PURPOSE: To inexpensively obtain an asbestos-free fiber-reinforced cement board excellent in strength by combining a mixture of pulp fiber and PP fiber with a specified cement matrix.
CONSTITUTION: 38-50wt.% cement, 32-45wt.% of α-quartz powder having ≥8000m2/g Blaine value, 3-10wt.% of pulp fiber having 200-500ml freeness, 0.1-1.5wt.% of PP fiber having 150-170°C m.p. and water are mixed to prepare a slurry with 12-25% concentration. The slurry is then continuously supplied in layers on a traveling water-permeable belt, water is sucked and removed from the lower surface of belt, and the water content of the layered slurry is controlled to 31-50%. The product is further dehydrated by a making roll to reduce the water content to ≤30%. The material is then cut to a plate, the plate is pressed and dehydrated at 200-700kg/cm2 pressure into a board, the board is cut to the shape of the product and cured at 140-177°C for 10-20hr in an autoclave, and a fiber-reinforced cement board is obtained.
HASHI KAZUO
NOZAKI AKITOSHI
MATSUTANI YASUO
