TAU1: Mysteries of a fountain pen

 THINGS AROUND US 

1.Mysteries of a fountain pen

The noblest pleasure is the joy of understating

- Leonardo da Vinci 

Fountain pen or a ink pen is a commonly used writing instrument.The early history of fountain pen is not clear but there are some evidences that  during the renaissance Leonardo da Vinci might have created a fountain pen because his notebooks had drawings of a modern fountain pen. Then from 17th century fountain pens were used in Europe,those were some basic models. Finally in  may of 1827 the Romanian inventor Poenaru received a French patent.

Parts of a Fountain pen

1.Ink reservoir: It is the part in which the the ink is stored. In modern fountain pens it is called as cartridge. Even though there are many filling mechanisms I personally use a injection to fill the ink.

2.Nib: Nib is the most important part of a fountain pen. It it is very similar to a V shape. The modern nibs are made using alloys to provide strength for long term usage. The nib is usually coated with gold or silver as it as a good property of wettability, which is the property of the solid to reduce the surface tension of the liquid in contact and spreads over it. All the nibs has the important parallel slit cut at the middle which is responsible for the capillary action and flow of ink.

3. Feed: It is the component that connects the ink reservoir and the nib. It has two functions. one is to regulate the flow of ink to nib and second regulating the air flowing back to the reservoir to replace the ink lost. (So in vacuum ink pens don't work). This feed mechanism also prevents the leakage of link. usually a feed had lots of divisions and has a rough surface.

How does a pen really works?

The physics behind it.

• Capillary

Capillary is a important concept in our life, the human body is functional because of the capillaries. 

Capillary or capillary action is the ability of the liquid to flow through a narrow tube or space without the assistance of any external force and opposing the other external force like gravity. This action can be seen in many place from plants drawing water from ground to liquid between the hairs of paint brush. Why this happens? When the diameter of the tube is small enough( Like smaller than the the diameter of hair i.e. 0.00011 m ) ,then the surface tension of the liquid and the inter-molecular of the liquid and the adhesive force (tendency of dissimilar surface or particles to stick together) between the walls of the tube and the liquid try to propel the liquid.

      FACT: THE FIRST CAPILLARY ACTION WAS OBSERVED BY DA VINCI.

• Capillary action in the fountain pen

The liquid(ink) is present in the cartridge. The feed prevents the ink to flow out from the nib when it is not in contact with the surface of the paper. When the nib is contact with the surface of the paper it the nib expand slightly creating a opening which is very similar to capillary tube thus causing the ink to flow from the feed to the tip of the nib and the ink is adsorbed by the surface of the paper.This is the capillary action of the fountain pen.

Due to this reason when the slit in the nib becomes large the ink does not flow and if the slit is closed the ink will not flow as the capillary action don't take place.