What are laser printers used for?

Why do you need a drum kit?

A drum kit contains an image drum and the housing that goes with it. In a laser printer, the toner powder is applied to the paper using static electricity from the image drum. With most laser printers, the image drum, i.e. the drum, is simply "used up" due to the constant charging and discharging after a certain page output. In order not to have to dispose of the entire printer, most brand manufacturers offer drum kits. These are usually exchanged with more or less great effort and manual skill. The printer is then fully functional again.

When does a drum kit have to be changed?

The change is usually requested by the printer itself, i.e. controlled by a counter. However, poor printouts with streaks or spots may also require replacement. Most users hope that the toner cartridge is to blame for poor printouts, but unfortunately it is often the imaging drum. Usually this is enough for the consumption of 10 or more toner sets, i.e. 10 times the page capacity of the cartridge. But at some point it is due. Just to give you an example: The Lexmark laser printer E 450 requires the toner cartridge E450A11E, which is sufficient for approx. 4,000 pages. The drum kit for this laser printer is the 0E250X22G, which has a page yield of 30,000 pages. So after 30,000 printed pages it is necessary to change the drum kit, regardless of whether there is still enough toner in the cartridge or not.

The drum kits are usually quite cheap in relation to the page yield of a printer. However, the costs should be taken into account when purchasing the printer. The price per printed page therefore not only consists of the price of the toner divided by the number of printed pages, but also the cost of the drum kit must be allocated to the printed pages.

Difference to the maintenance kit

With some printer manufacturers, the imaging drum is part of a maintenance kit. The replacement is usually a greater effort, since the conveyor rollers and gears are also replaced. The advantage is that the printer is completely overhauled after installing such a maintenance kit. The kit for the HP Laserjet 9000 is shown here as an example:

Read more about how a laser printer works here.