Remember when a case packer might have three or four servos? How about 18 servos doing everything from infeeds to case sealing, squaring and compression?
And this is not your standard case packer, this is Douglas Machine’s economical, small footprint Invex® 3S case/tray packer, in operation at PACK EXPO International 2008, booth S-2223.
Invex® is a line of machines intended to give lower volume packagers access to the attributes of high speed Douglas machines -- flexibility, repeatability, durability, product handling knowhow, reduced parts count and ease of maintenance. Although at up to 17 cases per minute, the 3-station Invex® 3S is plenty fast in an exceptionally small footprint.
Servo modules offer many customer benefits
The key is a mechatronic design that makes effective use of innovative servo module technology. The servo modules, supplied by Schneider Electric’s packaging specialist, ELAU, contribute to reduced installation cost and the cost, space and complexity of electrical cabinets and cabling.
The 18 servos also require only two power supplies in the electrical cabinet, with just two cables leading from the cabinet to machine-mounted modules. Compare that to 18 cabinet-mounted drives for conventional servo motors, with either 36 cables snaking through the machine to the cabinet -- or up to 54 cables for brake-equipped motors.
That allows Douglas to reduce assembly time, offering the customer faster delivery. For 18 servos, the cabinet measures just 48 x 36” compared to 72 x 72” for an 18-axis machine using conventional servos.
When comparing ELAU to conventional controllers, the ELAU architecture delivers inherently smooth and responsive motion by performing all logic and motion in the same program on the same processor, and closing all motor control loops inside the servo module. This control strategy eliminates latencies generated by multiple processors and hardware modules communicating over a backplane and closing position loops over the SERCOS network.
Software, servos deliver compact performance
Performance is the main advantage of the motion-centric Invex® compared to previous designs. The servos replace many mechanical motions, equating to smoother operation, fewer jams, reduced maintenance and quiet operation.
The servo-driven machine is more adaptable to a wider range of products and materials, not just format changes, because servo control is highly precise. The machine can handle wraparound and knockdown style cases with no tool changeovers. Adjustments within the machine’s size range are simply handled as an HMI entry.
An electronic handwheel provides effortless hand cycling when needing to view the entire machine function or an individual drive in slow motion. This helps maintenance staff analyze motion details, greatly increasing the efficiency of the troubleshooting process.
Unique motion profiles assure that product is handled gently, because according to Douglas engineering manager Joe Faust, different motion profiles handle certain products better than others. In a recent application, ELAU’s (booth E-6413) software modularity saved another week in software development time because instead of reprogramming functionalities, parameters are simply changed in the program’s software objects. Invex® also provides standards-based connectivity and an IEC conforming software structure that is PackML- and PackTags-ready.
The Invex® 3S saves floor space by using 3 stations to collate products at speeds to 17 cases per minute then load into the case. A 4-station Invex® 4S uses more floor space but operates at up to 25 cpm.
Packed cases are then indexed forward, where the machine applies adhesive to manufacturer’s flap, tucks the leading and trailing minors, indexes again, then glues and tucks the top and bottom majors, performs servo case squaring and compression, then indexes out of the machine.
About Douglas Machine, Inc.
Founded in 1964, Douglas Machine Inc. is recognized as a global leader in automated packaging solutions for paperboard, corrugated, and shrink-film. Today the company specializes in the design and manufacture of cartoners, sleevers, case and tray packers, and shrink-wrap systems. Customers from many different markets including food, beverage, personal care, and pharmaceutical, have come to rely on Douglas’ automation expertise and value-added services to maximize their throughput. Douglas Machine is based in Alexandria, Minnesota USA.
For more information, visit www.douglas-machine.com or email [email protected].
About ELAU packaging solutions
ELAU, Schneider Electric’s packaging specialist, equips over $1 billion worth of packaging machines annually. Currently, over 40,000 purpose-built ELAU packaging automation systems are deployed in machinery worldwide.
Through ELAU, Schneider Electric is the only controls supplier with a dedicated business unit focused exclusively on the automation of packaging machinery.
The market demands packaging operations that are more flexible, efficient and sustainable to fulfill marketing, supply chain and global business strategies. ELAU innovations have enabled a revolution in mechanical, software and hardware modularity to deliver these agile packaging systems.
For more information, visit www.elau.com or email [email protected].