| 摘要 |
In a continual process to make chipboard from palm fronds as described in prior fibreboard claim DE 10139987.1, the fronds are chopped and freed of sand. Following removal of leaf particles by winnowing, deciduous or coniferous wood chips are admixed as required to the chopped palm stalks. The mixture is reduced to fibre in a shredder and mixed with a suitable bonding agent powder and continually discharged to a heated conveyer which passes through a press and is converted to a fibrous chipboard. The winnowing process reduces the leaf content to approx. 15 per cent. The bending strength of the product is determined by the proportion of wood chips admixed. Prior to use the palm fronds are dried to contain less than 30 per cent moisture by weight. During the discharge of dry solids to a flat conveyer, the drop height is limited to minimise particle separation and dust generation. The mixture consists of a maximum 85 per cent palm stalks and a minimum of 15 per cent admixed other wood. The chipboard weighs approx. 770 kg/m3 and is 16 mm thick. A 50/50 mixture of palm stalks and other woods results in a bending strength of 26 N/mm2. Also claimed is a suitable assembly consisting of a drum shredder or slicing assembly, a particle cleaning unit, a winnowing machine, a particle pre-heater, an upright heater, a refiner, a particle scatter station and a heated press.
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