Is There An Ink Viscosity Test?

[old4570]

Is there a ink viscosity test that easily repeatable or do-able !

 

I had an idea along the lines of , printer paper ... Put one drop of in on the paper and see how long it takes the drop to be absorbed ..

( For comparison - one ink VS another )

 

????

Edited July 10, 2018 by old4570

[Chrissy]

That would only tell you how long it takes for a drop of ink to be absorbed on your particular printer paper. And can you get the drops to be the same size?

 

I'm not sure of what value it has in comparing two inks against each other that writing with them both, using the same pen on many papers, will tell you.

[Tweel]

I don't think you'd get a very good correlation between viscosity and absorption time. I'd think that the presence or absence of surfactants in the ink, for example, would swamp the effect of viscosity.

 

You could improvise the equivalent of a paint viscosity cup, with just a little pinhole in the bottom so the ink doesn't run out too quickly to accurately time.

[old4570]

I don't think you'd get a very good correlation between viscosity and absorption time. I'd think that the presence or absence of surfactants in the ink, for example, would swamp the effect of viscosity.

 

You could improvise the equivalent of a paint viscosity cup, with just a little pinhole in the bottom so the ink doesn't run out too quickly to accurately time.

Hmmm , Now that sounds interesting ...

Yes , a container with a small hole and a set volume of ink .. Hmmm , I will have to test that ..

( Writing ) Im not that sensitive to the ink ...

 

Lover viscosity should under the same conditions be absorbed by paper faster .. But yes other factors may influence absorption rates , there by giving false data on viscosity .

For example , how quickly the ink dries .

[amberleadavis]

Also, you need to check for surface tension, when you put an ink in a tiny converter it may flow great, but put it in a giant TWSBI and the ink may not flow. Surface tension in my opinion is worse than viscosity for pen troubles.

[old4570]

Also, you need to check for surface tension, when you put an ink in a tiny converter it may flow great, but put it in a giant TWSBI and the ink may not flow. Surface tension in my opinion is worse than viscosity for pen troubles.

Hmmm , that might be an environmental variable ...

So any ink put in such an environment would need to deal with said conditions ..

 

ATM I am interested in testing Viscosity , that would mean replicating a FP as well as possible .

I have some Small containers ( Vials ) , made of plastic ( hard ) .. I should be able to drill a small hole that maybe lets out water in ( ? ) , target might be 30 seconds ( ? ) .

Ink should flow slower than water , hopefully returning a meaningful result .

[Noihvo]

 

[A Smug Dill]

ATM I am interested in testing Viscosity

…‹snip›…

hopefully returning a meaningful result .

 

 

But why? What's a meaningful result to you, when you are essentially talking a bunch of numbers (each correlating to a different ink) that is either largely devoid of context or with too narrow of context, since there are effectively countless combinations of nib, paper and n-tuple of environmental factors but you're proposing to test on (one particular batch of) one particular type of paper and ‘replicating’ or modelling the performance of just one particular nib? I cannot even begin to think all the different parameters for a nib; I have three Platinum #3776 SF nibs and they don't all perform identically, so there must be parameters outside of brand, model, material and (category of) broadness to consider.

[Corona688]

But why?

Always an amusing question. If he had a good answer, he wouldn't need to ask.

 

I suspect he's trying to figure out how viscous a good ink is supposed to be - what he ought to be aiming for.

 

If it helps, I suspect most inks have a surface tension near that of water. Inks with less surface tension aren't effective in climbing up a feed.

Edited August 21, 2018 by Corona688

[A Smug Dill]

A good ink should be vicious enough to make even the most belligerent squids duck for cover!

[OCArt]

I was browsing a German pen forum and found measurements of surface tension and viscosity of Lamy, Montblanc, Pelikan inks and water. I don't feel right about quoting the data without the author's permission but you can see the information and discussion here http://forum.fountainpen.de/index.php?topic=4269.0

 

(I used Chrome browser to translate into English)

[A Smug Dill]

ATM I am interested in testing Viscosity , that would mean replicating a FP as well as possible .

What would it mean that? The viscosity – as a metric of which the values can be objectively determined and expressed – of a writing ink (or any liquid, for that matter) is independent of whether the ink is inside and/or used in a fountain pen.

 

( For comparison - one ink VS another )

If what you really want to know is some specific aspect(s) of writing performance of an ink when used in a fountain pen, but you want to make things simple by reducing that to a scalar value for comparison purposes, then the metric you choose ought to be:

v = f(x₁, x₂, x₃, ... , x_n)

where viscosity is just one of the many input variables x_i to the function f, and probably not even the most important of the input variables.

