Homogenisation of polymer melts with colour masterbatch, flame retardants, UV stabilisers, and reactive additives between extruder stages.
Coefficient of Variation (CoV) ≤0.01 for colour uniformity; ≤0.05 for functional additives. SX exponential layer multiplication is mandatory for high viscosity ratios. Element count 12–18 for viscosity ratio 100:1–10,000:1. 18–24 elements for >10,000:1. Pressure Drop (ΔP) must not exceed extruder head pressure.
Preferred MOC: Carbon steel or 316SS with chrome-plated bore for abrasion resistance. High-temperature alloy for Tp >300°C. Chromium-plated internal bore to prevent polymer adhesion.
Chrome-plated bore essential for polymer release and wear resistance. Removable element assembly for colour changeover cleaning. High-temperature design (up to 350°C operating). Pressure Drop (ΔP) calculation mandatory — constrain element count to available pump/extruder head.