| 摘要 |
<p>Blanks are made by pressing, extrusion, or casting, and are then immersed in a bath of liq. which removes the water. The liq. wets the blank, but is only slightly soluble in water, and keeps the pores of the blank open. After the liq. has drawn the water out of the blank, the latter is removed from the bath and the liq. is evaporated. The liq. is pref. hygroscopic and is esp. a monohydric or polyhydric alcohol, partic. ethanol or glycerine. The bath pref. also contains or consists of a tri- or tetra- chloro-hydrocarbon, esp. perchloroethylene. The bath is pref. heated to 105-150 deg. C.; and two baths may be used, the bulk of the water being removed in the first bath. The drying of ceramic blanks frequently leads to their distortion or cracking unless very slow drying speeds are used, by this method rapid drying is possible without distortion or cracking of the blanks.</p> |
