Monitoring the composition of copolymers and polymer blends in an extruder

3 Monitoring the composition of copolymers and polymer blends in an extruder 

The extmders were monitored using a pair of custom-made transmission probes inserted into the extruder die just downstream from the screws. Each probe consisted of a sapphire window brazed into a metal body a quartz rod behind the window piped the light to the end of the probe low-OH silica fiber-optic bundles connected the probe to the NIR analyzer, an LT Quantum 12001. Optical path lengths were typically between 0.3 and 2.0 cm. 

McPeters and Williams6 at Rohm and Haas (Spring House, PA, USA) used in-line transmission NIR to monitor the compositions of heterogeneous polymer blends and 

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