In-line Color Monitoring of Pigmented Polyolefins During Extrusion. I. Assessment

ABSTRACT The color of pigmented polyolefin melts was measured in-line during processing by using a fiber optic equipped visible-near-infrared spectrophotometer. Pigment loadings varied from 3.6 to 56 wt.% with some formulations containing up to 33.1 wt% calcium carbonate filler. Results showed that within specification color could be distinguished from off specification color. Also, pigment degradation and temperature tolerance could be assessed. Predicting needed off-line measured color from these in-line results will be the subject of Part II of this series.