How does a ballpoint pen work?
Designed to be as easy to use, and reliable as a pen can get, the ballpoint pen has some seriously sophisticated technology inside.
The ink is oil based, which mixes with the dye to create a smooth, quick drying paste, that will write on most things, this ink is kept in an internal reservoir, which can be either pressurized (allowing the user to write upside down, otherwise known as a space pen) or non pressurized, relying on gravity for the feed. Refillable ballpoint pens allow for this entire reservoir to be removed, disposed of and replaced by another, whereas a disposable ballpoint will have it fixed in place.
The mechanical structure that creates the ‘ball point’ is essentially a metal ball, held in a socket with small ink channels in, which will feed the ink from the reservoir to the ball. The tolerances of these parts is so small that it requires high precision machines to produce in a way that will write reliably, however over many years of mass production, this process has been refined to a point where they can be created in bulk, for a low price.
As a ballpoint pen doesn’t need a cap, the retraction mechanism is really just to keep the ball protected, and varies by brand, some choose a click mechanism , while some go for a twist of the cap.
Today, the reliability is consistent, and ballpoint pen manufacturers look to differentiate themselves by adding features like touch screen stylus’ to the end, or in fine writing, by designing them with precious materials, or in a trim to match their fountain pen counterpart.