 

The comparison (subsequently, by the reviewer of the output of all that testing) will be simple if a disproportionately great amount of work had gone into the test design

and test execution upfront. Whether it's worth distributing the total effort required that way depends on how many times and by how many individual reviewers you expect the comparison part of the work to be done.

 

I was browsing a German pen forum and found measurements of surface tension and viscosity of Lamy, Montblanc, Pelikan inks and water.

I still don't see how it would meaningfully inform a fountain pen user of how an ink will perform, or address any other practical concern he/she may have with regard to the handling and use of the ink.

 

At least the following comparison is more meaningful:

 

Platinum originally published that chart in its marketing collateral, although I can no longer find a web page on its web sites today displaying that type of information. It can easily be adapted to comparing different inks, instead of differently sized Platinum #3776 nibs, while holding other variables as constant as can be practicably achieved; the total writing 'distance' will inform readers/reviewers of the resulting ink comparison chart how well each ink flows when used with the specific test equipment including the pen. (Of course, the nib tipping will probably wear out sooner or later, and it will be hard to quantify the influence of that aspect on the metric.)

 

Is there a ink viscosity test that easily repeatable or do-able !

 

It would easily do-able and repeatable if you've invested sufficiently in test methodology, equipment and automation in the first place. Flush clean and dry the test pen, fully fill one of the hundreds of new and uncontaminated cartridge shells with the ink you want to test, plug it onto the feed of the test pen, then start the machine that will do the many-hundreds-of-metres of 'writing' or line-drawing for you, and inspect the output afterwards over the many-hundreds-of-metres of paper consumed with each test.

[Honeybadgers]

I think the OP is more confusing viscosity with surface tension.

[azbobcat]

I don't think you'd get a very good correlation between viscosity and absorption time. I'd think that the presence or absence of surfactants in the ink, for example, would swamp the effect of viscosity.

 

You could improvise the equivalent of a paint viscosity cup, with just a little pinhole in the bottom so the ink doesn't run out too quickly to accurately time.

Sorry to "sink" that idea. That is the idea behind the "water clock" the problem with that idea is that when the cup is full the water will exit more quickly than as it does when there is little water left in the cup. The only way to solve that problem is to insure that the tank is always full so that the presure in the cup or tank is always constant. The other problem is you would have to have a reference. Part of the reason the metric system works is that it is independent of where on the face of the earth you do the measurement 1 gram will always equal 1 gram, yet 1 pound will never always 1 lb depending upon where you make the measurement. Without a defined standard the rest falls though

[A Smug Dill]

I think the OP is more confusing viscosity with surface tension.

I could understand someone jumping to the conclusion that viscosity is the most relevant physical characteristic of the ink as a liquid, independently of anything pertaining to the filling mechanism and apparatus in a fountain pen, that would inform a prospective user of that ink how it would flow and/or write in a pen.

 

The best thing a peer in the user community can do for that person is not encouraging him or helping him with devising methods of measuring viscosity – or even point him to a partial list of already established results – but tell him he's wrong, why he's wrong, and send him back to the drawing board for the actual endeavour to produce the intended analysis.

 

Whether surface tension is more relevant than viscosity in how quickly a drop (or some volume) of ink is absorbed by a piece of paper is just letting him lead himself astray up the garden path, I'm afraid.

[BaronWulfraed]

Part of the reason the metric system works is that it is independent of where on the face of the earth you do the measurement 1 gram will always equal 1 gram, yet 1 pound will never always 1 lb depending upon where you make the measurement. Without a defined standard the rest falls though

Somewhat misleading. The gram is a unit of MASS (an inertial quality). The pound however is a unit of weight/force, not mass. The [imperial system] unit of mass is called the SLUG https://en.wikipedia.org/wiki/Slug_(unit) One slug will be a slug anywhere in the universe. The metric system unit corresponding to the pound is really the Newton.

Edited December 21, 2018 by BaronWulfraed

[amberleadavis]

I was browsing a German pen forum and found measurements of surface tension and viscosity of Lamy, Montblanc, Pelikan inks and water. I don't feel right about quoting the data without the author's permission but you can see the information and discussion here http://forum.fountainpen.de/index.php?topic=4269.0

 

(I used Chrome browser to translate into English)

 

 

That information is very interesting. Thank you.