Real-Time Moisture Measurement in Plastics Processing
Continuous moisture monitoring helps plastics processors prevent material degradation, optimise dryer performance, and stabilise product quality during bulk material handling.
Impact of Moisture on Resin Processing
In plastics processing, controlling moisture is critical to maintaining product quality and operational efficiency. Polymer resins, particularly hygroscopic types such as polyamide, PET, polycarbonate, and PLA, absorb atmospheric moisture. When heated during processing, excessive moisture causes hydrolysis, breaking polymer chains and weakening mechanical strength. This can result in brittleness, surface streaking, voids, and elevated scrap rates.
Moisture Variations Across Material Handling
Moisture levels fluctuate at multiple stages during material handling and bulk solids processing. Fluctuations occur during receiving, storage in silos or octabins, drying, conveying, and inside feed hoppers. Recycled and reclaimed plastics present additional challenges, as incoming material streams often display inconsistent moisture levels depending on their source and storage history.
Advantages of Real-Time NIR Measurement
Traditional offline laboratory testing, such as loss-on-drying or Karl Fischer titration, provides reliable historical data but cannot prevent active process defects. Non-contact near-infrared measurement systems monitor moisture levels continuously as bulk resin moves through the handling line. Real-time data allows operators to adjust dryer settings, optimise residence times, and prevent defective material from reaching processing machinery.
