Design and Fabrication of a Modular Three-Unit Pallet-Based Press for Wood Densification

Abstract

A modular pallet-based press was designed and fabricated to integrate preheating, progressive compression, and cooling under restraint for solid-wood densification. Three separately driven units provided an effective pressing length of 950 mm and width of 140 mm per unit. The prototype accommodated a specified workpiece envelope of 110 mm in width, 55 mm in thickness, and 800 mm in length. The compression unit combined a horizontal lower pallet track with an inclined upper track. Thickness-limiting metal molds were introduced after preliminary trials revealed pallet impressions. In the reported application, Scots pine and black poplar were processed at a travel-speed setting of 0.50 m/min to a mold-defined thickness of 20 mm under load. Preheating and cooling involved stationary dwell periods controlled using exposed side-surface temperature readings. Thus, the implemented sequence was intermittent rather than uninterrupted through-feed. Pallet warm-up to 200 °C required approximately 15 min, and one operating session extended to 10 h. For the reference case involving 26.7 mm-thick Scots pine specimens, the calculated in-line residence time was 13.6 min, and the theoretical steady-state throughput of approximately 11.2 specimens/h was consistent with actual production. The documented design and operating sequence provide a basis for further instrumented performance evaluation and process optimization.