| 摘要 |
PURPOSE:To prepare a board material prevented from the generation of warpage and strain, having dense grain and near to a natural wooden material and to further bring the same to a neutral state, by adhering a urea resin solution to a cellulosic material to bring the same to a neutral state before performing integral pressing. CONSTITUTION:A cellulosic material is a crushed chip material and drying treatment is applied to adjust the moisture content of said material to 15o/wt. or less. When pre-processing is applied to the said material in this state, the destructive phenomenon of the constitutional fiber structure of the material is induced and the compositional state of the fiber structure is destructed and the fiber structure is brought to a broken-up state. A urea resin solution is added and adhered to this material and not only heat drying is applied to said material in a range of 100-250 deg.C but also crushing and pulverizing treatment is applied thereto in the next step and the pH of the material itself is adjusted to an almost neutral range of 6-7. Thus obtained compositional aggregate materials are pressed to be brought to an integral structure such that tentacles 1b-1b are tightly entangled to each other and the entangled parts of tentacles are prevented from being released by elastic stress at the time of the release of pressure. As a result, the use of a neutral board material rich in water resistance and a heat insulating characteristic and having adequate hygroscopicity is enabled. |
