Delivering High Coverage and Impactful Graphics, at High Speed, for Boxes and Boards

A thriving e-commerce industry and a growing trend in big box retailing together offer a promising growth trajectory for the corrugated packaging market.

Known for its structural rigidity, the corrugated box offers good protection to heavy contents or fragile products and is a lighter weight than many other packaging substrates. These attributes show why corrugated has traditionally been used for shipping and functionality, but recent e-commerce and big box retailing market trends have led to an interesting evolution of the corrugated packaging marketplace.

Large retailers, such as Walmart and Amazon, brand the corrugated packaging they ship to customers. Amazon’s iconic logo is all a box needs to promote its brand. A single color and low ink coverage keep costs down, while also using branding to tell a story when shipping products to customers. Customers see the black logo on the packaging sitting on their porch and know exactly from where it came.

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Big box retailing requires most corrugated packaging to be printed toward a higher level of graphics with very high ink coverage (100 percent to 200 percent) in full color.
Photo courtesy of ValeStock/Shutterstock.com

Walmart takes a different approach with its shipping boxes. The retailer’s e-commerce packages require full ink coverage over the entirety of the box in full color. Many online retailers with monthly subscription services ship packages using colorful and engaging brand messages that entice recipients to learn more. Branded storytelling is crucial to these types of e-commerce retailers.

High-Impact Graphics

Similarly, larger unit packages are now an essential element of the marketing mix. These types of large corrugated packaging, such as those sold at membership stores like Costco, allow consumers to buy products ranging from personal care and household items to electrical goods, processed foods, craft beers, and wine and spirits, directly off the shelf.

These corrugated boxes are usually printed toward a higher level of graphics with very high ink coverage (100 percent to 200 percent) in full color, similar to the historically high level of print fidelity required on folding carton package printing, for years.

This trend in higher coverage corrugated postprint often involves more complex graphics with traps and can be produced on equipment without dryers. The inks need to dry fast, but not too quickly. Inks need to be uniquely designed to provide optimal transfer and coverage that minimizes common print defects such as pinholes or fluting.

The inks also require high-quality traps, often in the wet or semi-dried state for the underlying ink, and then quick setting to minimize tracking or offsetting onto cutting die anvils or pull bands. The inks need to provide high rub resistance to prevent color transfer and offsetting in the value chain.

Higher coverage and graphics in corrugated postprint have also included the increasing usage of special effects. For example, metallic inks and coatings are being used far more often now than ever before. Technology and chemistry have advanced in recent years to make these special effect products much easier to use in printing and improving the final visual effect.

Big box retailing is also driving capabilities to advance in the corrugated preprint marketplace, with packaging that is direct printed with extremely high print quality rivaling offset and litho-label applications.

“The newest high-efficiency and productivity presses are now producing at a rate of faster than 400 boxes per minute with setup times for changeovers in the two-to-three-minute range, a fraction of what was common just a few years ago.”

These boxes are typically large format and are produced with extremely long cylinder repeat lengths, approaching or exceeding 80-in. This places challenges on inks to adequately rewet for these repeat sizes and maintain extremely high print fidelity, especially with graphics pushing the envelope with plate linescreen and correspondingly extremely fine anilox rolls.

Push for Speed

New equipment in the market is also pushing production speeds up toward or above the 2,000 fpm level across all printing and converting platforms. This requires expertly designed and controlled inks, with extremely high resolubility parameters and low film tack, while still maintaining rub and scuff resistance properties required for subsequent converting, corrugation, box forming and handling. The latest technologies use cutting-edge resin design to balance all of these competing forces and performance properties.

The trend of high-speed printing is also a key driver for corrugated postprint. The newest high-efficiency and productivity presses are now producing at a rate of faster than 400 boxes per minute with setup times for changeovers in the two-to-three-minute range, a fraction of what was common just a few years ago.

Vacuum transfer coupled with high line speeds and higher shear ink pumping and delivery systems place challenges on inks that can hold up to the shear and air flow on this equipment. Inks need to be extremely viscosity and shear stable as the pumps and delivery systems can be prone to micro-foaming or gelling. These presses also often favor lower and press-ready viscosities.

In the folding carton market, press speeds are approaching similar levels of 2,000 fpm or higher. This requires a significant technology change to support clean printing at high speeds and corresponding lower ink film application weights. The latest technologies require inks with specifically optimized and balanced resolubility profiles and film tack through the drying phases.

