Pens are fascinating. While they may look very straight forward, there are composed of multiple parts. All which have to fit together perfectly, each with a function to perform. As I have toured the various pen factories, the parts, and the number of them, is something that stayed with me. Rings, particular sections, clips and nibs, they all have to be perfect.
There are a couple of aspects about owning a fountain pen that make it very different from the using a disposable pen.
Pens in some form have been around for a long time. Whether the simplist, a quill. Or later a stick with an iron nib that was dipped. Later, pens had resevoirs which ink was hand-dropped into using eye droppers. Then, the resevoir with ink drawn up into the pen. Over the years the the mechanism of the fountain pens continued to improve.
The first dip pens, with a steel nib was used at one's desk. Ink, bottles, blotting powder or paper were transported with the person to set up a writing table.
The next major innovation was to have the pen body hold ink. These pens generally had problems with ink flow. In 1870 Lewis Edson Waterman invented the now famous system to control the flow of ink from the ink chamber to the nib. He developed a three-channel feed that would allow air to travel up into the ink chamber while ink flowed out.
Pens went through some innovations, an eyedropper was used to get the ink into the ink chamber. Then the pens progressed so that the ink would be drawn up into the pen body through the nib.
Since that time there have been innovations in terms of the materials used to make the pens, however, the basic workings of the pen remain fairly consistent.
The links below provide further information about fountain pens.
I am not a chemist, but as it has been explained to me, celluloid is a vegetable derivative that is produced by combining cellulose with nitric acid and camphor.
It produces beautiful pens, but has it challenges in terms of a material to work with. The companies I have visited all showed how they store their celluloid rods in steel cabinets, or separate buildings, outside the main factory. That is because it is so unstable. I can attest to the pronounced small of camphor from the rods.
The curing is the skill. If the celluloid is not cured correctly, the celluloid will continue to loose moisture and shrink. The pieces are places in trays in ovens and baked for very long periods of time, at low temperatures.
When I visited with OMAS they explained the process in detail. It takes about 350+ days to make a celluloid pen.
A nib pen that, unlike its predecessor, the dip pen, contains an internal reservoir of liquid ink. Ink flows from the reservoir through a feed to the nib. It flows from the nib to paper through a combination of gravity and capillary action. An eye dropper can be used to fill the reservoir, or through a filling mechanism which creates suction (e.g. piston mechanism) or a vacuum to transfer ink directly through the nib into the reservoir. A fountain pen can use a removable reservoir, a cartridge.