Waterbased Inks on PE film

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Spyderv
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Joined: Mon Jul 24, 2023 4:42 am

Waterbased Inks on PE film

Post by Spyderv »

Hello everyone,
We are getting an in-line press for PE film. We are strongly considering trying out waterbased inks on this production line since the new press is suitable for both.
We have been printing with solvent inks for many years and have had minimal experiance with water based.
The film will be mainly for outdoor uses so UV and enviromental reistance of the ink is a big concern of ours.
Small differences in corona treatment level, anilox and cliche selection is also something we have been warned about.

What are the main things we should consider?

Also one of our guys claims that adding a little bit of solvent based varnish was a trick someone was using in a previous job to defoam the ink.
Frank Burgos
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Re: Waterbased Inks on PE film

Post by Frank Burgos »

Hello everyone, We are getting an in-line press for PE film.
If your printing on unsupported films, servos and chill rollers are probably involved, so you’ll need to learn how to service both
We are strongly considering trying out waterbased inks on this production line since the new press is suitable for both.
You will probably notice that water-based ink does not “lay down” like solvent-based inks, meaning a duller finish. Expect that.



The film will be mainly for outdoor uses so UV and environmental resistance of the ink is a big concern of ours.
Conduct outdoor tests. Look up the ISO standards. Also, I worked with an ink guy that used to put samples on the roof and analyze the results. Also, there are sometimes pigments options that are more light-fast. For example, I think 072 blue is similar to reflex, but more light fast. Don’t quote me. Talk to your ink supplier.

Reds are particularly susceptible to fading. Let you designer know. There may be opportunities to steer customers away from colors that disappear.
Small differences in corona treatment level, anilox and cliche selection is also something we have been warned about.
Big difference, not small. Very critical. Too must to write.
What are the main things we should consider?
Water-based ink is much more difficult to clean up. You want ergonomic cleaning setups with space and a hot water supply. Consider instant water heaters at the location.
Also one of our guys claims that adding a little bit of solvent based varnish was a trick someone was using in a previous job to defoam the ink.
Don’t play around with the ink. You will get out of control. Whether to add, what to add to an ink is determined through discussion and a process with your supplier and your team. Do not add anything until you know why and how you will control it and train everyone about it. And then control it.
We have been printing with solvent inks for many years and have had minimal experiance with water based.
You MUST control viscosity and pH. That’s something most operators do not appreciate or respect, so I always shout in their ear about it.

In fact, I trained some guys how to operate a 150” beast, printing with water-based ink, and the GM of the place sent me a picture of me with a bubble that says “La Tinta!! (see the picture below) that the guys set up next to their ink blending station so they could flick ink in my face whenever they liked.
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Spyderv
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Joined: Mon Jul 24, 2023 4:42 am

Re: Waterbased Inks on PE film

Post by Spyderv »

Thank you for the response,

One of the substrates we wish to print is stretch hood.

We are worried water-based inks will have a problem with stretching. Most of the ink suppliers we have contacted can't help us with this application.
(we are also worried that with water-based inks due to increased corona treatment the static electricity internally will increase, any advice on reducing static electricity is much appreciated).

Can anyone recommend ink suppliers for this application?
Frank Burgos
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Re: Waterbased Inks on PE film

Post by Frank Burgos »

I don't have advice on ink for stretch films, other than keep looking and asking.

As for static control, yes, there are things you can do and should do.

There are deionizing bars that can be strategically placed on you equipment and the converting equipment that follows the press. This link is the first site I found searching "static inonizers for printed film": https://www.exair.com/products/static-e ... 9b2be9596b

You should have something like this to reduce static.

Also, depending on the configurations and situations, operators can wear wrist straps to reduce the risk of shock. Sometimes, standing at the rewind section the operator will see a "lightning bolt" jump from the roll to him or her.

https://www.uline.com/BL_7401/Personal- ... c7a28d848f
longtimefan
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Re: Waterbased Inks on PE film

Post by longtimefan »

I have printed water base on a co extruded poly film. While this didn't stretch it worked fine on it



Inx makes great water base inks
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iteachflexo
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Re: Waterbased Inks on PE film

Post by iteachflexo »

With water based inks, you will not get the opacity needed running film substrates especially white. Also, if the majority of your label applications is for outdoor use, water based inks will fade.
Brian
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Re: Waterbased Inks on PE film

Post by Brian »

I agree that INX makes very good waterbased ink. They are our sole supplier. We started our change from solvent to water 15 years ago and have converted the plant to 100% water 10 years ago. While i agree that water and solvent show a difference i would say that gap has been significantly narrowed. There is still a definite gloss difference. We manage to hold a ~54% opacity on our whites using a conventional 300 - 5.0 anilox or a small GTT. We print PE and PP here. Surface print outdoor just use a different dispersion (fade resistant) when making reds or yellows. Blue and black have very good fade as they sit (use carbazole over methyl violet). One thing to keep in mind is that a crosslinker needs to used when surface printing and the product ends up in harsh conditions. I'm unsure about stretch film as we do not print that here, but it sounds like the same concept as shrink bundling film. This just uses a different extender with the same dispersions that allows the ink to shrink with the packaging when the film is applied to whatever it's bundling. Your ink supplier will answer those questions for you. There's a learning curve when converting from solvent to water but it can be done.
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