PFFC - February 2008 - (Page 12)

WEB LINES Thinking About New Equipment? 8 tips for specifying new equipment for any web handling process new year often brings new budgets and thoughts about new equipment. If you are lucky enough to be handed a project to buy new converting equipment, take some time not only to think about the “value adding” process involved (coating, printing, etc.) but also about the backbone of any converting line: the web handling process. If you haven’t figured out by now from reading my columns, I’m a process guy. More specifically, my career at 3M was mostly in the role of process development. So though I never had the lead role as new equipment project manager or equipment designer, I often was involved in providing the process specification for new equipment. tension (wide, thick, stiff) and low tension (narrow, thin, stretchy). A good starting point is to set tension at 10%–20% of the web yield or break point, whether in pounds per width or percent elongation. Step 3 | Process Tensions | What special tension considerations are needed in your different process steps? Consider noisy tension at unwinding, smooth speed and high tension at coating, low tension in heating films, and taper tension for winding. Break down a tension control plan from the process needs, including number of zones, preferred tension feedback by zone, and drive roller traction preferences. (I like to avoid nipped drive rollers). Include the proposed tension control plan in the specification to allow an apples-to-apples comparison of supplier quotes. Step 4 | Speeds | Include maximum speed and desired accel/decel rates as well as the need for emergency stopping. This will allow the control Include the proposed engineers to size the motors. Step 5 | Rollers | Specify roller surface to meet your traction needs, especially at high-speed, largediameter, low-tension conditions. Specify bearin the specification to ings, support, and alignment design. Specify roller straightness, deflection under load, diameter tolerallow an ance, and alignment needs. Step 6 | Guiding | Specify a web guiding plan: comparison Where do you need it; what accuracy; what type of guide is preferred; and what type of detector is preof supplier quotes. ferred? Specify brands of web guides if you have one or two preferred suppliers and want to avoid having to learn four different systems and spares. Get rollers on Also, in my role over the years as a process problem the web guides that match the rest of your process. Step 7 | Wrinkling | Specify any special locations solver, I’ve seen many equipment designs that I don’t that may need anti-wrinkle or spreading rollers and like because they make a process more sensitive to web handling and winding defects. Here are some tips what kind are preferred. Step 8 | Unwind/Wind | Specify core material on what to consider when ordering new converting and geometry; preferred core support (shafted vs. equipment for any web handling process. Step 1 | Process Flow Diagram | What are the shaftless, core grabbing mechanism); splicing type key process steps and their web handling and roll transfer needs; and preferred roll needs? I think about web handling loading and handling plan. Include a in the same order I cover the web performance spec on auto roll transhandling process fundamentals in fers and some winding quality feaclasses: web properties, tension contures (such as edge alignment). trol, rollers and traction, guiding, This isn’t everything, but it’s a wrinkling/anti-wrinkling, winding start. Add to this list cleanliness, BUYER– and unwinding. footprint, cost considerations, SUPPLIER Step 2 | Tensioning | What are the check-out plans, and start-up supROLES mechanical properties of your webs? port, and you’ve got a good start. Feel Think about the extreme cases of high free to send me your tips. A By Timothy J. Walker Contributing Editor tension control plan apples-toapples COMING NEXT MONTH Web handling expert Tim Walker, president of TJWalker+Assoc., has 20+ years of experience in web processes, education, development, and production problem solving. Contact him at 651-686-5400; tjwalker@tjwa.com; www.webhandling.com. 12 | FEBRUARY 2008 WWW.PFFC-ONLINE.COM http://www.webhandling.com http://WWW.PFFC-ONLINE.COM

Table of Contents Feed for the Digital Edition of PFFC - February 2008

PFFC - February 2008 Contents First Glance Calendar of Events From the Editor Web Lines Process Management News Clips Narrow Web & Label Reporter Narrow Web & Label What’s New Products Carton & Box Reporter Offset Printing A Triple Ply: Coating & Laminating Global Market Is Strong for Vacuum-Coated Products Melamine Innovation: A New Choice for Barrier Coatings How To Optimize Your Coating Solution’s Properties What’s New Products Contract Services Directory Custom Marketplace What’s New Products Services Directory Classified Marketplace Advertisers Index Experience Speaks

PFFC - February 2008

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