Machinery manufacturers are dedicated to making sure the “heart of flexo” is well maintained.

It’s said that the anilox roll is “the heart of flexo.” For human beings, taking care of one’s heart is of paramount importance to ensuring health and longevity. Much like how a proper diet and regular exercise is vital to heart health, a flexographer taking care of anilox rolls through proper care and storage is pivotal in providing high quality, defect-free printing.

Today’s label customer demands are often tied to pushing converters to lower prices and shorten job runs. Patrick Potter, vice president of operations at Flexo Wash, says that these factors have created for converters a dramatic increase in job changeovers and increased inventories, or both. “If the anilox roll is the heart of the flexo printing process and critical to maintaining a well-run operation, proper cleaning, care, and maintenance of your anilox inventory is essential to your survival. The absence of good cleaning practices will lead to increased downtime and inconsistent print results,” he says.

Joe Walczak, president of Sonic Solutions, notes that using a dirty anilox roll means that color densities on the final product will not equal those specified for the job. Because of this, he says, the printer will incur costs in wasted ink, paper, and labor to determine that there is a problem and then correcting for it. “An idle press is not generating revenue; and an undetected print error could ultimately mean losing any repeat business from the customer,” says Walczak.

In order to avoid the aforementioned downtime, inconsistencies and potential revenue loss, converters have various anilox cleaning technologies available to them, supplied by manufacturers dedicated to delivering the peace of mind that a clean anilox roll provides. What follows are descriptions of the latest machinery offered from some of the industry’s anilox cleaning experts.

FLEXO WASH

Flexo Wash was founded in 1990 by an inventive Danish label printer in response to increased demand for improved print quality, as well as a safe and efficient production process. Centrally located in Louisville, KY, USA for over 20 years, Flexo Wash, LLC provides Flexo Wash cleaning technology in North America for the flexographic and gravure printing industries. “Today’s inks and coatings can be difficult to clean, even when they are still wet,” explains Potter. “The longer an ink or coating has been allowed to dry in the cells, the more difficult the cleaning process can be.” Also, he says, plugged and dirty anilox rolls create surface tension that prevents cells from accepting and releasing the correct ink volume. “Converters cannot wait to cleaning their rolls until the anilox can no longer perform. The market is too competitive, and dirty anilox rolls cause inconsistent print quality, increased downtime, excessive waste and thereby loss of competitiveness.”

Potter stresses that with anilox cells getting increasingly smaller, there is a growing need for quality cleaning. “Otherwise, quality printing cannot be obtained,” he says. “Deeper cells can exasperate plugging issues. anilox rolls cause difficulties in getting the right color, poor color densities, and inadequate ink distribution. Wasted time, ink and substrate is also an issue – and expensive. Smaller cells mean a more delicate cell structure. Delicate cells are more easily susceptible to damage from improper handling, doctor blade scoring and poor cleaning methods. Abrasive cleaners, pads and brushes are no longer a possibility in deep or small cells.

Flexo Wash offers cleaning technology for converters needing to clean from one to nine anilox rolls during a single wash cycle. The Flexo Wash FW Anilox Cleaning Systems incorporate “plug ‘n play” simplicity, Potter explains. “Place the roll, close the lid and push the start button. The entire cleaning process starts with liquid spraying, then rinses with high-pressure water, and finishes with an air blow dry. The whole process is 100% automated. And the systematic cleaning process is safe and harmless to the anilox rolls, employees and the environment, and cell volume is completely restored in less than 20 minutes.

Adding to lower costs, the Flexo Wash Cleaning Solution is filtered for re-use again and again. Another benefit is its simple maintenance: “Change the filter monthly and clean the liquid tank every half year,” Potter says.

“Flexo Wash technology helps our customers print better,” he adds.  “We use a safe and gentle cleaning method that does not damage even the thinnest of cell walls. In fact, the cleaning method offered by Flexo Wash means that you can both deep clean the rolls and wash them on a daily basis without harming even the finest screens. It does not matter if the anilox is wet or dry. It does not matter if you need to clean water-based, solvent and/or UV inks, adhesives, lacquers, varnishes, laminates, etc. – it all can be cleaned in the same Flexo Wash FW Anilox Cleaning System with no changes to settings or liquids.”

