A Better Way
By Myles Le-Monte Shepherd
July 7, 2022
With the steady rise of e-commerce and increasing need for high-graphics printing further fueled by the COVID-19 pandemic, the demand for corrugated production is unprecedented. Yet the market is fragmented, with many corrugated printers and tough competition, making it increasingly important for printers to employ leading-edge technology at every step of the process to achieve optimum results.
With automated plate cleaning, drying, and infrared (IR)/UV curing systems in place, high-graphics corrugated boxmakers can produce works of unmatchable quality at unbeatable speeds in a manner that is safer and more eco-friendly than traditional methods.
The industry’s innovators have historically strived to make the press operator’s job easier and safer. The development of most technologies has been inspired by press operators themselves.
Automated Cleaning Advantages
Plate washing and the removal of print defects can cause significant downtime, and this can happen at all stages of production—at the beginning of the run at setup, within the print run, and at the end of a print run once the printed job is completed.
Downtime or microstops are not always accounted for by production managers, and huge amounts of time can be lost on each shift for many reasons, such as print defects caused by hickeys, board wraps, premature ink drying, and ink viscosity change, which all lead to the requirement to clean printing plates.
Cleaning also takes place before good boards are printed at the beginning of a print run, especially on multicolor work once the register between the colors is achieved, and at the end of the print run on the final washdown. With automated cleaning technology, the plates can easily be removed from the machine—clean and dry—and be directly stored in a matter of minutes.
Automated cleaning can optimize the productivity, quality, and efficiency in most print production environments. Technical advancements such as precision spray distribution, automatic plate-thickness adjustment, and high-speed air knife for eliminating moisture on the printing plate mean that hickeys can be cleaned in an instant and that full-plate washing and drying can be achieved in minutes. And printers have the option to clean plates simultaneously or on a selected unit.
The cumbersome and costly nature of manual cleaning that was the long-established norm in offset printing led to the development of automatic blanket cleaning. For many years now, almost every offset printing machine has had an automated system to clean printing blankets. It was a game changer in the offset world and has become an essential requirement and standard part of the print process.
With flexo printing, the same trend toward automation is happening because so much time is being lost through the task of manually cleaning printing plates. The requirement for the print quality to be maintained and for the machine to keep producing is essential—more so now than ever due to the demand of printed packaging.
Cleaning has a significant and direct impact on production and waste costs and becomes expensive for companies that are trying to compete without understanding and accounting for how much time they are losing and how much waste they are producing.
Along with the direct labor costs, consequently, time spent manually cleaning restricts output, which ultimately means fewer square meters of board produced from the machine.
Automated systems can eliminate all this wasted time in a very efficient way and help maintain the print quality. Story after story from printers using the technology demonstrate how attractive the return on investment (ROI) is by reinvesting on other machines once they see the huge savings in time and increased efficiency with an initial installation. Plate cleaning can also free up much-needed capacity to produce extra print jobs or additional maintenance time that is sometimes difficult to schedule.
IR drying is a critical factor in all high-quality printing processes. Not only does it facilitate a dramatic improvement in image sharpness and quality by reducing absorption into corrugated board, it dramatically enhances color vibrancy and opacity. IR dryers also boost productivity in corrugated printing processes, and the shortwave modular lamphead concept is still the most popular dryer configuration for corrugated printers today.
Automated drying systems strive to reduce human intervention while maximizing system performance and efficiency. For example, smart IR sensors measure the temperature differential before and after the dryer, automatically adjusting the power level to ensure the minimum amount of energy is used for any given speed, with the maximum drying effect achieved.
Prior to this type of system, operators would often have the dryer set for a given job and would not always reduce the power setting for slower run speeds or lower ink-density work. This resulted in wasted energy and, in most cases, far too much IR energy to the substrate, which can cause print unit overheating, printing plate dryingor, in the worst cases, a safety risk.
Easing Operators’ Burdens
Another consideration to explore in order to fully leverage the advantage of IR drying is whether the segments are modular and can be easily changed without any tools in the event of a lamp failure or other malfunction. Most of today’s solutions require tools and extensive downtime to replace a bulb. The most advanced systems ensure that lamp changes have a very minimal impact on the overall efficiency, which includes ensuring that removing the module from the lamphead is a toolless operation that can be completed in a matter of seconds.
