Brings Servo Speed to Goya Foods Packager
Story and photos provided by Bosch Rexroth Corporation,
Hoffman Estates, IL.
|KHS-Bartelt Formula 2000 Series Continuous Motion Cartoner
packages seasoning pouches for Goya Foods.
Because packaging lines are sequential, faster machines can become stalled when slower machines bog down the line. But many packaging equipment manufacturers, such as KHS-Bartelt Inc. of Sarasota, Fla., are implementing servo systems to remove these bottlenecks, increase the production rates of upstream machines and improve packaging line throughputs.
A Klöckner subsidiary, Bartelt manufactures packaging equipment for the food, pharmaceutical, health care, and electronics industries with products including cartoners, side seam gluers, fillers, pouchers, and bag makers. Using DIAX04 synchronous AC servo motors and drives and a PPC motion controller from Bosch Rexroth's Electric Drives and Controls division, Bartelt customized a continuous-motion cartoner for CPR International, a packager of seasoning pouches for Goya Foods, Inc., the largest Hispanic food company in the United States.
CPR installed its first high-speed seasoning line in 1993. Since then, the company has installed four additional lines, doubled the speed of its filler on the original line, added pouch-handling equipment, and, most recently, replaced its existing intermittent-motion cartoner with the continuous-motion cartoner from Bartelt to keep pace with the new filler. Compared to an intermittent-motion cartoner, which stops the product and carton conveyors during the product cycle, the continuous-motion cartoner inserts product into the carton while both are moving.
The Need for Speed
The Bartelt Formula 2000 Series continuous-motion cartoner automatically packages Goya seasoning pouches from a high-speed, continuous-motion pouching machine feeding directly into the cartoner. The cartoner opens the cartons, loads the pouches in quantities of eight or 12 pouches into the cartons at speeds of 1,100 and 1,300 pouches/minute, respectively, and then closes the cartons. The continuous-motion cartoner has the capacity to run at speeds up to 600 cartons per minute, depending on the application and product handling requirements.
"Servo drives on all of the cartoner's critical functions provide a level of reliability and repeatability that mechanical systems and components just can't compete with," notes Jim Lyons, Bartelt vice president of sales and marketing. "For our customers, servo-driven systems mean faster feed rates, greater uptime, quick changeovers, and overall less maintenance over the life of the machine due to fewer components that wear."
The machine's seven servo motors and drives are controlled by a Rexroth PPC motion controller that synchronizes all operations, including product conveying and insertion, carton feeding and opening, carton conveying, minor flap closing, and pouch conditioning. According to Lyons, the servos have replaced over 50 percent of the mechanical components associated with mechanical cartoners.
CPR's upstream filler and pouch-handling equipment feed the cartoner infeed conveyor by placing the pouches directly into the infeed buckets of the conveyor at the proper time and in the correct position for cartoning. The cartoner has a linear track cam (barrel loader) inside the product conveyor to make the insertion motion. Each cycle of the carton-unfolding axis takes a flat carton from a stack and unfolds it into the carton flight conveyor. To reduce waste and maximize uptime, the axis is programmed to skip a cycle when product is missing. If product is missing, the vacuum to the carton-unfolding suction cups is turned off for one cycle.
As the carton travels along the carton conveyor axis, it is opened, and product is loaded in one continuous motion. The leading minor flaps are then plowed closed and the trailing minor flaps are closed by separate servo-driven rotary flap closers located on each the side of the carton flight conveyor. The servo-driven carton flight conveyor then carries the carton to the carton closing section where it is glued closed. Two parallel opposing belts then grip the carton from the flap ends, squeezing the carton long enough to allow the glue to set under the flaps. Finally, the carton conveyor prints the date and batch code on the carton.
For Bartelt, the modular control strategy and open architecture of Rexroth drives and controls allow connectivity between different vendors and systems and are supported by Rexroth's Windows®-based VisualMotion software. VisualMotion controls servo systems to replace mechanical line shafts and timing, indexing, and start-stop mechanisms. The programmable motion allows no-tool product changeovers in minutes instead of hours. When a package size or recipe changes, the operator simply sets up the machine by selecting the new program at the control panel, so that electronic gearing ratios, camming setpoints, and motion profiles change instantly with the push of a button.
"Line speed is directly related to precision," explains Craig Thompson, Rexroth senior applications engineer. "Servo systems deliver that precision with intelligent, digital AC servo drives linked by a SERCOS interface for precise drive synchronization and high-resolution motor feedback for repeatable position accuracy."
Thanks to multi-axis digital motion control, cartoners can use servo drives to increase speed and functionality. For example, electronic camming permits adjustable flap tucking using different motion profiles for different size cartons without mechanical changeovers. Likewise, absolute feedback automatically keeps track of all axis positions, which eliminates the need to re-home and resynchronize if a jam occurs. A virtual master eliminates mechanical disturbances found in mechanical line shafts, assuring tight control over the electronically geared servo drives. Ultimately, the fast servo position loop updates and high-resolution feedback increase top cartoning speeds by tightly performing electronic gearing.