Earnshaw R
Aust Dent J. 1975 Feb;20(1):27-31. doi: 10.1111/j.1834-7819.1975.tb03512.x.
In the formulation of gypsum-bonded casting investments, small amounts of certain modifiers are sometimes added to increase the investment's thermal expansion. In the present investigation, a systematic study has been made of the effects on thermal expansion of adding boric acid and sodium chloride to the investment powder, and glycerol to the mixing water. The combination of 0.2 per cent of sodium chloride in the powder, and 10 per cent of glycerol in the mixing water, appears to offer most promise in the formulation of an investment with a high thermal expansion.
在石膏粘结铸造包埋材料的配方中，有时会添加少量特定的改性剂以增加包埋材料的热膨胀。在本研究中，已对向包埋材料粉末中添加硼酸和氯化钠以及向混合水中添加甘油对热膨胀的影响进行了系统研究。粉末中0.2%的氯化钠与混合水中10%的甘油的组合，在配制具有高热膨胀性的包埋材料方面似乎最具前景。
