When the printing is done right, glow-in-the-dark inks are really eye-catching, and are of much interest to consumer packaged goods (CPG) brands. They are also challenging to produce. For years, ink specialists have tried to come up with water-based glow-in-the-dark inks with little success.
Chromatic Technologies Inc. (CTI) has just solved that challenge, launching water-based glow-in-the-dark inks for flexo and gravure printing. These inks will be ideal for food and beverage applications. CTI offers two formulas – one for paper substrates such as QSR cups and secondary packaging, and another for film substrates.
Barry McCann, product director for CTI, said that printers have been looking for water-based alternatives for a while.
“These water-based flexo and gravure glow-in-the-dark inks have been in research and development since early 2020, primarily to have solutions for printers and converters who can’t use solvent and UV-cured inks for their applications,” said McCann.
McCann said that achieving a strong glow was holding back water-based glow-in-the-dark inks.
“In terms of performance, the glow strength of these water-based formulas equals that of our glow-in-the-dark solvent-based ink,” McCann observed. “The problem was that before, a water-based formula that’s easy to use on press and gives strong glow wasn’t available. Now it is, and it is opening up opportunities that weren’t there before for brands and converters.”
CTI reported that a single print station with a 10-13 (BCM) anilox allows print operators to deliver the same glow strength as CTI’s solvent-based GID ink.
To reach this result, CTI had to overcome numerous challenges.
First, McCann pointed out that water-based formulas and phosphorescent pigments don’t play nice with each other, and the formulas can be unstable.
Second, transferring glow-in-the-dark ink onto the substrate is tough.
“Heavy pigments like these almost always hard settle,” he noted. “After you pour the ink into a chamber and start running, you eventually print less and less glow-in-the-dark pigment and more and more vehicle, making for a pretty poor glow experience for the customer.”
Third, just preparing to use the ink for a commercial job could be nearly impossible if the pigment hard-settled.
“You have to literally use a stick to break up the pigment in the bottom of a bucket or drum, and then after mixing it for 30 minutes and beginning the press run, then it starts settling again in the doctor chamber,” McCann said. “CTI built these formulas from the ground-up so that the inks (1) don’t hard settle, (2) print nicely and (3) produce a strong glow when used according to our technical specifications.”
McCann said that food and beverage applications that can’t use solvent-based or UV-curable inks would be ideal opportunities for the new glow-in-the-dark inks.
“Ideal opportunities would be any application that requires water-based inks instead of solvent or UV-cured,” he continued. “Examples would include QSR paper cups, indirect contact food packaging, corrugated primary and secondary packaging, drugs (see the bottle in the dark), children’s toys that use printed labels, etc.
“CTI works closely with our customers on compliance requirements and migration testing to ensure that every printed product is, first of all, safe. Beyond that, we know that if you can’t see the glow, it’s not a great customer experience. Thus, we offer expert technical support to ensure best graphic design practices and appropriate ink coat weight,” added McCann.
McCann reported that CTI has just started commercializing these inks with a few printers and converters, but the initial feedback is very positive.
“They say that it’s the best water-based glow-in-the-dark ink they’ve ever seen and are surprised that the glow equals our solvent-based glow-in-the-dark ink that’s been used on many candy and snack packages for years now,” McCann added. “We can’t divulge who we’re working with because of confidentiality agreements, but some of the world’s biggest converters and brands are exploring using these inks for 2021.”
