| 摘要 |
<p>Sawdust, wood shavings, ground cork, peat, straw or flax is moistened with a hot or cold priming liquid and then mixed with finely-divided limestone, chalk, gypsum powder, or precipitated calcium carbonate, which has been rendered water-repellant by admixture with a small quantity of wool grease to give a filler suitable for use in the manufacture of cement or plaster. The priming liquid may be water in the case of sawdust from spruce or poplar, but is preferably dilute aqueous hydrochloric acid, optionally with a small quantity of copper sulphate, an aqueous solution of cuprammonium hydroxide, an emulsion of sulphonated fish oil, optionally with copper sulphate or silicate of soda, or an aqueous solution of borax with the addition of diamyl oleate-or triethanolamine oleate. Silica, crushed stone, or expanded vermiculite may also be added. Suitable proportions are 1 part of cement to 1.5 to 3.0 parts of fibrous binder.</p> |
