| 摘要 |
<p>PURPOSE:To obtain a fiber cement board having excellent strength, flexibility and flame resistance by forming a board material contg. cement, pulp fibers in which the fibers having large and small CSF are mixed and an aggregate. CONSTITUTION:This fiber cement board contains cement, pulp fibers as mentioned below and an aggregate. The pulp fiber contains those having large and small CSF. The pulp fibers are made from coniferous trees, the content of the fiber is controlled to <=6wt.%, the pulp fibers A having >=650ml CSF and the pulp fibers B having <=200ml CSF are mixed, and the weight ratio (A/B) of both pulp fibers is preferably adjusted to 25/75 to 60/40. The aggregate should consist essentially of silica. CSF is also called 'freeness' and expresses fuzziness corresponding to the beating degree of the fiber. The beating degree is increased as the CSF decreases and the specific surface increases, and the beating degree is decreased as the CSF increases.</p> |
