Method and print head for flow conditioning a fluid
AssigneeKodak Graphic Communications Canada Company
InventorThomas W. Steiner
Life of this patent
Estimating the term…
Abstract
A continuous inkjet print head jets a plurality of fluid streams from an array of multiple nozzle channels. The print head includes a flow conditioning means that establishes fully developed flow in one or more regions of the print head such that substantially equal flow conditions are created at each of the inlets of the multiple nozzle channels. The substantially equal flow conditions reduce nozzle-to-nozzle variations with respect to the required trajectories of the jetted fluids to improve jet pointing and thus lead to better print quality.
Claims42
A method for jetting at least one continuous stream of fluid from at least one nozzle channel of a multi-channel print head, the method comprising:
- establishing substantially fully developed flow in at least one first region of a fluid in the print-head;
- jetting the fluid in at least a portion of the at least one first region from the at least one nozzle channel;
- and
- wherein fully developed flow comprises a bounded flow in a conduit having the characteristics of an unchanging velocity profile within the conduit, where the wall shear is at least approximately constant and the pressure drops at least approximately linearly with distance along the axial length of the conduit.
A multi-channel print head for jetting at least one continuous stream of fluid, the print head comprising:
- at least one first flow conditioning means operable for establishing substantially fully developed flow in at least one first region of a fluid in the print head;
- and
- at least one nozzle channel in fluid communication with the at least one first region, the at least one nozzle channel operable for jetting the at least one continuous stream from at least a portion of the at least one first region;
- comprising a fluid accumulator, wherein the fluid accumulator is positioned between the at least one first flow conditioning means and the at least one nozzle channel.
A multi-channel print head for jetting at least one continuous stream of fluid, the print head comprising:
- at least one first flow conditioning means operable for establishing substantially filly developed flow in at least one first region of a fluid in the print head;
- and
- at least one nozzle channel in fluid communication with the at least one first region, the at least one nozzle channel operable for jetting the at least one continuous stream from at least a portion of the at least one first region;
- wherein the at least one first flow conditioning means comprises a least one backside tunnel, the at least one backside tunnel being operable for establishing the substantially fully developed flow in the at least one first region.
A multi-channel print head for jetting at least one continuous stream of fluid, the print head comprising:
- at least one first flow conditioning means operable for establishing substantially fully developed flow in at least one first region of a fluid in the print head;
- and
- at least one nozzle channel in fluid communication with the at least one first region, the at least one nozzle channel operable for jetting the at least one continuous stream from at least a portion of the at least one first region;
- wherein the at least one first flow conditioning means comprises a flow conditioning plate, the flow conditioning plate comprising at least one flow conditioning bore operable for establishing the substantially fully developed flow in the at least one first region.
A multi-channel print head for jetting at least one continuous stream of fluid, the print head comprising:
- at least one first flow conditioning means operable for establishing substantially fully developed flow in at least one first region of a fluid in the print head;
- and
- at least one nozzle channel in fluid communication with the at least one first region, the at least one nozzle channel operable for jetting the at least one continuous stream from at least a portion of the at least one first region;
- at least one second conditioning means operable for establishing a second flow in at least one second region of the fluid in the print head;
- and
- at least one additional nozzle channel of the multi-channel print head in fluid communication with the at least one second region, the at least one additional nozzle channel operable for jetting at least one additional continuous stream of the fluid from at least a portion of the at least one second region wherein the second flow comprises substantially fully developed flow;
- wherein at least one of the first flow conditioning means and the second conditioning means comprises at least one of:
- a back side tunnel and a flow conditioning plate.
Dependencies are inferred from the claim text.