A critical component of a laser printer is the fuser or fixing assembly. This assembly is used to “fuse” the toner to the media. Toner is made up of a plastic, pigment, waxes, and iron compound, which will melt when heated by the fuser assembly. After the toner is deposited to the media, it passes through the fuser assembly and the toner is melted into the fibers of the media. The fuser provides not only the high temperature via the upper temperature roller, but also pressure as the lower rubber type roller presses the media against the temperature roller. As the speed of printers increases, so does the speed of the fuser assembly and the associated components. Also the temperature must be uniform and transfer heat rapidly to the media since it passed through the fuser assembly more quickly.
Early laser printers used a halogen lamp suspended in a hollow aluminum tube as the heat roller. The outer surface of the tube was coated with a teflon compound to facilitate release of the media which tends to stick to the surface. You can see how the chemistry of the toner is very important and not all toner is the same.
Most current laser printer fuser assemblies use a plastic film roller sleeve which rotates around a solid state thin film ceramic heating element. This configuration offers greater efficiency in heat transfer and rapid heating of the fuser assembly roller by the ceramic element. With this configuration you can experience almost instant on printing. Attempts to decrease costs have resulted in easier shredding of the fuser roller and alternatives are being developed.
As with any mechanical part, the fuser assembly is subject to wear and is the main component of a laser printer maintenance kit. Data has shown a standard recomended replacement interval for office size printers and thus the “Perform Printer Maintenance” message that appears on the display at a pre determined page count. You may also have to replace the fuser assembly if the roller becomes damaged by a jam or jam removal, labels peeling and sticking to the coated surface and damaging the coating or mechanical failure of a gear or roller.
Tags: fixing assembly, fuser assembly, hp fuser, hp fuser assembly, hp maintenance kit, laser printer fuser, laser printer maintenance kit
