By Melissa Donovan
Corrugated board printing is driving new business into print service providers (PSPs). For this article, package printing refers to prototypes, packages, and point of purchase (POP) standees—anything structural in nature. There are challenges to printing directly on corrugated board. To address them, manufacturers create flatbeds with features that entice PSPs to utilize the newest digital technologies over traditional analog. These include enhancements to printer temperature, material handling, ink laydown, and productivity.
While challenging, PSPs able to print on corrugated board benefit from its popularity. EFI cited recently that the $130 billion corrugated packaging industry has more than 200 billion square meters of printed output per year—a figure that is more than 25 times greater than the estimated amount of annual signage and graphic output produced.
Understanding Ins and Outs
No substrate is immune to failure, but corrugated board does present its own set of unique challenges. The porousness of the material causes difficulty when it comes to remaining stable on the flatbed and in how ink is laid down.
“Corrugated board is a ‘living’ substrate, it is affected by the environment, manufactured in different conditions by different corrugation machines, it may be transported, and as such is susceptible to deformations,” suggests Amir Shalev, product marketing manager, HP Inc.
The material poses problems that could be foreign to a PSP. “Flutes in the boards create a challenge for digital printers as they don’t restrict the vacuum air flow in order to best hold down the substrate for printing,” says Jay Roberts, product manager, UV printers, Roland DGA Corporation.
“Corners bend easily, boards are very sensitive to temperature and humidity, and, in general, they don’t hold their shape the same way as some traditional rigid graphics materials,” explains G. Scott Wood, senior product manager, EFI. If a board’s corners are bent or the material is warped this increases the risk of printhead strikes.
A board may warp, curl, buckle, or swell due to heat within the printer, or can distort prior to being placed on the flatbed. “While keeping the media flat during printing is crucial, it’s also very important to keep the media flat prior to printing, while it’s in storage. The edges of many substrates can become dinged and bent very easily,” advises Roberts.
The environment the board is stored and/ or printed in plays a role. “An atmosphere where humidity is either too high or too low can cause the board to warp. Most flatbed UV operators are accustom to printing on materials that are not as volatile as corrugated,” suggests Jim Peterson, founding partner, Vanguard Digital Printing Systems.
“The distortion seen on traditional—nondigital grade—corrugated board can be far worse than other media a digital flatbed printer operator would be used to seeing on the substrates that he/she uses,” cautions Becky McConnell, associate product marketing manager, Fujifilm North America, Graphic Systems Division.
How ink is laid down on corrugated board also differs thanks to the absorbent nature of the board and its color. “Corrugated board tends to have a more porous printing surface that can absorb quite a bit of ink. In addition, when printing on a kraft surface the brown color can be quite challenging when trying to match colors,” shares Josh Hope, senior manager, industrial printing, business development and marketing, Mimaki USA, Inc.
Javier Mahmoud, VP of sales and marketing, CET Color, says in most cases the corrugated material isn’t white, which introduces the need for white ink to produce the correct color results.
“Most corrugated cardboard is uncoated and brown, which makes it very difficult to print accurate saturated colors because the pigment sinks into the material. For more money you can get corrugated cardboard with a white clay coat, which improves color reproduction. The other solution would be to put white ink under the colors so the ink cannot sink in and the base is white instead of brown,” recommends Ken Parsley, product manager, Mutoh America, Inc.
“A variety of materials are used for the facestock from raw porous board to white top or kemi board. Porosity varies with temperature and humidity and white top varies in composition. This variance creates a challenge for image quality, relative ink density, and ink finish,” adds Mark Schlimme, director of marketing, Screen Americas.
Carmen Eicher, VP of marketing, swissQprint America, Inc., says the porous nature of corrugated board means it is unsuitable for certain printing processes. “Liquid ink will seep in or spread, creating a blurred image. UV cured ink is the ideal solution, however, if the cured ink is too hard it may crack when the item is processed after printing.”
These issues require manpower to check each sheet to ensure it isn’t damaged prior to print and also during print to avoid any interruptions in the process. Because of this, throughput levels of printing on corrugated board are low.
“Up until now, there has been room for signage and graphics companies to develop a niche in digitally printed corrugated displays and maybe even in very short-run/prototyping packaging, but speed limitations have kept the market from adopting more full-production runs of corrugated packaging in the past,” admits Wood.
One way productivity is limited is when users are forced to combat the curl of corrugated board on a flatbed press by taping around the edges to hold it down, points out Larry D’Amico, director of sales – North America, Durst Image Technology US, LLC.
Digital Dives In
Aware of the potential of digital in the corrugated package segment, multiple flatbed vendors have created new products or enhanced older models to address many of the issues discussed above.
Combating the challenge of the flutes in the boards, which prevent the media from laying flat, flatbed manufacturers have adjusted or enhanced vacuum systems on their tables.
Agfa Graphics’ Anapurna 2540i FB printer incorporates a digitally adjustable vacuum controller for a dual ring blower vacuum system. “Our dual vacuum system on dayto-day normal POP substrates only uses approximately 50 percent of its capacity. This means we have a lot of overhead vacuum suction capabilities that we can ramp up when needed on difficult substrates like corrugated boards,” explains Bill Bouhle, senior application specialist, Agfa Graphics North America.
