Improved Graphics + Better Economics

The future of folding carton manufacturing


For the better part of a decade, the folding carton industry has been under pressure to reduce costs, deliver short runs quickly and produce more and more eye-catching graphics. As these pressures have squeezed some producers out of business, others have found ways to cope. Some of these coping mechanisms have included price-cutting, non-process-related cost reduction efforts (how many of your customers still have a receptionist to greet visitors?) and even taking contracts at or below break-even just to keep the presses running.
Fortunately, not all the ways to survive in this tough market have to mean such severe austerity measures. A growing number of paperboard and folding carton converters have discovered that in-line web printing and diecutting, principally using flexographic presses, offers tremendous cost savings while still producing the kind of graphic reproduction quality that the industry demands.

In order to understand this approach, one needs to grasp and accept two primary truths. First, the flexo industry as a whole has made tremendous advances in print quality. The historical “gap” between flexo and its nemesis, offset lithography, has narrowed to a point where it is largely an academic debate. Second, and no less important, is the economic advantage enjoyed by web-fed inline flexo over sheetfed offset. Productivity, paper savings and labour savings trump the higher costs of flexo plates and rotary cutting dies, making web-fed flexo the smartest choice for converters facing the “faster, cheaper” modern-day packaging industry.

Flexo Quality
Tight register. Miniscule reverse type. Smoothly fading vignettes. Life-like flesh tones. All these are printing characteristics that traditionally were the exclusive domain of offset printing. Flexo, by contrast, was relegated to cheesy one- and two-color reproductions on corrugated boxes. “Fragile – this end up” and “Made in Japan” may have been the primary things printed with this method. Process? Fuggetaboudit. Registration? Measured with a ruler.

No more. Digital plates, CTP platemaking, precision presses and rapid advances in ink curing, drying and the inks themselves have elevated flexography to a new plane. Anyone doubting this ought to take a look at the percentage of print awards handed out annually that are printed with modern flexo presses. Even seasoned veterans of the printing trades often cannot tell a flexo carton from an offset carton without a loupe. Even with a loupe, the differences are becoming harder and harder to spot.

Look at the state of the flexo press. Today’s machines are flush with the latest technology, including servo drives for every function from web transport to impression control. Hot air dryers and UV curing lamps are precisely calibrated, high-powered devices that allow for near-instantaneous drying. The press is a precision instrument, capable of churning webs at 1000 FPM or faster, while not only printing but diecutting, removing scrap and delivering finished blanks, ready for the gluer. Modular designs allow for the inclusion of many features that require separate passes in offset, such as hot- and cold-foil stamping, rotary screen and rotogravure print stations, backside printing and multiple embossing, scoring and diecutting operations.

Rotary diecutting deserves a special mention. Long thrown up as an objection by offset printers due to the higher price of rotary dies (when compared to steel rule dies typically used in platen diecutters), it is in-line rotary diecutting that unlocks much of the economy of the web-fed process. However, when addressing the quality aspect of folding carton production, it is diecutting that accounts for the most important physical feature of a carton – a consistent score.  Inconsistent scores are the chief cause of downstream processing problems, since folder-gluers and filling lines depend on the score’s consistency to operate reliably at high speeds.

A rotary diecutter delivers more consistent scores than a flatbed diecutter, period.  This is because steel is more precise than wood. Also, from the engineer’s point of view, imagine the difficulty of holding an exact dimension across the entire surface of a flat die compared to holding it across a single line (the tangency of two precision-ground cylinders, concentric within +/- .0003 of an inch). Then, take that flat die and bang it up and down 200 or so times a minute, while you smoothly roll the two cylinders together on precision bearings. Try to think of a single precision thing made of wood; now look at an airplane, a watch, or an automobile. So, it stands to reason that the quality of the die-cut carton, equally important as the graphics, will be superior when done with the rotary die.

At this point, if you accept this argument, we have printed quality which is by and large “offset-equal” and, better-quality converted cartons.  Now, on to the business case.

Flexo Economics
While we in the printing business like to pat ourselves on the back for producing Van Goghs on a daily basis, and our customers demand it as such, the stark reality is that we are in a commodity business. Service and flexibility are important to CPCs but, in the end, cash is king and price is perhaps the single most important factor in a print buyer’s world. So, it is imperative that we produce our products with a minimum of capital, labour and material consumption if we want to prosper.

In-line flexo printing delivers exactly that – high-quality cartons, produced in the most efficient manner possible. Productivity, paper savings and labour savings give the converter a means to compete and thrive, meeting customer demands while generating a profit for himself.