There is also a movement in the direction of using multicolor process printing in place of traditional 4-color process and spot colors. Adoption of 7-color printing has been primarily driven by efficiency. The usage of fewer spot colors may, on one hand, limit the number of colors to access, but it will also lead to fewer changeovers, which for some printers is a key driver toward production efficiency.

Importance of Sustainability

In addition to delivering higher coverage and impactful graphics at higher speeds, there is a strong push from consumers, retailers and brands for enhanced sustainability in packaging, with those demands now extending to inks as well.

Much of the design and standards for packaging today are driven by retailers:

Walmart wants packaging that is safe, affordable, recyclable, optimized and promotes sustainable chemistry

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Online retailers use their corrugated shipping boxes to promote their brands. Many require full ink coverage over the box in full color.
Photo courtesy of Andriy Blokhin/Shutterstock.com

Target expects packaging to meet the guidelines of the Environmental Protection Agency’s (EPA) Greener Living Sustainable Packaging Program, utilizing recycled or renewable content and no chemical of “high concern”

There are also many ecology-focused nonprofit citizens’ groups leading the charge for environmental changes. Non-government organizations (NGOs), such as Greenpeace, Sierra Club of America, Ceres and World Resources Institute, are strong advocates for certain environmental positions and help consumers and businesses alike recognize the need to change certain behaviors to become more sustainable.

Most printers already work under extreme pricing and profitability pressures and are always looking for ways to be eco-friendly, cut costs and keep expenses to a minimum. Reducing paper waste, lowering volatile organic compounds (VOCs) in the pressroom, and using eco-friendly inks are just some ways converters are cutting costs while also becoming more sustainable.

Corrugated and carton packaging often already possesses a high sustainable profile by being based on naturally and renewably sourced fiber, utilizing recycled content, and lending itself for re-pulping and recycling at the end of package life. Similar expectations are now being placed on inks, coatings, adhesives and other materials used on that packaging. Some ink companies have responded to the industry challenges by rolling out inks that meet all the eco-friendly, bio-renewable and biodegradable standards for which the industry, retailers and consumers are looking.

Some of these “greener” inks are formulated with high levels of biorenewable-sourced resins and can deliver the same critical performance attributes needed across a range of paper packaging applications that conventional solutions have provided in the past.

These inks should be formulated with significantly higher levels of biorenewable resin content compared to other market offerings and should not compromise quality or end-use and on-press performance. Inks that meet these standards should naturally also offer outstanding print fidelity and ink resolubility on press, quick setting for inline converting, and high levels of resistance properties to rub, abrasion, water and grease.

In today’s marketplace where there is a strong demand for convenience and on-the-go meals, retailers who stock the products packed in paper-based containers want an environmentally friendly solution at a lower cost. Good news: a series of water-based coatings have been formulated to impart or enhance resistance properties to paper and board substrates while being Food and Drug Administration (FDA) compliant for direct food contact. Designed to provide resistance to water, grease/oil, industrial chemicals and extreme temperatures, these aqueous coatings provide converters and brand owners an option to offer a more sustainable and less expensive package, replacing traditional barriers used in the market, such as polyboards and precoated boards, as well as wax and laminated films.

“Corrugated and carton packaging often already possesses a high sustainable profile by being based on naturally and renewably sourced fiber, utilizing recycled content, and lending itself for re-pulping and recycling at the end of package life. Similar expectations are now being placed on inks, coatings, adhesives and other materials used on that packaging.”

Resistance coatings of this type can be used on boxes, trays, wraps, liners and bags for fast food, allowing for the minimization of the package structure, while also being recyclable and re-pulpable, thus reducing the environmental footprint.

Desire Drives Dynamics

Key market trends, ranging from big box retail and the explosion of e-commerce to a demand for on-the-go meals and sustainability, have all contributed to significant growth in the corrugated and folding carton printing markets. The strong desire for packaging to be used as a marketing tool that showcases brands using high impact and powerful graphics has required that inks be developed that meet the dynamics of the printing press.

Higher speed presses require a whole litany of technical chemistries to master, so that those corrugated and folding carton boxes pop off the shelf without any print defects. Ink is the critical link that’s making corrugated and folding carton printing meet all the key trends in the marketplace.

About the Author

headshot Jeremy Teachman
Jeremy Teachman is field marketing manager for water-based inks at Sun Chemical. He is responsible for a variety of water-based ink systems and can be reached at 708-236-3798 or by email.