The Writing Machine

How does a Ballpoint Pen work? One way of explaining it is to describe its components: the ink cartridge, the ball, and the socket. Another way is to describe the process of writing.

The primary component of a ballpoint pen is the ball, that is why it is called a ballpoint. It is the buffer between the paper and the ink inside the long plastic tube called the ink cartridge. The ball rotates through the socket so that the ink is fed from the ink cartridge to the ball without spilling the quick-drying colored liquid.

The socket is perhaps the critical part of a ballpoint pen. It is designed to make the ball rotate freely, thus getting ink from the cartridge and leaving a mark on the paper simultaneously, once it touches the surface. It also keeps the ball in place so as to prevent the ball from getting into the cartridge or falling out from the socket.

As the ball uses the ink from the outside face of the ball, the ink fills up the inside face so that the pen will write when it rolls out. However, the ink used by a ballpoint pen is thicker than any other pens with the purpose of avoiding the ink to leak out from where the ball and socket fit together. Also, the ink is protected from drying up because of the the ball that is sealed at the socket.