About the only thing that remains the same for the redesigned, servo-technology-enhanced WP 100 wraparound case packer from SWF Companies is the machine’s compact footprint.
“Virtually everything inside the frame is different,” notes production engineering manager Dennis Ramsey. “We were able to totally eliminate the mechanical line shaft. We rebuilt the machine from the ground up around servo technology.”
Based on these improvements, lead time has been reduced from 24 weeks to 16 weeks or less. The initial programming for users to add new product sizes has been halved. Installation, which took 7 to 10 days, has been cut to 3 days. Despite these upgrades, the model retains its base pricing, its speed of up to 30 cases/min, and the time needed for changeovers.
Says product manager Thomas Jimenez, “We developed all the upgrades in conjunction with the latest offerings from Rockwell Automation.”
The WP 100 wraparound casing system uses Milwaukee-based Rockwell’s Allen-Bradley® MBL Series servos for all three axes of motion. The servos improve positioning accuracy and repeatability.
The packer uses Rockwell’s ControlLogix™ programmable logic controller. The onboard software is Rockwell’s RS Logix 5000.
Also, the previous keypad interface has been replaced with an Allen-Bradley PanelView™ 550 touchscreen interface. “This gives users access to everything,” says Ramsey, “including jog mode and starting and stopping of drives. Anything you could do through a PC hooked up to PLC can now be done through PanelView.”
Another improvement is the use of Rockwell’s DeviceNet™ network. It eliminates point-to-point wiring—some 400 to 500 individual wires, Ramsey says. This cut electrical assembly time by 33%.
“The electricals are now housed in three main trunks connected to various junctions boxes throughout the machine,” Ramsey points out. “Specific benefits of DeviceNet for end users include quicker maintenance and easier replacement of sensors and other devices.”
A direct result of the fieldbus is the improved troubleshooting and diagnostics. The machine is preset with more than 100 fault messages to help pinpoint any troubleshooting required. The machine is also data acquisition enabled. Jimenez says that “any user-selected machine motion or lack of motion as measured by time or positioning can be tracked.”
Switching from mechanical to electronic motion control reduced the mechanical content of the machine. SWF estimates that the total number of machinery parts was reduced by 700 parts from 4귔 in the prior design. Jimenez points out that most of those 3꼀 parts, including the servos, are nonproprietary and are readily available.
