Digital Printing, E-beam Coating, and More

The one application where e-beam lamination, as opposed to e-beam coating, is called for is when a customer wants a soft matte finish. “Today, you just can’t get the soft matte effect you want from a coating,” says Mages. “So in this case we purchase a soft matte polyester or OPP, reverse print it on the 20000, and e-beam laminate it to the sealant layer.”

An e-beam coating system relies on radiation curing, just like UV curing systems. But it uses electron beams as opposed to UV light. The e-beam system at AccuFlex emerged from a partnership of S-One, Custom Design Applications, and PCT Ebeam and Integration. S-One now offers the technology to the marketplace as an integrated system called CatPak. Tom Hauenstein, Global Sales Director at S-One, explains how this came about.

“The pouch-making business is changing to a model that needs to emphasize quick turnaround and greater sustainability. If a converter can buy from us a ‘pre-lam’ of metallized NatureFlex and sealant layer, they don’t have to reverse print polyester and then thermal laminate a layer of metallized polyester plus thermal laminate a sealant layer. Nor do they have to build in curing time of 24 to 48 hours before shipping thermally laminated material to their customers. They can surface print our pre-lam, e-beam coat it, and go straight to pouch-making in the same day. Recognizing nearly three years ago that this new model was beginning to establish itself, we wanted to become a source that would let converters buy from one turnkey provider an integrated system including not only an e-beam curing system from PCT but also the unwind, secondary unwind, and rewind station, and even a flexo deck if need be. And from that same turnkey source they would also buy the NatureFlex rollstock.”

Compostability a key goal

Another strategy adopted by AccuFlex to shore up its sustainable bona fides is its use not only of compostable films but of bio-based reclosable zippers. While the rollstock comes from Futamura, the bio-based reclosable zipper material comes from Elplast. According to S-One’s Hauenstein, dealing with these bio-based materials has its own set of challenges. Not only are there a variety of bio-based sealant layers to pick from—PLA, PBS, PBSA, Ecovio—you also have to pick the right compostable certified adhesive to marry the NatureFlex to the bio-based sealant layer.Seen here from the film infeed station is the pouch-making system operating at AccuFlex.

“Everyone’s gotten very efficient when it comes to laminating polyester to a linear low density polyethylene sealant layer,” says Hauenstein. “But it’s a labor of love sorting through the compatibility of all these new bio-based materials. And we have to test the finished structures if we want to certify them as being truly compostable. That might involve $15,000 and 90 days of evaluation.

“Some bio-based sealant layers are really strong and stretchy. So if you’re doing a vertical form/fill/seal package and you’re dropping in potatoes or something heavy, that would be what you want. But other bio-based sealants are more brittle and rigid, and those hold up better in a standup pouch because they actually help the sidewalls of the pouch stand up. Moisture resistance, too, is an issue, so if the package’s contents are moist that has to be taken into account. We really have to hold the customers’ hands a bit and understand clearly what each application involves.”

Bio-based zippers, says Hauenstein, are another whole can of worms. “If the bio-based sealant layer is, let’s say, PBSA and the bio-based zipper is made of BASF’s Ecovio—which is a mix of a couple of different bio-based materials—what temperature do I use to marry the zipper to the pouch? Bio-based sealants typically seal at lower temperatures than the tried-and-true linear low density polyethylene. So speed and tooling design and temperature settings on your pouch-making enter the picture in a critical way. Believe me, it’s tricky.”

Unique decorative effects

Which brings us to AccuLink’s use of Color-Logic software, a metallic color communication system for creating decorative effects on metallized substrates. “I create a file in Color-Logic and send it to the Digital Front End of the HP Indigo 20000,” says O’Brien. “The DFE pushes it through the RIP [Raster Image Processor], which basically then tells the press what dots to put down, where to put them, and whether to lay them on top of each other or not.”Pouches coming off of the pouch-making system go into this spout inserter.

Wherever the design file calls for the metallization to be masked out, Color-Logic software tells the press to lay down opaque white. But where the design calls for metallic colors to shine through, the software tells the press to lay down cyan, magenta, or yellow picked from a swatch book that is produced off of AccuFlex’s 20000 press. Which makes the swatch book AccuFlex’s own unique color system.

“It’s an accurate representation of substrate, inks, press condition, and the coatings found only at AccuFlex,” says Color-Logic Sales and Marketing Director Mark Geeves. “So where the design calls for a red metallic color, the press deposits not only the desired color but the precise shade of that color—a CL217-S as opposed to a CL218-S.” Geeves describes the metallic color system as “the most affordable system in the world for decorative effects. Only five inks are required to produce 250 metallic colors. It’s that converter’s own swatch book. There is no guesswork.”

When asked if printing, e-beam coating, slitting, and pouch-making are all one in-line process, O’Brien says it’s more like “near-line.” In other words, rollstock spends some time as work-in-process (WIP) as it progresses from one converting process to another—but not much. He also says that not all material printed, coated, and slit at AccuFlex proceeds to in-house pouch-making. “Some of the material coming off the slitter goes to customers who mount it on their form/fill/seal machines,” says O’Brien.

Both O’Brien and Mages are excited about what their fledgling converting company will be able to do with its unusual mix of technologies. As just one example, O’Brien points to a package now in the works that will include compostable metallized NatureFlex, a compostable zipper reclosure feature from Elplast, the metallic special effects made possible through the Color-Logic software, and a new variable-data-printing tool from HP Indigo called Collage that will make it possible to produce a run of 10,000 units where no two packages will be the same.

PACK EXPO Las Vegas and Healthcare Packaging EXPO (Sept. 27-29, Las Vegas Convention Center) will reunite the packaging and processing community, offering new products, technologies and solutions, while implementing up-to-date protocols for a safe and successful in-person event. Attendee registration is now open.

See how other brands are looking to Bio-Plastics as a solution.