A system integrator reengineers a drive system and employs a PLC and HMI to help Norse Dairy Systems decrease mechanical downtime and cut waste.

As one of the world’s leading suppliers of ice cream novelty packaging and filling machinery, Norse Dairy Systems, was watching its profit melt away through mechanical downtime and wasted materials on its production lines. It turned to Martin Control Systems for a solution that boosted production by more than 27%.

Norse Dairy Systems (NDS in Columbus, OH), a division of Interbake Foods, is considered to be the top manufacturer of sugar cones in the world. Four years ago, NDS management sought to improve the production of paper cone sleeves, which are used to hold the wafer cone. The machines that roll back the rim on the sleeves suffered from as much as 13% downtime and tens of thousands of dollars in wasted scrap paper.

The original rolled rim machine was chain-driven with glue applications, blunter, mandrel blow-off and vacuum, and rimming functions timed with cams. The cams, which are disks or cylinders varying in shape, travel in a rotary motion pushing against an actuator to achieve a linear motion. To adjust the timing for these functions, operators had to stop production and use hand tools to advance or retard the cam timing, then restart the machine to test the changes.

NDS contacted Martin Control Systems Inc. (MartinCSI) of Dublin, OH, in search of a solution. After conducting a system analysis, MartinCSI suggested re-engineering the drive system to incorporate a programmable logic controller (PLC). This solution would allow operators to make adjustments electronically on-the-fly. The system would be controlled by a Rockwell Automation Allen-Bradley CompactLogix PLC and use an Allen-Bradley PanelView Plus 1500 as the touch-screen human machine interface (HMI).

An Allen-Bradley PowerFlex 70 drive would be used for main drive speed control. An EMP Model 200 single motor registration system would be reused to control paper registration into the cutting knives. As part of the project, all chains also were replaced with timing belts for better control and timing accuracy.

For real-time monitoring of the machine’s timing, a resolver was mounted on the main drive shaft and connected to an Advanced Micro Controls resolver input module mounted in the CompactLogix rack. MartinCSI replaced the mechanical cams with an electronic timing schedule based on resolver position.

The new control system provides runtime details about machine performance such as sleeve count, production speed (cones per minute), percentage of the maximum speed the machine is running, roll diameter (inches), and gate plug location. The main drive motor status and the rimming motor status are also displayed on the touch screen.

Quick-start resolver calibration
For quick startup after maintenance operations, MartinCSI implemented a resolver calibration function that uses a button on the HMI to retime the resolver to the machine’s zero position. Using the touch screen, operators can also change main motor speed, which is controlled by the PowerFlex 70. The knives, which are driven through the timing belts in a 1:1 relationship, run at the same speed as the rest of the machine, as do the resolver counts. When the machine speed is changed, it is no longer necessary to re-time the functions to the resolver, as built-in compensation is provided for higher drive speeds.

Brake tension on the paper unroll is now adjusted electronically in real time while running, using an I-P transducer and an pneumatic disk brake. An ultrasonic sensor is used to monitor the diminishing diameter of the paper roll; as the diameter and weight of the roll decrease, brake tension is slowly reduced to maintain steady paper tension. The operator can establish diameter and tension ratios through the touch screen, and make adjustments while the machine is running.