| 摘要 |
<p>Building elements such as boards, blocks, tiles and slabs are manufactured by mixing sawdust and inorganic fibrous material such as asbestos with zinc oxide and with an aqueous solution of sodium silicate of 75 DEG Twaddell strength to form a plastic mix and rolling or otherwise moulding the mixture into the element between adherent flexible sheets such as paper and thereafter drying. The sawdust may be pretreated either by soaking in sodium silicate solution as described in Specification 606,847 or by heating as described in Specification 557,371. Specifications 10798/99, 26567/10, [both in Class 70], 551,658, 551,701, 557,370 and 559,761 and U.S.A. Specification 2,083,989 also are referred to.</p> |
