How do ball point pens work?
Ballpoint pens are also known as ‘biros’ in Britain and Australia and they carry with them a long history of development.
If the sources are to be believed, then as early as the 17th century, the famous astronomer and mathematician Galileo Galilei was trying to figure out alternative writing instruments. The first patent of a writing instrument which resembled modern day ballpoint pens was issued to a leather tanner, John Loud, in the year 1888. But the instrument was too crude for a paper. The development continued and in 1940, the Biro brothers of Hungary along with their friend, Juan Jorge Meyne, founded a company “La Compañía Biro-Meyne-Biro” and for the first time, made ballpoint pens available commercially. They named the pen ‘Birome’ (an acronym formed from the names Biro and Meyne).
The ballpoints pens consist of an ink cartridge (a reservoir), a socket and of course, a ball! And it works like this: at one end of the ink-cartridge lies a solid sphere of metal (a ball) which is adjusted in such a way that it can neither get into the cartridge nor fall out of it.
The ball is the most crucial element of a ballpoint pen. It remains in contact both with the ink and the surface one is writing on. The ball rotates when we write on the surface and in the course of its rotation it takes ink from the reservoir, transfers it to the surface and leaves an impression on it.
It is simple enough in theory, but in practice, the designing of a ballpoint pen is not that simple. For example, ordinary fountain pen ink can’t be used in a ball point pen. Reason: the viscosity of a fountain pen ink is low. The denser a liquid, the higher is its viscosity.
The second most common problem that a ballpoint pen engineer faces is to make sure that the ink doesn’t flow backwards when the pen is held upside down. The reason again lies in the ink. If the ink chosen is viscous enough ‘capillary action’ will hold it in place.
Category: Technology