Youngs maximises fish finger throughput

Frozen foods manufacturer Youngs Bluecrest Seafood has managed to increase throughput on its fish finger packing line by 40%, remove a production bottleneck and save around £180,000 a year as a result of upgrading the line with new servo systems Youngs' engineers 'did it themselves' with help from Control Techniques, suppliers of the new M'Ax servo systems which are equipped with SLM (speed loop motor) technology. The line takes frozen fish fingers and packs 50 at a time into five cardboard boxes. Previously, this had been a hand picking line, employing some 27 staff. Stuart Baker, factory engineer at Youngs explains: "We looked at the options available to us and realised that we could build a fully automatic machine ourselves for the same cost as buying in a semi-automatic. But it all hinged on the servo system." He continues: "After we undertook a technical appraisal we chose Control Techniques M'Ax 4-wire SLM because of its flexibility, ease of programming and reduced wiring effort." The packing line had been a bottleneck at the factory with a maximum throughput of 1.2 tonnes per hour. "Now, with half the number of staff on the line [the remaining 14 staff have been re-deployed elsewhere in the plant] we're working towards a target of 1.7 tonnes per hour on all products," explains Baker. The actual system now comprises a Control Techniques MC216 motion controller with 16-axis control, eight M'Ax single axis servo drives and eight Unimotors with SLM technology. Frozen fish fingers are fed across a vibrating deck, which collates them into 50 lines of product. Five packs at a time are indexed into the packing machine using the registration input to measure the carton distance to the pneumatic stop. This replaces 14 packers. As the fish fingers move down the deck, a servo motor provides a finger lifting and separating action from underneath to prevent them sticking. Servos then provide indexing into a collating plate, which pushes the blocks of fish fingers into the correct width for the box and a vacuum pick-and-place unit picks up five carton loads at a time and places them in their boxes. Finally, an acceleration conveyor quickly clears the boxes ready for the next batch. Overall control of the system is from the 16-axis MC216 modular motion controller. With high-speed multi-axis control (1 m/s per axis) the controller is able to perform tasks such as cam indexing and complex acceleration / deceleration profiles. SLM technology uses the motor-mounted SinCos encoder and DSP (digital signal processing) technology that provides very high-resolution control. Cabling costs are cut by two-thirds (since there are half as many cables to connect) and an error-free signal is ensured through a high-speed dedicated bus system. According to Baker, "SLM was a key factor… It simplified not only the build and installation, but also, with its extensive diagnostics, has reduced maintenance time too. We evaluated several systems and it was gratifying that the best was also British!" DP