MemberJune 10, 2011 at 6:47 pm
Hi guys I was wondering if any of you have ever considered a process a friend of ours from Birmingham does to cure his prints. He says he uses a hot / cold laminator and runs his prints in the hot laminator at a low heat and laminates right away. Its something he has only just started doing and therefore in mine and my husbands opinion is not truly tried and tested as who knows what the outcome after a little time has set in?? Mike told him to try it for a week or so first to compare shrinkage etc but I was wondering is this a practice anybody else uses as when we were told we found it odd??
Just throwing it out to the professionals 🙂
MemberJune 10, 2011 at 7:25 pm
on our JV3-160S with original or colorific ink, I do print onto vinyl quite warm (in the late 40s) and then within the hour I laminate at 40-50deg or whatever it is… never had a problem
MemberJune 10, 2011 at 7:39 pm
That’s interesting because we never thought it could be done that quickly. When we had our cold laminator we waited at least a day.. Is it the fact the heat helps it during laminating process?? Have you tried it on cold laminator?
MemberJune 10, 2011 at 7:42 pm
in theory it will not work.
air flow is more important than heat to finish the drying process
solvents need to evaporate, so covering the ink with laminate as it is heated will probably promote more of a problem than cold laminating.
Also, most vinyl laminates are design for cold lamination, so heating to much can cause the laminate to stretch as it is applied, then shrink when it cools, causing curl and shrinkage.
so for me its thumbs down,
having said that I had a rush job a few days ago, printed and laminated 4 hours later with no problems.
MemberJune 10, 2011 at 7:48 pm
as peter says ur trapping the solvent under the laminate… so it cant escape, should cause problems.
Think some of this is down to choice or material and how well u know ur ink and profile heat/settings/ink coverage.
After 8 years and doing many jobs, it hasn’t caused us any embarrassments.
MemberJune 10, 2011 at 8:49 pmquote Peter Normington:
Solvent does not evaporate Peter, it more or less disperses/falls as it is heavier than Air.
The best way to aid in ridding your vinyls of Solvent is to hang it by its shortest side. i.e. 10ft x 4ft print.
Hang it landscape making it 10ft wide by 4ft deep.
drape over a rope, or anything and it will be 10ft wide by 2ft deep.
there for the solvent only has 2ft to fall.
when a print has been done and its left sat face up on a table.
the the solvent sits on the surface, moving down into the media turning it to a chewing gum like state.
it then hits the adhesive and into the paper.
you will notice this when removing prints from the backing paper because the carrying paper has sorta been stained a yellow…
i know of folk fanning it dry, yes this will work too an extent, but it is kind fight gravity.
many folk on here talk about loossening the roll of printed media and sitting it on end. works to an extent, but as the solvent falls it is trapped in the lower end of the media thats coiled. it really should be elevated.
a good way to know the solvent is leaving the prints is to smell it.
nope, i dont mean holding one nostral and running your nose along the length of it in a rolled-up £20 note! :lol1:
as the print is sat on end or hung. as the solvent drops after some hours, the top should be less potent than the lower section.
MemberJune 10, 2011 at 9:04 pm
:appl: well said 😀
MemberJune 10, 2011 at 9:13 pm
solvent does evaporate, as does any liquid, its a scientific fact, its why things dry,
do a bit of research Rob.
MemberJune 10, 2011 at 9:16 pm
ummm.. almost agree rob but solvent smell is heavier than air and does drop, this is why sometimes it’s better to install a low-down fan for removal of smells… however a significant amount of solvent is evaporated into the air when it goes over the print heater, the solvent fluid (without getting too technical) is added to the pigments to be able to squirt it thru the printer, to make it wet. That why ur printer stinks at times, it because the solvent is in the air, boiled away.
Same goes for water-based inks, water is removed and that why u dont smell them, as water doesn’t smell.
So rule of thumb is ur nose, stick ur head onto the sheet and get high as kite, by the time u wake up after being knocked senseless with the smell, u be ready to laminate it. Touch sometimes gives u some indication but it should cure within 5 minutes to touch or sooner.
