QUALITY MONITORING OF RECYCLED PLASTIC WASTE DURING EXTRUSION: Ⅰ. IN-LINE NEAR-INFRARED SPECTROSCOPY

摘要

NIR provides an extremely flexible in-line composition monitor for recycled plastic waste. The monitoring site (within the extruder at different points or after the extrudate exits) and the NIR mode of operation (transflectance, diffuse reflectance or a combination of the two) can be selected to fit the need. In this work, NIR enabled the composition of recycled polyethylene-virgin polypropylene blends to be quantitatively monitored in the polymer melt near the die. SLR, MLR and PLS provided similar results with PLS showing the most accuracy and precision.