Practical extruder operation

The principles of steady operation of single-screw extruders have been developed in Chapters 6 and 8 and their implications for operation discussed in Chapters 9 and 11. The principles and operation of twin-screw extruders have been covered in Chapter 10, where it is shown that the wide variety of designs entails operation largely guided by manufacturer’s instructions. This is even more the case of dismantling and cleaning of twin-screw machines, which will therefore not be discussed in this chapter. However, an attempt is made to cover more practical aspects of operation to complement the theory of singles-crew machines, including methods of achieving and maintaining safe and steady operation, starting-up and changing running conditions, shut-down and cleaning, and scrap recovery.