1. General presentation

1.1 Definition and presentation

First of all, extrusion is a continuous process in which the heart of the device is an extruder (cf. articles , and ). This comprises one or more screws rotating inside a temperature-regulated barrel with heating and cooling systems. The polymer is fed in, often in solid form of pellets or powder.

The main functions of the extruder are to feed, convey, melt, homogenize and pressurize the polymer, so that it can finally pass through the die placed at its end.

Extrusion lines are mainly used for:

• the manufacture of finished or semi-finished products such as pipes, plates and various profiles;

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