Case Studies for Extrusion Processes with Contamination in the Product

The root cause of dark color streaks in gray-colored parts can sometimes be more difficult to determine since both poorly dispersed pigments and resin degradation products can be the source. In these cases, removing the color masterbatch from the process and operating with just the natural resin will allow the root cause to be identified. That Is, If the dark color streaks still occur in the product after the color masterbatch is removed, then the source of the problem is related to resin degradation. Two case studies are shown in Section 11.12 to illustrate these defects. 

Diagnosing and eliminating a problem that occurs due to an improperly operating extruder can be difficult and time consuming. This section contains several case studies where improperly designed processes created contamination defects in the final articles. The axial pressure profiles of the metering channels for these case studies and other studies in the next chapters were calculated using the method described in Section 9.2.1. The simulated axial pressure profiles are shown with solid lines while the estimated pressure profiles are shown by dashed lines. 

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Case Studies for Extrusion Processes with Contamination in the Product 501... 

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