In response to a customer request, Scandia recently designed and built its first minimally mechanical, full-servo overwrapping machine. The overwrapper uses eight servo motors to apply and heat seal film wrap over cartons of product containing just about anything from baby food to batteries.
“Before this, our machines were mechanically controlled,” says Art Goldberg, director of engineering at Scandia. “Timing was driven by a main shaft connected to chains and other mechanical components.”
In the new servo-based system, mechanical synchronization is replaced by a multi-axis servo controller called the MC224 from Trio Motion Technology (www.triomotion.com). A PLC from Rockwell (www.rockwellautomation.com) sends an output to the Trio controller, which is programmed to synchronize all eight axes of motion. These include
• main rotary indexer
• infeed conveyor
• film feed
• knife
• tucker of film
• heater
• second heater, and
• discharge conveyor
Servo motors and their complementary drives are from Danaher Motion (www.danahermotion.com).
According to Brad Steele, the Trio distributor who worked with Scandia in designing the overwrapper, ease of assembly, faster installation, and greater flexibility are the key benefits gained by Scandia now that it is building a servo-based machine. The end user who buys the machine benefits equally.
“With the mechanical linkages, you had to physically link axes together with chains and sprockets and so on,” says Steele. “Positions had to be adjusted manually, too. Now everything is linked and controlled electronically.”
