Author: Dr. Klemens Kohlgruber

Fundamentals, Technology and Applications

Co-rotating screws and/or extruders are used in many branches of industry for producing, preparing and/or processing highly viscous materials. They find a wide variety of applications especially in the plastics, rubber and food industries.

This book provides basic engineering knowledge regarding twin-screw machines; it lists the most important machine-technical requirements and provides examples based on actual practice. Better understanding of the processes is emphasized as this is a prerequisite for optimizing twin-screw designs and operating them efficiently. Besides basic functions, such as compounding, the book focuses on:

• the historical development of twin-screws
• the geometry of the screw elements
• material properties and material behavior in the machine
• fundamentals of feed behavior, pressure build-up and power input
• examples of applications for various processing tasks
• compounding: tasks, applications, processing zones
• potential and limits of modeling
• scaling-up various processes
• machine design incl. drives and materials