| 摘要 |
PURPOSE:To improve heat resistance of a dry starch mold for casting by adding a small amt. of clay mineral to starch in the stage of kneading starch or the like with silica sand. CONSTITUTION:A small amt. of clay mineral such as kaolinite, illite, montmorillonite, halloysite and hydrous halloysite is added to starch in the stage of adding the starch or the like in the form of powder or the paste prepd. by adding preliminarily water or warm water thereto silica sand and kneading the same. The starch is alpha-starch, starch phosphate, starch urea-phosphate, ether-crosslinked starch and the starch consisting of the combination thereof. |
