What is Printer Ink Made Of?
So, you’re sitting in front of your printer listening to the whirr of its internal mechanics. It’s late. You’ve just finished a thirty-page proposal that needs to be given to five different team members, which means you’re watching one hundred fifty pages be robotically churned out. You start thinking of the big questions in life:
- How did people function before printers?
- Are there tiny calligraphers living inside this machine?
- What is printer ink made of?
The first two questions quickly leave your mind, and you’re left wondering what is printer ink and what is it made out of?
Read below for the answers while your printer does its magic.
Toner or Ink?
When people mention “printer ink,” they are either referring to laser printer toner or inkjet printer ink. Don’t know the difference between the two?
- Toner for laser printers – A fine powder of granulated plastics, these toner particles are melted down and bonded to the paper from the heat of a fuser. They’re typically made from microplastics—these can be mixtures of petroleum plastics or plant-derived plastics—and pigments. Though the exact formulation differs manufacturer to manufacturer, a type of styrene acrylate copolymer, styrene butadiene copolymer, or polyester resin usually suffices. Everything from the size of the granules to the compounds melting points will affect the printer’s efficacy (detailed further below).
- Ink for inkjet printers – The liquid used in inkjet printers is equally complex. A mixture of glycol, dyes, pigments, and water create the aqueous inks and then are combined with nitrates, sulfonates, and other compounds to create ink that is durable, dries quickly, and is resistant to ultraviolet light. With inkjet ink, everything from how the fluid disperses to how quickly it dries will be affected by its chemical composition.
Toner | A Deep Dive
It may be strange to know that the “ink” from toner is really melted down pieces of plastic. It may be even stranger to try and picture how melted plastics could possibly create the page sitting on your desk.
To understand more about toner and laser printers, let’s do an in-depth dive.
Laser Printer | How It Works
By the simplest analogy, a laser printer works similarly to writing with clear glue and then blowing glitter onto the page. How so?
- Part 1 – Understanding the components. The components to understand are the Photoreceptor Drum, the Laser, the Toner Roller, the Fuser, and the Discharger. Yes, there are many more gears that are turning and switches that are flicking on and off, but that’s for another article.
- Part 2 –Setting a patterned electric charge. The photoreceptor drum can hold an electric charge. The laser rapidly scans across the drum and creates a pattern of letters and characters (either creating a positive electric charge or highlighting the negative space). This is done in rapid succession where the drum will be circulated and discharged by the discharger—essentially, “erasing” the charged sequence.
- Part 3 –Getting toned. Now that the electrical image is set on the drum, it turns past the toner roller where toner is applied. Because the microplastics can hold a responding electric charge, static electricity attracts and holds together the toner where there’s positive electric charge.
Note, this is where the “glue and glitter” comes into play. We warned you it was a simplistic analogy.
- Part 4 – Transferring toner to paper. The drum, now with the toner set, rolls onto the printing page which has been charged with a stronger electric charge. The toner is attracted to the page and then the page is discharged. Now, the toner is sitting atop the page with nothing holding the two together.
- Part 5 – Fusing the toner to the page. Finally, the paper glides through the fuser which consists of two heated rollers and melts the toner to the page.
One interesting note is that the paper doesn’t burn despite the roller being hot enough to melt the toner. This works because different materials have individual rates of thermal conductivity. Thermal conductivity accounts for phenomena like the ability to quickly touch a hot stove and pull your hand away before getting burned.
But that’s enough about the machine, let’s bring it back to the microplastics…
Toner Plastics & Dyes
Styrene acrylate copolymer, styrene butadiene copolymer, polyester resin—what do these terms have in common? They’re all hard to spell and harder to pronounce for the non-chemist. Joking aside, these terms are a result of chemistry nomenclature. Within these terms are “codes” for the chemical compounds that make up the type of plastic used. So, what is printer toner made of, really?
- Polymers – Polymers are linear chains of organic molecules (those with the Carbon atom as the backbone) or inorganic molecules (those without the Carbon atom backbone).
- Styrene – Styrene has a known chemical formula of C6H5CH=CH2. It’s a colorless liquid with a sweet smell that’s used in many plastic formations.
- Acrylate – Acrylates are salts that are commonly used as monomers in polymer plastics.