Modular segments have the added advantage of allowing the operator to manually adjust the width of the dryer depending on the board that is being run. In some cases, it is possible to automatically adjust the width of the dryer from the signal from the press, removing another step.
Intelligent control allows operators to go a step further and turn off individual modules where there isn’t any print. All these incremental savings add up to quite significant energy savings and improved overall process efficiency.
Automation takes away processes from operators where possible to reduce overburdening them. There’s no point in having optimum settings for a given job if the operator is constantly having to manually make adjustments. With an automated drying system, the operator can call up configured settings from previous jobs and enable them again to quickly have the best finely tuned settings for the conditions.
Integrated Internet of Things (IoT) is another invaluable feature that facilitates preventive maintenance by issuing prompts and eliminating unplanned downtime. This technology allows operators to view a system live to see if there’s anything starting to go wrong with it. It’s like the oil light in a car that comes on quite early, and once the oil is changed, it’s good to go. Without that early indicator, the next sign that the car is in need of oil is when the engine blows, which is a much bigger, more expensive problem.
Efficiency Meets Quality
The key to benefiting fully from cleaning and drying automation is accomplishing time savings alongside maintaining the overall print quality that brands and consumers have come to expect.
Operators generally spend huge amounts of time cleaning and are nonproductive at all stages of the process. It can take 10 or 15 minutes for each plate every time to stop. And that’s for each and every print job that could happen multiple times throughout the shift. Imagine having a four-, five-, or six-color print job and that most of these machines are anywhere from 2.1 to 2.8 meters wide; it’s an extremely time-consuming task to accomplish manually.
During the production run, a huge amount of time is lost from stopping the machine to clean hickeys off and to clean debris from the printing plate in order to maintain print quality, the demand for which is ever-increasing from customers. This all contributes to a loss of operating efficiency.
Printers are reliant on their operators to go into the unit to clean off the defects and get the machine running again. It’s all lost time on a regular basis—on every job, every shift, every day, many, many times over.
Automation removes all the manual requirements to clean and dry the plate, accomplishing it instead with just a push of a button in one pass, with the ability to clean and dry each and every plate singly or consecutively throughout the machine. All the ink and all the paper fibers can be easily captured in each clean in a matter of minutes—with systems that require only seconds of contact with the printing plate in the production room—versus 10 minutes on average with each stop for an operator to do it manually.
Today’s state-of-the-art automated cleaning technology can save around 98% of time from stopping the press during production and 80% of time lost at the beginning and end of a print run, so the ROI is significant.
Over the past few years, the corrugated industry has seen a sharp rise in the demand for increased print quality and complexity. Printers are seeking presses with more print units to achieve this quality work and the complexity of color. With that, there has been a trend of integrating lots of energy into presses to achieve a better drying effect. It’s a common misconception that more and more power and even bigger, wider cassettes are needed to achieve a strong drying result.
Tests have shown that there can be too much energy flowing into the ink and that having a large module—or lots of energy per print unit—can be counterproductive as the
ink film layer can only absorb so much energy. Overheating can also result in pigment melting, which reverses the drying effect. A more targeted system—intelligently controlled, closed-loop, and with minimal intervention—is the most efficient and best-performing solution.
Beyond profitability, companies are continually striving to be more sustainable, and the two can be achieved hand in hand with good, reliable, proven equipment. Case by case, we hear from printers using state-of-the-art cleaning and drying technologies that they are reaping the benefits by hitting targets that they’ve never hit before in production. We’re also having many repeat customers come back for new machines that they’re investing in and for retrofitting old machines.
There’s a need for printers to adapt and invest in the latest automated technology to increase time and to become more competitive. There’s no doubt that these technologies will become a standard installation on new machines in the future, and the trend is already evident.
On the cutting edge, alongside cleaning and drying technology, are inspection systems that complete a fully closed-loop system that can further enhance both productivity and quality. Those on the forefront of the next revolution are analyzing data and measuring metrics through connected machines and IoT technology.
Myles Le-Monte Shepherd is a sales executive, new markets, at Baldwin Technology.
Lee Simmonds is sales manager, U.K., Ireland, and Nordic regions, at Baldwin Technology.