The ham in the deli aisle seems unremarkable, but look closer and you'll notice the wrapping conforms tightly to every contour and its transparency reveals the meat's freshness. The plastic packaging is actually multiple layers, precisely bonded to achieve the meat producer's requirements. Food is kept safe from contaminants and has a longer shelf life, with the multilayer films and unique film coextrusion system.
Manufacturing the sophisticated blown film for this type of packaging, which can include up to 11 layers, requires equally sophisticated machinery and processes. Packaging machinery OEM Brampton Engineering develops these machines for producing protective films for use in many industries, including food and pharmaceuticals. Customers demand specialized, one-of-a-kind lines that produce high-quality blown film as quickly as possible, so they place a high value on flexible equipment designs.
“We need to offer our customers machines that will continue to operate as if they were new, even if the machine was built a decade earlier,” says Jagtar Singh, lead engineer of Control Systems for Brampton Engineering. “To do that, we need to build machines with one of the most modular automation systems available.”
“We needed faster design time, simplified programming and integration, and improved troubleshooting capabilities, all in a cost-effective package,” says Singh. “That required an integrated control approach that gave us access to data from individual components.”
To achieve these goals, Brampton selected an integrated control solution from Rockwell Automation. A ControlLogix programmable automation controller is used to control the process, from the extruder that melts plastic pellets into a molten sheet to the winders that collect the cooled film. The overall system architecture also includes RSLogix 5000 software, CompactLogix controllers with PanelView HMI, PowerFlex 700 vector control drives and Allen-Bradley POINT I/O modules. Each element is networked via ControlNet, so operators can interact with machines in the field and troubleshoot on a component-specific level.
The vector drives deliver precise torque and speed control to achieve the tight motor control required for ideal film thickness, clarity and strength. But they also offer a more cost-efficient alternative to servo drives, which are commonly used to achieve the speed and torque precision demanded by multilayer, blown-film applications.
“Using the PowerFlex vector drives as opposed to servo drives in our applications saves as much as 50 percent in raw hardware costs,” Singh says. “That's a savings we pass along to our customers, while still providing them with high-quality blown film.”
Using the Logix Platform with Premier Integration provides Brampton flexibility to help meet individual customer's needs without having to reinvent its control scheme and related programming each time. The RSLogix 5000 software's Premier Integration feature allowed engineers to seamlessly integrate the vector drives with the programmable automation controller. This approach reduces drive setup time and allows users of the vector drives, and other legacy Allen-Bradley drives, to consolidate drive system configuration, operation and maintenance into a single, integrated environment.
Brampton Engineering says it has seen more than a 50 percent reduction in design time, allowing them to build more sophisticated machines, including its AquaFrost system which uses water instead of air to cool the film, with the same number of engineering staff.