Scientific American Article From 1959, On Ink-Nib-Paper Relationship

[TenBladeSummitar]

An interesting article from Scientific American New Scientist (edited - thanks to those who pointed out the error), 1959, outlining the history of the development of quick-drying fountain pen ink, and how the ink and paper interact to influence perceived feathering or line spread. It also is clear how ink recipes can affect pen components or reliability thereof.

 

http://bit.ly/Science_of_Quick_Drying_Fountain_Pen_Inks

Edited June 16, 2019 by TenBladeSummitar

[BaronWulfraed]

The pages indicate they are from the British "New Scientist", NOT US "Scientific American"

Edited June 15, 2019 by BaronWulfraed

[silverlifter]

Thanks: that was an interesting read!

 

Correction: Scientific American New Scientist

[Tweel]

That was a very interesting read. It essentially outlines the composition of Parker inks such as Superchrome, and reveals the function of their ingredients such as amyl xanthate, which I've often thought was the mysterious Solv-X, plus other puzzles you find in Parker ink patents such as bentonite (clay!).

 

Thank you! I hope plenty of people find this thread and link.

Edited June 15, 2019 by Tweel

[amberleadavis]

I know it's been years, but this was very helpful.

[dipper]

Thanks @amberleadavis for bumping this topic into view. ( I failed to notice it in 2019. )

 

The New Scientist article has relevance to the current topic "An alternative look at ink wetness".

....the well-known fact that solutions of strong alkali penetrate well into cellulosic materials such as paper ...

So increased wetness ( as measured by @InesF ) is predicted with increased pH, independent of surface tension effects.

 

.... it was realised that ... the trouble could not be ascribed to too low a surface tension. Eventually it was discovered that the alkaline ink had a zero angle of contact with the metal of the nib ... flooding occurred.

That is another current issue in pen and ink wetness investigations. "Surface Tension" (of an ink) is a tension value specific to a liquid/air interface. That value alone does not define behaviour at a liquid/solid/air interface or junction. Knowing also a "Contact Angle" value does complete the picture.

Zero angle of contact at a liquid/solid/air junction means that the solid is highly wetable by the liquid.

 

.... quick-drying alkaline inks are unlikely to supersede conventional inks ....

The reasons given for that prediction have all been overcome since 1959.

 

More expensive? We are much more affluent now than in 1959 UK (I was there, and remember how grey everything was).

 

Special nib alloys needed? Stainless Steels of many types now readily available.

 

Need polymethacrylate pen bodies instead of nitrocellulose?

(Actually "celluloid", made from nitrocellulose & camphor.)

We now do have "acrylic" (acrylate polymers) as a common pen material, and celluloid has ceased to be used!

 

But Dr W.R.Harrison can be excused. A lot has changed in 63 years since his 1959 article in New Scientist magazine.

The magazine is still in regular weekly production here in UK.

 

[amberleadavis]

@dipper Thank you for the comparison with the new findings from you and @InesF. You two could probably publish your work. 

 

[InesF]

On 5/8/2022 at 2:03 AM, dipper said:

... it was realised that ... the trouble could not be ascribed to too low a surface tension. Eventually it was discovered that the alkaline ink had a zero angle of contact with the metal of the nib ... flooding occurred.

That is another current issue in pen and ink wetness investigations. "Surface Tension" (of an ink) is a tension value specific to a liquid/air interface. That value alone does not define behaviour at a liquid/solid/air interface or junction. Knowing also a "Contact Angle" value does complete the picture.

Zero angle of contact at a liquid/solid/air junction means that the solid is highly wetable by the liquid.

 

10 hours ago, amberleadavis said:

@dipper Thank you for the comparison with the new findings from you and @InesF. You two could probably publish your work. 

Thank you @dipper and @amberleadavis for digging out this thread and for commenting. I have bookmarked the article for later careful read. There seems to be significant information published - looking forward what to find in between the lines...

 

The difference between liquid/air tension and liquid/solid contact angel is something that rises more questions about ink behaviour during handwriting. Investigating the same solid material, in theory, the proportion between these two properties should be constant (or predictable in mathematical terms). But nib materials and tipping materials can vary a lot! While I do not expect a total opposite behaviour between different fountain pens, some variation (also in the ink wetness measurements) is possible.

Finally: that's a good reason why doing such investigations by keeping all other factors constant while observing dependencies between only two or three.

 

PS: the ink wetness manuscript is now accepted for publishing! 

[A Smug Dill]

34 minutes ago, InesF said:

PS: the ink wetness manuscript is now accepted for publishing! 

 

That is wonderful news! 👏 😃

[amberleadavis]

14 hours ago, A Smug Dill said:

 

That is wonderful news! 👏 😃

 

That is AWESOME!!

[dipper]

13 hours ago, InesF said:

The difference between liquid/air tension and liquid/solid contact angel is something that rises more questions about ink behaviour during handwriting. Investigating the same solid material, in theory, the proportion between these two properties should be constant (or predictable in mathematical terms).

A clarification, and (apologies) a bit of a damper on the hope for proportionality and predictability....

 

The molecules of a liquid are strongly attracted to each other. (If not so, then they would be a gas.)

In the absence of anything else interferring to complicate things, one result of molecular "cohesive" forces is surface tension. Nice and simple. More cohesion ... larger surface tension at a liquid/air interface.

 

The molecules of a liquid may also be attracted to any solid that they come into contact with (rubber, plastics, glass, metals, paper, etc).

