To obtain a cement board hardly generating a warp and a crack and excellent in dimensional stability by preparing a mixture by blending the mixture of wood chips, aggregate and fibers with the mixture of cement and aggregate and mixing the obtained mixture with water.
The production method of this wood chip cement board comprises a step 1 to obtain the mixture 1 by blending 5-30 pts.wt. wood chips, 5-35 pts.wt. aggregate and 0.5-10 pts.wt. fibers, a step 2 to obtain the mixture 2 by blending 100 pts.wt. cement composition and 5-35 pts.wt. aggregate, a step 3 to obtain the mixture 3 by blending the mixtures 1 and 2 and a step 4 to obtain a mixed composition by mixing the mixture 3 with 15-60 pts.wt. water. Steps 1 and 2 are carried out in parallel and subsequently step 3 and step 4 are done in this order. As the wood chips, the ones which are obtained by pulverizing wood pieces and each of which has preferably 2 mm or smaller average particle size can be used. As the aggregate, silica sand, fly ash, mica, diatomaceous earth, or the like, having 400 μm or smaller average particle size is preferably used.
SAWARA TAKASHI
NAKAO YOSHIHIRO
IKEMOTO YOICHI