SONIC SOLUTIONS

According to Sonic Solutions president Joe Walczak, the reason that anilox maintenance has grown over the last 20 years is because of the use of water-based inks and increased line counts. “Water-based inks leave a clear and hard resin in the porous cavities of the ceramics in an anilox roll’s cells,” he says. “Over time, the resin builds upon itself and slowly steals cell volume.”

Based in Mokena, IL, USA, Sonic Solutions’ method of anilox cleaning uses ultrasonic technology. Walczak explains,“Cleaning the anilox cells out thoroughly and safely is a lot harder than it might seem. But the physics of ultrasonics make it the best process to reliably remove 100% of the foreign matter from the cells.”

Increased line count anilox rolls have resulted in cells that are proportionately smaller and thus harder to clean. “At Sonic Solutions, we responded by changing the ultrasonic frequency level on all of our products from 43 kHz to 68 kHz. This means a smaller air bubble is created that effectively enters the smaller cells and safely and gently pulls out the built-up dirt,” Walczak says.

Walczak points out that label printers often struggle with cleaning rolls after they use certain opaque whites, metallic adhesives and coatings. “Ultrasonic cleaning blasts through these with relative ease,” he says. “Most printers already realize the importance of cleaning anilox rolls. The trend we’ve seen is that printers are cleaning their anilox rolls after every press run, assuring that the anilox will not be the cause of any problems on the next print job. The first comment coming from our detractors is that this will damage a roll, but that’s really not true. If the roll is cleaned after each use, then the roll isn’t getting all that dirty, plus the built-up contents of the cells are still relatively soft. For these reasons, the cleaning time is pretty short – approximately five minutes of soaking and then a brief application of ultrasonics. There is minimal impact on the anilox,” explains Walczak.

Sonic Solutions recently introduced its Phoenix Series, which is providing its customers with a better and safer ultrasonic cleaning process. “Also,”  Walczak says, “with the Phoenix line, we can now offer the industry’s best sleeve cleaning option. In the past, costly wash and blast systems were the only alternative. Now we can easily and economically stretch the process to accommodate any size sleeve, typically at half the cost of the other processes.”

According to Walczak, ultrasonic cleaning is the best cleaning process in the marketplace.  “It’s the same process used in hospital operating rooms as well as NASA – environments that rely on 100% cleaning of their tools and products,” he says. “Sonic Solutions’ equipment works much the same way. We’ve only added one step – the soaking process. Everything else works the same. We intentionally made the system easy and simple to operate with minimal input and variability to the user. We tell our customers all the time, ‘It’s not sexy…but it works.’”

The equipment consists of the ultrasonic tank and generator along with a rotating unit and support bar. All functions and variables are preset at what Walczak says are the safest levels in the industry. Just a few switches turn certain functions on and off for the generator, heater and rotating unit. With the Phoenix series, the generator is outside of the tank, allowing for safer generator function and also ease of replacing the generator by simply unplugging it and plugging in a new one.

FLEXOMAID
Flexomaid, based in Saint-Bruno-de-Montarville, Quebec, Canada received the 2016 FTA Technical Innovation Award for its Aeromaid cleaning technology, an off-press air-stream anilox cleaning system that is non-abrasive and contact-free.

The key to the Aeromaid system is its “smart” powerhead. Equipped with an advanced laser sensor, the powerhead detects the roll’s characteristics – diameter, length, surface – to optimize the rotation speed and powerhead movement pattern to provide consistent deep cleaning for any roll format. With its precision air-stream powerhead, Aeromaid  uses the minimal quantity of detergent and rinsing agent to ensure optimal cleaning results.

“In surveys, printers have told us that they need different types of roll cleaning for different situations. To meet those needs, we’ve included three customizable cleaning cycles – the express, daily and deep cycles – starting at just eight minutes per roll,” says Éric Thibault, Flexomaid’s business development director, adding, “Reduced cleaning times result in decreased downtime and increased productivity.”

Disposing of fluid waste is a growing environmental concern for label printers, Thibault adds. “Fluid waste disposal can be a major expense, limiting profitability,” he says. “With Flexomaid, you eliminate fluid waste management expenditures. An absorbent paper mat beneath the roll collects the few drops of wet residue. A specially-designed conveyor automatically displaces the paper mat a few inches after every cleaning.”

