How Does a Ballpoint Pen Work?
The classic "Parker" ball pen is a steel or part steel outer, with a self contained inner ink cartridge. But how does it work?
The point of the pen is a ball floating on ink. When you write you can, under some circumstances, start to create uneven wear on the area supporting the ball. You will then get the classic globs of ink that smudge, make the page untidy or get on your fingers or clothes. The way to avoid this is to use the button at the top of the ball point pen to close and open the pen.
This is because there is a shaped plastic top to the cartridge. When you "click" the pen, it spins the cartridge around a few degrees. When you then write, you will create an average amount of wear on the point, and avoid the messy splodges of ink.
The inner or replacement cartridge is also quite interesting. An amount of grease site on top of the ink, separated by it's density. As you write and use up the ink, the grease pushes the ink down, and cleans off the side of the inner. The grease acts as a push to make sure you get as much out of the inner as you can.
Some people like to see how much ink they have left. By inserting a paperclip through grease layer, you make a hole and cause damage to the inner, so that ink will mix and over fill the grease. You also will not see exactly how much ink is there - as you pull out the paper clip, the grease cleans off the ink.
Pens now work upside down, fresh from the freezer, and even underwater.