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FLEXO Magazine : September 2009
52 FLEXO SEPTEMBER 2009 www.flexography.org PLANTS & PROCESSES aligned in the stamping press. If not positioned to a tolerance of one millimeter, the output would contain defects. The pro- cess of registering the dies took multiple attempts and several hours of adjustment. Working faster alone didn't provide the necessary improve- ments. So, Shingo, along with a number of Toyota employees, began to structurally analyze the setup process and identify steps necessary to fundamentally change the setup process. Change didn't happen quickly and there were numerous setbacks. But with time, they were able to re-engineer the pro- cess over and over and eventually got the same die change process down to less than 10 minutes. Here is a brief overview of ways to reduce makeready time in the pressroom. Identify internal and external setup processes. Begin by videotaping multiple makereadies. Then use your operators to go through the video and to document the discrete steps required for a makeready. You want to be detailed, document- ing every second needed to complete each step. Have a stopwatch handy. As each step is recorded, identify whether the press is running during the process (external) or whether the press is stopped (internal). Convert internal setup processes to external processes. Next, systematically analyze each and every internal process to determine what would be needed to convert it to an exter- nal process. Is it possible to prep and color match ink prior to the changeover? Is it possible to stage anilox rolls prior to makeready? Is it possible to have plates mounted and staged ready for the makeready? The goal is keep the press idle for as little time as possible. Analyze, minimize, and standardize all setup tools and fasteners. Much time is wasted during a makeready swap- ping out wrenches for different fasteners. The goal here is to modify your equipment to minimize fasteners and to stan- dardize all tools and fasteners if possible. Color code bolts and wrenches so anyone immediately knows which wrench is needed to complete an adjustment. Use jigs and other positioning adds to speed setup time. The goal here is to place cylinders, dies, and anything else that needs precise positioning into the press pre-registered so that little or no registration is necessary. Imaging a "tick mark" on the plate such that the mounted print cylinder can be positioned at 12 o'clock gets all plate cylinders installed in the press within one tooth of registration. The goal is to brain- storm ways to minimize registration. Adopt parallel setup processes. If you ever watch a racing pit crew, you see two people changing tires. One changes the front tires and one changes the back tires. That cuts the pit stop down by half the time it would take otherwise. Some companies use makeready teams. Others use roving opera- tors. The goal is to minimize internal setup time, like a race car in the pits. Put tools and supplies close by and in an organized man- ner. If you have done your 5S work well, this step is complete. Either way, you want to constantly look for ways to minimize motion during the makeready. Many companies adopt setup carts, which are prepped ahead of time by a non-operator. These carts contain all necessary supplies and tools and are rolled right up next to the press. Everything is within arm's reach for the makeready. Work to eliminate adjustment. Much time is spent dur- ing a makeready on registration, adjusting impression, and adjusting ink. The goal of setup reduction is to minimize time that takes away from printing sellable work. If you spend a lot of time color matching on press, effort must be put into ink preparation using offline ink QC proofing systems. Standard- izing aniloxes is important in this process. Look for ways to improve and standardize impression settings and preregister the cylinders when installing in the press. Consider the impor- tance of the lateral position of a roll mounted on the roll-stand mandrel---every little detail matters. THE NEXT STEP Lean has many applications for printers. But it isn't for the faint of heart. It takes a big commitment to learning to see where waste exists in your current business. It isn't obvious until someone starts asking the questions: Why? How come? It also takes a big commitment to empower your employees. They must trust you and you must trust them. Without that, you are destined for failure. If you want to proceed on a Lean journey there are lots of good books out there. Start with a book I co-authored called Lean Printing: Pathway to Success and then check out some of Jeffrey Liker 's books. I truly believe that those companies who embrace lean and the culture necessary to sustain lean principles will be the companies left standing as we see ad- ditional competition in the year's ahead. ABOUT THE AUTHOR: Malcolm G. Keif is a professor in the Graphic Communication Department at Cal Poly State University, San Luis Obispo, CA. He oversees instruction in flexographic plating and press operations, as well as teaching course work in quality management, cost estimating, web off- set, and gravure printing. Keif is a frequent speaker at industry conferences and the author of two books: Lean Printing: Path- way to Success, and Designer's Postpress Companion. SETUP REDUCTION TIPS • Identify internal and external setup processes. • Convert internal setup processes to external processes. • Analyze, minimize, and standardize all setup tools and fasteners. • Use jigs and other positioning adds to speed setup time. • Adopt parallel setup processes. • Put tools and supplies close by and in an organized manner. • Work to eliminate adjustment.