Digital Printing Trends (I)

Digital Printing (Digital Printing) may not be as fast as digital photography, but there is no doubt that the trend is going to be digital. Even if we cannot replace traditional printing in a short time, digital and traditional complement each other, we can expect it. The four-year DRUPA printing exhibition will be opened next week. Digital printing should be one of the mainstream, and all manufacturers will show the best equipment.
Broadly speaking, any device that is connected to a computer and can be directly printed without the need for plate making can be called digital printing. The price of equipment varies greatly, ranging from less than US$100 to more than US$1 million. Digital printing fire digital printing, usually referred to as professional production, printing commercial prints and color proofing. Under this premise, speed, quality, and economy have become the necessary considerations. At present, there are two categories, Xerography and Inkjet. Early collisions, heat transfer, and dye dissolution are the conditions that meet the requirements. Technology is no longer applicable.
The static film printing is commonly known as laser, and the small particle powder (Toner) is attached and fixed on the paper for imaging. Although the printed programs have different labels, the principle is much the same, usually after the printed data is converted into small dots, the small dots are scanned with laser light onto a rotating drum, and the drum is made of light-sensitive material. , And with a positive static electricity, the part scanned by laser light is turned to the negative static electricity, when the drum is turned to the powder tank side, the powder with a positive electrostatic, so it immediately attached to the laser scan site, that is, to print In the image, a sheet of paper with negative static electricity appears below the roller. The strength of the electrode is slightly larger than that of the laser. The powder on the roller is then absorbed onto the paper, and after heating and fixing, the printing is performed. Just finished.
This process takes place in a single color and the color has to be walked four times (the CMYK four-color powder goes one drum each). The only exception is HP's Indigo, which uses only one drum to rotate four times. The imaged powder is very small, usually solid powder, and is also contained in a liquid crucible, with the exception of HP Indigo, called Electroink, which first attaches the liquid ink to the paper and converts it into a solid film. The static film digital system, with Canon, Heidelberg, HP Indigo, Konica Minolta, Océ, Ricoh, Xeikon, Xerox as the main manufacturer.
Inkjet printing is based on different techniques. Drops of ink are dropped onto the paper, and the combined images are very small, only 50 to 60 microns (Micron, one millionth of a meter) and more than human hair (70 Micron) also fine. The position of the ink drop is precisely moved by the ink head (Ink Head). Each ink can be up to 1000 points or more. With a variety of different color ink cartridges, full color images can be printed. There are two types of ink jet technology: dro On-Demand and Continuous Inkjet. In the early days, continuous inkjet was used as the main device. The nozzles continuously drip ink according to certain rules. The ink does not need to be printed on paper, it will spring out in an electrostatic manner and be recycled to the ink tank. This method is not efficient because it only developed ink drop-on-demand technology. The ink jet head went to the place where it needed to be printed.
There are two ways to control the ink drop, relying on heat and vibration. Thermal ink jet is based on the heat of a small resistor, so that the surrounding ink evaporates, creating a bubble. The expansion of the bubble presses the ink to dribble out of the nozzle. After the dripping, the bubble disappears and a new ink is sucked from the ink tank. This method is known as Bubble Jet because it generates bubbles. (To be continued)