We never unroll the media to let it dry… I think colorific / mimaki ink is fast drying and is touch dry before it reaches 4-5 inches out of the printer, so it can be rolled.
Tempreture and humidity will play a big part in printing, if its too wet in there (low humidity and cold) u run into drying problems, if it is baking in there than u be ready to laminate in no time.
Air movement helps a lot, really does, the only thing about using a rope and folding it over it, is a big fold in the middle of it but u have to decide if that will happen.
Another rule is dont print on the cheapest vinyl u can find, experiement with samples and get comfortable.
MemberJune 10, 2011 at 9:18 pmquote Robert Lambie:
not if you use a plastic roll end like the ones from metamark that have holes in them, allowing the solvent to escape!!
MemberJune 10, 2011 at 9:20 pm
Evaporation also tends to proceed more quickly with higher flow rates between the gaseous and liquid phase and in liquids with higher vapor pressure. For example, laundry on a clothes line will dry (by evaporation) more rapidly on a windy day than on a still day. Three key parts to evaporation are heat, humidity, and air movement.
MemberJune 10, 2011 at 9:26 pmquote Peter Normington:
nope don’t agree with you there peter, when anything is solvent printed it evaporates so much quicker with cool air not hot 😀
MemberJune 10, 2011 at 9:26 pm
Don’t tell me ur laminate ur laundry now Peter?
MemberJune 10, 2011 at 9:27 pm
all depends on ink load as to how long.
going to get the pop corn, back in a mo
MemberJune 10, 2011 at 9:29 pm
Peter is right, the drying process is by evaporation. It’s the solvent fumes (evaporated gas) that is heavier then air. I know this because I am really a chemist moonlighting as a sign maker 😕
MemberJune 10, 2011 at 9:30 pmquote Nicola McIntosh:
thats a misquote nik
the last one is air movement, which I emphasized, on an earlier post.
MemberJune 10, 2011 at 9:32 pmquote Ian Johnston:
yeh that’s what i was saying mate, if its "elevated"…
however, the coil also acts like four walls, which is fine also as it drops out the bottom, but with a coiled roll, the walls distances greatly vary and in many cases "touch" "pocketing air for longer periods than other walled areas… so the same coiled sheet of printed media will take longer to disperse the solvent than that of one hung with no surrounding walls at all, so to speak.
MemberJune 10, 2011 at 9:33 pmquote Phill Fenton:
I knew the latent chemist would come to my rescue!
that’s the second time you have openly agreed with me in about ten years!
MemberJune 10, 2011 at 9:33 pm
yes peter, google is an amazing resource mate. 😉 :lol1:
MemberJune 10, 2011 at 9:35 pm
Gaseous solvent will liquify again if the temperature is low, or the concentration of gas is high (lack of air flow will cause this) sorry guys but you’re wrong and Peter is right.
MemberJune 10, 2011 at 9:35 pm
right ok heres a job just printed, its on the racks and getting placed in front of gas blower (industrial heater) its on the hot setting…..oh! it does not dry..takes ages (client is waiting) same job going to dry with cool air from (industrial heater) guess what one dries quickest?
MemberJune 10, 2011 at 9:38 pmquote Robert Lambie:
It was actually wikipeidia that I quoted from Rob,
but i do understand basic chemistry.
I understand what you are saying about allowing the evaporated gasses to escape, and you are right, in that respect, but the drying process is evaporation. not dispersal.
MemberJune 10, 2011 at 9:47 pmquote Nicola McIntosh:
you are right, evaporation is based on transfer of molecules from the liquid to its gaseous form, this is best demonstrated with wind and the sea, in very hot climates around the equator, very little evaporation takes place, hence clear blue skies, most evaporation(cloud formation) takes place in colder places, these are my words, not googled, thats what I said earlier, pay attention please.
