N-propyl alcohol versus Isopropanol alcohol

[Tom_print]

2 in 1 fount is 80% Propyl Alcohol cas #71-23-8

Nothing wrong with that, if you dose it midway between what is recomended, you have 8%NPA and 2% actual fount being dosed in automaticly out of one drum

There is no need then to have IPA on the premisis which as you know has an extremly low flash point,,
The flash point of neat NPA is much higher then neat IPA, But since the NPA comes mixed with the fount, the flash point is even higher. And not to mention neat NPA is 20% lower VOC then neat IPA.

Look don't get me wrong, if there was an alcohol free fount out there that worked as good as this on polyester plates we would be using it,
A lot of people ramble on about the health benifits of their IPA free printing but if they took a close look at some of the MSDS, data that comes with that fount, they might be a little shocked to know that it's just as bad for you, then in some cases you have the printer adding IPA to help when their having problems in which case makes it even worse for the printers health.

Tom,

[Alois Senefelder]

Tom - you are wrong -- Isopropyl Alcohol (IPA) the pure "Anhydrous" 99% version ---


IS Miscible !!! Indentifier # CAS [67-63-0] and most important its Viscosity is ---

2.86 cP at 15 C

Regards Alois

[Tom_print]

Alois, your correct, seems I got it the wrong way around
IPA water miscebal
NPA Solubility:
Infinitely soluble

n-propyl Viscosity (20 ° C) 2.256mPa
I'm just wondering if your running IPA at 5% with a 2.86 cP at 15 C viscosity, would the fount still be more viscous then running with 8% NPA ? not sure how we could do a test to find this it.

Alois, most printers are trying to cut or elimnate IPA from their founts, and yes a lot of printers have managed to do so, but it is with the use of metal plates.
I would like to hear of anyone running IPA free on polyester plates, or even up to 5%ipa, on polyester plates. if there is anyone here that does, tell me can you run between 13500 - 15500 sheets an hour with fine screen rulings all year round, be it a hot summer day, or not. PMS colours/cmyk/gold/silver/fluro
We had been able to get down to 3% - 5% IPA, but our water window had shrunk greatly, and there was a fine line between working and not working, and the quality of work was lower then what we are producing with this fount.

So the bonus of this NPA, comes in, you want to run at 5% IPA but print quality isn't as good as it could be,, you switch to 2 in 1 with NPA in it, you can then run it at 8% and have fair superior printability, and your voc emissions are no higher then the IPA at 5%

Honestly this is the last post I have about the stuff, I will post back in a few weeks to let on if we still love the stuff,
Tom

[Green Printer]

2 in 1 is 80% VOC.

2 in 1 is 800g/1 Voc or 8g/l per each percentage point used
ipa is 1000g/l VOC or 10g/l per each percentage point used

8% 2 in 1 is 64 g/l voc
5% IPA IS 50g/l voc

[Lukew]

Green printer, you failed to add the VOC level of the IPA reduction/replacement fount to that IPA voc level, some of those founts have up to and beyond 30% voc levels.
so lets say a dose of 30%voc fount at 3% + 5% IPA theres 59 g/L VOC Even though its slightly lower then the 2in1 fount, your VOC emission levels should still thereticly be higher, given IPA's vapour pressure is double that of N-propyl
not forgeting the vapour pressure of 2in1 is Vapour pressure : 10 mm of Hg (@ 20•C)

N-propyl has a Vapor Pressure (mm Hg):
21 @ 25C (77F)

versus
IPA
Vapor Pressure (mm Hg):
44 @ 25C (77F)

Please do correct me if I'm wrong, but the lower the vapour pressure the less it readily evaporates,
there for, your getting less of the product evaporating into the air..


Still very interesting stuff though
Luke.

[Green Printer]

Lukew

A VOC is called that because it will evaporate. It doesn't matter about the speed of evaporation.

What doesn't directly evaporate into the air during production will be absorbed into the printed substrate and then it will evaporate later.

Ever opened a box of printed material that has been sealed.

When you open the box it has an oder and smells, that is VOC's being released that didn't evaporate during manufacturing.

It always evaporates, just where is what is different.

[Lukew]

Ahh I didn't know that,, this whole enviromental stuff is new to me.
so it may be healthier for the pressman, but not particully any better for the environment?
As I had first stated I was more interested in running the NPA with the fount we were using, at say 5-6%Npa.

[Alois Senefelder]

I said to the Boss we should have stayed with the "Stones" never mind these new fangled Polyester Plates !!!!!!!!!!!!


