New modular design concept for large multi-daylight presses
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Canfor-LP in Fort St. John, Canada, built a plant incorporating a 12-daylight Siempelkamp press. This giant press enables a raw board size of 12’ (3.6 m) x 34’ (10.37 m). With these dimensions the press can be compared to an 8-story building with a weight of 3,250 metric tons (3,600 US tons). Even more impressive is the 700,000 m3 (800 MMSF/Y) annual capacity of this press. This number is based on approximately 2,070 m3 OSB with a thickness between 6 mm (0.23 in) up to 32 mm (1.3 in) produced daily. Such a performance can only be achieved by a highly reliable and robust press.
Because of the giant size of this press, it was necessary to design a press concept that can withstand the enormous forces. The upstroke press with a modular press frame construction has eight hydraulic press cylinders. Each cylinder has a piston with a diameter of more than one meter (3.3 ft). This provides for a pressing force of 210 MN (42,600,000 lbf). A press with such a design feature is certainly a technical masterpiece. The immense forces and component dimensions in the case of the Canfor press made a numerical simulation in the design stage of the press indispensable. The Finite Element Method was used to examine and simulate all loads, stresses, and deformations occurring on all heavy parts of the press. It was then decided to use a cast-iron design instead of a welded design for the press. The press table and the upper and lower press beams were cast in Siempelkamp’s own foundry. Our foundry is one in a few capable of producing castings with weights of up to 300 metric tons (330 US tons). Siempelkamp is the only company that is capable of supplying such a press from one single source. Each press table has an enormous weight of 200 metric tons (220 US tons).
The vertical frame components are held together by upper and lower cross beams to form the press frames. The elements are not welded, but put together and fixed by bolts instead; this is to achieve a higher fatigue strength. The press cylinder and hotplatens are then inserted into this construction. The modular construction has another advantage: The parts are easy to transport and the press can be assembled quickly.
