Toner: The Evolution of an Essential Printer Component

Laser printers, and more recently LED printers, use toner. Toner is a powdered substance, a mix of plastic particles, carbon, and color pigments. Color printers typically use toners in cyan, magenta, yellow, and black (Cyan, Magenta, Yellow, and blacK, or CMYK). Via a drum (also known as an imaging unit), the toner is transferred to paper. A fascinating and complex process, which will be covered in a future blog.

The Development of Toner
At first glance, toner doesn’t seem particularly exciting: a very fine, colored powder. The technology is about 50 years old and has been significantly refined over the years. The first 30 years of laser printers were simpler, as everything was in black and white. With the introduction of color in the 1990s, toner formulations changed due to the addition of color pigments. The demand for higher resolution, and thus smaller particles, also grew as printers were used for graphic purposes.

Looking at Xerox’s recent history, several types of toner have been developed. The DocuColor 12, introduced in 1999, still used mechanically pulverized toner. The fusers in these machines also had an oil cartridge with silicone oil, which applied a layer to the fuser to prevent toner from sticking to the fuser rollers. This so-called “oil-requiring pulverized toner” was used in models like the DocuColors 6060 and 8000.

In the early 2000s, Xerox introduced EA toner, where EA stands for “Emulsion Aggregation.” In emulsion aggregation, toner particles are built up in an emulsion from extremely small nucleation points. This allows for precise control over the size, shape, and structure of the particles, resulting in a much more uniform particle size distribution. Xerox claims significantly lower toner consumption, reduced energy use in both production and printing, and sharper prints (up to 2400 x 2400 dpi). EA toner also eliminated the need for a separate oil cartridge for the fuser in most machines. Except for the iGen (a massive production machine), all machines using EA toner have fusers that no longer require oil. EA toner was used in machines like the WorkCentre C2128 and DocuColor 3535.

The successor was EA-HG toner, where HG stands for “high gloss” or “high grade.” This toner type includes additives that give prints more gloss than the original EA toner. The color formulation is also slightly different. EA-HG was used in machines like the DocuColor 250 and WorkCentre 72xx and 73xx series. EA-HG is somewhat compatible with EA toner: particle size, electrostatic properties, and melting temperature are the same, so toner for the DocuColor 3535 could theoretically (if the cartridge is adapted) be used in a WorkCentre 7335, and vice versa. However, this would result in differences in color and gloss levels.

In 2008, the first machines using EA-Eco toner were introduced. EA-Eco toner shares most properties with EA-HG toner but is specifically formulated to melt at a lower temperature. This results in printers using EA-Eco toner consuming less energy, as the fuser doesn’t need to get as hot. It also extends the fuser’s lifespan. The print speed of machines using this toner is significantly higher, as fuser cooling (the fuser loses energy with each printed sheet) is often a bottleneck for speed. EA-HG and EA-Eco toners are not really interchangeable: particle size, electrostatic properties, and color formulation are the same, but because the melting temperatures differ, EA-Eco toner becomes overly glossy when used in an EA-HG machine. Conversely, using EA-HG toner in an EA-Eco machine (e.g., DocuColor 250 toner in a DCP700) is likely to result in poor adhesion to the paper.

EA-Eco toner is now used in nearly every Xerox machine we sell, specifically in all A3-format machines. The AltaLink C80xx and C81xx series, as well as the Color C60/C70, were developed by Xerox and Fuji Xerox and use this toner. The cartridges are often interchangeable, with only the shape and chip differing. For example, the cartridges for the Color 560, C60, DCP700, and Versant 80 are identical, except for the toner’s “handle” shape and chip. Smaller models, like the VersaLink A4 series, are sometimes developed by or with other manufacturers and often use entirely different toner, not even produced by Xerox.

Latest InnovationsThe latest developments in EA-Eco toner include the introduction of “vivid” and “fluorescent” toners. The Vivid kit adds white, silver, gold, and transparent toner, while the fluorescent kit includes black and fluorescent cyan, magenta, and yellow toner. The beauty of these kits is that they can be swapped on the fly, allowing a single printer to produce standard CMYK prints and then add, for example, gold accents with the same machine.

The production of EA toner is an extremely precise process, as evidenced by the significant quality differences in compatible toner. This will be discussed in the next blog post.