When sourcing used equipment, you must prioritize the Screw and Barrel condition, as these are the heart of the extruder; check for signs of excessive wear or thinning. Evaluate the Degassing System (natural or vacuum) to ensure it can handle the moisture and ink levels of your specific plastic waste (e.g., PE, PP, PET). Additionally, verify the Screen Changer type—manual changers are cheaper, but Hydraulic Non-stop Screen Changers significantly improve production efficiency by reducing downtime during filter swaps.