Systems and methods for implementing an advanced inker unit surface conditioning system in a variable data digital lithographic printing device
A system and method are provided for providing an improved inker unit surface cleaning and conditioning system, including in a single anilox chamber blade system, for improving image quality, including eliminating ghosting, in a proposed variable data digital lithographic image forming architecture. Techniques are provided to remove acquired oil from an inking member. A particularly-configured containment encloses a cleaner (disturber) roller to emulsify the acquired oil on the inking roller. The cleaner roller is preferably configured with a pliable surface including a silicon roller surface over a porous base. The silicon roller (1) absorbs dampening solution oil; and (2) agitates ink that may be still held in certain cells/cavities of the inking member or roller. In embodiments, a vacuum pressure is applied to the inside of the hollow cleaner roller to better remove the residual ink and dampening solution from the inking roller.
1. An inker unit in a variable data digital lithographic image forming system, comprising:
an ink chamber that provides an ink supply in the inker unit;
an inking member that transfers ink from the ink chamber to an ink transfer nip between the inking member and a reimageable surface of an imaging member, the inking member having at least one of a roughened or pitted surface;
a leveling unit that levels a layer of the ink uniformly on a surface of the inking member;
a cleaner roll having a conformable surface and being positioned to contact the surface of the inking member at a position between the ink transfer nip and the ink chamber, the conformable surface of the cleaner roll having a comparatively low durometer silicone roller surface for penetrating into recesses in the at least one of the roughened or pitted surface of the inking member to disturb residual ink in the recesses that was not completely transferred to the reimageable surface and to engage residual products back transferred from the reimageable surface to the surface of the inking member; and
a vacuum system including a vacuum removal component that draws a vacuum through a permeable surface of the cleaner roll and a porous metal roller base formed with a hollowed core to extract at least a portion of the residual products from the surface of the cleaner roll.
2. The inker unit of claim 1 , the leveling unit comprising a doctor blade that contacts the surface of the inking member.
3. The hiker unit of claim 1 , the inking member being an anilox roller.
4. The hiker unit of claim 1 , the residual products including dampening solution on the reimageable surface.
5. The hiker unit of claim 1 , the ink chamber having a wiper blade at an entrance of the ink chamber that wipes the residual products from the surface of the inking member.
6. The hiker unit of claim 1 , further comprising at least one other roll positioned in contact with the surface of the cleaner roll to lift at least a portion of the residual products from the surface of the cleaner roll.
7. A method for conditioning a surface of an inking member in a variable data digital lithographic image forming system, comprising:
transferring ink from an ink supply chamber to a reimageable surface of an imaging member with an inking member having at least one of a roughened or pitted surface;
leveling a layer of ink uniformly on a surface of the inking member before the inked surface of the inking member contacts the reimageable surface at an ink transfer nip to deposit the ink on the reimageable surface;
contacting the inking member with a cleaner roll having a conformable surface positioned to contact the surface of the inking member at a position between the ink transfer nip and the ink supply chamber, the conformable surface of the cleaner roll having a comparatively low durometer silicone roller surface; and
penetrating into recesses in the at least one of the roughened or pitted surface of the inking member with the conformable surface of the cleaner roll to disturb residual ink in the recesses that was not completely transferred to the reimageable surface and to engage residual products back transferred from the reimageable surface to the surface of the inking member; and
applying a vacuum to a vacuum removal component that draws a vacuum through a permeable surface of the cleaner roll and a porous metal roller base formed with a hollowed core to extract at least a portion of the residual products from the surface of the cleaner roll.
8. The method of claim 7 , leveling being accomplished by contacting the surface of the inking member with a doctor blade.
9. The method of claim 7 , the inking member being an anilox roller.
10. The method of claim 7 , the residual products including dampening solution on the reimageable surface.
11. The method of claim 7 , further comprising wiping the surface of the inking member at an entrance of the ink chamber with a wiper blade to remove the residual products from the surface of the inking member.
12. The method of claim 7 , further comprising contacting the surface of the cleaner roll with at least one other roll to lift at least a portion of the residual products from the surface of the cleaner roll.
13. A variable data digital lithographic image forming system, comprising:
a reimageable surface on an imaging member;
a dampening solution source that deposits a layer of dampening solution on the reimageable surface of the imaging member;
an optical source that patterns the layer of the dampening solution on the reimageable surface according to an image input; and
an inker unit that inks the patterned reimageable surface, the ink being transferred from the reimageable surface to a substrate at an imaging nip to form an image on the substrate, the inker unit comprising:
an ink chamber that provides an ink supply in the inker unit;
an inking member that transfers ink from the ink chamber to an ink transfer nip between the inking member and the reimageable surface on the imaging member, the inking member having at least one of a roughened or pitted surface;
a leveling unit that levels a layer of the ink uniformly on the surface of the inking member;
a cleaner roll having a conformable surface and being positioned to contact the surface of the inking member at a position between the ink transfer nip and the ink chamber, the conformable surface of the cleaner roll having a comparatively low durometer silicone roller surface for penetrating into recesses in the at least one of the roughened or pitted surface of the inking member to disturb residual ink in the recesses that was not completely transferred to the reimageable surface and to engage residual products back transferred from the reimageable surface to the surface of the inking member; and
a vacuum system including a vacuum removal component that draws a vacuum through a permeable surface of the cleaner roll and a porous metal roller base formed with a hollowed core to extract at least a portion of the residual products from the surface of the cleaner roll.
14. The variable data digital lithographic image forming system of claim 13 , the inking member being an anilox roller and the leveling unit comprising a doctor blade that contacts the surface of the anilox roller.
15. The variable data digital lithographic image forming system of claim 13 , the residual products including the dampening solution on the reimageable surface.
16. The variable data digital lithographic image forming system of claim 13 , the ink chamber having a wiper blade at an entrance of the ink chamber that wipes the residual products from the surface of the inking member.
17. The variable data digital lithographic image forming system of claim 13 , the inker unit further comprising at least one other roll positioned in contact with the surface of the cleaner roll to lift at least a portion of the residual products from the surface of the cleaner roll.