Abstract: The invention provides an inkjet printing apparatus that includes at least one inkjet print head adapted to dispense fluids onto a substrate and at least one delivery aperture adapted to direct a gas toward the substrate. The apparatus may also include at least one recovery aperture adapted to draw materials away from the substrate and evaporate liquids from the surface of the substrate.

Abstract: A guard barrier arrangement is used in an O-ring seal arrangement to limit reactive species in coming into contact with an O-ring. The arrangement is supported in a chamber passage for exposure to the reactive species. An o-ring is compressed so as to peripherally resiliently bias the guard ring arrangement further into the chamber passage configuration toward the chamber interior to limit access of the reactive species to the o-ring. The passage configuration can use a narrowing surface arrangement against which the barrier arrangement is urged. The barrier can include an annular configuration that can change responsive to being biased into the chamber passage configuration.