The Flexible Packaging HALL of FAME

Trends and innovation. These are the two areas at the heart of nearly every trade show, every educational seminar and every business publication having to do with the flexible packaging industry. Walk around any industry event, and you’re bound to overhear any number of conversations dealing with one or both of these topics.

That got us to thinking. As an industry magazine, we’re always writing stories about current and future trends, and cutting-edge technological innovations. But what laid the groundwork for today’s flexible packaging products and processes? What are the most important and influential inventions, breakthroughs and processes that eventually served as the foundation for today’s industry?

With those questions as the backdrop, Flexible Packaging set out to examine a handful of these influential innovations, and essentially ‘induct’ them into our virtual Flexible Packaging Hall of Fame. Since 2007 marks the 100th anniversary of plastic, we thought it fitting that this be the year we honor a few techniques, processes and products that shape the everyday production of flexible packaging.

The hard part was identifying our inaugural class of inductees. Early on we tried to be as specific as possible, but that led to a very large number of candidates. In the end, we decided to choose three important, though broad, areas of influence that have shaped the look, feel and shape of modern flexible packaging. Our inductees are: Flexographic Printing; Modern High-Tech Inks; and Reclosability.

 

The common definition of flexography appears in the “industry manual” publication Flexography: Principles and Practices, published by the FFTA. It defines flexography as:

“A method of direct rotary printing that uses resilient relief image plates of rubber or photopolymer material. These plates are affixable to plate cylinders of various repeat lengths, inked by a cell-structured ink-metering roll, with or without a reverse-angle doctor blade, and carrying a fast-drying fluid ink to plates that print onto virtually any substrate, absorbent or non-absorbent.”

Flexography is the fastest growing conventional printing process for packaging, and represents about $70 billion worth of printing annually, or 22 percent of all printing worldwide. Flexo is the primary printing process employed by flexible packaging converters in North America and has enjoyed a surge in quality and versatility in recent years, thanks to hard work and creative innovations from industry experts.

Today’s flexographic printing was originally called aniline printing because of the aniline dye inks that were used in the process. The first aniline press was built in 1890 by Bibby, Baron and Sons in Liverpool, England and used water based dye inks.

In 1905 C. A. Holweg built an aniline press at the end of a bag machine and in 1908 he patented the aniline press. The ink metering and control on these presses was sloppy and erratic until 1938 when the anilox roll was introduced. The anilox roll, patented by Douglas Tuttle and Col. Joe Viner, employed a mechanically engraved copper coated roll with controlled cell sizes. The idea was developed and adapted from watching the rotogravure printing process

Eventually, the original aniline inks were replaced with those based on polyamide resins for a number of reasons. Not the least of which was because the aniline dyes were made from coal tar, were toxic and were banned from food packaging by the FDA. These new, stable, fast-drying inks enabled web speeds to increase from 150 to 750 feet per minute.

 

In 1951, Franklin Moss, head of the Mosstype Corp., started a campaign to change the name of the printing process. His company was a pioneer in rubber platemaking for both aniline and letterpress printing, but the name ‘aniline’ carried with it negative imagery due to the old toxic dyes.

In his publication, The Mosstyper, Moss asked for readers to submit suggestions for a new name for the printing process. He received more than 200 submissions, and had a group from the Packaging Institute’s Printed Packaging Committee narrow the choices down to three finalists: permatone process, rotopake process and flexographic process. The name ‘flexographic process’ won convincingly via mail-in ballots.

Recent innovations in flexography include the changeover from rubber flexo plates to photopolymer plates in the 1970s, which facilitated a marked improvement of the quality of flexographic printing. The push for environmental responsibility in the 1980s led to the use of more water-based inks in flexo. Today, the quality of flexographic printing is approaching that of offset and gravure, and web speeds are routinely seen approaching 2,000 fpm, the result of fine-tuning a very efficient printing process.

 

According to David Lanska, author of the book Common-Sense Flexography – A User’s Guide to Improved Pressroom Productivity, flexography offers a combination of benefits not realized by other processes, including value, speed and cost-effective changeovers.

“Flexography once had a reputation as a simple, rubber-stamp print method. It now offers tremendous versatility combined with unprecedented levels of quality,” writes Lanska in his book, published by the Printing Industries of America/Graphic Arts Technical Foundation (PIA/GATF). “No other print process has come so far so very fast. Offset and gravure have both lost market share to flexo. If they don’t recognize flexo as a threat now, they certainly will as more and more offset and gravure jobs get snatched up by flexo print jobs.”

While he agrees with the standard definition of flexography, Lanska would like to update it with some of the more out-of-the-box thinking that has developed due to flexography’s impact on flexible packaging.

“Flexography is not defined by what it is, but rather by what it does,” he writes. “Flexography is the mechanism consumer product companies use for direct marketing to consumers. Flexography turns an ordinary package into a stand-alone point-of-purchase display. The package itself becomes a three-dimensional billboard, providing information, advertising the contents, exuding qualities of the product, conveying image, promoting the brand, creating product awareness and executing marketing promotions.”

 

Lanska notes that the ultimate power of good flexographic printing is the idea that packaging and graphics entice people to purchase 20-oz. bottles of water for $1.29, which works out to $8.25 per gallon.

“Consumers’ perception is that the bottled water is somehow better, more pure, and more refreshing…” writes Lanska. “They have that perception because we give it to them with our remarkable powers of persuasion—e.g., colors, graphics, specialty inks, screens, vignettes, process images, lenticulars, laminations, etc.

“Flexographers don’t simply print a package. Flexographers make a sale!”

In the end, flexo printing is all about adding value to a flexible package, facilitating the fact that 75-80 percent of purchase decisions are made at the point of sale. Lanska distills the role of the flexographer down to its essence:

“It is our job to get the consumers’ stomachs to growl and their mouths to water from seeing ink droplets applied to [a substrate].”