- Butadiene – Isolated, butadiene is a colorless gas that will condense to a liquid at around 4 degrees Celsius. It is commonly used in synthesizing rubber.
Because most plastics are bland or colorless, toner relies on the dyes and pigments to bring the page to life, not too dissimilar to inkjet ink.
Ink | A Deep Dive
As mentioned above, ink utilized in inkjet printers is equally complex to the toner used in laser printers. And the mechanisms by which the printers use the ink are equally fascinating.
Inkjet Printer | How It Works
The heart and soul of the infamous inkjet printer is the print head, which consists of a series of tiny nozzles that push out a small drip of ink. What becomes fascinating is how the ink actually gets pushed onto the page. There are a lot of problems that using microplastics (toner) instead of a fluid solves. The trouble with aqueous ink is:
- The size and precision of the dot must be tiny and exact. The dots made on the page are about 50–60 microns—that’s smaller than the diameter of hair.
- High resolution typically means about one million dots per square inch.
- The dots also have to be made incredibly quickly.
- Liquid naturally disperses when it’s met with a flat surface.
- Liquids also attract inward. It’s why water droplets are always spheres—the molecules arrange themselves to create polarization.
To combat these phenomena, inkjet printers are set up using one of two droplet systems:
- Thermal bubble – Also known as bubble jet, this technique uses resistors to heat the ink and create a bubble. A tiny amount of ink squirts onto the page through the nozzle, and when the bubble bursts, a vacuum sucks up a little more ink from the cartridge. Because resistors can be heated and cooled quickly depending on if charge is running through them, this ends up being a highly effective method of ink distribution.
- Electric vibration – Another technique to create the ink droplets come from a crystal vibrating back and forth when an electric charge runs through it. This causes a tiny amount of movement, pushing ink out of the nozzle and being refueled by the ink cartridge simultaneously.
Ink Cartridge Ingredients
Ink is a concoction of other commonly unknown compounds from glycol to nitrates to sulfonates. Let’s break these down further to get a better understanding.
- Glycol – A glycol is a set of compounds from the alcohol family (ethylene glycol, propylene glycol, etc.). These are commonly found in liquids with anti-freezing properties.
If you ever wonder why beer and wine freeze in the freezer while vodka or whiskey doesn’t, consider the alcohol content!
- Nitrates – Nitrates are naturally occurring polyatomic ions. They’re common in mixing agents, acids, and fertilizers.
- Sulfonates – Sulfonates are the sulfur equivalent of nitrates. While nitrates’ chemical composition is (NO3), sulfonates are part of a functional group of SO3.
Again, these terms are coded with chemical information that makes it easier to discuss and improve upon in research and development labs. Once the formulas are created, the fun aspect for ink comes from the pigments and dyes.
Pigment Ink vs Dye Ink
Today, the differences between pigment ink and dye ink are hard to decipher. The reason is that both chemical formulas have been improved upon over time to cover the disadvantages of using each. For example:
- Pigment Inks traditionally had a smaller color range and were more expensive to manufacture.
- Dye Inks were cheap and versatile, but they would be ruined by a drop of water (because they were water soluble).
Now, however, the only difference in pigment and dye ink is which your printer prefers.
What is Printer Ink Made Out Of?
Printer ink is a collective term for whatever substance is on the page when it’s printed. The word “ink” implies a liquid, but with today’s modern printer technology, it doesn’t have to be. Toner is made up of tiny microplastics that stick to the page through static electricity and then are melted on. This turns out to create efficiencies where liquid would otherwise be a hassle.
Either way, whether your printer uses aqueous liquid or tiny microplastics, you always end up with the same product… five perfectly done proposals for your team.
If you’d like to know more about how many pages an ink cartridge can print, the different types of printer cartridges or which ink you should choose, be sure to talk to the experts at Supplies Outlet!
HowStuffWorks. How Laser Printers Work. https://computer.howstuffworks.com/laser-printer10.htm
The Engineering Toolbox. Thermal Conductivity of selected Materials and Gases. https://www.engineeringtoolbox.com/thermal-conductivity-d_429.html
HowStuffWorks. How Inkjet Printers Work. https://computer.howstuffworks.com/inkjet-printer.htm
Encyclopedia Britannica. Glycol. https://www.britannica.com/science/glycol