Maximizing Doctor Blade Life

Day-to-day press operation often comes with challenges.

One of the most common—unpredictable doctor blade failures—also comes with a number of additional concerns, such as safety, quality, service and cost. As technical advisors for professional print operators across the country, Daetwyler encounters these situations on a daily basis. This article will address problem areas regarding optimum press operation and doctor blade life, while also reviewing ways to reduce risks, frequency and side effects of doctor blade failure.

Doctor Blade Safety

Many companies claim safety is their No. 1 goal. While the position is certainly to be applauded, this does not always happen in practice. Press teams are under pressure to meet schedules to preserve the company’s bottom-line, and the easiest way to achieve that is to cut corners on some safety guidelines and clean up messes before anyone notices.

Poor doctoring leads to substandard performance and lower-quality outputs related to dirty print, leaky chambers, density, and dot gain.
All photos courtesy of Daetwyler

Take for instance this scenario: A major increase in print volume with tight delivery timelines. It is not uncommon for operators to skip steps during changeovers, such as not replacing items, which can lead to unscheduled messes when systems fail. It is an accident waiting to happen, all because of a decision to push quickly through the changeover.

In a competitive and fast-paced manufacturing environment, there must be a healthy balance between making safety a top priority, while also protecting profitability by properly utilizing the necessary tools and procedures for completing projects and achieving company goals.

Doctor Blade Quality

Balancing quality with productivity is an area of concern where pressrooms often struggle. Effective, trouble-free doctoring is critical for consistent, high-quality outputs. Poor doctoring leads to substandard performance and lower-quality outputs related to dirty print, leaky chambers, density and dot gain.

All these issues can directly impact customer satisfaction, which ultimately damages profitability. Under-processed material and increased setup times, due to cleanup of uncontrolled messes, have the same impact—inefficiencies that add up to decreased productivity, more waste, increased costs and, once again, poor bottom-line financial performance.

The adage that doing things right the first time costs less than fixing problems afterward is a smart rule of thumb to weigh against many decisions regarding doctor blades. With a realistic quality benchmark in mind that is an achievable standard, these decisions become easier for teams to make across each and every job.

Doctor Blade Service

When the size and number of jobs decline, the simplest way to maintain or stabilize revenues is to simply complete more jobs in the same time period. As the industry continues to see reductions in job sizes and requests, it becomes more and more important to speed up changeover times in order to accommodate multiple runs in a single day or week. When teams are established to conduct QCO (Quick Changeover) evaluations, it becomes clear that a significant loss of time is attributable to changing doctor blades and end seals.

The definition of “non-value-added activity” is an action taken that does not increase the worth of what is delivered to the customer. Changeovers fall solidly within this definition—and the longer they take, the more they ultimately cost the company in terms of production and on-time delivery.

Process improvement teams’ primary focus should be to remove all non-value-added activities, so it makes sense to use long-life doctor blade and end seal products that can last the entire work week, or until the next scheduled blade change, as opposed to relying on doctor blades and end seals that require changes during each and every changeover.

There will always be occasions in which specialty setups may be necessary, but beside those instances, the complexity of each changeover increases the amount of downtime when presses aren’t producing work. Advancements in doctor blade technology for longer life and anilox protection have proven effective across a wide variety of applications, which means frequent blade changes can add up to huge potential waste, in terms of valuable press time and associated material costs.

Being able to eliminate non-value-added activity should be one of the primary influencers of changeover procedures—with a final decision that reflects a company’s business model and production goals.

Printers will often struggle with dirty print and dot gain issues, controlling tonal values and impacting overall print quality. Pressure is the culprit.

Doctor Blade Cost

Many businesses still regard doctor blades and end seals as merely consumables, rather than important tools for high-quality output. Because of this, pressrooms tend to struggle with the perceived price versus the value and savings that quality doctor blades provide.

This is why an ROI calculator is so important. It allows press operators and businesses to quantify the true costs—both in terms of materials, as well as in labor and setup—of selected materials, equipment and procedures. What these calculations often reveal is that what seemed to be a lower initial price, actually costs companies thousands of dollars in lost productivity.