| 摘要 |
<p>1. Process for the manufacture of gypsum boards, characterized by the fact there is used as a bonding agent protective colloid, an amount of amylaceous material representing from 0.2 to 2 % by weight with respect to the weight of plaster employed, said amylaceous material comprising, on the one hand, a proportion of at least 30 %, preferably at least 45 % by weight of particles of native wheat starch of dimension less than 10.7 mu m and, on the other hand, a proportion of at the most 20 % by weight of particles of native wheat starch of dimension greater than 35 mu m, the presence of these two granulometric fractions being determined by a method A of analysis.</p> |
