One of the best loved varieties of Swiss cheese - Gruyere AOC, is traditionally made in small villages in the Swiss cantons. At about three months old, these are delivered for maturing at the Fromco SA aging cellars in Moudon, eventually to be exported around the world. As part of the aging process, each cheese is carefully brushed once a week with a special saltwater mixture, but with increasing global demand for the cheese, Fromco has increased volumes and it became necessary to extend the line and automate the brushing. Swiss automation specialist, Patric Concept was appointed to undertake this work.
Fromco had been using Interoll drum motors for its conveying systems since 1994 and was impressed by their reliability and all-in-one hygienic sealed design. They were thus first choice for the new automated line. Types 165E and TM220M drum motors were selected, the 165E 0.75kW model being employed to handle the heavy cheeses along the flat sections of the conveyor line, and 2.2kW versions of the TM220M model for transporting the cheeses down inclining and declining sections of the conveyor line. To provide the extra friction needed between the drum motor and conveyor, a polymer coating is applied as standard to the motor’s stainless steel drum.
With 160,000 cheeses on four processing lines, the number of stops/starts is extremely high at 40,000 per motor every week, or over 2 million per year. Able to tolerate these mechanical stresses and resist exposure to the salt solution, the Interoll units have also helped Fromco to keep down electricity costs. Conventional geared motors need to transfer energy and torque through a ninety degree angle, which is energy inefficient, whereas drum motors optimise energy consumption, as energy transfer is in the direction of the motor only.