Functional Process Analysis

Chapters 5 and 6 on fundamental principles and important polymer properties are meant to be a preparation for the material covered in this chapter. In this chapter, the central part of this book, the six main functions of an extruder will be described and analyzed. The main functions are solids conveying, plasticating or melting, melt conveying or pumping, devolatilization, mixing, and die forming. The material in this chapter is key to developing a thorough understanding of the extrusion process and indispensable in taking an engineering approach to screw design, die design, and troubleshooting.