PLF fills up with Schneider Electric

Edited by the Engineeringtalk editorial team May 1, 2002

PLF International has equipped its latest six-head inline filling machine exclusively with control and automation products from the brands of Schneider Electric.

PLF International, one of the UK's leading manufacturers and refurbishers of powder and liquid filling equipment, has equipped its latest six-head inline filling machine exclusively with control and automation products from the brands of Schneider Electric.

Key requirements for the purpose-designed machine, which is used to put powdered baby formula milk into cans, were that it should be easy for the operator to monitor and control, and yet should be versatile enough to cope easily with possible future changes in the user's requirements.

Engineers from PLF International based the design of the machine's control system on a Modicon Micro PLC with an integral AS-i master.

To provide a flexible and intuitive operator interface, the PLC was complemented with a Magelis touch-and-click HMI panel which combines the convenience of a touch-screen unit with the positive tactile feedback which can normally only be obtained by using a separate keypad.

During normal operation, the Magelis screen normally provides an overview of the operation of the entire machine, but the operator has the option of calling up screens which give more details of individual machine sections, such as the filling heads.

The display automatically provides alarm messages in the event of a fault, and also provides the operator with guidance on diagnosing and fixing the problem, thus helping to keep costly downtime to a minimum.

The Magelis display, along with the emergency-stop and other pushbuttons, are housed in a Telemecanique Tego Dial assembly.

The modular Tego Dial system allows IP65 operator stations to be assembled quickly and easily with virtually no drilling, and allows problem-free modification when requirements change.

Accurate control for the filling heads was an essential feature of the design, as the high cost of milk powder means that give-away must be kept to an absolute minimum.

To achieve the required degree of operating precision, the motors controlling the filling heads are controlled with Altivar 28 drives.

Similar drives are used to control other motors on the machine, and all are linked to the PLC by an AS-i network.

Other components from the brands of Schneider Electric, which are used on the machine, include Telemecanique contactors for power switching, Merlin Gerin miniature circuit breakers for circuit protection, a Telemecanique switch-mode power supply for the PLC, Telefast plug-in connector modules which simplify PLC I/O wiring, Preventa safety relays, and sheet steel wall- and floor-mounting enclosures selected from the Sarel range.

The machine is also equipped with Telemecanique proximity and photoelectric sensors.

In particular, an XUKT transparent-object photosensor is used to monitor the position of the cans as they are being filled.

This apparently unusual choice was made to allow the machine to be used, without modification, for filling glass or PET containers, should this prove desirable.

"By choosing to work with Schneider Electric, we have a single source of supply for every key automation and control component", said Mark Emond, PLF International's managing director.

"This not only simplified our purchasing processes, and allowed us to negotiate very attractive prices, it also meant we were guaranteed that all of the equipment would operate together without problems.

We also benefit, of course, from a single point of contact for technical support, and we have been very favourably impressed with Schneider Electric's services in this area".

Other factors which influenced PLF International's design to buy exclusively from Schneider Electric for this project were the breadth of the available product range, and the organisation's established reputation for product quality and performance.

The availability of local support in virtually every country of the world was also important, as many PLF International machines are destined for the export market.

"Our experience with this first exclusively Schneider Electric machine has been very positive", said Emond, "and we will, without doubt, continue to adopt this approach for future production.

We are totally satisfied that we have found an unbeatable combination of product quality, support and value for money".