The Argentum printer uses a twin inkjet cartridge system. When printing conductive elements, the print head must be loaded with one Silver Nitrate and one Ascorbic Acid cartridge. The user can however load in an unmodified cartridge containing a regular printer ink - this can be used for silk screen and artwork printing. Some simple maintenance steps are required for the inkjet cartridges to ensure their longevity and to prevent any blockages forming over the cartridge nozzles. The following is a set of principles that should be followed to maintain a fully operational cartridge for its full lifetime.
Before Each Print
Note: Don't ever let any ink from one cartridge touch the nozzles of another cartridge! Silver will form and block the nozzles permanently.
Before each print, the cartridges must be primed to ensure that the liquid inside is prepared for maximum flow from the first set of firings. This is as simple as placing a piece of sponge, paper, or cloth over the nozzles and swinging the cartridge in a downward motion to force a small amount of liquid out (DO NOT use the same piece for both cartridges or you may block the cartridges). Some automated solutions to this process are currently being prototyped (including a small, low powered centrifuge and a small form factor pump that engages within the printer). Visually inspect the cartridge nozzles for blockages and if you are concerned, a cheap USB microscope will often reveal any problems (such as that included in the experimenters kit). Blockages will not occur if the cartridge is treated as per these guidelines (it will most likely be caused by having Ascorbic Acid wiped onto the Silver Nitrate cartridge or vice versa).
If you discover a clear blockage, it may not affect your prints too drastically as each cartridge contains 104 nozzles to provide redundancy for failures. You can test fire all of the nozzles in a cartridge using the 'FIRE ALL' command, instructions can be found here.
If the blockage begins to cause print problems, the best solution is to immerse the cartridge nozzles in an ultrasonic cleaning tank (these can be purchased cheaply from eBay and a perfectly suited, cheap solution may become available at the Cartesian Co Web Store in the future).
See Loading Cartridges for how to now properly insert your cartridge for printing.
During Each Print
During a print, try to ensure that the surface of the substrate does not scrape against the print head. The print head has a small protective clearance ring to avoid collision with the actual nozzles but if any cross contamination between the conductive cartridges does occur, Silver precipitates may form over some of the nozzles. Do not leave the cartridges exposed in the printer for periods longer than ~2 hours as they may begin to dry out (depending on the ambient climate). Upgrades are currently being prototyped to allow automated 'parking' of the print head that seals the cartridges (this mechanism will also be used for priming and wiping the print head).
The reasons that the mechanism from a standard printer can't be used for parking, wiping and priming are as follows:
- Generic priming mechanisms waste large amounts of ink, a method of optimizing to minimum waste would be ideal.
- Wipers and sealing mechanisms in most printers will use the same piece of silicone for multiple cartridges, this would cause cross contamination between conductive cartridges, potentially causing serious Silver precipitate blockages.
After Each Print
After you have finished printing, the nozzles must be sealed to prevent them from drying out (as stated above). It is vitally important that the cartridges are placed into their correct respective 'holders' as mixing them up will cause cross contamination of chemicals and possibly Silver blockages. Cartridges will always be clearly colour coded and a small triplicate cartridge holder (Silver Nitrate, Ascorbic Acid and Silkscreen) is currently being prototyped with reverse polarized magnets to prevent incorrect storage. This potential issue may also be resolved in the future with an automatic parking system or a jig that locks the two conductive cartridges side by side for printing and storage.
Long Term Storage
Extreme heat or humidity environments may begin to prevent maximum longevity. Current prototypes have been in operation through an Australian Summer with extremely high ambient humidity and temperatures up to 40C (~100F) and have retained long life simply by being stored inside with the provided clips covering the nozzles.
To dramatically increase the shelf live of the cartridges, we recommend storing them in the fridge between prints. Make sure that the Silver cartridge is kept away from all food products. To store cartridges during long periods of non-use, consider freezing the cartridges. Freezing should not harm the bag inside the cartridge, however we are unsure of long term effects to the cartridge. DO NOT attempt to print with a cartridge directly from the fridge or freezer, allow it to return to room temperature first.