Cell plugging is a common issue associated with anilox rolls. It is a costly problem that can be controlled or eliminated from your process through the use of recent technological advancements and a preventative maintenance program. Instead of listing the many problems that cell plugging creates, I’ll get right to the real focus of this article: how to maintain consistent anilox volume control. We all know that there are an enormous amount of variables in the Flexo process. In order to stabilize those variables and maximize your investments, it is up to you to control the issues that are within your power. This article is intended to give you the tools to do just that.
The Anilox Roll
The anilox roll is the mechanical heartbeat of every Flexo process. With each beat of that anilox heart, there is either a sellable or a non-sellable product being created. Managing the variables of the anilox process is where the preventative maintenance program really comes into play. Controlling, tracking and performing scheduled preventative maintenance are the keys to ensuring the making of a consistently sellable product.
Press operators and their support team are the human heartbeat of preventative maintenance. Their cooperation and proper training will maximize your anilox investments and facilitate the production of consistently sellable product off the press. The process is as follows: the volume of each anilox correlates directly to the ink film thickness consistently being transferred to the plate; the ink that is being metered by the anilox must be maintained at optimum and recommended pH/viscosity levels to ensure precise and uniform ink release, as well as a decrease in plugging issues. Common practice by press operators is to add base to ink on press to compensate for inadequate printed ink density and this is costly. A individual anilox rolls unanticipated volume loss, creates the need to make ink adjustments or change anilox rolls. Due to the intricacy and importance of the anilox roll, operators need to; care for them, get to know them, and subsequently trust each roll in their mix to maintain the highest levels of productivity.
Technologically speaking, recent advancements have given rise to improved cell geometry and greater consistency of engravings. Pamarco’s EFlo engraving is a prime example of an advancement in anilox cell geometry. This new technology provides the ability to improve both productivity and metering consistency.
The EFlo engraving is an extended cell that allows for 15% more ink release, while having the shallowest, flattest-bottomed cells. The shallow shape of the cells means longer running press times without the need for stopping to clean up. Longer press times means increased productivity. Cell-plugging issues are also reduced through the use of the shallow cell geometry, making it easier to thoroughly clean and maintain consistent ink films. These translate to an increased line screen of your anilox roll when converting from conventional → EFlo, due to the improved control of ink release.
Cell Plugging & Effective Anilox Care
Information compiled by Pamarco through anilox evaluations points to many converters struggling with both cell plugging and effective anilox care. Cell volume is one of the keys to understanding these problems. The cell volume is measured in Billion Cubic Microns or “BCM.” This is the volumetric capacity of ink or coating that an individual engraved anilox cell can carry. Maintaining uniform volumetric capacity throughout all of the engraved cells on an anilox roll is critical in effectively producing consistent, quality products. It only takes a 10 to 15% reduction in cell volume because of plugging to create consistency issues on press. Pamarco’s Cell Restore has been proven to be a solution to this difficulty throughout the industry, and was formulated specifically for breaking down cross-linked, water-based resins.
Cell plugging is caused by a build-up of dry ink or coating in the cell bottoms. Cell Restore was engineered with a focus on breaking down and swelling the dry ink, and that’s exactly what it does. It is a neutral pH, spray-on solution that fractures cross-linked resins on a micro emulsion layer, without jeopardizing the life span of the ceramic coating. It is also very user friendly. After applying the Cell Restore and letting it work for 5 minutes, a micro-fiber pad is used to remove the swelled and suspended resins from the cells. It is recommended to incorporate this cleaning solution into your regular Preventive Maintenance schedule to prolong the time period between major cleanings (I.E. Soda Blasting Units from Eaglewood Technologies Sanilox System).
In conclusion, incorporating a comprehensive program focused on maintaining the integrity of your anilox roll inventory will add value to your investment. Your process will see a reduction in hidden costs, improved quality and greater consistency. The print nip for each unit of a Flexographic press should be looked at as a body, surrounding its mechanical heart (the anilox roll). It works to the favor of both the printers and the converters to collaborate with and draw upon the expertise of their vendors. When properly utilized, the relationship that you have with your anilox roll vendor can greatly benefit your business.
Committed to the market since 1946. From offering the most extensive portfolio of products on the market, to offering the best consultative advice, to delivering an overall superior customer service; all underpinned by their passionate corporate culture, Pamarco has been able to build enduring and meaningful relationships with converters and OEM suppliers all around the world. To find out what Pamarco can do for you, visit www.pamarco.com.