| 摘要 |
<p>The pref. initial mixt. contains 4-5 pts. vol. peat or turf, 1 pt. vol. quicklime, and 0.5 pt. vol. aluminium sulphate. Quantities may vary within reasonable limits. The mixt. may also contain metal oxides added to impart desired colour to the imitation wood. The initial mixt. is pref. slightly moistened, homogenised, and shaped in a closed mould under pressure of several tens of kg/cm2, esp. ca. 80 kg/cm2, where the pressure is applied immediately after placing the mixt. in the mould. The moulding are very solid, and have mechanical properties similar to those of wood, so they withstand tensile and compressive stresses of the type normally applied to wood. The mouldings can be easily machined, planed, and cut with shears.</p> |
