Beverage companies continue to develop package configurations for consumer products. One popular design is the 12-count refrigerator pack, which fits on a refrigerator shelf and dispenses cans to consumers. Other beverage package trends include specialty items such as coffees, fitness drinks and high-energy drinks typified by non-traditional container sizes also offered in smaller four- or six-count packages.
For Thiele Technologies Inc., Minneapolis, MN, a leading packaging equipment manufacturer and subsidiary of Barry-Wehmiller Companies, Inc., these trends acted as catalysts for significant design changes in its cartoning equipment, sparking a shift from traditional mechanical drives to the greater flexibility and control provided by an all-servo motion system. The ServoBeverage Packer is specifically designed for the beer, soda and specialty beverage industry.
With the help of distributor Motion Tech Automation MTA, Oakdale, Minn., and the servo technology from the electric drives and controls group of Bosch Rexroth Corp., Hoffman Estates, Ill., Thiele engineers designed an all-servo cartoner that erects up to 240 cartons per minute and handles up to 2,200 containers per minute in a variety of heights and configurations from 6.5 ounces to 16 ounces.
From four-packs to 30-packs to the popular two-by-six configuration of the refrigerator pack, the ServoBeverage Packer increases uptime, reduces the number of moving parts, simplifies operation and maintenance, and takes up less floor space than its mechanically driven predecessors.
Packing in control
The new packer’s servo system has ten servo motors individually controlled by a servo drive, a master PPC motion controller with a DeviceNet interface and programmable limit switch. Visual Motion software synchronizes all operations. The base machine’s ten servo axes include a rotary placer, six infeed starwheels, carton flights, barrel cam loader, and overhead confiner, all orchestrated by DKC servo drives using SERCOS and SGP Firmware and MKD servo motors with absolute feedback. The servo drives fit control and positioning tasks up to 27 kW. These tasks include positioning block mode, angular and velocity synchronization and cam and camshaft functions, plus an integrated virtual-axis generator. Compact drive electronics allow the use of standard 300 mm cabinets. The MKD servo motors are IP65-rated and offer peak torque to 187 Nm.
Stephen Kaye, Thiele cartoning and casepacking product manager, says this cartoner is special because of its servo-controlled pack pattern change. “Previously, mechanical change took an hour. Now it takes less than ten minutes,” he said. “The servo-controlled starwheel infeed ensures full cartons, even with a low surge product at the infeed.”
The starwheel offers overload protection. When bulk material is introduced, the infeed side of the starwheel checks for overload for fewer crushed or broken containers. In addition, the starwheel’s gentle container-handling characteristics reduce the number of product scratches and dents. One of the design challenges was the machine’s small footprint. Thiele used SolidWorks 3D modeling software to condense the machine’s size. The smaller dimensions of the servo controls also helped reduce size.
Another challenge was the time to market, which was less than four months. Thiele had a commissioning time for the controls of less than one week so it was a tight schedule.
A “back breaking” challenge
According to Kaye, there are several challenges with the design of a cartoner to handle the refrigerator pack. “The first was erecting the carton from a flat blank because the length and width dimensions are almost equal, making it square when viewed from the end,” explained Kaye. “Square cartons, as opposed to rectangular cartons, frequently ‘back break’ against themselves and fold into an L-shape instead of opening during set-up at high speed.”
Thiele uses a proprietary method to open and erect square cartons at nearly 100 percent efficiency. The cartoner’s servo-driven rotary carton set-up allows electronic timing between it and the carton flight system. This feature reduces debugging time during start-up and simplifies the fine-tuning required to accommodate material variations on the customer’s production floor.
The second challenge was to simplify the pack pattern changeover. The refrigerator pack is two cans wide by six cans deep—a configuration accomplished using six servo-driven starwheels. Thiele’s unique starwheel design is better than the old selector bar systems because it allows pack patterns to be changed electronically rather than mechanically. The starwheel handles beverage cans, PET (polyethylene terephthalate) bottles and glass bottles, orienting the containers into the pack pattern without damaging the product.
“If the customer wants to run a two-by-six 12-pack configuration and then change to a three-by-four 12-pack configuration, for example, the operator simply selects the pack pattern change on the HMI touchscreen, which alters the servo parameters to achieve the new pack pattern,” said Kaye.
The HMI is simple to operate and troubleshoot with touchscreen controls such as product selection and recipe adjustment, PLS control adjustment, PLC zone adjustment and servo axis phase adjustment. The HMI also supplies servo position monitoring, servo motor torque load feedback, a product shift register tracking screen and production statistics, including product count and fault history. Additionally, HMI screens are displayed in English or Spanish.
Because the refrigerator pack is only two cans wide, the pattern could separate when pushed into the carton using the previous selector bar technology. The new beverage machine uses a servo-driven overhead guide system that eliminates pack separation during the carton loading process. Again, because the guide system is servo-driven, it automatically and precisely adjusts to different pack patterns and assures quick, consistent carton feeding, even in the event of upstream stoppage. A “No Can/No Carton” feature also detects missing cans before insertion.
A final challenge of the refrigerator pack is the special glue pattern required for the can dispensing feature built into the carton. The specific glue patterns are controlled through the servo drive so that a pattern automatically changes depending on the selected pack pattern. The servo drive also automatically adjusts the glue pattern timing depending on machine speed.
Success is brewing
The ServoBeverage Packer recently began production with Modelo, a leading brewery in Mexico that produces Corona and Modelo beers. In the Guadalajara plant, which produces beer at a rate of about 125 million gallons per year, the packer handles 12-count refrigerator pack as well as 18-count cartons.
The Grupo Modelo personnel responsible for selecting and implementing the packer explained that the plant’s downstream equipment, specifically the cartoning area, had been unable to keep pace with a recent change in equipment upstream. They also noted that previously the plant could only run one carton presentation, whereas now the innovative cartoner allows them to run a variety of configurations to serve new market demands.
315 27th Avenue NE
Minneapolis, MN 55418
USA Phone (toll-free): (800) 932-3647
Phone: (612) 782-1200
Fax: (612) 782-1203
Motion Tech Automation MTA
615 Hale Avenue North
Oakdale, MN 55128-7534
E-mail: [email protected]
Bosch Rexroth Corp.
5150 Prairie Stone Parkway
Hoffman Estates, IL 60192-3707
Tel: +1 (847) 645-3600
Fax: +1 (847) 645-0804
300 Baker Avenue
Concord, MA 01742
Tel: 1-800-693-9000 US and Canada
Tel: +1- 978-371-5011 Outside the US and Canada
Filed Under: Packaging, Motion control • motor controls