SWT Extrusion Knowledge Center
Professional technical articles, troubleshooting guides, process knowledge, and practical solutions for sheet extrusion and thermoforming.
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Learn why high light transmittance can coexist with haze or poor clarity, and how extrusion engineers diagnose cloudy films, blurred text and optical defects.
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New From Our Engineers
Practical production knowledge for sheet extrusion and thermoforming teams.
Understand how screw geometry changes residence time, shear, pressure build-up and plasticization — and why lubricant strategy must be matched to the actual extruder design.
Explain how temperature, screw speed and output interact in twin screw extrusion, and how response surface methodology helps find the optimal processing window.
Learn why calcium carbonate is added to plastics, how GCC, PCC, nano and activated CaCO3 differ, and how to select fillers for PVC, PE, PP, PLA and PBAT processing.
Learn how to diagnose extruder or injection screw wear without removing the screw using pressure data, a five-minute pressure-drop test, process analysis, and industrial endoscope inspection.
Learn why plastic sheet extrusion produces periodic transverse lines, vibration marks, and bamboo-like patterns. Discover solutions related to mechanical vibration, speed mismatch, and excessive shear stress.
Learn how an extruder back pressure valve controls melt pressure, improves melt homogenization, removes bubbles, and stabilizes extrusion output for better product quality.
Learn how to identify and eliminate gel defects, fish eyes, black specks, and hard spots in extrusion, blown film, cast film, and extrusion coating through a practical four-step troubleshooting method.
Why does molten polymer escape from an extruder vacuum vent? Learn the four main causes and a practical troubleshooting sequence, from feed rate and vacuum adjustment to screw configuration and vent-port design.
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