If you own or have used laser printers for some time, you may have been wondering: what is a toner cartridge and what is a drum unit, and how are they different?
Both of these are essential components for a laser printer to function properly, but, while you may have seen and changed a toner cartridge for your printer, you may not have had to replace the drum unit yet.
To understand these two components better, let us first look at the definitions.
A toner cartridge is basically a container that holds the toner powder, while the drum unit is an electrically charged cylinder that fuses the toner powder onto paper. Without a drum unit, the toner powder cannot be transferred to the paper to create text and images. In other words, your printer cannot print without a drum unit.
Some laser printers use a separate toner cartridge and a drum unit, while others, like most HP laser printers, have the drum unit built into the toner cartridge.
If your printer has both the toner cartridge and drum unit as a combined unit, you will only need to replace the toner cartridge. However, if the design of your printer has the drum unit and the toner cartridge as separate units, you would need to replace both.
If your drum unit is built into the cartridge, then there is no need to replace it separately, as every time you buy a new toner, you are also replacing the drum.
Standalone drum units, on the other hand, will generally need to be replaced after about three to four toner cartridge changes. This, however, depends on the specific printer, and your printer should inform you when it is time to change the drum.
Or, if black spots or lines start appearing across your printed page, it is probably time to replace your drum.
There is no real difference in both variations in terms of performance, although buying a new toner/drum combined unit will ensure that your print quality remains consistent.
The difference to note, however, is in the cost, as the prices of the two variations can differ quite significantly. Toners that combine with the drum unit are usually more expensive than the ones sold individually, and that makes sense, because you are essentially paying for both a new toner cartridge and a drum unit every time you need to replace the toner.
It depends on several factors, including: how often do you use your printer? If you constantly need to replace the consumables for your printer, you may prefer having the immediate cost savings of a separate toner cartridge.
On the other hand, if your business relies on consistent print quality, and you do not want the hassle of having to go out to buy the toner cartridge and drum unit separately on different occasions, a combined unit may work better.