In 2023, a client approached us with a critical issue affecting their extrusion line for rigid PVC sewer pipes. The problem involved material leakage, significantly hampering their production capacity.
🔧 Challenge
The client faced a persistent issue with their 80 mm counter-rotating twin-screw conical extruder. Gelled material was escaping through the degassing holes, forcing them to reduce their extrusion line capacity by 30-35%. This reduction was necessary to keep the screws less full, limiting their production capabilities.
🚀 Solution
After visiting the client and examining the screw geometry, we discovered significant discrepancies. The gaps between the crests in the cylinder's terminal section were not suitable for maintaining proper material retention under high back pressures. We redesigned the screws, focusing on critical zones contributing to the defect. The new screw pair was produced and installed on the client's machine in May.
🎯 Results
The installation of the modified screws resulted in a substantial improvement. The system's tolerance to back pressure increased, eliminating the material leakage issue and enabling the client to restore full production capacity.