Apparatus replacing atmospheric oxygen with an inert gas from a laminar air boundary layer and application of said appartus

Apparatus to replace atmospheric oxygen with an inert gas such as N2 from the minimum of one laminar air boundary layer (3) of substrates moving in the direction of advance (2), for instance rapidly running lines of material that include a first chamber (41) which is open only toward the substrate and otherwise is enclosed by the surrounding outside space (40), said first chamber comprising in the vicinity of a front sealing edge a front corona electrode (5) fed with high-voltage DC and perpendicular to said direction of advance and associated with a mate electrode (7) situated on the other side (42) of the substrate (1), also comprising a further corona electrode (6) behind the front corona electrode (5) on the same side as latter and situated at the rear sealing edge which is perpendicular to the direction of advance (2), the electrode (6) being fed a high DC voltage and being associated with a further mate electrode (8) on the other side (42) of the substrate (1), and further comprising a device feeding the inert gas (15),

• characterized in that
• the device feeding the inert gas (15) is configured directly behind the partial-vacuum zone (12) forming behind the electron/ion flow (9) of the further corona electrode (6).