How does Uniball Fusion ink chemistry work?

[NeoPTLD]

I bought some Uniball Fusion pens. Eh... I didn't really need them, but I bought them anyways because it was nothing like what I've seen before and I think this is exactly what they want the consumer to do. Oh well.

It is built like an ordinary Uniball. There is a transparent reservior that let you see the ink inside and there is a plastic thing between the pen tip and the reservior that looks somewhat similar to a high voltage porcelain insulator.

What makes it unique from anything else is that the ink inside the reservior is a clear fluid with mineral oil like viscosity. They're available in a few colors and they all hold a clear liquid in the reservior, but once it hits the tip, it turns to its respective color. It writes like the older uniball and the clear ink has no delay at all for the color to develop.

Anyone have a clue how this thing works?

I have four possibilities in mind.

1. It's really got a hidden reservior filled with the writing ink color.
2. Ink reacts with air
3. Catalyst develops it into color in high surface area, porous catalyst near the tip and keep the ink near the tip developed to the color of pen.
4. It develops color upon being exposing to pressure as the ball rolls around.

 

[DrPizza]

1. I don't know.

2. Each of your hypothesis are fairly easy to test.
Take the pen apart... see if there are any hidden reservoirs. See if the ink reacts to air. See if the ink reacts to pressure.

 

[Mday]

Originally posted by: NeoPTLD
I bought some Uniball Fusion pens. Eh... I didn't really need them, but I bought them anyways because it was nothing like what I've seen before and I think this is exactly what they want the consumer to do. Oh well.

It is built like an ordinary Uniball. There is a transparent reservior that let you see the ink inside and there is a plastic thing between the pen tip and the reservior that looks somewhat similar to a high voltage porcelain insulator.

What makes it unique from anything else is that the ink inside the reservior is a clear fluid with mineral oil like viscosity. They're available in a few colors and they all hold a clear liquid in the reservior, but once it hits the tip, it turns to its respective color. It writes like the older uniball and the clear ink has no delay at all for the color to develop.

Anyone have a clue how this thing works?

I have four possibilities in mind.

1. It's really got a hidden reservior filled with the writing ink color.
2. Ink reacts with air
3. Catalyst develops it into color in high surface area, porous catalyst near the tip and keep the ink near the tip developed to the color of pen.
4. It develops color upon being exposing to pressure as the ball rolls around.

chemical reaction with something in the air.

 

[Cogman]

Has to be a chemical reaction. Im guessing with the air or some chemical used to make the paper. One of the signs that a chemical reaction has taken place is a change in color. Another is heat so if you want to feal the paper while writing 🙂.

 

[NeoPTLD]

Originally posted by: DrPizza
1. I don't know.

2. Each of your hypothesis are fairly easy to test.
Take the pen apart... see if there are any hidden reservoirs. See if the ink reacts to air. See if the ink reacts to pressure.

I'm asking here, because I don't want to take them apart. I just got them and they're kind of expensive. $4 for a two pack.

 

[DrPizza]

I'll vote for chemical reaction then. Most likely, with the oxygen in the air. I spent a couple of minutes actually trying to find info online, and discovered that $4 for 2 is too much 🙂

On a side note: Imagine if you could get enough of the stuff to fill a clear balloon. Make a clear ink balloon and allow someone to play with it... 😀

 

[Particle Man]

Reminds me of those secret decoder pens with "invisible ink" and "decoder ink." I believe it is a simple chemical reaction similar to lemon juice on paper when exposed to heat.

There are many types of metal complexes that will change color in air or with a different solvent, almost instanteously. That is probably why that the ink cartridge is very well protected.

 

[Mday]

Originally posted by: DrPizza
I'll vote for chemical reaction then. Most likely, with the oxygen in the air. I spent a couple of minutes actually trying to find info online, and discovered that $4 for 2 is too much 🙂

On a side note: Imagine if you could get enough of the stuff to fill a clear balloon. Make a clear ink balloon and allow someone to play with it... 😀

i am thinking it's the nitrogen. i could be wrong.

 

[everman]

Well you could always cut one open to find out. Either reaction with the air, or the actual ink is is hidden.

 

[DrPizza]

Originally posted by: Mday

Originally posted by: DrPizza
I'll vote for chemical reaction then. Most likely, with the oxygen in the air. I spent a couple of minutes actually trying to find info online, and discovered that $4 for 2 is too much 🙂

On a side note: Imagine if you could get enough of the stuff to fill a clear balloon. Make a clear ink balloon and allow someone to play with it... 😀

i am thinking it's the nitrogen. i could be wrong.

Woohooo! we've got an experiment to perform!