Corrugated Production: Finding the Right Fit
For corrugated packaging printers, the decision to print directly to the board versus a top sheet to be laminated to the board is one that often comes down to quality and cost.
Louis Salters, manufacturing manager for International Paper’s Tucker, Ga. facility, says directly printing on the board is inexpensive, and with jobs that do not require high graphic images, the quality can be strong. Flexographically printing on a top sheet, however, typically produces a better quality image than printing directly to the board.
“The drawback for any customer to this printing preference is that the cost for the work is more expensive,” he says in an email. “To achieve the highest quality print in flexography, printing on the uncorrugated substrate is the best route. Recent innovations like digital printing have begun to challenge that narrative, but I still strongly believe, given exposure to all three methods of printing, that printing on the top sheet gives the best quality image for the cost.”
Eric Stanton, sales manager for Sutherland Packaging, based in Andover, N.J., explains direct printing is a step-saving process in which, upon the creation of printing plates, printing is a one-machine project. By contrast, a litho lamination top sheet requires multiple steps and can therefore be a little slower in the ramp-up process.
A key component of the decision making equation is the size of the application being printed. As the format enlarges, cost savings for direct printing increase. For example, due to its size, a pallet skirt may skew toward direct printing due to its cost for customers.
“Conventionally, litho’s big advantage has been image clarity, as it carries the potential to produce crisper images simply due to the substrate, with corrugated being a somewhat “grainier” surface,” Stanton says. “However, in recent years, direct-to-corrugated digital printing has changed these equations considerably. Whereas digital was once seen as exclusively for short-run jobs, we’re now seeing longer and longer runs incorporating digital that successfully competes with litho in terms of both cost and quality — especially because digital completely eliminates printing plates.”
The BoxMaker, a corrugated printing company in Kent, Wash., has added digital printing capabilities in the form of an HP PageWide C500 press, which provides direct-to-board, single-pass, inkjet printing. Richard Brown, president of The BoxMaker, explains that the addition of digital printing has provided an increased level of flexibility.
“With digital print, ink is applied directly to the material surface — with no print plates required to transfer the image,” he says. “This method enables many benefits, including elimination of most make ready, full CMYK color printing, reduced tooling costs, reduced production timelines enabling faster speed-to-market, variable artwork capabilities, and reduced minimum order volumes. If you’re short on time, desire any level of variable graphics, or have specific volume needs, digital print provides an excellent solution.”
Litho lam meanwhile, prints to the liner board before it’s attached to the corrugated fluting, providing it with the advantage of printing on a smooth surface. Litho lam also permits CMYK plus spot PMS colors, metallics, and an array of finishing options beyond that of digital. Brown explains that when running tens of thousands of identical impressions, litho lam may be the more competitively-priced choice over digital.
However, he says that litho lam often requires generous lead times and a high minimum volume order, along with tooling and setup costs for the manufacturing of print plates.
Impact on Production
Salters notes the method of printing directly on the board adds an additional layer of inspection and setup during production.
“Setups increase and the chance for error increases on this step, which we normally refer to as post-print,” he says. “Printing on the top sheet that gets laminated or glued to the board simplifies work for the converting operation, but adds a separate step in the production process.”
Despite the reputation top sheets have for superior quality, Robert Sweet, sales manager for Lee’s Summit, Mo.-based Bennett Packaging, says that the quality gap is becoming narrower. He adds that the amount of material used in the process can be another important consideration.
“While top sheets historically have garnered higher-quality print outputs, direct-to-sheet printing has come a long way in competing,” he says. “And the fact that printing direct to the sheet reduces the raw materials used and wasted during production, clients are starting to weigh the advantages and disadvantages a little differently than they did in the past.”
Stanton notes that given the differences between the two strategies, the size of the finished product plays an important role.
“Once you start getting over, say, 28x40˝, litho starts getting increasingly pricey, and the cost of lamination must also be considered,” he says.
For Sutherland Packaging, color matching for its brand owner customers is very important. With four-color process in litho, it can be challenging to match colors exactly. With direct printing however, spot colors can be implemented.
“One advantage that litho has traditionally enjoyed is that its images have a higher clarity potential,” Stanton says. “However, advances in technology have closed this clarity gap considerably, as digital printing offers enhanced process control and visual clarity.”
When debating between which printing process to use for a certain job, the specific branding needs of the customer should be considered.