MemberJune 10, 2011 at 9:51 pm
The main principle is that higher temperature and airflow will speed up the rate of evaporation. You can have a situation whereby low temperature and high airflow will result in quicker drying time than high temperature with low airflow. e.g when a print is loosely coiled up and the air is stagnant (unable to flow)
MemberJune 10, 2011 at 9:55 pm
yeh whatever…..you both are now taking the p!ss
MemberJune 10, 2011 at 9:57 pm
no, why would we do that?
sept it is Friday Night 😀
MemberJune 10, 2011 at 10:00 pmquote Nicola McIntosh:
MemberJune 10, 2011 at 10:02 pm
um.. nik…. as i was driving home i thought i switch on and post this:-
both me and u have worked in silk screen, we got our Polyplast ink (which i think is water based, cant remember) it is mixed with retarders to slow down the drying process as we need it runny for the screen…..
We print thru onto vinyl and we want to get on with printing the next colour, how many times did we used to just "give it a blast" with a hair-dryer to cure it quickly… we shouldn’t really but we do.
Air movement yes…. but heat accelerates it or why an earth do we have a "print heater" in solvent (30-50degrees) and latex printers (100degrees)
The exception is UV ink which is different all together curing process.
And for the first time for a long while, I am agreeing with Peter 😀
MemberJune 10, 2011 at 10:12 pmquote Dave Rowland:
um dave yes i have worked since the age of 16 in screenprinting like many on the boards…..and polyplast was not water based…..the only water based ink i used was textile inks, and if i was printing a multi colour job…..giving each colour a blast would be with cold air as it was quicker? and the volume I printed a hair-dryer would not even cut it (excuse the pun) …..and yes uv is the way to go from experiance from today, each rush job took just ten minutes to print 😉
MemberJune 10, 2011 at 10:29 pm
Honestly a really interesting read. My husband has always done it the way Rob suggested hanging short side with a fan above pointing down and extraction at the bottom. The question arose because this friend of ours has only just started to do it this way and we felt we advised Him correctly by saying its not going to work. But he has assured us it’s been ok the last few times he’s done it. Incidentally he uses Rtl inks so maybe there is something in the suggestions of inks and profiles that may also help?
Maybe the heat from the laminator accelerates the evaporation or fall of solvent gas??
I have to point out the process he uses is to run it through a laminator alone with no lamination first then he laminated it after . I should have explained more clearly in my first post
MemberJune 10, 2011 at 10:29 pm
thinking about it, it was the 1-2 offs that we would use a hairdryer, never cured quick enough. But shelf drying was the way we did it with a door open, movement of air really as heat can effect the sheets a little.
from sericol data sheet
Polyplast PY: Jet drying: 55-65°C 15-20 secs. Air: 8-15 mins.
So, heated is 20secs and cold is 8-15mins… we always used a small hair dryer quite a lot, i suppose it was to dry the screens, long time ago when i was 17.
Textile, yeah flash curing, burns all that water out or whatever it was.
PY, i really cant remember whats in it, but google pointing more toward water but its not clear enough
MemberJune 10, 2011 at 10:46 pm
Maybe there is something in the fact the lightly warmed up laminator helps push and dissipate the gas and the movement helps push this away from the vinyl. I’m going to his unit next week so will witness If this actually works. If it does then great more time for coffee and biscuits!!!
MemberJune 10, 2011 at 10:50 pmquote Dave Rowland:
if that was your long time ago…ha-ha what was mine dave :lol1:
keeping on the subject of drying, polyplast had its own thinners, anyway we are steering off topic here and I am looking forward to hearing what the other valid inpits are 😀
MemberJune 10, 2011 at 11:14 pm
These googled scientific theories are all good and well, but which one is based on
the actual job in hand here?
Have you googled results talking solvent soaked bed sheets on a washing line, paper out of a printer, or solvent ink soaked onto an adhesive backed “vinyl” media, mounted onto silicon faced carrying paper? I doubt it very much! The drying theory may very well be correct, but doesn’t mean it is the best solution given “our” day to day task of drying ink soaked vinyl. Or have I missed that part?
Porous media like fabrics will allow air to pass thru, vinyl will not.
Vinyl is not porous as such, and how it is positioned will greatly vary on how it dries/flashes off and acts as a result of the chemical attack. By that I mean…
It is a far slower process for the chemicals vapours trying to pass thru a vinyl substrates face, adhesive, and then silicon paper. Than it is to fall from its print surface.