 

Flexographic printing could not be the workhorse it is in today’s North American flexible packaging market without the functionality and formulations of modern inks. Modern inks used on flexo presses have come a long way from the aniline dyes of flexo’s infancy. But the basics are not far from those of years past, according to Tony Renzi, Global Director of Technology, North America, at Sun Chemical Corp.

“The basic building blocks for flexible packaging inks are the same with regard to resin/solvent/pigment and functional additives. Inks today and 50 years ago both contain these four basic ingredient categories. The big difference lies in the chemistry of these basic building blocks today versus 50 years ago,” he says.

Food packaging regulations (from the FDA), environmental issues (from HAPS), and health and safety factors (from OSHA) have limited the list of acceptable ingredients in today’s inks.

 

In the past, inks were used only as decoration on a package. Today, inks play a more integral role in contributing to the functionality of a package and can impart properties to enhance end-use applications, says Paul Hunt Sun Chemical’s Global Director of Technology, Europe.

“For example, lamination inks evolved to the point of maintaining their bonding properties even under extreme temperature and pressure requirements,” says Hunt. “This allowed flexible packaging to move into areas of boil-in-bag, microwave applications and recently into the growing retort packaging application. Combining the higher performance of the inks as a functional component of the package and the movement of the raw material building blocks to those chemistries regarded as safe for indirect food applications, inks pushed the flexible packaging industry into new markets once occupied by cans and glass bottles and spurred the growth of flexible packaging.”

 

Many innovations in modern inks resulted from environmental and food safety concerns. New developments in non-migratory functional additives for adhesion, energy curing and flexibility have been critical to the development of innovative ink systems and the growth of the flexible packaging market, according to Richard Pettifor, president of Sun Chemical North American Packaging.

“These innovations have not been trivial and some of the alternatives have challenged ink suppliers to formulate products that achieve comparable performance with solvent and inorganic pigment-based past chemistries,” says Pettifor.

While modern inks are of course limited by the specific printing processes employed, most-often flexo, they are also designed specifically to improve and enhance the current print processes and press speeds.

“Technology innovation has to be a competency of an ink supplier in today’s market if they intend to meet the needed performance and open new markets to flexible packaging,” adds Pettifor.

While printing on flexographic presses with high-tech, modern inks is the most obvious and most common way to add value to a flexible package, there is one feature that has revolutionized many markets within the flexible packaging industry and has worked its way into the public consciousness to the point where today it is a must-have feature: reclosability.

Reclosable and resealable packaging (specifically, zippers and sliders) is one of the most important innovations in packaging — not just flexible packaging — over the last 50-plus years.

The story of reclosable zippers and sliders dates back to 1951, when Flexgrip, Inc. developed the first PVC vinyl zipper products for storing school supplies such as pencils and crayons. In 1959, Minigrip (now Zip-Pak) manufactured the first reclosable zipper on a plastic bag in the United States. Over the years, the product continued to be developed and improved, including the introduction of Ziploc food storage bags.

Eventually in 1986, Illinois Tool Works and Dow Chemical partnered to form Zip-Pak and produce the first resealable packaging for a consumer product group. The brand: Sargento. The product: cheese. Since that first introduction, the potential impact of the press-to-close zipper was obvious.

 

“Starting with zipper, the original idea was to save the consumer a step,” says John Schneider, vice president and general manager of Zip-Pak. “They had been using a Ziploc bag to store their leftover cheese or leftover pet treats or snacks and candies. We just put the zipper directly on the package and let the consumer use what they want and then reclose the package.

“And for the brand name companies, they were able to keep their brand name in front of the consumer. So that if [someone else in the household] went shopping and was told to buy shredded cheese, they would get the right brand.”

Part of the allure of the PTC zipper was freshness – both actual and perceived. Another was convenience, which enhanced the consumers’ experience with the product.

“What we've seen over the years is the evolution of flexible packaging from being a basic bag for storage and keeping the product fresh until the consumer had it in their hands,” says Schneider. “Today, I think there's a lot of functionality being added to flexible packages.”

That added functionality doesn’t end with the PTC zipper.

 

After zippers became an obviously important part of flexible packaging, the time came to improve on and add to the success of that reclosable system. Again, Sargento played a key role in the development of the next step in reclosable packaging.

“Sargento cheese.” They were the first company to put their product in press-to-close 20 years ago. Then Kraft followed and then the whole world followed,” says Steve Meli, national accounts manager for Pactiv Corp. “And then five years ago they were the first to put their product in a package with a slider. Then Kraft followed and now you’re seeing sliders become more and more prevalent, and it’s really because of Sargento starting it.”

Adding additional ease-of-use to the established functionality of the PTC zipper resulted in the slider zipper, and now it seems like in specific segments, a PTC zipper or slider is a must.

“PTC, these days, is a given,” says Meli. “You’re going to have some type of recosability on your package. But more and more in the last five years, sliders have become more prevalent. Some of the things that are driving that are the club stores that offer larger packages. They’re really making a big push here for a reclosable package. Slider is becoming the norm because with those big packages, it’s harder to do the press-to-close – slider is a sure thing, it’s closed every time. You’re sure you have a positive close, so we’re seeing a lot of growth in that club store area.”

The need for easy-to-reclose flexible packaging comes from not only the added convenience for the average consumer, but for those segments on opposite ends of the age spectrum – aging Baby Boomers and young children. Both the young and the old can easily manipulate the press-to-close zippers, and if that becomes a problem, the slider zipper is an even easier solution, offering a properly closed package every time.

Sliders and zippers are here to stay in the flexible packaging industry. Their impact on the industry as a whole, along with Modern Inks