How does a fountain pen work? A fountain pen works because of gravity, surface tension, and capillary action.
The fountain pen essentially has three parts. At the back, underneath the part you hold, is the ink reservoir. This is usually a disposable cartridge, but it can be a refillable one. The cartridges are sealed until you push them into the pin, and the end of the feed section ruptures the end of the cartridge and frees the ink. The second part of the pen is called the feed, and this is the part that gets the ink from the reservoir to the nib and on to the paper. The last part of the pen is the nib, which is the part that brings the ink in contact with the paper. Then, of course, there is the case and the lid that holds all of these pieces together.
When you start writing, you have the pen upright in your hand with the nib pointing down and the base of the pen pointing upwards. Gravity pulls the ink to the bottom of the cartridge and into the feed. The feed has two important parts. The first is a channel that brings the ink from the cartridge down to the nib. This channel is very narrow, and the ink is drawn along it by capillary action. The second is a series of holes that bring air back into the pen. If you cannot replace the space in the ink cartridge with air, you will end up with a vacuum, and the ink will stop flowing. However, the holes have to be the perfect size because you don’t want too much air getting into the cartridge. There has to be enough air pressure to let the ink move out, but not so much that the ink is pushed out. The ink flows down to the nib, which is a shaped piece of metal or plastic. There is a small slit in the nib, and that is as far as gravity brings the ink.
This is part of the magic of a fountain pen. The ink gathers at the end of the nib, but it doesn’t pour off. The surface tension across the ink holds it to the end of the nib in perfect balance. It is only when the pen is placed on the paper that capillary action draws the ink out of the nib. Capillary action is when a liquid is drawn through a narrow space, without the help of gravity. It happens because the spaces are so narrow that the surface tension of the liquid and the connection between the liquid and the channel push the liquid on. Paper is a very porous substance, and the ink is pulled out of the pen into all of the tiny pores on its surface. Once you take the nib off the paper, the ink stops being drawn out and beads at the nib again. The place where the ink collects at the nib is actually called the collector. It is a collection of tightly spaced fins on the underside of the nib that hold the ink.
Early pens were quills or some kind of stylus that could only be used when they were dipped into a pot of ink. They sucked up a little bit of the ink and could only be used until the ink ran out, and then they had to be dipped again. The ink stained the hands and the clothes of the writer. There has long been a search for something to fix this problem, but, as the number of people who could actually write wasn’t that high, there was not so much impetus to invent something. It is said that something like a fountain pen was invented for the fourth Fatimid caliph. He wanted a pen that wouldn’t stain his clothes, and was provided with a pen that worked on ink out of a reservoir. It is also thought that Leonardo da Vinci also invented a fountain pen. He only left drawings and no actual working examples, but his drawings appear to work in a very similar way to modern fountain pens. His handwriting is also consistent with someone using a pen filled from an internal reservoir and not with someone dipping a pen when it runs out of ink. You might think that people used pencils before they had pens, but that is not actually true. Pencils weren’t invented until graphite was discovered in Northern England in about 1560.
There were a lot of advances in fountain pen technology over the 16th, 17th, and 18th centuries. Filling a pen with ink wasn’t difficult, but getting it to flow out at just the right rate to use was. Pens at the time leaked terribly. It took the invention of the feed and the collector to stop drips. Although it was the invention of precision manufacturing and then plastics that really stopped pens from leaking. The invention of ink cartridges helped as well because people didn’t need to keep a bottle of ink with them at all times. Every year, more than 100 million fountain pens are sold. That can be compared to the 5.4 billion ballpoint pens that are sold a year.
Sources
https://en.wikipedia.org/wiki/Fountain_pen
https://cultpens.com/pages/the-history-of-the-fountain-pen
https://goldspot.com/blogs/magazine/when-was-the-fountain-pen-invented
https://en.wikipedia.org/wiki/Capillary_action
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