Extrusion International 3-2026

37 Extrusion International 3/2026 rial by limiting molecular mobility and thermal reaction during downtime. Correctly applied freeze strategies typically deliver: • 30 to 50% reduction in black-speck incidents after shutdowns • Shorter restart scrap lengths • Lower incidence of corrosive degradation residues By contrast, incorrect dynamic use of freeze material often results in higher material consumption with little or no improvement in cleanliness or restart quality. The Hidden Cost of Incorrect Practice Misunderstanding twin-screw fundamentals and mis- using freeze compounds leads to measurable losses, in- cluding: • Extended start-up waste of 20 to 40 minutes per changeover • Increased compound consumption with no performance bene t • Chronic surface defects misattributed to raw materials • Higher maintenance and polishing frequency for screws and dies These losses are rarely captured on a single KPI but ac- cumulate across shifts, products, and weeks of produc- tion. A Low-Cost Opportunity for Performance Improvement Importantly, none of these issues require new capital investment. Plants that focus on process understanding typically achieve: • Downtime reductions of 10 to 20% • Scrap reductions of 2 to 5 percentage points • Improved output consistency with lower thermal stress In today’s cost-pressured environment, these gains represent a signi cant competitive advantage. Conclusion Twin-screw extrusion delivers its true value through understanding, not assumption. Treating it as a high- output “black box” and misapplying tools such as freeze compounds undermines performance, quality, and pro tability. • Manufacturers who revisit basic processing prin- ciples and use freeze materials correctly can unlock measurable improvements in ef ciency, stability, and long-term asset life – without changing a single piece of equipment. Author : Dariusz Kozlowski is a PVC extrusion professional with hands on experience across technical, production, and leadership roles. He has worked as a Technician at Centaur Manufacturing, Production Leader within Red- diplex Group, and Head of Extrusion at RAM Extrusion. His focus is on twin screw process optimisation, opera- tional stability, and reducing scrap and downtime in rigid PVC extrusion. RAM Extrusion Unit 203 Pointon Way, Stonebridge Cross, Droitwich, Worcestershire WR9 0LW, UK Dariusz@ramextrusion.co.uk https://ramextrusion.co.uk/