| 摘要 |
A process for forming wood fibre comprising breaking down acetylated wood, preferably from wood chip (1), to produce acetylated wood fibre having a moisture content from about 5 % w/w to about 8.5% w/w (preferably 6.5 6.8 %) after it is comminuted to form wood fibre. The process preferably includes a first moisture-introducing step for increasing the moisture content of the acetylated wood elements in form of water (5) and a second moisture-introducing step, separate to the first, for increasing the moisture content of the acetylated wood elements in form of steam. The steam in the range of 160 210 ºC is used to heat up the chip. Optionally, a digester (8) and a refiner are used to process the wood chip to form acetylated fibre. The refiner comprises two discs at a distance of 10 18 mm operating at a speed of 1300 1600 rpm and in a pressure chamber. The process further used a compressive screw feeder (6), which is adapted to process acetylated and non-acetylated wood chip. Preferred acetylated wood fibre articles are MDF boards with an MDI resin. |
