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 : November 2008
TECHNOLOGIES & TECHNIQUES With that being said here are some suggestions: Cleanliness. Keep the cutting station clean and clutter free. This means no razor blades hanging within the die station, or tools like Allen wrenches and adjustable wrenches lying over or around the die station. The anvil should always be clean and free of adhesives. An effort should also be made at least once a year to have your anvil inspected to make sure it is parallel and concen- tric. This is a service your tooling supplier can do. Tools for tools. Use the right instrument for the job. This goes FIGURE 4. The finishing process, prior to machine sharpening, was prone to human error. ing process. This natural distortion can be compensated by sim- ply making the tool larger in diameter while in the rough milling stage and then grinding to the needed size through a finished grinding process. Not the case with the flexible die. Thus came the laser harden- ing process. A laser beam is directed specifically at the very tip of the blade. This is an induction hardening process, and it hardens the tip of the flexible die blade to a 60 to 62 HRC (Rockwell C hardness), giving the die sustainability and life that matches that of a hardened rotary die. The other common hurdle that exists to this day with ma- chine sharpened rotary dies is the “burr” factor. When any piece of steel is machined it will always leave a metal burr along the finished edge. Even if a die is fully machine sharpened, a hu- man being still has to take this burr off by hand. This issue has been a longtime headache to both tooling manufacturers and converters alike, as it certainly affects both die life and die strike consistency. Until a few years ago, there was no real remedy for this specific issue. The latest innovation, commonly used by flexible die man- ufactures today, is what is known as “chemical polishing.” This process completely removes the need for a human hand to even touch the blade. A chemical process simply disintegrates the burr left on the edge as a result of the machine finishing. CARE AND MAINTENANCE As a tooling manufacturer, I welcome damaged tools. It usu- ally means another P. O. But let’s face it—it should never have to come to that. With all of the costs incurred through daily operations, the last one that should be of concern to any printer/ converter is added tooling, not to mention some safety issues that can result from lack of training and knowledge. I am often amazed at the lack of the most basic care and main- tenance principles that are not followed within the industry. This stems from all of us within the tooling industry not offering the proper training to our customers. All tooling manufacturers have the experience to offer this most valuable service and should do so regularly. 40 F LEXO NOVEMB E R 20 0 8 www. f l e x o g r a p h y. o r g without saying. A carpenter would never, or should never ham- mer a nail with a screwdriver. The right tools will mean longer life out of your dies and a safer environment to work in. The right tool, in this case, would be a die lifter for your flexible dies. There have been far too many pints of blood spilled from taking a flex- ible die off using a fingernail or a razor blade. Your tooling sup- plier will always have die lifters on hand and can supply you with as many as you need. The same can be said for placing a large rotary die in the press, or taking it out of the press, with lift holes located either in the die itself or within bearing blocks. I have seen quite a few bent journals that end up resulting in a new tooling purchase. Why wrestle with it and take the chance. I recommend lift holes be placed in the bearing blocks for magnetic cylinders. This will give you the ability to maximize your flexible die plate width. Proper Handling. Poor housekeeping has always been a leading contributor to die damage. I have seen many opera- tors place a die on a rag on the table forgetting that there is a wrench underneath that rag. This is also a safety concern, as a clean environment is a safe one. Remember that wedding rings, jewellery, metal-to-metal contact etc. can spell disaster to a delicate cutting edge, whether the die is solid engraved or flex- ible. This is also a safety issue. Under no circumstances should anyone wear any kind of jewellery around machines with mov- ing parts. Post press. Remove a flexible die off of the magnetic cylin- der using a die lifter pulling from the corner edge of the plate away from the bearer. Clean the tool, freeing any remaining FIGURE 5. Backgrinding offers extreme tolerance concerning the blade height and the kind of die strike that will result during the converting process.