Regards, Alois

[Lukew]

We had been in contact with our suppliers, and none of them sold N-propyl so we had two options, keep using our current fount, with a dose of 3.5% IPA or give the 2in1 fount a trial,

Trialing of the 2in1 got the nod, and it has been in the press for 2 weeks now,
Our main reason for giving it a go, was the fact that if it was to work we no longer had neat IPA on the premisise, + if it lived up to all its hype it would be a god send.

Our current fount had given us the ability to get down to 2% IPA, but as the days started getting warmer, this % number started to increase, to a point were we hovered between 3.5% - 5% IPA and up to 7% on tricky jobs, Our water % feed rate was starting off at +50 - 60 and ending as high as 75-80 on some PMS coloured jobs, which was simply too high and we could see that come summer time it would only get worse.
also the water feed % rates was unpredictable, you could print the same job the following day and have totaly different settings, this of course lowers the acuracy of cip 3 as the different water % feed rates plays havoc with ink density.

So in comes the 2in1 fount. dosed so we get a reading of 8% NPA
our water dials are starting on 35% and ending no higher then 40% by the end of shift with only the last deck near the IR dryer going up to 42 % on the odd time. the last few days they have ended no higher then 38% These figures are with both cmyk or PMS inks.
As you can see with such a stable water feed % rate, it gives you the ability to fine tune cip3 even further,
whether we're going from a light coverage job to a full coverage job, our water feed rate is near the same, and we're at correct density within 30 sheets.

The plus's we have noticed
- no picture framing (ink buildup on the impression cylinders) we used to have this problem with all the other founts we have used
- minimal water needed to keep a smear free print, so much so we have now been able to run in intergrated mode when needed, which has nearly completly eradicated our banding problem on solids without any emusification problems
- there is more detail in our work now, as even the finest screens are open, looking at the dot structure under a 40X magnifying glass shows us why, its simply holding its shape and is incredibly sharp.
-We are using less ink to achieve density, especially with PMS colours. (before hand with low IPA we did strugle with certain colours and had to run an incredibly high water % feed to stop scumming up in screens)
- Start ups are fast and scum free.
-registration is much better, less water means less distortion of the sheet.
- drying time has improved
-no more cording from the metering roller

Anyone that runs or has run polyester plates would know that they do strugle to hold fount esspecialy when the temp gets up towards the end shift, but this fount seems to knock that problem on the head, and allows the plate to run near identical to metal plates.

I had a run of 30000 sheets 2 colour PMS,now normaly by the end of a run lenghth like that I would have increased my water feed rate by at least 25 points, but with 2in 1 I had only rasied it by 5points.

John, so fair your concerns of emusification by way of the n-propyl being too good a solvent has not arose.
I feel one of the main reasons it won't is because you have the ability to run such a fine amount of water, that there is very little water feed back into the ink rollers
We printed one PMS colour which normaly gives us emulsification problems as a test, and we were amazed at how sharp the print was. with no emuslification.

I will say that, while we are not as low voc emision wise as where we were at, our print quality has greatly improved,
Its not often that you can put a new fount in and straight away, throw your hardest jobs on the press for a trial, and have it just simply work, effortlesly bonus!

I can now honestly say, I like printing with poly plates, and up until now, you would never ever hear me saying that..

[BMM Print Ltd]

Hi Tom, we are pleased you are "blown away" by our 2in1 Fountain Solution!

We have recently started using that 2 in 1 fount, and we are simply blown away by how well it works, expecialy on polyester plates. Its set to dose so we get 8%NPA and 2%fount which emissions wise roughly equates to running IPA at 5 -6 %
We had trialed numerous founts ranging from your IPA repacement to normal founts with a dose from 2.5% up to 10% IPA, and this product simply outperforemed all of the other founts.
Its ability to keep the plate wet, keep fine 95% - 97 % 175 line screens open with minimal water is amazing. And thats with polyester plates..

Our back cylinders are staying clean and we get no more anoying picture framing on the cylinders which is normaly just a hassel to cleanand more downtime

It prints a much sharper dot compared to the other founts we had trialed
Drying time has been slashed, and there's simply less water needed and less ink needed to achive density, As you know you generaly need less ink to achieve density when going from say a fount with 10%ipa down to below 5% IPA well with this fount your ink keys are closed even further..and your running lower water settings even when compared to 10% ipa

We have always had a problem getting band free solids due to press design(water roller diamaters too small,) In which case if you run metal plates you get very little because of such a low water setting needed to obtain a scum free image, but with this fount, on poly plates the banding is nearly totaly disapeared a huge improvement from what we had.

As I said we have only recently begain running this so I will give a heads up down the track, but so far its simply briliant..

So for those that say it can't work, simply haven't run the 2 in 1 product or have a hidden agenda.
Also its fogra approved and contains none of thr nasties that some of the IPA free founts contain.

I just wish I had come accros the product sooner,

Tom