Application Story

Wrapping Up in Automation

[picture of PS416 and Tunnock's Wafers] To achieve more cost-efficient and higher quality production, Thomas Tunnock Ltd., the UK’s largest independent biscuit manufacturer, turned to leading automation solutions provider, Moeller Electric and systems integrator, Applied Automation, for a new PLC solution to control its biscuit wrapping machines.

Thomas Tunnock's 20,000m² plant in Uddingston, near Glasgow, produces five million biscuits a week. A popular part of its range is the Caramel Wafer bar with its distinctive red and gold striped wrappers. To wrap these at the rates needed to sustain their massive home and export markets, a Klockner Hansel foil wrapping machine, located on each production line, wraps bars at the impressive rate of 400 per minute. Downstream a Klockner Tevopharm flow wrap machine wraps sets of four or eight bars into multipacks. On two of this product's production lines, Bridgend-based Applied Automation upgraded the control of the wrapping machines by replacing the existing Moeller PS22 PLCs with the very latest in PLC technology – Moeller's PS4-416 PLC.

High-speed machines require commensurate performance from PLCs – Moeller's PS4-416 delivers! A 0.33µS/bit processing time and up to 1Mb program memory ensures optimum process control, regulation, monitoring and calculation. With input frequencies up to 50kHz the PS4-416 is ideal for use in fast machinery, whether for high-speed counting or registering the signals of incremental position encoders. Comprising a variety of modules, including power supply, CPU, digital and analogue I/O, expansion modules and networking cards (Suconet, Profibus, Interbus, Modbus and serial communication), the PLC provides a highly capable and flexible solution.

Keith Rodmell, production engineer for Thomas Tunnock's said: "A major attraction of the PLC was its speed and memory. Its flexibility is also essential for us to ensure that we get the best from our equipment, now and in the future, without incurring high costs." Matthew Anderson, managing director of systems integrator Applied Automation, added: "A particular advantage with Moeller's PLCs is they are designed to make system upgrades as easy as possible. The PS4-416 features import filters that allow the program on the old PLC to be imported into it, thus saving us valuable commissioning time."

This page last updated: 15 January 2004