by clicking the arrows at the side of the page, or by using the toolbar.
by clicking anywhere on the page.
by dragging the page around when zoomed in.
by clicking anywhere on the page when zoomed in.
web sites or send emails by clicking on hyperlinks.
Email this page to a friend
Search this issue
Index - jump to page or section
Archive - view past issues
FLEXO Magazine : August 2013
Some of the factors that must be considered are: • Structural rigidity of the roll itself • Diameter in relation to the distance between bearings • Rigidity of the supporting structure of the bearings Table 2. Allowable TIR for Various Shaft Speeds Shaft Speed Allowable TIR RPM Inches Microns 100 0.02000 508.0 200 0.00500 127.0 300 0.00222 56.4 400 0.00125 31.8 500 0.00080 20.3 600 0.00056 14.1 700 0.00041 10.4 800 0.00031 7.9 900 0.00025 6.3 1000 0.00020 5.1 1100 0.00017 4.2 1200 0.00014 3.5 1300 0.00012 3.0 1400 0.00010 2.6 Although all factors must be considered, the following is recommended: • All rolls, regardless of press speed, should be in static balance • Rolls operated at 300–500 rpm should be in dynamic bal- ance within 10 ounce inches • Rolls operated at 500–1 ,000 rpm should be in dynamic balance within 5 ounce inches • Rolls operated at more than 1,000 rpm should be in dy- namic balance within 2 ounce inches Table 1 converts press speed in feet per minute into roll speed in revolutions per minute for various roller diameters and/or circumferences. Image 2 indicates centrifugal force as a function of roll speed for various units of imbalance in the base roll. n Editor’s Note: Flexographic Technical Association, Foundation of FTA and its Technical Education and Services Team (TEST); with the support and commitment of an extensive, highly experienced cadre of industry volunteers, recently engaged in a far reaching and comprehensive update of FTA’s flagship textbook: Flexography: Principles & Practices 6.0. It was re- leased in late April. This article is an excerpt from the publica- tion’s chapter on press mechanics and drive systems. FP&P features 600+ pages, 29 chapters, hundreds of vibrant illustrations, a detailed glossary and an extensive troubleshoot- ing guide. Both print and Kindle editions are available for purchase. Visit www.flexography.org/fpp for details. 42 FLEXO august 2013 www.flexography.org FTA Member Rate: $15 each or $40 for the set Build your foundation of flexographic knowledge with these practical pocket guides. An Introduction of Flexography Gain a clear definition of what flexography is and how it came to be the process it is today. This booklet reviews the fundamentals of flexography, inks & ink metering systems, substrates, types/sections of flexo presses, and more. Anilox Handling & Care Improper handling of anilox rollers can cost time, money, and press downtime. This booklet reviews the: types of anilox, proper handling methods, guidelines for care and maintenance, and more. Ink Handling & Maintenance Proper ink handling and maintenance is critical to the flexographic printing process. This booklet explains such topics as: ink types, ink prep (transfer, opacity, viscosity & pH), drying and curing, proper cleanup, and more. Get all the details at www.flexography.org/101 FLEXOGRAPHY 101 Booklet Series