There are a great many things to way up, take into account and more, and I doubt very much the quick googled results will give you that.
My reply is based on around 8 years’ experience of a pretty high volume of printed vinyl’s applied to vehicles. Every single one of them laminated! Coupled by personal advice from very reputable sources over the years, of which have far more experience than me. So I will stand my ground on what “I know and have tried and tested myself for many years” Peter, rather than Googling for your answers… 😀
Also, I would have thought it pretty much a no brainer to work out heat and air aid/works in drying solvent prints. Around a foot from spilling out of everyone’s printer gantry, the prints are dry to touch! Look at grand format printers, the spill zone has heaters and fans all along them…
It’s the 24-48hr hour process of ridding the vinyl of the solvent that’s the task and initial question to this thread…quote Peter Normington:
Peter, I noticed you mentioned about laminating some hours after printing and you had no adverse effects. I would say that’s a pretty poor advice to give as a professional. As we all know, there is a great many reason why things do and don’t go wrong. I don’t think advice on tempting fate, is the best, sorry…
Oh and peter, these are all my drink induced words mate, google free zone here. 😉 as you say, Friday night after all :lol1:
MemberJune 11, 2011 at 1:38 am
Sadly no drink induced words for me but the thought of having a good night out is all tempting. I simply can’t sleep so here I am writing nonsense to waste my time. Maybe I’ll try some solvent flush to get me to sleep as we have no alcohol here 😉
I think the best thing to do in this field is to rally all great ideas to form your own. And obviously strive your own and be a leader. I like the logic of all the theories and facts about this subject. Truth is I guess we all have to do what’s best in our situation. I’m with Rob on this one as it’s the way my husband did his prints. Plus it simply worked.
Will try and sleep now :/
MemberJune 11, 2011 at 6:28 amquote Robert Lambie:
I agree with all you are saying, except your above quote.
solvent DOES evaporate.That’s the process of drying, the gasses that fall to the floor have evaporated from the ink, fact.
the gas left then needs to be shifted like you say, by being able to move unrestricted, thats when the airflow comes into it. it helps evaporation, and removes the residue.
and I did not need to google to know that.:wink:
I did NOT advise laminating after a short time, just that I did it once and had no ill effects, I always leave my prints a minimum of 24 hours before laminating. more for 3m ij 380, when 48hours is the recommended minimum. The Print and laminate is not the only thing to consider when drying, the adhesive is just as important, this needs time to out gass and recover also.
Last week I did not recieve artwork till the day before a customer wanted his prints for an exhibition, I explained the possible consequences of laminating too soon and he agreed to take the risk.
Hope that clears up any Friday night statements
MemberJune 11, 2011 at 7:14 am
For what its worth, I loosely roll my prints, place them on a raised grill and place it under an old exhaust fan. I reverse the fan so it blows down over the loose roll rather than suck.
In terms of drying, its the airflow that dries the solvent ink more than the heat. I’ve used hot and cold air, and its made little difference in the overall scheme of things. Movement of air is the key. A print laying on a table has been proven as not drying because as rightly stated, the solvent is heavy and will just sit on the surface. However a fan will rectify that issue. The problem is then one of space. Loose rolls is the better proposition in that case.
The best way to see if the print is dry is by feel – not smell. Close your eyes and lightly run your finger over the print. If you know by feel when the print starts or finishes, then its not totally cured. A fully dry print should have the same feel on printed and non printed sectors.
And for those that have pushed a print thru in a few hours then laminated, as I have done, should know that it depends on the laminate you are using.
Anti graffiti being a poly base would be a big no no. It doesn’t breath. From personal experience, the thicker the laminate the more chance of a problem. Also, aqueous glues v solvent glue on the laminate will also produce different effects.
