Inkjet printers and printed flags
|Release time:2013-11-14 Source:admin Reads:|
| Most commercial and industrial inkjet printers and some consumer printers use a piezoelectric material in an ink-filled chamber behind each nozzle instead of a heating element. When a voltage is applied, the piezoelectric material changes shape, which generates a pressure pulse in the fluid forcing a droplet of ink from the nozzle. A DOD process uses software that directs the heads to apply between zeros to eight droplets of printed flags, only where needed. Most printers attempt to prevent this drying from occurring by covering the print head nozzles with a rubber cap when the printer is not in use.
For instance, the "use-before" date is often applied to products with this technique; in this application the head is stationary and the product moves past. Requirements of this application are high speed, a long service life, a relatively large gap between the print head and the substrate, and low operating cost. After printing, the ink is cured by exposure to strong UV-light. Ink is exposed to UV radiation where a chemical reaction takes place where the photo-initiators cause the ink components to cross-link into printed flags. Typically a shuttered mercury-vapor lamp is on either side of the print head, and produces a great amount of heat to complete the curing process. UV inks do not evaporate, but rather cure or set as a result from this chemical reaction.
No material is evaporated or removed, which means about 100% of the delivered volume is used to provide coloration. This reaction happens very quickly, which leads to instant drying those results in a completely cured graphic in a matter of seconds. This also allows for a very fast print process. The idea is that because the head need not be replaced every time the ink runs out, consumable costs can be made lower and the head itself can be more precise than a cheap disposable printed flags, typically requiring no calibration.
cker lP�s/�l X�l nvention of mechanical movable type printing led to a large increase in printing activities across Europe within only a few decades. From that time on, it is assumed that "the printed book was in universal use in Europe".