Xerox has offered a look inside "non-contact flash fusing" – a major technology breakthrough in high-speed colour printing which enables colour xerographic continuous feed printers to achieve speeds of nearly 500 colour pages per minute.
By flashing a high-intensity Xenon light more than 2 000 times a second, Xerox printers fuse the colour toner to a wide variety of paper and substrates without any components ever touching the paper. As a result, the new fusing technology enables colour continuous feed printing at speeds that rival black-and-white continuous feed printing while creating high-quality images.
Conventional toner-based printers heat the entire paper and pressure-roll the toner in order to fix the image onto the paper. This has limited print speeds to only 110 pages per minute and restricted printing on surfaces that have adhesives.
Xerox's new flash fusing method depends on newly developed colour toners that melt and fuse the image entirely through the energy from the xenon lamps, producing up to 650 images a minute in monochrome and 493 images a minute in full colour. In addition, plastic identification cards and peel-off labels on statements, price tags and stickers as well as RFID transponder inlays can now be printed at extremely high speeds.
"This fusing technology is a great example of how Xerox innovation drives the development of colour products with functionality never before seen in the marketplace," says Daniel McCue, vice president and chief technology officer: Xerox Production Systems Group.
"As we expand our portfolio of continuous feed systems, we are giving print providers more options on how to print faster, in full colour, on different materials and papers. This innovation brings another Xerox technology breakthrough to market, providing high reliability xerographic printing at extraordinary speed and print quality."
Flash fusing uses xenon lamps similar to those used in super bright headlights on luxury cars. There are eight flash lamps placed in a unique design inside the continuous feed printer.
"Think of the instant pulse of heat you would feel if you were to hold your hand in front of a flash camera," says Peter Crean, a research
fellow at Xerox's Research Centre of Webster.
"Now imagine thousands of those firing at high speed. In fact, the lamps that line up along the paper path inside the machine pulse light sequentially 120 000 times a minute, exposing and fusing the toner to the paper as it passes by at 226 feet a minute."
In order for flash fusing to work, Xerox scientists had to change how cyan, yellow and magenta toners absorb energy from light. To solve this problem, Xerox created colour toners that contain special infrared energy-absorbing material. This allows the individual colour toners to absorb enough energy so that each fuses as fast as the black toner that absorbs all light.
As a result, the toners are laid down in the order of their absorption rate with the black at the bottom. As each toner is overlaid on the preceding toners, the energy builds with each flash providing just the right amount of light to fuse each colour perfectly.
The new flash-fusing approach also provides dramatic improvements in reliability and quality. Because only the toner, not the entire paper, is heated, moisture is maintained in the paper, minimising stock shrinkage, paper curl and static electricity.
This also improves front-to-back registration, a challenge when printing on both sides of the paper at high speeds, and results in higher productivity and reliability because the paper feeds dependably during the printing and finishing processes.