Method and apparatus for applying a plurality of superposed layers to a web by curtain coating
AssigneeAgfa-Gevaert
InventorJacques G. Kerkhofs
Life of this patent
Estimating the term…
Abstract
Method and apparatus for applying a plurality of superposed layers to a web by curtain coating in which only some of the plurality of layers are, and in the extreme case only one layer is, in contact with the curtain guides. The width of the remaining layers is smaller than the width determined by the curtain guides, and preferably smaller than the width of the web.
Claims13
In a method of applying to a travelling web a plurality of layers of at least one flowable composition, comprising moving said web along a predetermined pathm, delivering such flowable compositions to a plurality of slot-like orifices to form a plurality of distinct flowing layers of such compositions, flowing said layers into face to face contact with one another to form a composite layer and delivering said composite layer as a free-falling curtain onto said web at a locus extending transversely of said path, said curtain being held in said locus by adherent contact of its lateral edges with curtain guides, said curtain falling on said moving web, the improvement wherein at least one of said plurality of layers has a width greater than the width of the web, and at least one of said plurality of layers has a width smaller than the overall width of the curtain whereby at least one but not all of said plurality of layers are in adherent contact with the curtain guides.
In an apparatus for applying to a moving web a plurality of layers of at least one flowable composition, which comprises means for moving said web along a predetermined path, a plurality of elongate slot-like orifices, means for delivering to such orifices said flowable compositions to form a plurality of distinct flowing layers thereof, means for bringing the layers of coating compositions that have been formed by the flowing of such compositions through said orifice into superposed contact with each other to form a composite layer, and means for delivering the composite layer onto said moving web as a free-falling curtain at locus extending transversely of said path, and curtain guides at the lateral limits of said locus for adherent contact with the lateral edges of said curtain, the improvement wherein at least one of said plurality of slot-like orifices has a length that is substantially equal to the initial distance between the curtain guides, and at least one of said plurality of slot-like orifices is smaller in length than said distance between said guides.
Dependencies are inferred from the claim text.