Apparatus to produce coated paper, cardboard or other fibrous webs with at least one thermo-sensitive layer and a method to operate an apparatus of this type

The invention relates to an apparatus to produce coated paper, cardboard or other fibrous webs with at least one thermo-sensitive layer as a functional layer through the application of at least one liquid or paste-like thermo-sensitive coating medium onto a carrier web by way of a unit which forms a functional layer, the units each include at least one applicator device and one drying section following the applicator device. The two units are capable of being installed in series and each form at least one functional layer on the carrier web, whereby in the merging area between the two functional layer forming units a web turning device is located, creating a first web path and a device to bypass the web turning device, thus creating a second web path for the carrier web between the two functional layer forming units. The invention further relates to a method to operate an apparatus of this type.