I’m in the process of replacing several prints I did 10 months ago on Calendered print material, and force dried the print with a quick blow dry then laminated with a calendered UV laminate. The job looks fine except the trapped solvents that hadn’t cured properly turned the removable glue into a super adhesive and it has become very permanent. The other problem that developed was that it looks like mold has grown under the laminate. It’s obviously not mold, but there seems to have been a reaction with the solvents and the laminates adhesive over time.
As far as thinking that a heated lamination will be a simple fix, I’d not like to put my reputation on the long term results.
Just like drying paint or filler or plaster with a quick shot of hot air is a good quick fix occasionally, I’d not want to make it the standard when producing printed material.
End of the day there is a right way and a wrong way. Curing the printed material properly before lamination is the only right way. Although we can get away with the ‘wrong way’ every now and then, I’d not be encouraging anyone to be pushing the envelope on a regular basis.
Just my 2c worth anyway.
edit to fix typo’s 🙂
MemberJune 11, 2011 at 11:21 am
My two penneth worth supports the theory that heat definitely aids the curing process
I have over 25 years experience in the screen printing industry and most of those years were spent printing double sided estate agents boards. Back in the day we would be doing runs of 50 – 100 boards and the only way they would dry in time in order to print the other side was by using heat. Our setup was basically vertical racks where the boards would be slid in flat and rested on nails either side, an extractor fan at ground level to take away the fumes and a space heater in front to heat and blow air at the boards
In simple terms…Fan on and no heat = Boards don’t dry quickly enough in order to turn over and print other side……Fan and heat = Boards dry in about 5 minutes
We now have a three quarter automatic line. The drying unit uses hot air which allows us to print around 400 prints an hour. Try doing 400 prints an hour with no heat on the unit and you’d be left with a complete mess in the collection tray
Although we have had our Grenadier for about 10 years now we have never needed to laminate for the applications we use it for so I can not offer any advice or theories as to how long to leave it before lamination. I do think however that supporting Peter’s theory….If you were to leave the lid off your solvent inks, I doubt very much that you would have the same amount of ink in the bottle after a week or so
My own theory is that the way Rob hangs his prints is the most effective way to allow the solvent to evaporate.
MemberJune 11, 2011 at 12:25 pm
I don’t think we can compare screen printing drying characteristics to Digital printing inks.
Screen inks are much denser, heavier and thicker when they are screened on to a substrate. Solvent levels would be different as would drying times as a result.
Screen inks go on to a surface 10 to 15 times thicker than a digital inkjet image.
The solvent content and nature of both ink is different too. It would figure then that its drying reaction would also be different.
Heat may very well assist the drying of screen inks simply because they are so thick when laid onto a surface. The thickness of a digital ink layer would be minimal by comparison, however the components that make up the inks are very different.
MemberJune 11, 2011 at 12:47 pm
My background was 26 years as a screen printer and I can tell you that drying with heat only hardens the surface, it does not fully cure the print as the solvents are still trapped under the cured skin. This does make it dry to the touch but it’s not cured. All of the tunnel dryers use more airflow than heat as this disperses the solvents quicker.
As for solvent digital printers….well I only have 8 years experience and have very rarely had to laminate before the drying time is up, so I just leave them as exposed to the air as much as possible and then laminate. I am led to believe that laminating before they are properly dry could lead to de-lamination as the solvents attack the laminate adhesive, but have never seen this yet.
The idea of printing and then laminating straight away goes against all that I have been taught, so I hope there are no serious comeback’s for this guy.
MemberJune 11, 2011 at 12:48 pmquote Chris Wool:
Good call Chris :lol1: :lol1:
MemberJune 11, 2011 at 1:02 pm
As I say though Peter……this thread is all about accelerating curing times.
Just to repeat my point about the print line that we use……..we run it at 55 degree heat and the boards travel about 8ft in distance and come off dry (no re-wetting when the boards are stacked together……..If I ran the line with temperature set to zero which would still have the same air circulation than with the heat on the boards would be wet. It would be a lot cheaper to run if we could run them cold
I’m not saying that they are fully cured but in my simple mind the curing process has definitely been accelerated by the introduction of heat
Same thing with our Grenadier…..we have the heaters on so we can use the take up roll……No heaters = sticky prints and problems on the take up roll….heaters on = no problems on the take up roll
I’m no chemist but I would also imagine that most people are drying their prints at room temperature which I would have thought would cure quicker than someone drying their prints in an outside shed with no controlled heating
I might have got this totally wrong but I just can’t see how heat doesn’t play a part in accelerating curing times
MemberJune 11, 2011 at 1:19 pm
If i might add my own thoughts here.
