Flexible packaging printing via inline-style narrow web flexo presses is a growing market for label printers in North America. Slower growth in the label market segment, coupled with increased pricing pressures, contributes to traditional narrow web label converters seeking growth opportunities in the flexible packaging marketplace. Aided by the latest generation of state-of-the-art, multi-substrate narrow web flexo presses, these printers are afforded access to a wide variety of flexible packaging applications.
Expectations for flexible packaging growth by the market research firm The Freedonia Group project U.S. demand to increase 3.3 percent annually to $20.7 billion in 2019. Another B2B research group, MarketsandMarkets, forecasts worldwide plastic packaging markets will reach $113.65 billion by 2022 at a compound annual growth rate (CAGR) of 5.2 percent. This includes standup pouches, flat pouches, gusseted bags, wicketed bags, wraps, rollstock, material (plastic films, paper, aluminum foil, bioplastics), etc.
Changes & Innovations
It is safe to say it has been a natural progression for label printers to move into markets for flexible packaging printing, as they have been printing flexible packaging constructions with self-adhesive labels for many years. Their label customers are purchasing printed packaging films, and with relationships in place, label printers over the past 20 years have increased the percentage of non-pressure-sensitive (PS) films they are printing year over year. Brand owners have seen the benefits of working with narrow web printers capable of addressing their flexible packaging needs, especially for shorter run lengths and quick turnarounds. Narrow web printers are very active and assertive in markets for roll-fed film labeling, shrink sleeve labeling, pouches and stickpacks.
In the 1990s, label printers started to see narrow web flexo presses designed with features that allowed for printing on thin film substrates. Key press areas that needed to be addressed were web transportation of the film substrates, print register and heat management. Label press manufacturers took on these new challenges targeting designs capable of film printing. One manufacturer had the foresight to look at wide web flexible packaging printing presses that utilized temperature-controlled central impression (CI) drum presses offering excellent web transportation, print register control and temperature management.
This started the introduction of the driven, chill roll-designed narrow web label press with a drum after each flexo print unit. Web handling was greatly improved, as was print register; other key concerns such as the drying of aqueous inks and UV curing were also addressed. All were better handled using these heat sinks to manage web temperatures, while affording more and better drying, leading to higher press speeds.
The narrow web label printer had equipment available to it to take on food and non-food flexible packaging applications alike with success. Label printers needed to be educated on packaging substrates, inks reacted differently and ink drying issues needed to be addressed. Many packaging applications required lamination of some sort. Food packaging offered many opportunities, but careful consideration was needed as to what was acceptable for the label printers to use for both indirect and direct food contact. The cry went out: This move to flexible packaging printing was not as easy as it looks.
MPS Systems North America took the need for multi-substrate printing presses seriously when it launched its first narrow web flexo press in 1996. It serves as just one example. Not only did it target the desire for a press to handle thin film substrates, it embraced servo drives and the need for narrow web flexo presses to print without gear marking and banding and barring, common in the 1990s.
Inline-style narrow web flexo presses use servo-driven infeed and outfeed nips to isolate web tension and successfully transport a wide range of substrates. These nips are ideal, as they grip the substrate evenly and can manage tension at acceptable levels. High-speed photography confirmed that disruptive nipping action is created at each flexo print position—Printing units were acting as nip units. Differing levels of surface area on the plates (a process plate versus a line plate) printing against a driven impression roll disrupt web tension and contribute to registration errors.
One added advantage of printing against a non-driven impression roll is the ideal match of web speed to plate speed, regardless of the thickness of substrate being printed. Today’s servo-driven label presses with driven impression rolls require the operator to make adjustments in speed as substrate thicknesses change. If this is not done, tension issues can arise, contributing to registration and printing problems, such as unwanted banding.
