Inkjet Basics
2008-03-14 09:11  ???:1455

  I'm learning about inkjet, which seems to be popping up everywhere I look. A print buyer called me just last week, looking for recommendations on an inkjet printer. He wants to print his organization's color brochures in house.

  In the industry press, drupa, the upcoming mother of all trade shows (www.drupa.com), has been dubbed the "inkjet drupa."

  I admit: I didn't know as much about this technology as I ought, so I did some research. Here's what I learned.

  Digital printing uses either toner-based technology or inkjet technology.

  Toner-based printing, AKA electrophotography or xerography or laser printing, is based on particles of pigment that are moved around by electrostatic charges. The pigment may be encased in plastic, and when the toner passes through the fuser, the heat (roughly 400 degrees) melts the plastic particles, effectively binding the pigment to the paper.

  Toner printing uses both wet (liquid) toner and dry (powder) toner and can be either sheetfed or roll-fed.

  Laser printer quality is getting closer to offset printing quality. Laser printers print at 40 to 110 ppm (pages per minute) for sheetfed systems, and 130 to over 200 ppm for roll-fed systems.

  Toner-based printing is the dominant technology because of its high quality and the fact it can handle variable printing. You have options galore, as well, as there are over 100 models of toner-based printers out there, from the low-end sheetfed machines to high-end sheetfed and roll-fed.

  Inkjet printers work like this: they deposit or spray tiny droplets of ink onto paper and other substrates. There are three types of inkjet technology:

  1. Thermal (AKA "thermal bubble" or "bubble jet"): heat vaporizes the ink to create a bubble. When the bubble expands, ink is pushed out onto the paper.

  2. Piezo or piezoelectric ("Piezo" is of Greek origin and means "to squeeze"): An electric current is applied to a piezo crystal, whose structure causes a physical displacement of the ink. This current makes the crystal vibrate; and when it does, it creates a pressure wave that pushes out a tiny amount of ink. This technology uses less heat than thermal C consuming less power.

  3. Continuous inkjet: this is faster than the other inkjet technologies. It is also based on pressure, which causes a continuous flow of ink onto the paper.

  Quality of inkjet technologies has been improving lately, particularly for display signage and industrial applications at 300 - 600 dpi, but not yet for commercial work.

  Why the Current Interest in Inkjet?


  According to an article by Frank Romano in the November/December 2007 issue of Management Portfolio (a PIA/GATF publication), the key reasons are these:

  Inkjet is less complex.


  It has more potential for reproducing spot colors (which is a big drawback for toner printers, except for one).


  There's barely any makeready.

  Inkjet is fully scalable from the desktop to the shop floor.


  Inkjet systems consume less power.


  The key equipment manufacturers for inkjet systems include HP, Kodak, Lexmark, Memjet, FFEI, Canon, Epson, Ricoh, Fuji-Film Dimatix, Brother, Konica/Minolta, ToneJet, Toshiba Tec, Panasonic, Videojet/Willet, Domino, Stork, Imaje, Hitachi Machinery and XAAR (as reported in November/December 2007 Management Portfolio).

  In an article entitled, "Inkjet on the Horizon" in the same issue of Management Portfolio, Jackie Bland, managing director of PRIMIR (Print Industries Market Information and Research Organization) writes, "While the bulk of inkjet printing today is devoted to display signage, global manufacturers see markets such as graphic arts, packaging and manufacturing/deposition as the next opportunities for growth. This belief is clearly supported by the study forecast that graphic arts will go from $84 million in 2006 to over $274 million, packaging from $44 million to $526 million and manufacturing/deposition from $25 to $120 million by 2011. (Visit www.primir.org for more information.)

  Things are definitely heating up in the digita