Bagmaking Guiding: Air Solution

Productivity runs at a fast pace at privately owned Duro Bag Mfg. Co. with corporate offices in northern Kentucky. Founded in 1953 and with more than 2,500 employees working at 12 manufacturing facilities across the country, it's easy to understand why.

As a full-service bag manufacturer, Duro Bag's production includes grocery bags and sacks, handle bags, merchandise bags, paper lawn and leaf bags, bread bags, food service bags, and more. Bagmaking equipment is supplied by Newlong, H.G. Weber, and others. Six-color flexographic printing is accomplished on presses from Research & Development Inc., now maintained by Madsen Machine Co.

Duro Bag produces millions of imprinted bags annually. That equals a lot of webs — and a lot of web guiding. In fact, web guiding had been given special attention lately as the company sought to reduce component maintenance and related downtime.

Paper Dust a Challenge

For many years, Duro employed conventional electronic web guide systems. According to David Weathers, engineering and maintenance manager at Duro's Jackson, TN, 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, TN, plant, Duro runs virgin white, recycled white, kraft, recycled kraft, and grease-proof papers on 30 different production lines. Web widths of 28 in. move along at line speeds of 500 fpm and more. “At this speed,” notes Weathers, “alignment between the printer and bagmaking 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 from Coast Controls that actually blew dust away from the sensors. In fact, this 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.

Quality Improvements Documented

The all-air web guide systems were first developed more than 16 years ago for the converting industry as an alternative to electronic systems. Using only low-pressure plant air, these systems employ a reportedly innovative method of monitoring changing air pressures to detect web edge positioning and use 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 11 Coast guides currently in use, Weathers has been impressed with the simple operation, ease of training, and low maintenance costs. “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 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.”

Converter Info
Duro Bag Mfg. Co. | Davies and Oak Sts., Ludlow, KY 41016 | 800-879-3876 |

Supplier Info
Coast Controls |

Newlong |

H.G. Weber & Co. |

Madsen Machine Co. | 205-345-6500

A Green Alternative

As the movement against plastic bags intensifies, Duro Bag Mfg. Co. has created an eco-friendly option, the Perfect Bag, a reusable nonwoven bag.

The Perfect Bag is constructed with folded edge piping and full length inside handles for extra durability. The heavy-duty material can hold up to 20 lb and is water and heat resistant up to 275 deg.

“These bags are so eco-friendly that even the ink is water-based,” says Chuck Kessel, VP sales & marketing. “When the bag is no longer needed, it can be recycled, too.”

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