and exotic materials to perform the same function the pitch of the modules is typically 20 33 mm the individual layers of the laminated stack as well as the cover molding 39 and distribution molding can be glued or otherwise bonded together to provide a sealed unit the ink paths can be sealed by a bonded transparent plastic film serving to indicate when inks are in the ink paths so they can be fully capped off when the upper part of the adhesive film is folded over ink charging is then complete the four upper layers 52 56 60 62 of the laminated stack 36 have aligned air holes 54 which communicate with air passages 63 formed as channels formed in the bottom surface of the fourth layer 62 as shown in fig9 b and 13 these passages provide pressurised air to the space between the print chip surface and the nozzle guard 43 whilst the printer is in operation air from this pressurised zone passes through the micro apertures 44 in the nozzle guard thus preventing the build up of any dust or unwanted contaminants at those apertures this supply of pressurised air can be turned off to prevent ink drying on the nozzle surfaces during periods of non use of the.