At the grocery counter, getting just a little bit more than paid for can be a benefi t for consumers. But even a small difference between the advertised and actual weight of an item – known as “giveaway” in the industry – can significantly impact a food producer's bottom line. Marchant Schmidt, a family-owned business headquartered in Fond du Lac, Wisconsin, provides innovative cheese converting solutions designed to minimize giveaway and waste – and maximize yield. What began 50 years ago as a company focused on the needs of local farmers and businesses has grown into a global organization recording nearly 50 percent of its sales from outside the United States. Recently, Marchant Schmidt redesigned the cheese portion cutting module on its Vision Cutting System (VCS) to optimize the speed and accuracy of its offering. In incremental and rapidly executed steps, the VCS solution can reduce the size of an initial 640-pound block of cheese into exact-weight After leaving the guillotine cutter, the portion enters a check weigher. Products that are either overweight or underweight are automatically rejected. “Our machine is designed to keep off -weights to an absolute minimum,” said Mike Haseleu, controls manager, Marchant Schmidt. “Through automatic feedback, the control system monitors the weight and then adjusts the cut calculations if portions are running slightly heavy or light.”
To improve rotational cutting speeds – and reduce stress on the machine frame – the company replaced the linear actuator on its guillotine shears with a crank-style mechanism. The company also upgraded the module's Rockwell Automation control and information solution to incorporate the latest technology. An Allen-Bradley® ControlLogix® programmable automation controller manages all weighing and measurement applications and overall machine control. The controller is also integrated with the vision camera system and Allen-Bradley PowerFlex® 525 and 527 AC drives via an EtherNet/IP™ network. Two PowerFlex 525 drives provide motor control on the infeed segment of the conveyor. On one outfeed conveyor, a PowerFlex 527 drive is installed to control the position and speed of the outfeed induction motor.
An Allen-Bradley Kinetix® 6000 multi-axis servo drive controls an Allen-Bradley MP-Series™ food-grade servo motor on a second outfeed conveyor, which correctly positions the cheese. Servo drives supply motion control in all areas that require precise positioning, including the guillotine cutter. “The PowerFlex 527 drive was ideal for this application,” said Haseleu. “We needed to match the profi les of the two outfeed conveyors to synchronize the machine. New drive functionality made that much easier.” Since the PowerFlex 527 drive uses the same configuration and integrated motion instructions as the servo drives, programming could be accomplished quickly through common programming techniques within the controller. The guarded machine incorporates Allen-Bradley SensaGuard™ non-contact interlock switches and Guardmaster® safety relays. The system is monitored on Allen-Bradley PanelView™ Plus 6 1000 graphic terminals. Marchant Schmidt has recorded impressive speeds on its redesigned module. While similar cutters on the market average 100 to 150 pieces per minute (ppm) for a typical 8-ounce (227 gram) portion run, the Marchant Schmidt machine achieves speeds up to 200 ppm. “Our portion cutting module is very accurate – and can be easily modifi ed for global markets,” said Wright. “It's also the fastest machine we've built to date.”
With the help of Rockwell Automation solutions, the company completed the development of their machine rapidly as well. “We started using Rockwell Automation solutions pretty much from Day One,” Haseleu said. “The support the company provides and tools – like the Drives and Motion Accelerator Toolkit – help reduce our overall development time. There's really no reason to go anywhere else.” portions. The portion cutting module is located near the end of the converting line – after initial size reductions and before final weighing and shelf-ready packaging. The cheese typically enters the portion cutting module in 3½ -inch by 5½ -inch sticks of varying lengths. Utilizing 3-D vision scanning software and cameras, the system measures the stick and automatically determines a custom cut solution to maximize yield, based on exact-weight portion size. “Since the module includes two infeeds, two sticks can be cut at the same time,” explained Dennis Wright, project manager, Marchant Schmidt. “However, each stick can have a unique cut solution.”
Published September 1, 2014