| 摘要 |
<p>A method for producing asbestos-free cement boards, such as by a scoop-sieving process to obtain inorganic hardening compositions for curing utilises a cement slurry which includes fibrillated wood pulp having specified characteristics optionally unbeaten virgin pulp and if necessary, filler and reinforcing fibers for obtaining 4 to 15 wt. % of the total solid in concentration and below 5 cm<4>/sec for filtration coefficient for the slurry. The amounts of the fibrillated pulp and the virgin pulp are 1 to 5 wt. % and 0.5 to 1.0 wt. % of the total solid content, respectively. The pulp is bleached or unbleached wood pulp from conifer and/or broadleaf tree. The filler is sepiolite and/or bentonite, and/or crystal or noncrystal silica of below 5 mu in grain size, in an amount of 1 to 10 wt. % of the total solid content. The reinforcing fibers are vinylon and/or acrylic fibers having specified characteristics and being present in an amount of 0.3 to 2 wt. % of the total solid content, or wollastonite in the amount of 2 to 15 wt. % of the total solid content.</p> |
