Improvements in Toner Technologies are Leading to New Opportunities
By Sean Milmo
The impressive growth of inkjet printing could be slowed by laser printing, which some commentators have predicted would eventually be overwhelmed in the digital printing market by its highly versatile liquid ink-based rival.
It has also been making inroads into laser stronghold of copier or electrophotographic printing in shared networks and in-house printing facilities in large offices. In some niches, inkjet has proved itself to be far more successful than laser in expanding digital printing into the commercial printing market, mainly by penetrating the lower end of the sheetfed sector and some packaging segments.
However, recent major technological improvements in electrophotographic equipment and particularly its toners are helping laser printing not only hold its own in key sectors but to take away sales from inkjet in others. It is even opening up opportunities for creating its own niches.
“Even though inkjet has been expanding at a double-digit rate in digital color printing, electrophotographic color printing is growing at around 15-25 percent a year,” said Christophe Bulliard, industry marketing manager for digital printing and photography at Ciba Specialty Chemicals.
“Electrophotography has, on the other hand, started from a much lower base in color printing, whereas inkjet color printing has been around for a much longer time,” he added.
The technological advances in electrophotography have enabled laser printing to benefit from the volume growth in in-house and large office printing.
“The number of pages printed by the installed base of our machines grew by more than 25 percent last year,” said Ben van Assche, CEO of Punch Graphix, whose core Xeikon business is a leader in Europe’s sector for high-end, digital color printing systems, software and consumables.
At the same time, new technologies are helping laser printing gain a bigger foothold in the market for product identification, where inkjet has also been in the ascendancy.
The technological innovations in laser printing have stemmed from higher investment in R&D by equipment manufacturers. For example, Punch Graphix has allocated 10 percent of its revenue to R&D.
Over the last few years, there have been a steady flow of launches of better performing electrophotographic presses and other laser equipment by leading operators like Punch Graphix, Oce, Fuji Xerox, Hewlett Packard, Canon and Konica Minolta.
Most of the presses have faster speeds, are more productive and, significantly, have lower capital costs and are less expensive to run. As a result they can print more pages per minute, possibly as much as 50 percent more. Costs per printed page are falling by as much as two-thirds.
Among the biggest changes has been a much higher quality of color reproduction as a result of new technological advances in the production and structure of toners, many of which are developed and produced by the equipment manufacturers themselves.
Traditionally, toners are made by mixing the ingredients – binder, pigments and additives – liquefying and then solidifying them into solid strands which are pulverized into small particles. Now systems have been developed as alternatives to pulverization so that the size and shape of the toner particles can be more carefully controlled. More importantly, smaller particles can be produced which when properly dispersed could provide enhanced color reproduction.
Xerox Research Center has developed a chemical approach for the economical production of smaller toner particles. It enables toner particles to be made under controlled conditions so that they have the right size, shape and structure. As a result, sharper images can be printed with as much as 40 percent less toner.
Konica Minolta synthesizes in an aqueous solution resin particles with a diameter of approximately 100 nanometers. These are then chemically coagulated and fused with color pigments and additives to create toner particles of a uniform size of nearly 3 microns in diameter.
With the help of a similar particle-shaping technology. Xeikon has introduced a polyester-based toner which provides more vivid colors with the potential for a broader range of applications. Punch Graphix develops and manufactures toners at its own state-of-the-art plant at Westerlo, Belgium.
With a capability to provide high quality colors within a broad gamut, electrophotography is able to profit much more from the strong demand for digital color printing, from which inkjet has so far got most of the benefits.
“Digital color printing was the fastest growing of all printing technologies (last year) with a wider range of printers adopting new applications,” said Mr. Van Assche. “In addition, ongoing trends such as the increasing use of color printing and a widening use of personalization in printed media have contributed to the growth.”
Gains in Digital Photography
Laser now has a bigger presence in the rapidly expanding market for printing of digital photographs. This sector has been considerably bolstered by the arrival of mobile phones with cameras as a standard feature.
Initially a lot of the printing of digital photographs was done at people’s homes. But increasingly consumers are making greater use of printing facilities offered by retail chains or specialist services, which have either their own in-house printing facilities or outsource to large central laboratories.
“Laser printing is an attractive option for these big laboratories because of its low unit costs and high speeds,” said one digital printing executive.
Three crucial factors in the digital photo printing market are cost, image quality and color fastness. Inkjet inks are being reformulated to make them a better match for laser toners – even if it means going back to the use ofless expensive dyes in preference to pigments. Epson launched late last year in Europe a dye-based inkjet ink which was not only less expensive than pigmented inkjet ink but printed images that were as long lasting.
“We are now seeing dyes being developed for inkjet inks whose light fastness is comparable to that of pigmented ink systems,” said Mr. Bulliard. “Dye-based inkjet inks can be used in parallel with pigmented inks. One advantage of dye-based inks is that they cost much less to produce than pigmented ones.”
UV curing in digital printing had been mainly the reserve of inkjet because most toner systems could not tolerate solvents and were not heat resistant above 65°C. Toners have now been developed which are able to withstand high temperatures and solvents.
Xeikon has introduced a dry UV-curable toner which stays intact even at temperatures as high as 280°C and can endure most solvents.
The toner should be a platform for moves into new or extended applications for laser printing. Since it does not contain solvents, volatile organic compounds or low molecular weight components, it should not have difficulties gaining the approval of regulatory authorities as an additive to packaging for food and pharmaceutical products. The company claims its combination of digital printing and UV curable toner is “the perfect tandem” for the printing of heat-treated blister packaging for medicines, particularly when short-run variable data and security features are required.
Development of new toners is not the only recent innovation in laser printing. In the product identification sector, new technologies have led to the fast growth of direct non-contact printing of data by relatively inexpensive laser equipment.
“Laser marking has established itself as a cleaner and more environmentally acceptable imprint medium versus the traditional methods, such as inkjet and pad printing,” the market research organization Frost & Sullivan concluded in a report published this year. “This emerging technology comes out across the board as being much less expensive than conventional ink marking by a factor of one-third or one-half less.”
Laser marking has been around for several decades but has had limited use because of high costs and a narrow color range. The development of low cost equipment for emitting laser beams such as those powered by carbon dioxide gas and advances in color-change additives have suddenly accelerated sales of laser marking equipment and consumables. Demand has also been considerably helped by the introduction of European Union regulations which make traceability of medicines, foods and other products mandatory.
Datalase, a startup specializing in color-change coatings activated by laser beams, has developed a system for low-powered CO2 lasers which enables last-minute marking of food packaging with nutritional, safety and other information. The data can be printed onto the packaging as it is dispatched from the warehouse, eliminating the need for pre-printing of information which can lead to unnecessary waste. The coatings in the Datalase systems have pigments which are activated by heat, light or radiation.
Ciba has launched a color change solution for laser marking which is neither a pigment nor a dye and has no need for solvents. One of its advantages is that unlike with pigmented systems, it is transparent.
“There is the potential to make greater use of color with our Pergamark system, which at the moment produces predominantly black print,” noted Jonathan Campbell, head of new paper effects at Ciba. “We’re also looking to ways of putting Pergamark into an ink so that it can be printed onto packaging by flexo or gravure processes before the color change is activated by laser printing.”
Laser marking seems likely to open up another potentially large market for laser printing in which inkjet may have difficulty keeping pace with its technological advances.