Method for changing the material in an extrusion device

Abstract

The present invention relates to a method for changing material in an extrusion device 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 the extrusion device, preparing the supply devices for changing the material, separating at least two supply devices from the feed of feedstock to the extruder, discharging feedstock from the separated supply devices, filling subsequent material into the empty supply devices.

We claim: 
     
         1 . A method for changing material in an extrusion device 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 the extrusion device,   preparing the supply devices for changing the material,   separating at least two supply devices from the feed of feedstock to the extruder,   discharging feedstock from the separated supply devices,   filling subsequent material into the empty supply devices.   
     
     
         2 . The method according to  claim 1 , wherein the filling level of the supply devices is reduced to a changing filling level to prepare said supply devices. 
     
     
         3 . The method according to  claim 1 , wherein a discharge container is cleaned to prepare the supply devices and is fastened to a container interface of the respective supply device. 
     
     
         4 . The method according to  claim 1 , wherein the steps at least of identifying, of preparing, of separating, of discharging or of filling in are carried out automatically, based on a manual or an automatic activation. 
     
     
         5 . The method according to  claim 1 , wherein the steps are carried out in a production machine comprising at least two extrusion devices, wherein each extrusion device produces one layer of the plastic film. 
     
     
         6 . The method according to  claim 5 , wherein an analysis of all feedstock and of all subsequent materials, on the basis of which a change order is output, which provides the execution order at least for the individual extrusion devices or for the individual supply devices of the extrusion devices, takes place after the identification of the change request. 
     
     
         7 . The method according to  claim 1 , wherein a cleaning step is carried out after the discharge of the feedstock from the separated supply devices. 
     
     
         8 . The method according to  claim 1 , wherein the subsequent material is brought to the extrusion device to prepare the supply devices for changing the material. 
     
     
         9 . The method according to  claim 1 , wherein the material is changed in parallel at least sectionally in terms of time for all supply devices of an extrusion device, except for a last supply device. 
     
     
         10 . The method according to  claim 1 , wherein a completion signal is output after the discharge of the feedstock, which indicates the completion of the discharge to the operating personnel. 
     
     
         11 . The method according  claim 7 , wherein the cleaning step has the form of a cleaning program of a cleaning device. 
     
     
         12 . The method according  claim 8 , wherein the subsequent material has the form of a container feed.