 

There is then a tug-of-war between "adhesive" forces, pulling the liquid towards the solid, and "cohesive" forces trying to hold the liquid together as a compact blob. Results include the "Contact Angle" at a liquid solid air junction and "wettability".

(For instance, at the edge of an ink patch, extending out from under a pen nib, being pulled out onto the solid paper, whilst also being pulled in towards itself.)

 

Unfortunately there does not seem to be any simple relationships between the strengths of cohesion and adhesion when different pairs of liquid and solid are examined. A solid that has a relatively high adhesive force with one liquid may display a relatively low adhesive force when paired with a different liquid.

It would be nice if each solid and each liquid had just a single value of "attractiveness" that would apply to whatever other substances they might interact with. But unfortunately things are not that straightforward.

The reasons why that is so is best explained by a chemist. Molecules are darned complicated things. Sometimes the two ends of one molecule will totally disagree with each other about what other substances they find attractive! Very confusing for us, though usefull for doing the laundry (detergents).

 

If we allow the liquid (ink) to be a mixture of components, all sorts of crazy things can happen. For example, in the New Scientist article, surfactant (wetting agent) molecules in ink were found to be gathering together at the ink air interface in the nib tines slit and slowing evaporation.

 

Result of all this confusion of forces is that we have to look-up in reference tables what value the contact angle is between any given pairing of a specific liquid and a specific solid.

That does not seem so bad. After all, there are lots of measurements being made and published.

But even the references reveal more complications.

Here are two example complications relevant to fountain pens:

1) Contact angle can be two different values, depending on whether the liquid edge is advancing or retreating. So when ink decides to stay "locked" up at the back end of a converter we could blame a large "advancing" contact angle.

2) Contact angle for Water/Gold is something very low (=highly wettable) but the table listing that result describes the gold surface as being specially cleaned. For "normal" gold, with some slight surface contamination allowed, the same table gives a rather wide range of possible values, all being larger contact angles (not so wettable then).

 

This can all become too much for mathematical calculations to handle. Or, if the maths is within our scope, then the simplifications, assumptions, and approximations used can give calculated results far removed from what actually happens when nib and ink meet paper.

 

I am currently wrestling with ink columns rising up in extra-narrow bore capillary tubes (160mm rise and more!) The maths is simple. You can even look it up on Wikipedia. But my extra-narrow tubes are doing exceedingly strange things that I have no explanation for.

🤔🤔🤔😣🤣🤔🤔🤔

[LizEF]

1 hour ago, dipper said:

Sometimes the two ends of one molecule will totally disagree with each other about what other substances they find attractive!

Multiple personality disorder?

 

1 hour ago, dipper said:

This can all become too much for mathematical calculations to handle.

So, we're back to:

  

On 8/31/2021 at 3:49 AM, InesF said:

I'm not sure which one would be solved first, either the great universal theory of the Universe or the great universal theory of ink wetness.

 

1 hour ago, dipper said:

But my extra-narrow tubes are doing exceedingly strange things that I have no explanation for.

Did you by chance leave the liquor cabinet unlocked?

[amberleadavis]

[InesF]

On 5/8/2022 at 2:03 AM, dipper said:

The New Scientist article has relevance to the current topic "An alternative look at ink wetness".

....the well-known fact that solutions of strong alkali penetrate well into cellulosic materials such as paper ...

So increased wetness ( as measured by @InesF ) is predicted with increased pH, independent of surface tension effects.

Thank you @dipper for pointing at this part of the article.

Meanwhile I have read it carefully and I'm surprised by some of those facts which contradict to my own measurements. Unfortunately, I didn't have found the New Scientist article before completing my own manuscript.

 

Interpreting the text from 1959 and the image of ink lines (drawn with flex nibs), an alkaline ink should spread more because of rapid distribution along paper fibres (in all directions), resulting in a quick disappearance of the "wet" surface. Such a line should look flat and the writing impression should be "dry".

Comparing to my own measurements which were done with ink compositions of 2020 to 2021, the acidic inks showed slightly increased feathering and increased delivery amounts per ink line length. At the high end, the highest pH was much lower than what was seen necessary in the 1959 article with none of them increased feathering more than the expected caused by surface tension.

 

The use of copper and vanadium salts in alkaline inks was a big surprise. No surprise was destroying cellulose pen bodies and nib points with pH 11.6 (why should the ink have high affinity to paper cellulose and no affinity to pen body celluloid?)

 

Unfortunately, the article ends before the story ends. There are many questions left open. Quick drying inks of the 1959 mentioned composition did not make it to modern times, despite the rise of plastic pen bodies. Comparably high pH (around 8.5 to 10) of some Japanese inks (Iroshizuku, Sailor ink studio) combined with comparably low surface tension does point in the same direction as the New Scientist article. Maybe other components of a modern fountain pen ink can replace excess alkali with a similar effect on paper but avoid corrosion and feathering.

 

Indeed, the Great Universal Theory of the Universe seems to be simple compared to ink dynamic on molecular level.  

[LizEF]

I feel like we should do some cross-linking:

 

[bidn]

On 6/15/2019 at 11:31 AM, TenBladeSummitar said:

An interesting article from Scientific American New Scientist (edited - thanks to those who pointed out the error), 1959, outlining the history of the development of quick-drying fountain pen ink, and how the ink and paper interact to influence perceived feathering or line spread. It also is clear how ink recipes can affect pen components or reliability thereof.

 

http://bit.ly/Science_of_Quick_Drying_Fountain_Pen_Inks

Thank you,

unfortunately the article was removed from the page, and I can't find it on the internet.
Would someone have saved a pdf and could make it somehow available?