System features include contactless deep cleaning for any cell volume, line screen or surface geometry, and the cleaning head does not spray any solid media or generate any wet residue. Affordable and eco-friendly technology, Thibault notes that the technology is safe for bearings, gears, aluminum and sleeves. The biodegradable soy-based detergents effectively remove UV, water-based and solvent-based inks. Fresh detergent solution is used in each cleaning cycle.

APEX INTERNATIONAL
Apex International, the anilox roll manufacturer known for its patented GTT technology based on open slalom ink channels, has recently launched its Opticlean line of anilox cleaning equipment. The system features two rubber rollers at the bottom of the cleaning tank with the anilox rotating on top. This results in perfect cleaning, according to Markus Pflügl, Apex’s technical engineer and the developer of Opticlean, because the cleaning agent is not only dripping off the roll surface with only little time for weakening the dried ink in the cells, but it is sprayed between the anilox surface and the rubber rollers.

“This guarantees full coverage of the surface – with a very homogenous distribution – and the rubber ‘renews’ the cleaning agent within the cells at each turn and brings also a kind of pressure to release the dried inks easier and faster,” Pflügl  explains. “This is why the Opticlean is the perfect solution for very high screen rollers and is most probably the fastest cleaning machine available.”

Pflügl  points out that when you lay down the anilox only on top of the two rubber rollers, you can achieve absolute flexibility in format sizes. He says, “If you have different printing presses and sizes or types such as sleeves or rollers of aniloxes, you can have perfect cleaning without touching or adjusting anything within the washing tank. No axles or bearings have to be adjusted for each wash.”

Opticlean has three cycles: washing with a chemical agent, rinsing with high-pressured water and then drying with pressured air. Pflügl says, “All three cycles are fully automatic and you only have to push one button to start the machine. When the procedure is done, the machine signals that it is ready for the next roll. Of course you can program the cleaning and cycle times depending on the situation with each anilox roll.” Apex also has a new system for sealing anilox sleeves at their sides for easy handling. Explains Pflügl, “These are pneumatic expansion adapters, so that even with wide sleeves they can be handled easily by only one operator.

Cleaning Chemistry: One size does not fit all
Tower Products, based in Easton, PA, USA, is a manufacturer of pressroom chemical products with a focus on flexographic and offset print processes. Rick Principato, Tower’s president and CEO, says one of the greatest challenges for label converters when it comes to cleaning anilox rollers and plates is not having the correct compatible chemistry with the type of equipment being used.

“This can lead to plugged cells in the anilox roller and that will affect printing quality. There is also a challenge in selecting the right chemical cleaning product for inline cleaning (cleaning the anilox roller while it is still in the press) versus offline cleaning in a hot tank or ultrasonic unit.  Chemistries have changed and need to be compliant to regulations and safety concerns while still performing at a high level of efficiency, and one size or product does not fit all. White UV ink can be a troublesome cleaning challenge, but we have formulated products that are able to address this cleaning issue,” Rick says.

According to Mark Principato, product Manager for Flexographic Products at Tower, the growing trend for variations in run length has led to an increased need for scheduled cleaning of the anilox rolls, with cleaning efficiency being of paramount importance. Mark adds, “The trend for more and varied UV inks also creates challenges for formulators like us to make sure you can clean without damaging the roller and insuring worker safety and environmental compliance.”

Tower Products’ two most popular anilox roll cleaning products are its SmartFlex Anilox Roller Cleaning Gel and SmartFlex High Tech Anilox Cleaner. The SmartFlex gel is an inline cleaner that is applied to the anilox roll and brushed in and rinsed out with water. “It does not contain any pumice or harmful abrasive chemicals, and it is a low VOC product with great cleaning efficiency while being very easy to apply and work with,” Mark says. “And our SmartFlex High Tech Anilox Cleaner is a breakthrough liquid technology that works in a hot tank, ultrasonic or parts washer environment to quickly clean and sequester ink so it does not re-deposit on the roller. It is a deep cleaning that is unsurpassed in cleaning efficiency and strength in our industry.”

Tower Products uses 52 years of chemical cleaning experience in its anilox roll cleaning formulations. Concludes Rick, “We always formulate with the idea of safety and environmental compliance in mind and our products are available and locally stocked by Tower authorized distributors throughout North America. We also have a field technical service team to back up our products and our distribution partners at the label converter level.”

Written for: Label and Narrow Web Magazine

Written By: Steve Katz, Editor | July 15, 2016

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