Separation between printing and web transport addresses tension and registration issues when printing thin film flexible packaging substrates. Critical factors needed to consistently print high-quality film substrates are stable register, sharp HD dots and no banding or barring. With a solution like MPS’ Crisp.Dot technology, the flexo printing plate is not printing against a transport or chill roll, but against a separate, free-running impression roll. This prevents friction in the printing process, resulting in a higher quality, optimum registration and significantly fewer banding errors. Web transportation is precisely controlled by servo-driven, temperature-controlled chill rolls, and servo infeed and outfeed systems. A short web path is possible when UV or LED curing.
The result is the ability to print in stable register the most demanding quality labels, thin mono-films and carton board, as well as shrink sleeve, in-mold labels, tube laminates and aluminum substrates.
Automated Pressure Settings
One of the most pressing issues in the label and package printing industries is finding and retaining skilled operators. This trend emphasizes the need for companies to invest in automation to secure both productivity and print quality. In a day and age when most presses are servo driven, the real question is whether a press is equipped with servo-controlled print pressure settings.
Modern press technology allows the setting up not only of stored jobs (from memory) but also new jobs faster with a calibration database. It allows the operator to utilize servo technology while giving objective numeric feedback. Integrated controls allow the press to automatically adjust pressure accordingly as the machine speeds up and slows down to provide consistent print results. On top of that, thanks to available camera technology, it is possible to set up print pressure settings automatically by using a closed loop feedback system.
Touchscreens & Quick Change Tooling
Studies show the motivation of a press operator is the No. 1 factor influencing the performance of a press. Therefore, ease of operation is key and this is where user-friendly, digital control buttons, which work together with the control screen at every print unit, play a part.
As pressruns are becoming shorter and shorter, making it necessary for quick changeovers, press design has adapted to include features such as quick lock doctor blade holders, aniloxes with handles and quick change ink pans with integrated metering rolls. As a result, extremely fast changeovers can be achieved without the need for tooling or gloves.
Combining Printing Technologies
There are also inline-style flexo press platforms which offer the possibility to combine processes. Gravure is one example of a combination printing technology that can be added to a flexo press used to produce flexible packaging substrates. Special applications, such as cold seal, can be accomplished on a combination printing press.
Today, combining digital printing with flexo printing in a hybrid press approach is proving to be effective for label and packaging markets, particularly for such things as shrink sleeves and stickpacks for single-use cleaners, car wash soaps and fuel additives. Seven-color expanded gamut (EG) digital printing is combined with flexography using the advantages of both processes to tackle promotional packaging requirements and a proliferation of SKUs, with the opportunity for variable printing and data to be combined in one-pass printing.
Narrow web press builders have designed and brought to market wider, faster (with longer print repeats) inline-style flexo presses. Many times, these presses are delivered to address specific end-user requirements and may be dedicated for a single end-use market application, such as shrink sleeve labeling, decorating solid and laminated tube structures, printing pouch constructions, or aluminum lidding, where special coatings are required to perform specific tasks in hands of the consumer. As speeds increase, so do drying requirements, and these larger narrow web presses allow for additional drying options, such as extended air dryers.
Test & Examine
With the newest generation of narrow web and growing wider inline-style presses, new markets for flexible packaging printing are in reach of label printers. Take your time to do your testing, examine all the attributes of the equipment you are considering, and know that flexo printing technology can deliver the printed results you need today to answers the demanding requirements of your customers and prospects alike.
About the Author: Denny McGee has been in the flexo industry for 45 years. He received the FTA President’s Award in 1997 for his efforts to further flexo education at the high school and college levels. In 2005, Denny was inducted into the FTA Hall of Fame. Today, Denny represents several leading flexo equipment manufacturing companies specializing in equipment for label and packaging printers. He has represented MPS Systems North America for 14 years. You can reach Denny at [email protected].
MPS technologies referenced in this article include its Automated Print Control (APC), iControl and the EF model label and packaging flexo printing presses. These multi-substrate presses are available in 13-in., 17-in. and 20-in. web widths. Available with single-drying systems such as air dry for pursuing food packaging markets, or a combination of both air dry and UV or LED curing.