Electronic servo control improves machine reliability, increases changeover speed, and reduces maintenance costs.
As manufacturers find new ways to produce goods at faster speeds than ever before, OEMs are being asked to build machines that are in turn faster and more reliable — as well as flexible and scalable. Thiele Technologies Inc. of Minneapolis, a packaging machine designer and builder for more than 100 years, is well aware of these escalating requirements. The company makes cartoning, case and tray packing, palletizing, and bagging equipment for a variety of industries, including food and beverage, cosmetics, pharmaceutical, household goods, pet food, and industrial products.
So when a leading brewery contacted the company about building two new tray former packing machines, Thiele knew it would need control technology to meet the brewery's speed, accuracy, and flexibility specifications. The machines, slated for plants in California and Georgia, would be used to load cans and bottles onto trays to create cases and packages of various sizes and configurations.
To accommodate the beer producer's beverage line, the machines needed to be versatile enough to handle a variety of can and bottle sizes and packaging configurations. Reliability and throughput also were crucial design objectives to satisfy high-volume production demands. Yet another challenge: The brewery must be able to quickly adjust to frequent line changes with minimal operator involvement. Finally, machines had to be quickly designed, built, and installed.
To meet these requirements, Thiele sought a standard control platform that allows easy programming and configuration, along with electronic servo motion control technology to meet the accuracy, speed, and versatility required in the brewer's packaging operation.
Tray former packer uses integrated control
Thiele used controls from Rockwell Automation, Milwaukee, Wis., for its Nigrelli Envoy Tray Former Packer, a continuous motion, high-speed packaging system designed for loading cans, cartons, and bottles onto corrugated trays, U-board, or pads. The Envoy processes up to 3,600 containers per minute with extremely accurate positioning. At the heart of the machine is Rockwell's Kinetix Integrated Motion featuring an Allen-Bradley ControlLogix controller, Kinetix 6000 multiaxis servo drives, and MP-Series servomotors. Together they coordinate all major machine functions, including control of the rotary tray and feeding system, and placing and carrying trays through the machine.
Unlike other motion control systems that require multiple controllers and programming packages, ControlLogix ties all control functions into one multitasking platform. Motion functions are embedded in both the controller and the programming software. Engineers used a SERCOS interface module for integration with the compact servo drives, reducing wiring time. The low-inertia motors start and stop quickly, and drive machine components at easily adjustable speeds. Operators can view machine status and performance parameters through a touchscreen HMI. In fact, the machine's user-friendly features allow the beer producer to easily manage product changeovers. Operators need only enter product parameters once using the HMI: After they indicate the container size, servo drives adjust accordingly.
Integrated motion instructions in the software also minimize the need to write and coordinate two programs on different controllers. Predefined motion control commands in ladder logic programming language make servo motion programming simple. Once basic movement commands are programmed, engineers can duplicate them for other program axes, dropping them in where appropriate.
New machine is fast and green
The tray former packer is one of the fastest machines of its type on the market. With its integrated, electronic servo motion design, the machine features tray placement and transfer accuracy with speeds up to 150 trays per minute. The machine's servo technology is more efficient than mechanical line shaft options, including pneumatic or hydraulic systems, which are two of the most energy-expensive sources of motion in a factory. Packaging performance is enhanced as well, because all system control elements reside within the same multiprocessor control architecture. The result? Real-time communication and data manipulation for motion control, translating to greater precision and throughput.
The controller automatically configures the drives over the SERCOS interface when powering up, thereby accelerating machine setup and installation. Detailed drive and motor status information is accessible from the controller, which allows operators to monitor performance and minimize unplanned downtime. Engineers also saved time developing the system architecture by using the Kinetix Accelerator Toolkit CD, which provided files, program codes, and manuals for implementing the controls. From there, the toolkit offered recommendations for hardware selection, system layout, and even wiring schematics, which helped Thiele reduce its control system design time by about 30%.
The machine's servo-based controls shorten recipe-based changeovers from several hours to just 20 minutes: With recipe control, the brewer sidesteps the repetitive process of tuning the machine during a line change by saving and managing multiple settings. That way, the switch from a 12-oz to a 16-oz can is a simple keyboard entry, rather than an engineering design function. Electronic servo control also minimizes wiring, which cut commissioning time in half and reduced installation costs — so Thiele installed each machine in a single day, compared to several days for a mechanical-based system.
This month's handy tips courtesy of Rockwell Automation Inc. For more information, visit www.rockwellautomation.com.