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FLEXO Magazine : June2010
mon to see cell counts more than 1,200 for process and more than 800 for combination work thanks to the deeper volumes that are achievable today. Once you have evaluated print samples from a banded roll trial, you can then make a confi- dent anilox selection and move forward with anilox inventory review and adjustment. Making Changes You may discover you have some or all the needed aniloxes already in your inventory to fit your standardization without having to buy anything at all. Before you begin a standardiza- tion program, discuss with your operators what aniloxes they use most for their jobs. You may decide to fingerprint to those specifications. Determine if any adjustments to the anilox inventory need to be made to take advantage of ink film thick- ness reduction and opportunities to improve print quality and consistency. If you find that your anilox selection matches your standardization process, you may not need to add additional anilox inventory. However, don’t overlook the potential that you may find that there are not enough rolls to support the demand of the presses. If your operators are forced to run a variety of aniloxes for process printing, this is an indication your inventory is lacking. Circumventing the standardization process with anilox substitu- tion yields consequences in dot size and density changes. Have your operators refrain from using aniloxes where the cell count or volume is correct, but not both. You are allowing aniloxes that don’t fit the system to dictate accommodations from the ink and plate with the added result of color and print inconsistency. You will need to add additional rolls of the same cell count and volume to maintain the benefits of standardization. Your goal of having enough of the right aniloxes prevents substitution and does not invite print variability back into your process. You must also consider if your anilox inventory is giving you the best performance for ink usage. Developments in ink strength technology have given anilox manufacturers the op- portunity to increase cell counts and lower volumes; enabling you to have a finer metered amount of ink while achieving color, density and printability. The only question is does the volumes of your current aniloxes match what you require to achieve color and printable viscosity? If the anilox inventory is dated, more than likely the volume they carry is more than you need for the latest ink systems. Aniloxes cannot deliver different film thicknesses without adaptations to the surface energy of the plate and solids content changes in the ink. Added ink strength opens the door for smaller volumes. Cer- tainly, you can adjust the ink strength by addition of a clear varnish/extender, but are you willing to put the time and cost into the adjustments and unnecessary film thickness or would you rather be optimized for minimal ink adjustment? Take advantage of getting the same color in a thinner ink film. In this day and age, making an ink adjust to anything else than its own requirements for density and printable viscosity ends up wasting your money on the unneeded ink film thickness. To put some bite into this theory, remember that cost factors dictate the printing methods we apply and the ink inventories we must carry to accomplish our printing mission. For example, you may find that ink volume requirements may drop from 4bcm2 to 3bcm2 or even 2.5bcm2. Do you still want to extend the new ink system to reduce ink strength? It doesn’t make sense when you can print a thinner ink film with a lower volume. Ink performing at the 2.5bcm2 level from the old 4bcm2 equates to a savings of 37.5 percent in ink usage, due to the lower ink volume. Additional cost factors in labor and in- creased ink inventory just don’t legitimize the manipulation of inks to accommodate an outdated anilox selection. Strongly consider adjusting the anilox inventory to realize major sav- ings in the consumables that go into your product. Comparison of standardization and uncontrolled anilox inventory: Standardization: Anilox Accommodates Ink and Plate (Valid) Uncontrolled Inventory: Anilox Dictates Ink and Plate (Invalid) Anilox volume works with printable viscosity and film thickness requirements for color achievement Anilox is at a set line and volume Ink is stable and prints consistently throughout run Ink volume is determined by anilox capacity Anilox cell count supports plate dot requirement Ink is weak: Density increased by pigment load, cost increases and printability may suffer Plates stay clean and print consistently Ink is strong: Film thickness is extended instead of reduced, no ink cost savings Ink savings in inventory and usage Increased Ink Inventory Plate is determined by testing against support limitations of anilox, may not match customer requirements Plates print inconsistently/dirty over time sustaining standardization Now that we understand the benefits of standardization, how do we sustain it? We need to make sure inks are also standard- ized. Advances in proofing methods have become an eco- nomical way to determine required volume as well as assuring consistency in the ink going to press. Repeatability and consis- tent impression are the hallmarks of true proofing. If you are currently using a proofer and you have correlations to the tooling in press, you can do lab adjustments with tiny quantities of ink and pull proofs in experimentation. There is no need to use press time and the accompanying costs to determine the right volume for the ink you are testing. Have your proofing method evaluated by the ink or anilox supplier to verify you have a consistent and reliable method. A proofer is an essential tool of standardization, which requires monitoring of incoming materials and finished Technologies & Techniques 44 FLeXO june 2010 www.flexography.org Repeatability and consistent impression are the hallmarks of true proofing. FLX_June2010_mech.indd 44 6/10/10 9:39 AM