I must admit that I’ve not spent a lot of time considering what the phrase, “The whole is greater than the sum of its parts,” means. Yet, it came to me as I was considering the connectivity of elements in a manufacturing process like flexographic printing.
As I see it, the objective of the flexo process is to deliver a label or package that meets all the print buyer’s requirements in terms of quality, delivery, and price. While at the same time, allowing the pressroom to achieve an acceptable net profit. So, the printed product is the whole and is a result of how a lot of elements or variables are brought together.
From our beginning 28 years ago, FLXON was fortunate to have SWEDEV AB as our partner. Just a few years earlier it entered the printing industry in Europe with the launch of SWED/CUT. At the time it was a new type of ink metering blade and one made from a more refined carbon steel. Not only was the blade able to wear slower and meter ink more uniformly; it also had a lower level of friction, making it a safer choice for printers concerned about anilox damage and wear.
The partnership was forged because we shared a common business development strategy: we do not just “sell” products, like doctor blades. Instead, we provide solutions for pressrooms wanting help in their quest to better control their printing process to achieve a predictable outcome and satisfactory bottom line.
This consultative approach requires a thorough knowledge of the ink transfer process, including key performance indicators, which determine if a print process is optimized or not. We begin our engagement by asking pressroom managers if they are satisfied with their press performance. And if not, why not?
Most admit their presses are not performing at the level they expected when a press was purchased. Start up and run waste is too high. Mid-run press stops rob profit from a job. They have become accustomed to running at speeds far below their machines’ rated speed. Unfortunately, these concerns are usually the tip-of-the-iceberg. And most pressrooms have not monetized what they are paying for remaining status quo.
Leaking
At this point we go deeper to uncover contributing factors and root causes. As an example, why do end seals leak and why is back doctoring such a big concern for wide web pressrooms?
These problems are not only a huge waste of ink, but they can require mid-run press stops. These press stops can add up to hundreds of hours of lost production per press each year. Monetized, these press stops can easily cost $200,000 per press in a year. In our experience, few pressrooms monetize their process waste, downtime and so on. Once that number is known, pressrooms are ready to solve the leaking and back doctoring problem. See Figure 1.
All images courtesy of FLXON
End seal leaking, back doctoring and press stops are just a few of the numerous issues contributing to low productivity in our industry. Make it your business to understand the root causes of these and other problems. Like us, learn that, there are multiple related factors contributing to end seal leaking and back doctoring. See Figure 2.
To begin, once a print job is up and running, it becomes more difficult for anilox cells to fully reload with ink. Air pockets develop in cells reducing the ink’s transferred density. To overcome this form of starvation, operators often increase the pump’s delivery to the chamber. Added ink flow increases chamber pressure, causing end seals to leak.
A common response is to increase the chamber-to-anilox pressure. As this happens, the metering blade bends, so the blade’s edge no longer engages the anilox. Instead, the blade’s side is against the anilox. This wide contact area allows more ink to move under the blade causing hydraulic lift, which permits more ink to reside on the anilox surface. The result: dot gain, dirty print and back doctoring.
Solutions to leaking problems are not always straight forward and require a bit of investigation. Questions that should and must be asked, in order to determine a corrective action plan that leads to sustained solutions include:
- Are chambers square to the anilox?
- Are end seals 100 percent matched to the anilox circumference and do they have memory; the ability to return to full dimension once compressed?
- Do the seal’s apex points engage the anilox a nanosecond prior to the blade’s edge?
- Are blades set into clean clamps?
- Are the meter and containment blade edges equidistant and parallel their entire length?
- Are the planes of the blade and seal the same so there is no blade lift when it crosses onto the seal?
- Is the steel and edge used for the meter blade capable of sustained, tight ink metering while containing low frictional properties?
- Is a different steel and edge used for the containment blade, one that easily allows returning ink back into the chamber?
- Is the ink’s viscosity and cleanliness compatible with the chamber’s setup properties?
- When are blades and seals changed and why?
- Are the SOPs covering chamber setup clear, current, and practiced?
Once the proper moves come into view, implementing changes to pressroom practices should achieve established goals.
Solutions depend on specific pressroom applications. Are blades and seals expected to achieve precise ink metering on long running jobs or multiple short run jobs; each achieving millions of feet of production? Metering blades and containment blades tailored to meet current industry applications, are more efficient than their predecessors. As a result, the annual blade spend in many pressrooms has decreased over the past few years while output per blade dollar spend has increased.
Over the years, I have come across or developed products that support customers’ goals for process and productivity improvement. Today, a firm like FLXON, offers a focused range of products and services dealing with ink transfer that support process control and waste reduction. The sidebar accompanying this story contains details.
Solutions to these leaking problems are not always straight forward and require a bit of investigation. Collective focus, as described in this article brings together and achieves a greater result than engaging the marketplace individually. The synergy extends from one end of the supply chain to the other–manufacturer to pressroom.
In our case, the Whole Result is Greater Than the Sum of its Parts!
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