As an engine of economic growth, productivity is hard to beat. Every economic expansion since the industrial revolution can be traced, in some degree, to increases in worker productivity. This is the essence of making more with less. When we apply this concept to printing and diecutting folding cartons, it takes the form of throughput speeds, minimal work-in-process inventory, and single pass production. These are the three main supporting characteristics of the web-fed process.

First, consider throughput speeds. Modern flexo presses typically print and diecut cartons from a web at 500 to 1000 feet per minute. Sheetfed offset presses, by contrast, can print upwards of 12000 sheets per hour, but diecutting is still limited to 6000 sheets or so for many boxes. Thus, the net throughput is held to the speed achievable by the diecutter irrespective of printing speed.

It is difficult, at first glance, to equate linear feet per minute to sheets per hour since the units of measurement differ. In order to properly compare the two, one must convert to a common measurement. Square inches of board is a convenient way to do this. So, for example, we can compare a 26” wide inline flexo to a 28” x 40” sheetfed system as follows:
Clearly, other measures could be used to increase sheetfed’s output. A second diecutter would increase throughput to 12,000 sheets per hour, but would require additional capital and labor, or additional shifts could be added. Either way, the converter must spend more to achieve the same output. This represents a net loss of profits, and/or increases the price the converter must charge for his products to stay in business.

Paper Savings
Substrate costs, whether a converter is independent or affiliated with a paper mill, represent the biggest single chunk of cost in the making of a folding carton. This inescapable fact makes paper savings an extremely important part of continued profitable operations. A flat sheet imposes limitations that simply do not exist in the web world. Firstly, the sheetfed process requires gripper edges to transport the paper through the process. Gripper edges are unnecessary in a webfed press since the web, once fed into the machine, pulls itself through. Second, a web offers opportunities for tighter nesting of cartons than often don’t exist, or don’t exist to the same degree, in a sheet plant. The following diagrams illustrate this point.

It has been estimated that webfed folding carton converting has the potential to save between 8% and 11% on substrate usage, across a wide range of sizes and styles. This saving drops directly to a converter’s bottom line, without any other measures being necessary.

Labour Savings
With most cartons produced in a single pass, flexo printing affords considerable labour savings. In an age where we are competing with very low labour cost countries, it is only logical that we ought to employ a process where we can reduce the labour hours necessary to produce our product.

In a typical sheetfed operation, paperboard must be sheeted, transported to the press, printed, transported to the diecutter, and sometimes transported to a stripping department. All this has to happen before the cartons are ready for the folder-gluer.

In a web flexo environment, paper rolls go on one end of the press, and finished, gluer-ready cartons come out the back. Because of the modular nature of these presses, even fairly complex cartons can be made this way.

Depending on the makeup of any given plant, in-line web flexo can reduce the number of workers by ½ to 2/3. This clearly makes possible considerable cost savings, and results in greatly increased revenue per labour hour. This certainly demonstrates that we can reduce the labour cost component considerably.

So, with all these benefits, why are more carton converters not flocking to this way of doing things? As one whose livelihood depends on persuading carton companies to do so, I have asked myself that question many times. We also discuss this in detail with many offset printers, with no single clear answer emerging. The answers range from the standard “dies cost too much’ and “my customers won’t accept flexo quality” to fuzzy generalisations about the company culture and how difficult it would be to change, etc.

We recognise it is a new process for many, and the uncertainty associated with such a sea-change is daunting. However, maybe a simple analogy helps explain the industry’s general reluctance to make the leap:

If one has gotten around for years successfully on a bicycle, he is very comfortable with that. If I offer him a motorcycle to replace the bike, it is a scary proposition. Sure the motorcycle gets him there faster and with less physical effort, but it is new and different. The thing jumps out from under him when he lets out the clutch. For that matter, the clutch itself is a new concept that has to be learned. The much higher speed potential of the motorcycle is also a bit frightening, even though he can imagine what he could do with all the time he saves. So, in the end, he sticks with the bicycle, just like most of his friends do, and continues in the same way, ignoring the few who speed past him on their new motorcycles. He’s safe, hasn’t taken any risks, and life continues on as it always has.

It is often said that species that survive for long periods of time on earth are not the biggest, strongest or meanest, but those best able to adapt to change. In a changing folding carton market, those who adopt the tools to best serve their customers changing demands will be the long-term survivors.

Michael R. Pfaff is Director, Paperboard & Folding Carton Press Sales, COMCo Product Group, Mark Andy Inc.