Printer with foaming system for cleaning ejecting face

1. An inkjet printer comprising:

(a) a printhead having an ink ejection face;

(b) an ink supply system for supplying ink to said printhead; and

(c) a foaming system for generating a liquid foam on the ejection face, the liquid foam being a matrix of liquid membranes forming randomly-packed Voronoi polyhedra.

2. The printer of claim 1 , wherein the printhead has ink supply channels, and the printer is configured to selectively position the ink supply channels in fluid communication with either said ink supply system or said foaming system.

3. The printer of claim 2 , wherein, in a printing configuration, said printhead is in fluid communication with said ink supply system, and in a maintenance configuration, said printhead is in fluid communication with said foaming system.

4. The printer of claim 2 , further comprising a valve configurable in first and second positions, wherein in a first position said printhead is in fluid communication with said ink supply system and in a second position said printhead is in fluid communication with said foaming system.

5. The printer of claim 2 , wherein said foaming system supplies a gas to ink supply channels in said printhead, thereby expelling an ink foam from nozzles in said ink ejection face.

6. The printer of claim 5 , wherein said foaming system comprises a pump for supplying air to said ink supply channels.

7. The printer of claim 6 , wherein said foaming system comprises an accumulator vessel pressurizable by said pump.

8. The printer of claim 7 , wherein said foaming system is configured such that said pump and said accumulator vessel cooperate to supply pressurized air to said ink supply channels.

9. The printer of claim 5 , wherein said ink supply system comprises a priming/de-priming system for de-priming said nozzles prior to foaming and/or re-priming said nozzles with ink after foaming.

10. The printer of claim 1 , wherein said foaming system comprises a foam dispenser having a nozzle for directing liquid foam onto said face.

11. The printer of claim 1 , wherein said ink supply system comprises one or more ink reservoirs.

12. The printer of claim 1 , further comprising:

(d) a foam removal system for removing the liquid foam from said face.

13. The printer of claim 12 , wherein the foam removal system comprises a transfer surface onto which said foam collapses.

14. The printer of claim 13 , wherein said transfer surface does not contact said face.