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AssigneeMan Roland Drickmaschinen AG
InventorsUlrich Jung, Thomas Walther
Estimating the term…
A method and apparatus for treating the surface of substrates such as printed sheets, with improved surface quality. The apparatus includes a first roller (2, 7) rotatable in a first direction and forming a placement surface for traveling printed sheets, one or more second rollers (4, 5, 6) mounted parallel to the first roller (2, 7) for defining a roller nip with the first roller through which the sheets are directed and for exerting a predetermined radial pressing force against the sheets, the second rollers (4, 5, 6) being rotatable in a direction opposite to the direction of rotation of the first roller (2, 7) and at least some of the second rollers (4, 5, 6) having a heating device for heating the printed sheet in the area of the roller nip between the first and second rollers.
In an offset printing machine having at least one printing unit in which a printing substance is applied to sheets and the printed sheets are directed through the printing machine comprising an apparatus for treating surfaces of the printed sheets, said surface treating apparatus including a first roller (2,7) rotatable in a first direction and having a placement surface for sheets during travel through said machine, a second roller, (4, 5, 6) mounted in axially parallel relation to said first roller (2,7) for defining a roller nip with said first roller (2,7) through which printed sheets are directed, said second roller (4, 5, 6) being mounted with a preset radial force in the range of 10–25 N/cm against said first roller (2,7) at said nip, said second roller (4, 5, 6) having a diameter smaller than the diameter of said first roller (2, 7) and being rotatable in a direction opposite to the direction of rotation of said first roller (2, 7), and a heating device (11, 12, 15, 16) operatively associated with said second roller (4, 5, 6) for heating the surface of the second roller in the region of the roller nip between said first roller (2, 7) and the second roller (4, 5, 6) to a temperature of at least about 350° K as the sheet passes through the nip whereby the heat and pressure on the printed sheet smoothes the surface of the printing substance on the printed sheet passing through the nip.
A method for surface treatment of printed sheets in a sheet fed printing machine comprising the steps of printing a printed substance on the sheets by passing the sheets through at least one printing unit, subsequently conveying the printed sheets to a roller nip defined by a roller surface of a first roller and a roller surface of a second roller, pressing the sheets against the first roller surface by means of the second roller surface with a force in the range of 10–25 N/cm, and heating the roller surface of the second roller in the region of the nip to a predetermined temperature of at least about 350K during the pressing step for heating the printed sheets at the location of said nip between said first and second rollers as they are directed through the nip to smooth the surface of the printed substance on the sheets.
Dependencies are inferred from the claim text.