Method for coating using an open-ended ink chamber having restrictions for partially limit ink flow
AssigneePaper Converting Machine Company
InventorEdwin K. Schaeuble
Life of this patent
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Abstract
A method [and apparatus] for coating wherein the horizontal flow of coating liquid is restricted adjacent the ends of the coating roll to overcome foaming by high flow rates of liquid flow while avoiding fouling of the roll journals.
Claims11
In a method for applying a liquid coating to a moving web by applying ink to a rotating roll for transfer to said web, the steps of introducing a coating liquid generally centrally of a horizontally elongated chamber having said roll mounted for rotation therein while positioning a vertical chamber wall closely adjacent to said roll, said wall adjacent the bottom thereof being equipped with a doctor blade for metering liquid to said roll, the improvement comprising applying said coating liquid to said web while partially restricting the flow of liquid horizontally along said wall slightly inward of the ends of said roll to provide a substantially uniform liquid level in contact with said roll along the length thereof while avoiding both foaming of liquid and fouling the roll end faces said partially restricting including the positioning of barrier inserts at least about 2 mm away from the ink applying surface of said roll collecting the liquid flowing past said roll ends and reintroducing the same into said chamber.
Apparatus for applying a coating liquid to a moving web comprising a frame, a roll rotatably mounted in said frame to transfer coating liquid to said web, said frame being equipped with a horizontally elongated chamber adjacent the lower portion of said roll for partially confining said coating liquid, said chamber including a vertical wall positioned closely adjacent said roll, said wall adjacent the bottom thereof being equipped with a doctor blade for metering coating liquid to said roll, said wall adjacent the roll ends but slightly inward thereof being equipped with restriction means to partially limit the flow of liquid coating horizontally to maintain a substantially uniform level in contact with said roll along the length thereof while avoiding both foaming of liquid and fouling the roll end faces, said restriction means including inserts positioned at least about 2 mm away from the ink applying surface of said roll and collection means operably associated with said chamber for collecting the liquid flowing past said roll ends and for reintroducing the same into said chamber.]
[11. The apparatus of claim 10 in which a liquid receiving pan constituting said collection means is provided about the lower portion of said roll, said pan having end walls spaced at least 60 mm. from the adjacent end faces of said roll.]
Dependencies are inferred from the claim text.