N-propyl alcohol versus Isopropanol alcohol

[Alois Senefelder]

Hi Carosp, you should be using -- Isopropanol -IPA (Ispropyl Alcohol) NOT N-Propyl which is a different member of the Alcohol Family. The rest of your message is not making sense !!!!!! Please PLAIN English.

Regards,
Alois

[Lukew]

Carosp,
What fount solution are you using with the n-propyl ? is it the 2 in 1 fount thats already premixed?

Alois
It would seem that the use of n-propyl alcohol is very popular in some area's of the world. south africa / some area's of europe..specificly the 2in1
N-propyl is only 20% lower in voc then IPA so in the end if you have to run 8%-10% of n-propyl it's hardly worth the change, as running IPA at 6% would yeild great results anyway though if you where to use the 2in1 you no longer have neat IPA on the premisise.

[Alois Senefelder]

Lukew, read the answer give by J.Lind earlier in the Discussion, I repeat IPA has more beneficial properties for Lithographic Printing than using N- propyl, bear in mind that the use of IPA is the "de facto " alcohol used in fountain solutions since its introduction in the late 1940s. Anyway the we should be trying to eliminate " Alcohol" from the Pressroom, speaking from my own experience ie Web-Offset, the firm I worked at until I retired !! - we went "Alcohol Free" in the 1980s BUT even running alcohol free was not with out its problems.

Lukew -- explain 2 in 1 fount please ??? IS it American English for something I should Know !!!!!!!!

Regards,

Alois

[Lukew]

Alois, Yes I know Ipa is the recognised and prefered alcohol to run in fount solutions..
2in1 is made in Aouth Africa basically you put the alcohol dosing hose into the drum of 2in1 which as the name sugests is premixed with n-propyl and fount solution.. you can then run it so you get an accurate feed of say 2% fount and 8% n-propyl


My main interest of N-propyl is if I could have got drums neat of it to use, as that 8% is going against what we are aiming for.
We run poly plates, and although we are running IPA at 3.5% its not as easy as it should be, and some jobs I have had to bump IPA back up to 7% just to get the job through.As I'm sure your aware of, the last thing a printer needs is to be using something that makes his life dificult. + our water %feed is high and come summer time it will get worse..

[Alois Senefelder]

Hi Lukew, Now I understand your problem ! are you using 2in 1 Fountain Sol. from the South African Company - BM Management SA ??????

I have no experience of printing from Polyester Plates !!! BUT


Regards, Alois

[Lukew]

No no, not using that fount,, just using a normal fount and dosing in IPA, was just curious of the posibility to doseing in NPA instead of IPA..

Have you heard of that particular fount, or run it before?

[Tom_print]

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

[jlind]

Hey pardner, no hidden agenda. Just recounting a number of years of reading and printing. I'll follow your next report of progress. I think it would wet a polyester plate better than isopropyl alcohol. That's not how the coversation started out. Good luck.
John Lind
Cranberry Township, PA
724-776-4718

[Tom_print]

John, I understand the original poster is more focused on the enviromental side of things, but below is his post just after your first reply.

With the n-propyl having a slower evaporating rate then isopropanol, could this mabee be a benefit for polyester plates, which are notorious for not wanting to hold fount,, especially towards end of shift when there's a fair amount of heat in and around the machine.
If pressmen are having to run their IPA % higher to compensate for any evaporation before it reaches the plate, then could it not be possible that running with a lower % of n-proyl would give similar effects but with a substansial drop in VOC emmisions.
Luke..

Also this 2 in 1 fount has a vapour pressure of 10mmhg @ 20c which is on the low side.
I believe that the bonus of using this stuff on poly plates is because its evaporaton rate is lower then that of IPA, there for it's getting its job done better before evaporating
One interesting note is N-propyl is water misceble, where as IPA is water soluble, I'm wondering if this is whats giving it better effects as well.

Tom

[Green Printer]

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