At FTA’s Forum 2017, I was honored to receive the Gary Hilliard FQC Scholarship. It provided me the ability to continue my education as well as opened up opportunities in the field of flexography. Of course, one of the requirements to complete my scholarship obligations was to execute a research project that would allow the industry and I to explore new opportunities with trending innovations.
For my research project, I selected the study of correlation between minimum dot size and floor height. In the beginning stages, I needed to determine the scope as well as the process used to complete my study and analysis. This then allowed me to determine my project’s mission statement: “Should FIRST-recommended reliefs be optimized using current innovations?”
There has been a number of plate innovations since the advent of FIRST (Flexographic Image Reproduction Specifications & Tolerances) methodology. These innovations include the rapid changes in flat top dot technology, presses with automated controls, plate rollers and sleeves, as well as mounting tapes and plate materials. All have contributed to giant leaps forward in the flexo process.
The Plate Process
In order to execute my project, I had to first identify and define my variables. I then had to produce my artwork files, produce my own plates, analyze my plates and then perform all the running of these variables on press myself. It was quite a learning experience from front end to sample evaluation.
The FIRST-recommended variables for plate relief were used as a default to begin my evaluation. This was based on running a narrow web press utilizing 0.067 plates with a relief of 0.018 to 0.022. I used six different relief variations and three different plate materials during the evaluation. These plate materials were DuPont Cyrel DFR, Cyrel FAST DFM and Cyrel FAST EASY EFX. These were all of different Shore hardness, which allowed me to determine the optimum variable in the end results. I also used a range of reliefs from 0.013 to 0.040 to help determine the optimum results. This made a total of 18 plates tested to collect data points.
I created a characterization test file that was used to produce all plate materials. This file included minimum dot size, minimum font size as well as minimum line. This would allow me to measure and collect the printed results to determine the optimum variables. To measure and record my plate data, I utilized a Betaflex and digital micrometer. After all the plates were run on press, I gathered all samples for complete evaluation and charting (see the below chart).
Results & Next Steps
I determined that, with the data I gathered and interpreted, there was a consistent trend: As the floor height was increased, I was able to hold a finer minimum dot percentage. From the parameters of my project, however, I could not confirm an exact ceiling of detail in the trend. There are simply too many variables in the process that influence the data points. Although my research and data clearly support that there is a direct correlation between relief height and minimum dot size, a true understanding of just how much will require a much broader sampling of variables in each state of use and application. This would then allow us to have a better understanding of how these new and innovative trends have influenced our process to better support the next generation of FIRST and the methodology it presents.
As far as next steps, testing can continue on narrow web, mid web and wide web presses utilizing different variables to optimize results. What I have learned, more than anything, is that the possibilities are endless; I can see great opportunity for growth and improvement as our process continues to evolve with new and exciting innovations.
My very special thanks go out to the Flexo Quality Consortium (FQC) Committee for honoring me with the very rewarding Gary Hillard FQC Scholarship and the opportunity to grow in the flexographic industry. Special thanks also goes out to DuPont and all the suppliers who supported me on this research project. I look forward to all the industry has to offer.
About the Author: Christopher Teachout is a student at Central Piedmont Community College, Harper Campus.