Lamination on standard 2-cylinder can create overpressing problems on smaller size boards. These presses have thicker hot platens which encourage thermal bending and this is usually compensated by additional heating. 

Siempelkamp’s multi-piston press concept, with up to 4 cylinders, has more small diameter cylinders distributed across the hot platen. Six pressure zones are available for a full-size board. For small size boards, the outer zones are switched off to allow variable pressure distribution. 

On standard presses, pressure distribution is compromised over small size boards. The multi-piston press provides better pressure distribution, in both width and length, on both large and small boards. 

The main benefit of the multi-piston press is even pressure distribution. Reduced maintenance is another advantage - because the smaller, lighter cylinders on the multi-piston press have less bearing load, they require less maintenance and are easier to change. In addition, because of optimum temperature distribution, they can utilize less heating circuits, reducing energy demand. 

Overall, the multi-piston press offers higher potential for optimizing the lamination process and higher production flexibility. Some production runs can even be done without press cushions. The press can handle all board sizes and types with less rejects.

Currently, Siempelkamp has 14 multi-piston presses installed worldwide.

Information based on a presentation by Dirk Kolze of Siempelkamp at the 2008 TAPPI DIL Symposium.