A small test

[Lukew]

Can you tell me what this means & which would be classified as the most suitable. Possibly it means jack & I've just wasted a small period of my time.

Today I had eight small glass jars with lids & four different brands of fountain solution. I partly filled four jars with each concentrated fountain solution, then the remaining four jars with each premixed(press ready) fountain solution.

I then added a very small blob of ink to the concentrated FS jars, and observed.
I noted that three of the four jars the ink sank to the bottom of the jar after a small period of time. One jar the ink continued to float.

I then put the lids on the jars and gently agitated them and noticed that the jars where the ink had sunken to the bottom, the ink started to break up with little particles of ink floating around in the concentrated fountain solution mixture, once left to settle they would drop to the bottom of the jar.

The Jar where the ink had continued to float, once agitated the ink stayed intact & there were no particles, once the jar was left to settle the ink would float to the top again

I left these jars on the bench and went onto do the same test with the premixed fountain solution jars. Noting the same results as prior, but on a slightly slower rate.

Looking back at the original jars you could see the ink blob dissipating in three jars and effectively melting into the FS, but one jar the ink was still intact and floating.
The same results happened with the premixed fount after a period of time.

 

[easiprint]

Can you tell me what this means ...

That you have too much free time on your hands ???

Sorry, couldn't resist!!

 

[UK Printer]

I second that

Tim

 

[Dan Roll]

We used to call this the 'peanut' test as you dropped a pea size drop of ink into the liquid of your choice and then went nuts trying to figure out what it meant. There are so many factors that complicate this that I regard it as a waste of time. I was presented with a rather extensive 'peanut' test presentation done by a researcher for a large plate company at a now closed facility north of Denver CO long ago. They had evaluated a lot of fountain solutions and alcohol substitutes with magenta ink (a sheetfed ink, I forget whose it was) but had neglected to match each test done with a control done in plain water. To make a very long story less long, the ink they had chosen was revealed to contain a water soluble dye to adjust the color of the pigment. The ink maker was unaware of the presence of this material in the pigment, the pigment was sold to them based on the accuracy of its shade. The less water the samples tested contained, the less red they turned, with the pure water sample looking like cherry Kool-Aid. All of this had nothing to do with how the ink ran or the quality/fitness for use of the fountain solutions or alcohol substitutes.
The best test instrument for ink and fountain solution compatibility is a printing press.

 

[Kaoticor]

GATF does have a procedure for a test like this, seeing if you are getting pigment bleed. If I remember right, tests were done with different concentrations of fountain solution as well as with straight water, then the beakers were drained through a filter to see if the pigment was bleeding in to the fountain solution. It's been years since we did this here, but I seem to recall a certain type of ink that we were ordering that was extremely unstable and when this test was done, it showed a horrible bleed from the fountain solution. I don't think it would be necessary in every circumstance, but perhaps with the right conditions, it could prove useful.

 

[Alois Senefelder]

The Devil finds work fo Idle Hands !

The Devil finds work fo Idle Hands !

Lukew,


You seem to have a lot of idle time on your hands !!!


Anway follow this link to a PDF page 4 of the thread: Postive Ink Feed etc

http://printplanet.com/forums/sheetfed-web-offset-discussion/22836-positive-ink-feed-simulation-test


Regards, Alois

 

[Dan Roll]

I used to work with a guy (he is still in the ink business) who at the time believed so strongly in the Surland Water Pick-Up test he had his own personal Duke machine, set-up to be portable so
he could take it with him when visiting customers. The problem was, often he would do pick-up tests on-site and pronounce a particular ink/fountain solution combination to be incompatible while it was running trouble-free on a press right next to him. To be fair, his results were right as often as they were wrong/. I collected many hundreds of Duke results back in the early nineties and when graphed they are literally all over the chart. Looking back, I do not think they ever meant anything, but they kept a patient lab technician busy for years. A lack of trust in the Surland method eventually led to the development of the Kershaw device, but I am afraid the results produced by this method are no more predictive than any other 'bench' test.

It is too bad on-press testing is so expensive (the cost of an adequate amount of paper is usually the problem) leading to press testing, when done at all, to be done on ridiculously short runs. A plate company in England invested a lot of money in a fountain solution (I was involved in a brief dispute with them over the trade name they and I were using at the time) they proved in press testing to clean up better than anything else, but the runs during the testing were limited to 50 impressions. This would have worked out great for them if you could have printed more than 75 impressions without totally stripping the rollers and blinding the plate, but this problem only showed up when they sold the product to customers.

We used to joke about the 'FountainSolutionoMeter', a device you could put a 50m of fountain solution in, push a button, and get a result calibrated in dollars of how much of it would be sold over the next ten years with no formula modifications. Every boss I have ever had in the fountain solution business seems to think I have such a device and I only withhold the results due to my embarrassment over the low numbers.

 

[Lukew]

That you have too much free time on your hands ???

Sorry, couldn't resist!!

A sign of the dwindling industry I guess.... You can only do so much maintenance, set the rollers so many times. The day prior I had 18 four colour make readies and a two PMS colour make ready. Just a pity this isn't an everyday occurrence.

So effectively I have wasted my time.. Should note that each of the three fountain solutions where the ink sank, they all sank at varied timeframes.

Some also the ink bleed into the fountain solution faster then others.

Tested the ink in straight water and it doesnt disolve into the water

 

[Lukew]

I personaly feel, if a fountain solution isn't agressive towards ink then the ink should have held together and not break up and disolve.

I will say that the higher the glycol content in the fount the faster the ink broke up and disolved.

 

[Dan Roll]

Referring to ink as if it is a uniform commodity akin to beer overlooks the fact that no two ink companies make ink from the same set of ingredients or purchase those ingredients from the same suppliers. Variations in vehicles, pigment systems, waxes, oils, etc can be pretty significant and all will have some effect on the test you started this thread with. To choose just one example, some larger ink companies use flush (pigment sold as a paste or liquid) that is chosen primarily for its ability to be pumped through complex piping systems. The anti-agglomerates used to keep these flushes adequately liquid are present in some ink colors in quantities higher than the fountain solution content of glycols, glycol ethers, or surfactants. These anti-agglomerates are surfactants of a type that would never be used in fountain solution and will cause a certain amount of bleed in a peanut test. In sheetfed ink we saw a major ink supplier in the US using a material to improve ink drying that was considerably more soluble in water than it was in ink and when any kind of ink/water testing was done would turn the water a rich looking brown color. None of these things prevented these inks from running well for a large number of customers running a wide array of fountain solutions.
The wide variety, and ever changing nature, of ink formulations is just one of the many factors making the fountain solution business complicated.