Method for inking printing plates

Claim 1

A method for applying a controlled balance of ink and dampening fluid to a lithographic printing plate at a fluid transfer area between the lithographic printing plate and an applicator roller, comprising the steps of (A) forming a continuous uniform ink layer having a desired thickness on the applicator roller for the conveyance into said fluid transfer area and onto said lithographic plate, including the steps of (1) depositing an excess of ink on said applicator roller, (2) providing a metering roller adjacent to said applicator roller, (3) metering the ink deposited on said applicator roller by forming a fluid metering nip between said applicator roller and said metering roller, said applicator roller and said metering roller cooperating to form a reservoir for said excess of ink, (4) supporting said applicator roller and said metering roller in a preselected pressure indented relation to form said nip, (5) rotating said applicator roller and said metering roller such that adjacent surfaces move in opposite directions at said nip and at a preselected speed differential, (6) controlling the thickness of said continuous uniform ink layer formed on said applicator roller by (a) forming a continuous uninterrupted uniform ink layer on the metering roller by placing a doctor blade in cooperation with said metering roller, (b) controlling the physical properties of said layer of ink on said metering roller by controlling temperature of the ink so as to provide a continuous uniform metering surface of ink having uniform physical properties at the said metering nip which upon contact with the ink on said applicator roller will remove all but a uniform layer of ink of a desired thickness from said applicator roller, (c) adjusting said doctor blade for thus adjusting the thickness of said ink layer conveyed by said metering roller into said metering nip in order to create and maintain a desired precision controlled thickness in the said layer of ink conveyed by said applicator roller into the fluid transfer area, (d) adjusting the relative surface speeds of said metering roller and said applicator roller, (e) adjusting the pressure between said metering roller and said applicator roller, (B) applying dampening fluid in a variable amount in accordance with the thickness of the ink layer formed in step (A) to the said layer of ink conveyed by said applicator roller at a point between the fluid metering nip and said fluid transfer area to form a controlled balance of ink and dampening fluid conveyed by said applicator roller into said transfer area without introducing dampening fluid into said metering nip.

Claim 2

A method for applying a controlled balance of ink and dampening fluid to a lithographic printing plate at a fluid transfer area between the lithographic printing plate and an applicator roller, comprising the steps of (A) forming a continuous uniform ink layer having a desired thickness on the applicator roller for the conveyance into said fluid transfer area and onto said lithographic plate, including the steps of (1) depositing an excess of ink on said applicator roller, (2) providing a metering roller adjacent to said applicator roller, (3) metering the ink deposited on said applicator roller by forming a fluid metering nip between said applicator roller and said metering roller, said applicator roller and said metering roller cooperating to form a reservoir for said excess of ink, (4) supporting said applicator roller and said metering roller in a preselected pressure indented relation to form said nip, (5) rotating said applicator roller and said metering roller such that adjacent surfaces move in opposite directions at said nip and at a preselected speed differential, (6) controlling the thickness of said continuous uniform ink layer formed on said applicator roller by (a) forming a continuous uninterrupted uniform ink layer on the metering roller by placing a doctor blade in cooperation with said metering roller, (b) controlling the physical properties of said layer of ink on said metering roller by controlling temperature of the ink so as to provide a continuous uniform metering surface of ink having uniform physical properties at the said metering nip which upon contact with the ink on said applicator roller will remove all but a uniform layer of ink of a desired thickness from said applicator roller, (c) adjusting said doctor blade for thus adjusting the thickness of said ink layer conveyed by said metering roller into said metering nip in order to create and maintain a desired precision controlled thickness in the said layer of ink conveyed by said applicator roller into the fluid transfer area, (d) adjusting the relative surface speeds of said metering roller and said applicator roller, (e) adjusting the pressure between said metering roller and said applicator roller, (B) applying dampening fluid in a variable amount in accordance with the thickness of the ink layer formed in step (A) to the said layer of ink conveyed by said applicator roller at a point between the fluid metering nip and said fluid transfer area to form a controlled balance of ink and dampening fluid conveyed by said applicator roller into said transfer area without introducing dampening fluid into said metering nip.