Servo System

A world wide plasterboard company required a new design of plaster board, complete with recessed strips for fixings, they quickly solved the problem of the long edges, as this was a simple roller applied to the board edges at an early point in the manufacturing process. However the indentations required at the top and bottom of each board presented a more complex problem.

Working with a precision mechanical company, Concept have helped develope a "Flying Press" system, which involve using a pair of high specification Linear Servo systems, to lock on, and follow an exact point on the travelling plaster board, and then use a high power hydraulic servo, to operate a pair of RAMs to apply 200 Tonnes of pressure to form the indent.

The system includes full integration within the main production lines, and has dual level functionality to allow the system to use local (via the HMI) or Plant setpoints for each different aspect of the individual boards. These settings are stored using a Recipe system, allowing rapid selection, and avoiding costly mistakes during product changes.

One of the more fascinating aspect of Plasterboard Manufacture is that it the production line can be almost a kilometre long, and essentially manufactures a single sheet of board along it's full length. As the Press tool is near the end of the line (for forming and cutting reasons), it is essential that the system includes not only traditional safety circuits, but also specialist emergency release (blow off) elements to open the press and avoid trapping the baord if a problem occurs. A failure that trapped the board could result in damage and unpredictable board movements for some way back down the line. This involves the use of high pressure accumulators that can be triggered at the first sign of a potential issue.

There is also the major concern of safety when moving tonnes of equipment at high speed, and applying high pressure loads. These are all covered using a sophisticated safety system, that includes pressure bleed offs, and multiple safety interlocks.

Overall this project required a wide range of experience, and knowledge of many different aspects of manufacturing and safety design to become a reality.

The system combines advanced technology from Rexroth, Siemens and Parker, and designed to be very robust in operation, with a high degree of adjustability to the forces applied during the press cycle. All of this being handled at production rates over 1 metre per second, and with overall cycle times of under 2 seconds. At times this involves accelerations that put Formula 1 cars to shame, but the design still retains high reliability, due to the attention to detail when designing the underlying cycle and making sure that lost time is eliminated wherever possible.