What you are trying to doing with all these different inks and media is drying the print.
Inks dry by the evaporation of the carrying solvent (be it water, alcohol or any other carrier).
Evaporation occurs faster in all circumstances when you add energy to the system allowing the molecules to become more vigorous thus increasing the rate at which they bump into each other, some bumping into each other near the surface and gaining sufficient energy to break free of the surface tension and escape out of the medium i.e. evaporate.
MemberJune 13, 2011 at 12:43 pm
I dont think the laminator trick will cut it for curing…….
I just stand mine on end for at least 12 hours. I have attached a photo of what happens if gassing is not complete before laminating……
This job has been up for only 18 months. Been like this since 6 months after installation. (or so says the client, who only informed me recently)
I left the prints on the printer before going home (about 25x prints 1200 x 1200mm)
The next day while the guys were applicating, they spoiled 1 print. So I quickly re-printed, and laminated within the hour. This is how it now looks. The rest of the signs are still perfect.
The "discolouration" you see around the printed areas is the result of gasses being trapped by the lamination, resulting in the brownish "soft shadow" :lol1:
MemberJune 13, 2011 at 2:04 pm
Now now Gert, I’m pretty sure that sign does not conform with RT’s epic brand guidlines – not enough R’s space at the top 😀
Edit: to not be found by google
MemberJune 13, 2011 at 2:48 pm
Uranium, not because of nuclear fallout?
MemberJune 13, 2011 at 3:14 pmquote Gavin MacMillan:
LOL, a 137 page document on "how to" and "how not to" !!
BTW, "1R" space to the top and sides of the red strip :lol1:
Strictly speaking it is not to specs. The "Rossing Uranium Limited" part on the sign is NOT according to the brand guidelines. But the MD insisted, so an "executive decision was made, and there it is!
Namibia is likely going to be the next "Middle East" w.r.t. energy supply. We have HUGE uranium reserves. We have single deposits that contains more uranium than the entire USA deposits, and single mines that output more than the USA’s total production. The current growth here means in a few years time we will produce 25% of the world’s uranium – all from mines in the Namib desert around Swakopmund. All the mines and their subcontractors get all their signage from me, either directly or via a middleman….
MemberJune 13, 2011 at 3:26 pm
haha, yeah it was the mine name that stood out! We have done many that don’t meet the guidlines!
‘I want such and such a sign, just make sure it fits our brand guidlines’
‘here’s your proof’
‘I like it, just make it A4 size’
‘err, you can either have it 2′ or 4′ wide’
‘can I not have it A4?’
‘yup but it wont meet you brand guidlines’
‘ok, make it A4 then’
MemberJune 13, 2011 at 4:00 pm
I have quite a few clients with these epic guidelines. They call ME to double check on what is allowed or not!
Obviously, when I make signs for them, I sometimes choose to "selectively interpret" the guidelines. I’m always right – nobody argues with me 👿
MemberJune 13, 2011 at 5:51 pm
Maybe its the uranium in the air having an effect ONLY JOKING BTW
OK SO OUR ORIGINALTHOUGHTS WERE SPOT ON.
TO REPEAT THOUGH LAMINATION WAS ONLY DONE AFTER OUR FRIEND RAN THE PRINT THROUGH HIS LAMINATOR WITHOUT LAMINATE FILM PUR SIMPLE PRINTED VINYL GOING THROUGH MACHINE HE SAID HE THEN LAMINATES IT THROUGH THE SAME MACHINE AN HOUR LATER AND THINKS ITS OK. ANYWAY IM CONCLUDING THIS ONE AS A NO GO AREA AND ITS NOT GOOD ADVICE TO DO SUCH TRICK 🙂
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