Control apparatus for producing and/or handling a plastic film and associated method

Method for manufacturing plastics films, in particular for manufacturing plastics flat sheet films, cast films, monoaxially, uniaxially, sequentially biaxially or simultaneously biaxially stretched plastics films, or for manufacturing blown films, including double-bubble films, tri-bubble films or multi-bubble films in general, comprising the following method steps:

• a control apparatus is used which is designed so as to be two-stage or at least two-stage,
• for this purpose, a control apparatus is used that comprises a sensor module and/or a sensor model on the one hand and a process module and/or process model on the other hand,
• the machine-dependent sensor module and/or sensor model and the production-dependent process module and/or process model are mutually associated by means of production variables,
• the sensor module and/or the sensor model links or associates settable machine variables with production variables on the plant side,
• the settable machine variables include one or more machine variables from the group comprising the cooling water temperature, the heating temperature of heating systems, fan speeds of ventilation means, tensile stresses in the transverse and/or length direction of the plastics web that is to be drawn off,
• the production variables include one or more production variables from the group comprising the plastics film temperature, film tensile forces acting on the plastics film in the transverse direction and/or length direction,
• the process module and/or process model links or associates the production variables with process variables of the plastics film to be manufactured by the plant, and
• the process variables include one or more of the values from the group of film temperature, tensile strength, E-modulus, film thickness and film turbidity