Not long ago, the standard short-term product in the outdoor advertising industry was as it had been for a hundred years: a short-lived paper poster printed with solvent-based inks.
The outdoor advertising industry's new standard involves next-generation polyethylene (PE) printing substrates and UV-curable printing inks. Driven by an application from Lamar Graphics (www.lamargraphics.com), Canada-based PE manufacturer Interwrap Inc. and San Leandro, CA-based INX Digital Intl. Co. (www.inxdigital.com) — along with the assistance of many other suppliers including HP — the more durable, lightweight product works on all industry-standard poster structures. A one-piece woven polyethylene substrate is printed with zero-VOC, UV-curable inks and warranted for 60 days. Full-size PE billboards also are being printed using more heavyweight materials designed to last one year and survive monthly relocations.
After one of Lamar's PE posters or billboards has served its purpose, it is sent for recycling into products such as decking, rail ties or garden pottery. Nothing is sent to landfill.
Greg Gauthier, now Lamar's manager of strategic projects, had seen various types of woven coated polyethylene used as recyclable packaging material, and he decided to run some of it through a printer using standard solvent-based inks. “It printed beautifully,” he recalls, “[but] the ink came off like talcum powder or wiping dust off a window. The ink adhesion was zero. We thought PE was a good substrate, but finding out how to print on it was a real challenge.”
Gauthier experimented with a solvent-based ink formulation from INX Digital, which could adhere to polyethylene without a top coat and enabled the use of older printing equipment. And after further development, he found INX's Triangle UV-curable ink fit the bill.
“We designed inks that not only adhere to this very thin media, but have automotive-grade pigments with a long life, which allows advertisements to be kept up for longer periods,” explains Ken Kisner, president, INX Digital Americas. Beyond engineering the inks, INX provided color management support and helped Lamar with bonding UV inks to the PE substrate. “We put our color team with Lamar to do a detailed study on how to achieve proper color and minimize ink usage,” says Kisner. Interwrap helped refine the substrate and resolve issues such as wrinkling and surface finish. Lamar produces the billboard graphics on an HP Scitex XP5300 printer.
“[INX Digital] helped us through the complete transition to UV,” says Lamar Graphics general manager Rachel Tempanaro. “We began transitioning in late 2007, and by the second quarter of 2009, both of our plants (Baton Rouge, LA, and Columbus, OH) were printing the majority of orders using PosterFlex and FlexiLite PE substrates.”
For Lamar plant personnel, printing and finishing PE was a whole new ballgame.
“Initially, there were huge hurdles for us to overcome,” recalls operations manager Charlie Peek. “Adhesion issues, color profiles, understanding all that we needed to do to make this product viable was not an easy task, by any means. After creating our profiles, we freely gave them to other companies. We shared the rest of our knowledge to enable them to print on PE, and we continue to do so.”
Peek says training field crews to install polyethylene was crucial. “Vinyl is stretchy, almost like a rubber band, and we had crews that were used to muscling the material to pull out wrinkles using ratchet straps capable of pulling 3,000 lbs.” But PE has very little stretch. When crews lay it out on the board, it must be almost wrinkle-free before they can tighten it down. Although PE is very strong, tensioning it requires a lighter touch.
Recyclable PE and UV inks have led to greater productivity and efficiency, with fewer roll changes (a master roll is 7,000 yards vs. 2,000 yards of vinyl). And Tempanaro says the plant no longer smells like chemicals: “We were able to go from being a large source [VOC] emitter to almost not needing a permit.”
“We have totally eliminated cardboard from our outbound shipping,” Peek adds. “PE posters are put into recyclable PE bags. This eliminates tons of waste, reduces weight and allows us to put more on a truck or plane.” Peek also has seen a tremendous savings in reposts due to damaged product.
While some large billboards still utilize vinyl media, Tempanaro says, “We're leading the way among outdoor companies, [and] it's a continuous process.”