flow that exits the die. The extruder and melt pump are primary sources of instability at the origin of the flow. However, the design of the piping system has a profound effect on the amount of this flow instability that reaches the product. Even just the arrangement of pipes and filters between the extruder and die will affect the ultimate uniformity of the product. Analysis of flow stability for polymer delivery systems is available. Optimization of the piping sizes and arrangement to provide a configuration for the most stable exit flow is possible with a special computer model designed for transient flow of polymers in piping systems. No other means is available to optimize the delivery system for maximum product flow stability.
The basis for this model is summarized in "Calculating Surge Dampening in Melt Delivery Systems" by Stephen J. Derezinski, Society of Plastic Engineers ANTEC '97 Proceedings, 1997, pp. 341-346.