CET Color’s flatbeds include two vacuums with a four-zone isolation system. This enables the operator to stabilize areas of the corrugated material as it is printed.
The Mimaki JFX500-2131 and JFX2002513 both feature user-adjustable vacuum zones that allow for greater control of the vacuum system by turning off areas of the print bed not being used. This creates a stronger vacuum in the areas where the corrugated board is.
Roland’s VersaUV LEJ-640FT offers a robust vacuum hold down in addition to vacuum zones. These help hold down the media by restricting airflow to specific channels, increasing the suction in those areas.
To address distortion of the board during the print process, manufacturers take into account the temperature of a printer and material handling features.
The Rho P-10 250 series and Rho 1300 series from Durst offer skis to hold corrugated material down. Unique to the ski system are pneumatic pumps and digital movement of the skis for accuracy.
EFI developed cool cure LED technology on its flatbeds, which eliminates the heat component that causes boards to warp. It addition, it now offers a series of material edge guides for its VUTEk GS and HS hybrid printers that hold boards in place as they run through the printer.
Fujifilm’s Onset X series offers three automation choices to help with the handling of corrugated board. For example, a robot automation system uses vacuum-to-vacuum transfer to ensure precision handling starting with a robotic arm pickup, continuing with placement on the print bed, to stacking of the printed board. To avoid crushing the flute and compromising the structure of the corrugated board, the vacuum pickups do not apply pressure.
The corrugated versions of HP’s HDR series—HP Scitex 15500 and 17000 Corrugated Presses—feature the HP Corrugated Grip solution that enhances hold-down power to handle industrial-grade corrugated boards.
Vanguard Digital’s VR5D and VK300D flatbed UV printers include LED curing technology to reduce the heat on the corrugated material during printing. Each Vanguard Digital flatbed is also equipped with PrintGuard crash sensors, which that protect the machine in the unlikely event of a material obstruction.
In regard to challenges with ink laydown, Schlimme says printer and ink manufacturers are teaming up to design and formulate inks targeted specifically for printing to porous corrugated board. He points out that the ability to print a fast and opaque white for image quality critical images is important. Higher end printers can vary ink gloss finish by controlling cure energy and timing.
Mutoh manufactures three LED UV wide format printers—the ValueJet 426UF, ValueJet 1626UH, and ValueJet 1638UH. All of which are equipped with white ink and varnish.
swissQprint ink for its flatbed printers is formulated to be flexible to withstand creasing and folding. CMYK is offered standard on the machines, however up to five additional color channels can be added—white or light colors, orange, violet, and green. Varnish for visual and tactile effects is also an optional feature.
Speed is a concern, especially as digital filters into production-level industrial environments. New printer models offer enhanced production levels.
EFI debuted the EFI Nozomi C18000 1.8-meter corrugated board press at drupa 2016. It runs at speeds of up to 8,100 square meters per hour and can print on boards up to 1.8×3 meters in size. Double-lane printing features increased throughput up to 9,000 80×60-centimeter boards per hour.
A Satisfying Leap
Despite a learning curve, working in the corrugated package printing segment to create anything from prototypes and packages to POP standees is something PSPs should seriously consider.
“As best we see it, the corrugated market is about a $120 to $130B market and growing,” cites Deborah Hutcheson, director of marketing, Agfa Graphics North America.
EFI estimates that the total addressable market for inkjet printers and ink in the corrugated board space is north of $9 billion per year. “That makes it one of the largest market segments we reach across the entire company,” shares Wood.
“While outdoor advertising is competing for consumer attention with electronic displays and with multiple other media streams, printing on a corrugated box or merchandising display puts the marketing message as close as possible to the consumer—in the famous last three feet,” explains Shalev.
In regards to corrugated board, Robson Amorim, international sales manager, Ampla Digital, says “it is a versatile and low-cost material, which with the correct printing and eventually decorative finishing, will add value to the final promotional piece.”
The advantages of digital, with costeffective short runs or larger runs with multiple versions, furthers the appeal of corrugated board.
“The ability to capture local markets in national campaigns has great advantages over traditional printing. I have customers using large run, traditional printing in conjunction with UV digital printing onto pre-printed pieces. Using variable data, they are able to customize these pieces for specific, local markets, allowing for extremely effective, targeted advertising,” says Roberts.
Hutcheson shares that digital corrugated printing is lucrative because PSPs can produce prototypes quickly and efficiently. Or, they can print customized corrugated end caps for one account with hundreds of locations across the country.
“In a world where brands are struggling to be recognized by consumers, directto-board digital printing enables endless customizing of print campaigns and eliminates prepress costs, as no plates or pre-coating processes are required,” agrees McConnell.
Risk with Reward
Corrugated board is a tricky material, but the newest digital flatbed devices are designed to handle it—from vacuum hold down to advanced media handling and the correct ink. The growth potential in the packaging segment is high and PSPs willing to learn the nuances of printing to corrugated board are sure to benefit in the long term.
Oct2016, Digital Output