SPARE CHANGEOVER (Will personnel concerns limit quick-changeo
(Will personnel concerns limit quick-changeo
by Jessica Millward, Associate Editor
IF TIME TRULY is money, interruptions in production translate into significant economic sag for package printers. The industry has never been more aware of this fact, with the rise of short runs and their requisite changeovers. Advanced sleeve systems whittle away at downtime between jobs, but limited training/personnel resources anchor printers to the changeover times of yesterday's equipment.
The demand for profitable shorter runs cultivated many of the wide-web flexo press design trends so popular today: servo drives, sleeve systems, and automated set-up among them. Fischer & Krecke (F&K) VP/Sales Manager Kurt Flathmann points out the complementary nature of these technology advances, stating they can be used in combination to reduce changeover times "by more than the sums of the individual timesavings."
Sleeve evolution has especially influenced changeover capacity of wide-web flexo presses, though the quest for easier-to-handle sleeves is sometimes at odds with improved press performance. Suppliers have created bridge sleeves to lighten the load of the system, but their usage introduces new tolerance issues. "A mandrel, bridge mandrel, and sleeve combination can have no better than 0.0025˝ to 0.004˝ tolerance when new," attests Joe Tremper, sales manager, Windmoeller & Hoelscher (W&H) Corp.
Questions about the efficacy of sleeve systems also surface in regards to extremely wide-web presses. Tremper explains, "If sleeves become so cumbersome that a sleeve-handling robot is required … then the true advantage of the sleeve press … has been lost."
On the standard wide-web unit the sleeve system's mettle has been proven repeatedly, so manufacturers have focused much of their development efforts on that press aspect. F&K premiered an improved sleeve system on its Flexpress 16 S, while the new sleeve presentation system on PCMC's Infiniti press was also designed to cut changeover time and reduce sleeve damage and operator injury. W&H has introduced an automatic sleeve extracting system, through which pneumatic collars break bonds formed between mandrels and sleeves.