摘要 |
Air knife designed to be used in coating machines or equivalent to finish and smooth the coating by blowing air onto it, e.g. to remove excess coating material, said air knife comprising a main channel into which the air is blown in the axial direction of the channel at least from one direction, the main channel being so constructed that there are two air jets flowing in opposite directions and having equal and constant velocities over the whole length. Thus the air jets discharged from slits next to a partition between the two main channel sections, after being merged, flow in a direction perpendicular to the slit and the air flow is evenly distributed over the whole length of the slit. By using a construction in which the partition is movable, the location of the point at which the two jets mix can be varied, thus allowing the turbulence of the air jet blown at the web to be controlled and, consequently, an influence to be exerted on the properties of the coating surface.
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