Guest article by Danny Mertens, Corporate Communications Manager at Xeikon.
With its theme of Touch the Future, drupa 2016 is shaping up to be one of the best ever. There will be significant focus on technologies such as production inkjet and 3D printing at the show, and those are important topics for the industry.
But we shouldn’t lose sight of what’s happening in the world of electrophotography. On the dry toner side, manufacturers continue to make strides in quality and functionality. Mechanically ground and chemically made toners are enabling smaller particle sizes and higher quality. There are also now dry toners that use a much lower fusing temperature than in the past. This not only reduces energy costs but also enables the use of a wider range of substrates, including heat-sensitive materials.
Xeikon’s ICE toner is an example of this; it lowers the fusing temperature by 10⁰ to 15⁰ C over previous toners. bsb-label, a fast-growing, independent arm of Bielefeld-based printers bsb-bentlage GmbH and Co KG, was an early adopter of ICE toners. The company specializes in the production of self-adhesive roll labels. Brigitte Alers, managing partner, has been pleased with the results the firm has achieved in terms of print quality and fade resistance as well as its opaque white results. She adds, “The demand for PE products from our customers is high, so we are pleased to have found a fitting solution with the ICE toner.”
The other aspect of electrophotography that is gaining increasing momentum is liquid toner, which comes in two forms: low-viscosity Isopar toner using polymer blends, and high viscosity liquid toner. Liquid toner has a long history dating back to the 1950s, but it is only in recent years that we have seen liquid toner digital printing solutions that can deliver high quality production-level printing in full color, beginning with the introduction of the Indigo digital press in 1993.
drupa 2012 saw a number of new entrants to the liquid toner space, most of which have not yet been commercialized as of this writing. One exception is Xeikon’s Trillium, which was shown at drupa 2012 as a technology demonstration and is now being placed in customer locations as the Trillium One press. It uses a high viscosity liquid toner and an ink transfer process that uses four wet-on-wet transfers. Toner particles measuring 2 microns by one micron are suspended in a white oil liquid carrier, most of which is recycled for reuse in the press during the toner deposition process.
For comparison purposes, the optimal size for dry toner particles is in the 6- to 7-micron range. Any smaller than that, and they become too difficult to control during the imaging process, and potentially unsafe to handle as well. Since this high-viscosity toner imaging process doesn’t require evaporation of or fusing out of the carrier oil, there are no VOCs in the printing process and no need to vent the press to the outside.
Another advantage of liquid toner is the high quality it delivers without the need for any type of specially optimized papers such as those required for many inkjet applications today. It also lays down a thinner film than dry toner.
The 4-color Trillium One press prints at a speed of 60 meters (200 feet) per minute at 1200 dpi, with a print width of 500 mm (19.7 inches). Trillium One is specifically designed for high quality production of high volume direct marketing materials, and catalogs. And it uses a low fusing temperature that supports a broad range of substrates.
The press features a very tiny space between rollers – two microns, to be exact – which we call microgapping. This means that base materials have full contact with each other as the image is transferred through the process. For comparison purposes, inkjet typically has a gap of 1,500 microns between the inkjet heads and the substrate, while dry toner and low viscosity liquid toner typically feature a gap of 200 microns. This microgapping is a significant contributor to the high quality that is delivered by high viscosity liquid toner technology.