Digital Magazine

Green Bay gears up for specialty labels

Green Bay Packaging's Coated Products Operations unit commissions custom equipment from Faustel to take advantage of the growing market for specialty label stock.

The Coated Products Operations unit of Green Bay Packaging Inc, Green Bay, WI, got the message when it was approached by more and more customers wanting specialty label materials. They included a leading brewery wanting to produce an eye-catching bottle decoration and a shampoo manufacturer needing a flexible label that would be as squeezable as the plastic bottle itself. Green Bay realized that the increasing demand for specialty labeling materials warranted the purchase of equipment that would enable them to tap into this growing market.

Using the Technical Center Facilities at Faustel Inc., Green Bay Packaging managers teamed up with Faustel's engineers to design a customized coater/laminator to meet their own unique specifications as well as the needs of its customers. "We chose to work with Faustel because of their reputation in the industry for building specialty coating lines for film applications," says Tom Mecklenburg, GM/VP of the Coated Products unit. After testing various coater/laminator features and working closely with Faustel's design team, Green Bay ordered a machine that would suit the customized, short-run business common to specialty labels - a coater that provides flexibility and quick changeover features and is able to effectively handle thin films.

Because of its flexibility, the machine allows Green Bay Packaging to offer a broad range of film liners to go with its full line of film facings. The two-station coater/laminator can handle many different material combinations, including film to film, film to polycoated paper or film to paper labels.

To eliminate heat-induced distortion of film liners, the machine uses ultraviolet curing for the silicone release coating. The first coating station, which is equipped for differential offset gravure coating, applies General Electric UV-curable silicone. The coated film then passes under UV lamps from Fusion UV Curing Systems, Rockville, MD, for curing. The second coating station applies a water-based, pressure-sensitive adhesive, using the reverse gravure method. Both coating stations use a fountainless/enclosed applicator featuring an internal doctor blade enveloped by Faustel to improve performance. The internal blade is designed to aid in filling the gravure cells when using higher than normal viscosity coatings, particularly at high speeds.

Space constraints were a key consideration affecting the coater/laminator's design. "We had only 30 feet for a thermal oven," explains Mecklenburg. "So, Faustel suggested installing an infrared booster to jump-start the adhesive drying process." An electric IR oven begins drying the adhesive before the the web reaches the gas-fired, hot air oven, which then completes the drying process. The 30-ft, two-zone stainless steel convection oven is continuously monitored for web tension and temperature, so sensitive films won't be overheated and stretched.

The machine runs at speeds to 500 fpm and has a web width range from 30 to 60 in. While speed is an important factor for a specialty coater/laminator, flexibility in operations is paramount. To improve productivity levels, the machine includes a quick-change Speed Sleeve system on both the silicone applicator and adhesive cotter backup rolls to allow for ten-minute changeovers. With this pneumatically operated system, the entire change sequence can be accomplished in minutes without the need for lifting equipment or special tools. A retractable oven hood, along with the oven level walkways, is designed to make it easy for the operators to thread substrate into the machine or clean and maintain the oven. With the hood retracted, the interior of the oven cools faster, so a safe access temperature is quickly reached. Also contributing to the line's flexibility is a digital drive system that can operate in either ratio or tension mode to allow processing both extensible and nonextensible substrates without distortion.

Doing the Job with Paper

Film liners such as polyester, polypropylene, polystyrene, and polycoated kraft provide a smooth surface for coating. Paper, on the other hand, is rough when viewed under a microscope, and when adhesive is applied to it the adhesive will assume this same roughness, which can adversely affect its transparent properties. Adhesives applied to film liners will exhibit a smoother, cleaner appearance that won't detract from the label graphics or the appearance of the product behind the clear label.

There are some cases where paper liners are still preferred, particularly if the moisture level in the liner can be controlled to eliminate potential curl problems that could adversely affect downstream operations. Moisture lost in drying and curing can lead to overly dry paper, which can be a major contributor to curl in labeling operations. To combat overly dry conditions, Faustel installed a thermo-electron steam remoisturizer to replace lost moisture. Not only can moisture levels be controlled, but remoisturization can be "profiled" to add varying levels of moisture across the width of the paper as needed for maximum curl control. Servo-motor controlled steam valves, spaced at strategic intervals, respond to a microprocessor-based operator control system to achieve the correct moisture content.

A History of Innovation

Originally known as the Green Bay Box Co., Green Bay Packaging was founded in 1919 as a manufacturer of wooden cheeseboxes. Soon after, it began to manufacture corrugated shipping containers and folding cartons. Today, Green Bay's major operating divisions are Corrugated Containers, Linerboard Mills, Folding Cartons, Woodlands, Pinecrest Lumber Co., Bay Fibers (wastepaper procurement), and Coated Products.

Growth is a tradition with the Coated Products Operations unit, which is a spin-off of the company's packaging operations. In 1980 the demand for coated products was such that a separate operating unit was established, and a new facility was built in suburban Green Bay to house the rapidly expanding operation in 1985. An additional coating and converting plant has been built in Winchester, VA, and distribution centers with in-house slitting capability have been added at geographically strategic locations to better serve customers. In addition, a major expansion of the Green Bay facility, adding both manufacturing and office space, has just been completed.

The tremendous growth of Coated Products Operations has been up until now, primarily in the paper label market. To develop a presence in the market for specialty label stock, Green Bay spent two years running film on high-volume tandem lines that were designed primarily for paper label grades. The division needed to prove to its customers, as well as its own corporate management, that it could be a major player in the film market. They were successful but quickly realized that a long-term strategy demanded the purchase of a dedicated coating/laminating line that would be used exclusively for the specialty labels. After two years of running film, the engineers at Green Bay Packaging knew what kind of features and capabilities they would need. Together with Faustel, they were able to custom engineer a coating/laminating machine that fills all of the unit's needs.

Computer System Ties it Together

In addition to creating the two-headed coating machine, Green Bay Packaging and Faustel worked together to customize Faustel's Converting Management System (CMS), a personal computer-based information system used for machine setup and monitoring and also for recipe and report generation. By automatically setting and monitoring factors such as moisture levels, temperature, web tension, and speed, the CMS enables machine operators to ensure they are running to specification.

To help the machine operators, Faustel rewrote parts of CMS language so it would generate machine performance reports that were similar to those on their existing coating lines. "We had a meeting of the minds with Faustel when it came to designing our reports," says Mecklenburg. After examining the company's existing formats, Faustel customized the CMS to match their needs. "We've saved worker training time, since our operators can more easily move between the three tandem lines and the specialty line," Mecklenburg reports.

The Faustel Converting Management System offers other productivity-enhancing features. For example, a recipe of machine settings can be assigned to each product. Each time a product is run, the machine can then be accurately set up according to the product recipe for consistent results.

CMS tracks utilization and productivity of the machine and its operators. Readouts report how much time was spent running, how much time was spent in shutdown and in startup, and how much time was spent making good versus "start-up" or off-specification product. Using real-time feedback, the system periodically records machine operations and flags any out-of-specification events, creating a history of machine conditions that can be cross-referenced to a particular work order for accurate recordkeeping.

After two years of market research and careful machine design, the Coated Products Operations of Green Bay Packaging has built a label stock manufacturing line that positions it strongly within the specialty market. It currently carries a full complement of film facings and film liners, enabling the company to provide customers with virtually any combination of specialty label materials. With its new line, the Coated Products Operations unit of Green Bay Packaging Inc. is poised to be a full-service supplier to the label converting industry for years to come.

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