Printing on flexible, plastic films and pouches is the most effective and ubiquitous way converters add value and shelf appeal to their unique packages. In the world of flexible packaging, especially in North America, those printing jobs generally involve flexographic printers.

Flexography is a very attractive alternative to rotogravure printing, because the low associated costs and increased “flexibility” with flexo. Utilizing the light, flexible and inexpensive plates and sleeves saves not only up-front capital, but also greatly reduces downtime with very quick changeovers from job to job.

In the past, the knock on flexo was the print quality when compared to gravure. But as flexo technology evolves, the print quality gap narrows and flexo will continue to strengthen its case as the printing process of choice for flexible packaging.

“For some time now, flexo has enjoyed the larger share of the packaging market and that share continues to grow,” says Paul Teachout, product development manager, Aquaflex. “Recent advances in flexo print quality combined with lower costs on short-runs make flexo a very attractive process for packaging buyers.”

While the quality gap is closing, President of Retroflex Perry Lichon says that it’s closing very slowly, and gravure still serves an important purpose.

“Yes, the gap is closing little by little,” says Lichon. “Gravure also continues to make improvements in its overall process and this continually raises the bar for flexo in many applications.  In certain applications, gravure still has the edge with print quality and gravure has an edge in many long run printing applications.”

Guido Verini, executive vice president of Uteco North America, adds, “We have seen gravure jobs done in flexo with very similar quality. The two processes are separated by the difficulty of maintaining good quality in medium/long run.”

Job specifics

Comparing and contrasting the advantages and disadvantages of both processes can be tricky, and often the differences really depend on the specific job involved.

“The application of lean manufacturing principles encouraged shorter production runs with greater diversification.  These factors have favored flexo because it is more cost effective for those shorter runs.  Certainly photopolymer plates are much less expensive than engraved cylinders-combine this fact with the quick changeover capabilities of flexo and you have an ideal fit for a market driven by JIT delivery demands,” says Teachout.

“Gravure machine manufacturers and the PLGA have recognized flexo’s advantages and they have taken steps to address them.  Gravure is still very strong and cost effective in long-runs and as the packaging market continues to grow, there will a productive place for both processes in the future.”

Verini echoes those thoughts: “The main advantage of flexo has always been the capability of printing on thin and extensible materials like LDPE. The disadvantage was the change over time. Gravure has still a problem with extensible films, while flexo, with the sleeve technology, has reduced  time for changeover to levels even lower than gravure press with trolley.”

Lichon agrees, adding, “Depending on the press configuration gravure can lend itself better to allow the application of more colors and coatings and do so with easier job changes. Flexo has made great strides with on press sleeve changes and servo drives however gravure has also adapted these improvements and combined them with cart type systems that make for an easy and fast changeover.”

“While many of these advantages or disadvantages have been around for a long time, gravure continues to raise the bar, which in turn causes flexo to step up with improvements.  In the end this sort of competition has made for a better more cost effective product whether you choose gravure or flexo,” he says.

Evolution of Flexo

Today, flexo is an evolving technology.

“Great leaps in technology and overall in the final product quality have come from advances in plate making and initial graphics quality, sleeved anilox and gravure rolls, servo drive systems, automated registration systems and tension controls,” says Lichon. “These are just a few areas that have seen major improvements through the years.

“While the basics of these items all help to improve the final product one must be sure that they are all applied correctly. Otherwise you just end up with an expensive process that will not give you the return on investment you need.”

Teachout adds: “There continues to be advances in inks, anilox and CTP technologies, as well as computer controlled servo-drive systems. Together they have made flexo a cost-effective high-performance printing and converting platform ideally suited for today’s packaging market.”

New Technology

What will be the next major technological breakthrough in flexo?

According to Lichon, inks and automation will have a significant impact.

“I see improvements in inks that will allow for higher speed printing and I think we will see fully robotic presses.  This meaning unwind and rewind roll changes, anilox and plate sleeve changes and doctor blade system changes all done by robotics,” he says. Teachout agrees, and goes one step further, saying that the impact will go beyond mrerly flexographic printing.

“The “next big thing” for flexo technology will be automation. In many respects, servo technology has paved the way for greater levels of automation by replacing mechanical systems with electronically controlled systems,” he says  “This will allow easier integration of multiple processes to create even greater flexibility with shorter set-up times. Everything will eventually be controlled through a computer.  And, automation will not be a flexo exclusive-it will also dominate the gravure and offset processes.