8. Preform die

The material is shaped in the die, or to be more precise, "preformed", since the width and air gap of the lips leaving the die are always greater than those of the finished sheet, which is then stretched and cut.

Sheets or plates are semi-finished products cut to order or thermoformed. Their market is not governed by any structuring standard as may be the case in other markets (standardized diameters-thicknesses for tubes in construction and industry): it is the characteristics of the thermoforming or printing machines that impose the width-thickness values.

For an extrusion line with in-line thermoforming, the die is monolaize, as the extrusion capacity has to match the output of the thermoforming equipment. In all other cases, the aim is for the extrusion line to operate at maximum productivity, which means choosing the widest possible...