Using a non-optimisable motion control system, ice cream manufacturer Birds-Eye Walls faced efficiency issues and product wastage transferring Magnum ice creams from its production line to a packaging machine. A redesign initiative, with Festo, froze the problem out and delivered a tasty solution.
Originally, the automated packaging unit employed a transfer buffer mechanism between the production line and packaging feed line which employed standard pneumatic cylinders. The motion profile of the original actuators was fixed and could not be adjusted to take account of fluctuations in the packing cycle. Inevitably, the result was a build-up of Magnum ice creams in the buffer store leading to misfeeds, compromised line efficiency or even the need to halt the line. The line restart cycle takes 20min, and with an average throughput of 291,000 Magnums per shift, the resulting finished product waste from line stoppages was significant.
A customisable solution from Festo was deployed to solve the problem, using an SPC200 servo-pneumatic control system and rodless cylinders. DGP range rodless cylinders were used to deliver variable velocity actuation with high peak speeds.
Festo’s SPC200 servo-pneumatic controller was used to drive the cylinders and permitted precise definition of the transfer motion. Velocity profiling allows the cylinder driven by the controller to move at different speeds in the same direction.
Using the SPC200 in a stand-alone mode, the velocity profile is tailored to the applications: in this instance, providing a fast approach speed then progressive deceleration to an optimum speed that gently transfers 30 Magnum products at a time onto the packaging line. Next, the cylinders return to the initial position at high speed, ready to transfer the following product batch. Festo supplied the transfer system as a pre-wired and tested cabinet assembly directly to the Birds-Eye Walls factory in Gloucester. The system was designed to be interfaced to the existing PLC by Birds-Eye Walls’ own technicians using a simple digital I/O handshake.
In fact, only six electrical connections were required to integrate with the host PLC. This installation process, plus full hardware and software commissioning and user training, was completed in just one eight-hour shift.
The total investment for Birds-Eye Walls was a highly cost-effective £4,500.
The tangible benefits to Birds-Eye Walls were a dramatic reduction in finished product wastage, substantially less line downtime due directly to the elimination of product misfeeds and zero maintenance or repair activity despite six-months of non-stop operation estimated at 1.8 million actuator cycles – that is equivalent to 5,400km of cylinder stroke!
On top of this, Birds-Eye Walls has enjoyed a commercial advantage with a 16% increase in throughput capability when depleting the transfer buffer. This potentially equates to the processing of an additional 65,000 Magnum ice creams per week.
Festo Tel: 01252 775000