The Basics of Ink Cartridges
Ink cartridges are components of inkjet printers that contain the liquid deposited onto paper or some other substrate during the printing process. Ink cartridges are designed with the use of inkjet printers. They are relatively simple containers that contain the pigmented fluid used to produce an image or text on the print surface.
How Ink Cartridges Work
The fluids most used in ink cartridges are water or some form of solvent but there are other fluids less commonly employed, such as latex and oil based. The base fluid acts as a carrier for the pigment (also known as the colouring agent) and is, in the case of water-based fluids, absorbed by the substrate. The pigment forming the image is left on the surface. Solvent-based ink cartridges are used where the substrate being printed on is not porous, vinyl or some other plastic, for example. The fluid carrying the pigment is not absorbed but evaporates off the substrate leaving the pigment behind.
Most consumer inkjet printers, other than Epson, use a thermal process to propel the bubble or droplet of fluid and pigment onto the substrate. In a fraction of a millisecond, a heating element using a tiny resistor is heated, and the fluid in contact with the heated resistor is vaporised into a steam bubble inside the printhead nozzle. The tiny droplet is forced out of the nozzle onto the substrate. Successful, continuous printing depends on the uninterrupted flow of fluid which cools the resistors and prevents them from overheating. When the fluid is depleted and printing takes place with insufficient flow, the heating elements often burn out, permanently damaging the printhead. Epson printers use a piezoelectric crystal instead of a heating element. When current is applied, the crystal bends or changes shape or size, pressurising the fluid in a very small channel and forcing a droplet from the nozzle.
Ink cartridges contain one or more fluid reservoirs, and many manufacturers also add a microchip that communicates with the printer. The communication between the microchip and printer will usually include information about how much fluid is left in the cartridge. It will also confirm that the unit is a genuine original equipment manufacturer (OEM) consumable. In some instances, the printer will not function if the microchip is not present, or damaged or if the microchip declares the unit is empty.