Method for changing the material in an extrusion device

A method for changing material in at least four extrusion devices, each comprising at least two supply devices for supplying feedstock for an extruder, comprising the following steps:

• identifying a change request for changing the material in at least one of the at least four extrusion devices,
• preparing the supply devices for changing the material by lowering a filling level of the at least two supply devices of the at least one of the at least four extrusion devices, wherein the filling level is lowered to a changing filling level which is held fluctuating to not fall below the changing filling level,
• separating the at least two supply devices of the at least one of the at least four extrusion devices from a feed of feedstock to the extruder,
• discharging feedstock from the separated supply devices to empty the at least two supply devices of the at least one of the at least four extrusion devices,
• filling subsequent material into the empty supply devices, wherein a discharge container is cleaned to prepare the supply devices, wherein the discharge container is removable from the respective supply device after the discharge container is filled with discharged feedstock,
• wherein the steps are carried out in a production machine comprising the at least four extrusion devices, wherein each of the at least four extrusion devices produces one layer of a plastic film.