Toner cartridges are easy to forget about, mainly because they’re so simple to use. Just open the box, pop them in and get printing. But have you ever thought about how, exactly, your printed page happens?
We’ve gone over the mechanics of how toner powder gets on to the page and how it stays there, but we’ve never looked at what goes into making the powder itself. We thought we’d save you the fuss (and a whole lot of mess) by digging deeper into what’s inside your toner powder.
As it turns out, toner powder is mostly powdered plastic, which has two properties that are important for laser printing – it’s easy to move around with static electricity and it melts at a relatively low temperature. Most early versions of toner powder contained carbon black (for the colour) and iron oxide (to make it magnetic and easier to move around), leading to our favourite description of toner as being made of rust, dust and soot.
Iron oxide, however, wouldn’t work for colour toner – it would darken to colours too much to get a true representation of the images you wanted to print. Printer manufacturers had to come up with other additives and components to make colour cartridges work properly.
After much trial and error, the perfect recipe was found. And it remains largely unchanged to this day. Aside from a few special ingredients that are unique to each manufacturer, the components are fairly similar.
Polyester makes up 85% to 95% of colour toner. This holds the static charge that makes it possible for toner powder to cling to the imaging drum and get the printing process started. Polyester might be more expensive than the old standby, styrene acrylate, but it’s less smelly, makes for brighter colours and has a lower melting point.
Early laser printers used radiant heat to melt the plastic in toner powder, with the unfortunate side effect of setting your prints on fire. With the advent of the fuser roller, all this changed, but toner would end up sticking to them. To solve this, manufacturers added polypropylene wax as a lubricant and have kept it ever since.
Carbon black is used to make black toner cartridges. It’s essentially high quality soot, made from burning tar or creosote. While it is carcinogenic and the reason you shouldn’t sit too close to the printer while it’s printing, once it’s melted and sealed into the paper, it’s perfectly safe to handle.
To make colour toner, various coloured pigments are added to clear polyester. To make yellow, pigment yellow 180 is added, for magenta, manufacturers mix in pigment red 122 and pigment blue 15:3 is used for cyan.
Microscopic glass beads, known as fused silica, sit on top of toner particles to ensure a fast and even spread of toner powder over the page to speed up printing and making sure that the toner powder doesn’t clump or cake in the cartridge.
Finally, charge control agents like iron, chromium or zinc help to boost the static charge of toner and make it cling more firmly to the drum. This can of course lead to colourful dust explosions if you ever decide to vacuum spilled toner powder without the right filters.
We hope that this deeper look into the inner workings of your toner cartridge has helped you get a better understanding of the printing process. Remember, if you ever have questions about, or need help with, your printer cartridges please feel free to contact us.