Customer: Duro Bag Manufacturing Company

Use of Air Helps Reduce Delays and Boost Quality

As the world’s number one paper bag producer, Duro Bag Manufacturing Company, with corporate offices in northern Kentucky, has over 2,500 employees working at 12 manufacturing facilities across the country. Productivity runs at a fast pace here.

As a full-service bag manufacturer, Duro produces grocery bags, grocery sacks, handle bags, merchandise bags, paper lawn and leaf bags, and various specialty bags including lunch bags, pharmacy bags, liquor bags, freshness paper™ bread bags, food service bags, and more. Manufacturing embraces both converting and printing processes, with flexography, offset and rotogravure presses producing millions of imprinted bags annually.

That’s a lot of webs – and web guiding. In fact, web guiding has been given special attention lately as Duro continued to seek reductions in component maintenance and related downtime.

For many years, Duro employed conventional electronic web guide systems. According to David Weathers, engineering and maintenance manager at Duro’s Jackson, Tennessee plant, these systems have required significant maintenance time for sensor cleaning and for addressing sensor and motor failures. “We were definitely looking for a more reliable option,” says Weathers. “We can’t operate without proper web guiding, but in our kind of converting operation, we can’t afford to let web guide issues slow us down, either. We knew there had to be a better solution.”

At the Jackson plant, Duro runs virgin white, recycled white, craft, recycled craft and grease-proof papers on 30 different production lines. Web widths of 28 inches clip along at line speeds of 500 fpm and more. “At this speed,” notes Weathers, “alignment between the printer and bag-making machines is critical.”

As with most paper converting operations, Duro recognized that paper dust posed a constant challenge to electronic web guide sensors. Consequently, plant engineers took great interest when introduced to a web guide system that actually blew dust away from the sensors. In fact, this unique web guide system didn’t have any electronic components – it was all air actuated. Cautious, yet optimistic, Duro started with a trial installation. Plant engineers were surprised by the immediate results.

The all-air web guide systems from Coast Controls (Sarasota, Florida) were first developed over 16 years ago for the converting industry as an alternative to electronic systems. Using only low-pressure plant air, these systems employ an innovative method of monitoring changing air pressures to detect web edge positioning, and air-actuated cylinders to quickly and accurately correct the web path. The nominal air discharged by the edge detectors also keeps them clear of paper dust or other environmental contaminants – an important feature for Duro Bag.

After a successful trial period with an all-air web guide, the Duro Bag plant began replacing electronic units with the custom displacement web guide model CD2 from Coast Controls. With eleven Coast guides currently in use, Weathers has been impressed with the simple operation, ease of training, and low maintenance cost. “The all-air web guides have really been a good choice for our converting operation. Every unit installed has performed absolutely maintenance-free,” he reports. “They’re very reliable and easy to operate, plus they cost less than electric models.”

While reducing maintenance costs and production delays with the new web guides, Duro Bag Manufacturing has discovered an additional benefit. “We have documented significant quality improvements based on specific feedback from our employees and our customers,” according to Weathers. “The all-air web guides have proven to be very good systems. I just can’t imagine how you could ask for any better web guide performance.”

www.durobag.com