Printing is a process for reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Nabonidus. The earliest known form of printing as applied to paper was woodblock printing, which appeared in China before 220 AD. Later developments in printing technology include the movable type invented by Bi Sheng around 1040 AD and the printing press invented by Johannes Gutenberg in the 15th century. The technology of printing played a key role in the development of the Renaissance and the scientific revolution, and laid the material basis for the modern knowledge-based economy and the spread of learning to the masses.

inkjet printing technology

is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper, plastic, or other substrates. Inkjet printers are the most commonly used type of printer, and range from small inexpensive consumer models to expensive professional machines.

Type of inkjet printing

There are two main technologies in use inkjet printers

• continuous (CIJ)
• drop-on-demand (DOD).

Continuous inkjet (CIJ)

The continuous inkjet (CIJ) method is used commercially for marking and coding of products and packages. In 1867, Lord Kelvin patented the syphon recorder, which recorded telegraph signals as a continuous trace on paper using an ink jet nozzle deflected by a magnetic coil.

Drop-on-demand (DOD)

Drop-on-demand (DOD) is divided into thermal DOD and piezoelectric DOD.

thermal DOD

Thermal inkjet printing induces the ejection of the ink droplet by super heating a small portion of a solvent-based ink. The heating, performed by a small resistor or other heating element, causes a bubble to form and eject the ink droplet. The inks involved are usually water-based and use either pigments or dyes as the colorant. The inks must have a volatile component to form the vapor bubble; otherwise droplet ejection cannot occur. As no special materials are required, the print head is generally cheaper to produce than in other inkjet technologies.

piezoelectric DOD

The piezo printing method contracts the ink chamber by applying electricity to a piezoelectric substance which moves when energized. A droplet of ink is ejected onto the print media. Piezo printing has not been adopted by as many mainstream photo printer manufacturers. However, it has found more uses in industrial printing and specialized large-scale printers, including special surface printing where a greater variety of ink bases can be used.

4 Advantage of inkjet printing

Compared to earlier consumer-oriented color printers, inkjet printers have a number of advantages.

1. They are quieter in operation than impact dot matrixor daisywheel printers.
2. They can print finer, smoother details through higher resolution. Consumer inkjet printers with photographic-quality printing are widely available.
3. In comparison to technologies like thermal wax, dye sublimation, and laser printing, inkjets have the advantage of practically no warm up time, and often lower cost.
4. Some types of industrial inkjet printers are now capable of printing at very high speeds, in wide formats, or for a variety of industrial applications ranging from signage, textiles, ceramics and 3-D printing into biomedical applications and conductive circuitry.