Salters points toward Amazon as an example. The company’s ubiquitous and widely recognized logo is successfully branded and marketed on boxes utilizing the basic forms of direct/post print flexography. Because there are minimal graphics and colors on these boxes, direct print makes for a preferable technology.
“A customer, however, like Huggies or Pampers, that want to convey not just their logo but also project imagery of lifestyle and potential uses for their product, will require the use of more advanced printing like preprint, lithography, or most recently digital printing,” Salters says. “The complexity of the image and the volume of product needed help with making the decision for the customer and the brand on which solution works best.”
The Digital Print Decision
Recently, Sutherland Packaging expanded its digital print capabilities by incorporating an HP Scitex 15500 digital corrugated press.
“The multi-pass, six-color press allows us to produce high-quality short runs more cost-effectively with pristine graphics and quick turnaround times,” Stanton says. “It is designed specifically for corrugated converters that produce temporary and permanent displays, retail ready packaging and other short-run corrugated applications.”
Such presses, he notes, are valuable assets, as they offer benefits such as hands-free and stack-to-stack operation, auto loading, and zero setup — saving both time and labor costs.
Customization options are a significant benefit of digital equipment. For example, one of the advantages of the HP Scitex 15500 digital corrugated press is the ability to print from a matte finish all the way up to a high gloss.
“We can even highlight parts of an image,” Stanton says. “So it’s a very versatile form of printing that, again, is generated automatically with limited setup time. The printing industry is just beginning to explore and implement the nearly limitless options that digital printing is bringing to the game.”
International Paper recently invested in an EFI Nozomi C18000 digital printing press, which prints high resolution graphics on a corrugated board prior to the board being converted into its final use.
“We currently use it predominately on low volume items; the cost of inks and overall operation are still very high due to the infancy of the technology,” Salters says. “Economies of scale have not been attained in this technology yet. Customers that have a small volume demand for high graphic printing — think retail displays, limited edition launches of products, medium-sized retail product businesses, event marketers — all benefit from this option because it works well on small volume runs.”
This technology, once perfected, can serve as a vital tool in the portfolio or toolbox of any packaging company that services customers with wide ranging needs. Not only will it give the customer more choices, it helps the company optimize its utilization of resources and equipment.
With The BoxMaker’s HP PageWide C500 single-pass direct-to-board inkjet press, Brown says it amplifies the company’s ability to support client needs by delivering all the benefits of digital print to orders of any quantity, with the added benefits of offset quality print and true water-based food-safe inks.
Making a Choice
The primary strategy International Paper uses is preprint flexography since its customers tend to order in large quantities and the company produces more than 1 billion square feet of business each year.
“The biggest driver for our company to opt for preprint flexography for the customers that I directly service is complexity of print, volume of product and cost of the application,” Salters says. “Ultimately, it is the customer’s decision. There are a host of factors that weigh into each business decision for package printing; package printing is important but is not the sole factor that decides the strategy used for printing.”
Cost is always a consideration when determining printing application and solution. As the graphic complexity increases, the cost of production increases.
“Direct printing on board is the most economical of all the printing options, then there is a spectrum of options before getting up to the most expensive option which is some form of preprint flexography,” Salters says. “Preprint flexography becomes economical if you have a consistent level of volume to be ordered.”
One of International Paper’s largest customers is Kimberly-Clark, which operates a variety of consumer brands, including Huggies and other tissue products.
“For this customer and the project of meeting their needs for their entire portfolio of products, as a company, we utilize both direct printing and preprint,” Salters says. “It was vitally important to offer a wide range of product solutions to satisfy their suite of products. Some of their containers only require a simple one-color logo on brown corrugate. Other items in their product portfolio that we service require high graphics and a higher level of flexographic printing. For this reason, we offer to them direct printing, lithography and preprint flexography.”
When deciding which printing method to use, Sutherland Packaging runs the numbers for both methods and weighs it against the specific customer requirements. From there, it provides customers with options and recommendations that work best for them.
“As a print house fully capable of both methods, we find that a transparent customer servicing process yields premium customer satisfaction, as well as best-possible end products,” Stanton says. “All the factors must be considered when determining whether a particular job should be performed using [direct to corrugated] or litho. These include quantity, format size, clarity requirements and other variables.”
For one client, Sutherland Packaging mocked up both a litho and direct-printed display, and because it was a large format, the litho was rather expensive.
“We showed how we could achieve the same look and save about $2 a unit — $8,000 over a 4,000-piece order, including the cost of the plates,” Stanton says. “The customer was thrilled.”