Rapid sorting and weighing
Teltek, based in Örebro, Sweden, develops, designs, programs and installs dynamic scales, primarily in the food and drink industry but also in other sectors like chemicals and hardware (weighing screws as part of the verification process). Virtually all the scales supplied by Teltek are tailored to meet customer requirements. The scale supplied to the fish factory was designed to sort incoming fillets of fish for packing in 400 gram units, at a rate of approximately 55 packs per minute. This is about what two people can manage when working at the conveyor.
Digital load cells are the key
Teltek's approach involved six parallel buffer plates on each side of the scale, with room for a total of twelve fillets that have passed through the two fish sorters. A combination of fish fillets is selected to come as close as possible to the target weight of 400 grams per pack. The central components of the machine are the six digital HBK PW15AHi single point load cells, with a pneumatic motor to advance the belt. "Obviously, the primary function of the machine is weighing, but a lot of thought went into how the fish is handled and transported – this is a delicate raw material that can easily fall apart. We clearly want to keep waste to a minimum", says Tomas Moqvist, who has learned a lot about raw fish during the project.
Built-in intelligence
Unlike many other scales, in which Teltek uses a combination of analogue load cells and in-house filters, the decision was made to use digital load cells in the new fish scale. As a result, a certain amount of intelligence could be built into the load cells directly, for example signal filtering functions.