A web guide technology overview confirms the progression of electronic controls, automation and custom approaches.
By Susan Friedman
Hardly an unfamiliar concept, web guides are often a taken-for-granted component of presses and converting lines. A closer look at this technology's latest developments can help converters squeeze further efficiencies from even the most intricately tailored press configurations.
Web guides' longevity hasn't completely wiped out usage misconceptions. When Allen Rausch, application engineering manager for BST Pro Mark, Elmhurst, IL, is in the field, he often sees guide sensors positioned too far within the exit span of the guide frame. To work best, sensors should be in the first third of the exit span, he explains.
In addition, choosing among pneumatic, hydraulic or electronic web guide controls may not be as clearcut as prevailing wisdom suggests. "There's a common belief that you can't use electronic web guides in explosive or hazardous environments, but many of them feature explosion-proof motors and intrinsically safe barriers, or limited energy circuits, that prevent sparks," says Joe Klimczak, project engineer at AccuWeb, Madison, WI. He adds there is a misconception that hydraulic or pneumatic guides are the least expensive control options, when they may harbor high installation costs.
The current web guide marketplace necessitates both competitive purchase prices and efficiency returns. Klimczak likens the guide industry to the computer market, stating, "As technology increases, prices decrease." Waste and downtime reductions are specific to the application, "but plant managers won't spec a guide system unless ROI is less than a year."
Pneumatic, hydraulic and electronic guides all have solid application windows, though electronic guides appear to be a frequent conversion choice. "For narrow-web, high-speed applications, electronic guides offer the cleanest power source and are probably the most efficient," comments Steve Tannenbaum, president of Hydralign, Avon, MA.
Donald Ross, VP sales at Erhardt+Leimer, Spartanburg, SC, observes a gradual change from hydraulics to electronics due to hydraulics' continually running motor requires more maintenance, and the systems' leakage tendencies can be problematic for food packages or environments that need to stay clean. He believes pneumatic guides have taken over a lower-cost niche, and offer proven advantages in explosive environments.