The two GEI Mateer-Burt (Wayne, PA) auger fillers that deposit spices on McDougall's new line are servo driven and each is linked to a high-speed weighing system from Rice Lake (Rice Lake, WI) that tares out everything but the weight of the spices. The scales and the servo motors are part of a computerized system that allows corrections in weight on the fly. Here's how it works.
Included in each weighing system is a load cell over which each cup rides. The scale indicator sends out an electrical signal of known voltage to the load cell and receives back a signal whose voltage is different because the weight of the cup on the load cell causes resistance in the electrical circuit. The scale indicator assigns a weight to the difference between the two signals and then relays that information to the Mateer-Burt Microset Control computer on board the auger filler. The computer calculates the average spice weight in 10 cups and adjusts the auger turn automatically if that average falls outside preset parameters.
Servo motors, says GEI Mateer-Burt's Tony Izzi, are critical to this kind of system because they can process the digital information from the computer and can then make adjustments in auger rotation that are in the range of 1/4000 of a turn. An auger filler without servo motors, on the other hand, can only be adjusted in increments of 1/200 of a turn, says Izzi.
Plant manager Nick Vacalo had just completed the final calibrations for this computerized control system when Packaging World visited. Its accuracy is to within ±1/2 g on fills up to 10 g. The firm needed this level of control because spices are very costly, and McDougall's wants to minimize giveaway. Cost aside, the spices strongly affect product flavor. Even if the fill varies minutely from cup to cup, the product won't have the consistency that McDougall's feels is absolutely critical to consumer satisfaction and repeat purchases.
