Reducing drying times on uncoated stocks
Increasingly it seems we're being required to produce everything with lower than ever turnaround times - I'm sure everyone knows the feeling - and, more and more, that includes uncoated stocks.
The question is how to reduce drying times with our regular setup?
We've been using hard-drying inks which are great but they're expensive and mean an ink change every time they're used so long term, it's not a viable solution.
We use Druckfarben's Eco Perfecta Intense range with Bottcher S3006 fount & 5% alcohol on Komoris - a 528 and 1028P, both with IR dryers that are currently out of commission due to what we consider to be uneconomical repair.
So far I've had thrown up - adding driers, adding a small amount of varnish to the ink, using IR drying, coarser screen ruling (not sure about that one at all - won't affect solids). None of these suggestions are met with universal agreement, opinion is based on experience so you get a different idea whoever you speak to.
Generally speaking we're not unhappy with the drying times, they're good across the board, if there's anything we can do for uncoated stocks it would be great.
Anyone have any ideas?
Many people have a strong confusion between "Rub / Scuff Resistance" and "Drying."
If you are looking for better dry times on uncoated stock, certainly a Hard Dry version of ink isn't going to help. Hard Dry inks, similar to high solid inks, will give you a better cure and bonding once the ink is dry thoughout all levels of ink on the sheet. Hard Dry Inks actually dry slower than standard inks.
Adding dryers to the ink will speed up the oxidation process but won't help with rub or scuff if that is your problem. I'm saying that because someone is bound to suggest a drying additive to add.
You might want to talk to your ink supplier and see if they can give you a "High Rub Resistant" or a "High Slip" ink for those specific applications. In summary, they will add additional waxes to the ink that will allow the sheets to be handled without the fear of scuffing in a shorter time ratio. The inks set as well or as fast as a standard ink, just have better rub. This ink should not be used if you are going to foil stamp, laminate, or UV coat the job, after being printed. Those particular waxes are generally not going to be finish friendly.
Again, it's a special ink that you might not want to inventory or spend the money on. With ink being 3% maximum of the entire job, what's another 25% higher price on the ink if it works and saves face in front of your client..
Last edited by Asures; 07-13-2011 at 10:28 AM.
Aaron Sures - Pressroom Technical Specialist
Gans Ink & Supply Company
Just curious if you're running any type of ink saving software. The reason I ask is less ink on a page should result in faster drying times.
Premedia Software Inc.
We were having the same trouble along with some drying and picking issues on our gloss stock. We were using Gans Bengal line. After talking with our sales guy we switched to their Eco-sure line. We can turn jobs faster and have less scuffing on our uncoated stock. I would talk with your ink salesman.
You mentioned that you are "required to produce everything with lower than ever turnaround times" and that you want to reduce ink drying time.
On average what is your required turnaround times. I am trying to establish how significant the ink drying time is in the total time (From order receival to delivery)
Take a look at the newest Cougar swatch book from Domtar (we printed it over a year ago so you may have the latest copy). If you look on the back cover of your book and see that it was NOT printed on a Komori, then you've got the old version. Anyway, the ink we used to print the book is called Truetone Hi-Def and it is made by a company called Alpha Technologies. The person you'll want to speak with is Jeff Thompson 1-630-886-4378. You can tell him Tony Drummond from Classic Color sent you. He may be able to help you with this issue and also open your eyes up to a really cool product. The ink has a wide gamut and also reduces typical dot gains that you see with conventional processes.
Thanks to all for the input so far.
I suppose I'm referring more to drying than scuff/rub. The ink on the sheet feels tacky and is very susceptible to marking and setting off under the guillotine clamp. At the same time though even when dry to touch it's prone to scuffing on post processes.
We do have ink saving software but not using it on every job; it's something that will help for some applications so I'll definitely look at using it more.
Regarding turnaround time we could be looking at anything as low as 3-6 hours after coming off press.
Upwards and onwards!!!
That's a quick turnaround for an uncoated sheet. Good luck. Let us know if you find anything that will work.
I would consider talking to customers. Also this is more of a problem if you care tuppence about the environment when choosing products.
As stated Ink saving is one way to do what you can. We usually offer them to use a semi coated paper if they insist on short turn around times.
Airing sheets sometimes helps, but it depends on the print run. If you need to finish the job printing 80% screened varnish may help not to smear colour during finishing, but there is the risk of getting moire on the magenta. (100% varnish will slow deep drying)
Some times the customer has to understand the limits of the real world rather that live in their concept of bullet time. If you look at production there is usually a long process before the job comes to you, and they need to see that sitting at a copywriters desk for two weeks because he is a "creative" will jeopardise the whole production if they expect chemistry to work outside the laws of nature.
Unfortunately this is partly due to an educational system which praises theoretical over practical knowledge.
Last edited by Lukas Engqvist; 07-20-2011 at 09:35 AM.
Reason: note about airing and varnish
When I look at different ink formulations I typically see these generalizations:
Hard Dry Inks - Slowest setting, glossiest, best rub resistance, suitable for synthetic substrates and particular uncoated stocks, such as index stocks.
Quick Setting Inks - Fastest setting, flatter, rub resistance will vary, suitable for all paper stocks, caveat on your dull coats.
"Slower Setting" Inks - Moderate setting, glossier, rub resistance typically better than quick sets, suitable for all paper stocks. A better match for jobs when not coating and dull-coat stocks.
I recommend that you ask your Ink Manufacturer for a good Quick-setting ink with the best rub resistance they can give you. This should allow you to turn your jobs much quicker and is hopefully set hard enough to take the guillotine after 6 hours.
"The truth I knew yesterday turned out to be my ignorance."