Green sands were prepared with silica sand and different additives, which are bentonite, sea coal, cellulose, dextrin and/or core sand including CO{sub}2 sand, furan sand or shell core sand. Eight groups of green sands were mulled in four different mixing times. This produced 32 sets of sand samples. The compactability of each set of green sand was controlled on the range of 43±12 %. Afterwards, the sand properties including shearing strength, compressive strength, moisture and moldability were tested. Green sand molds were then made by using jolt squeeze molding machine with three different pattern plates. After molding, match plate was stripped upward or downward from green sand mold. The results of this study showed that the soundness of mold cavity as match plate was stripped downward was better than that was stripped upward. In the meantime, the soundness of mold cavity of using patteern with retangular cross section was better than that of round cross section. For green sand without the diluted core sand, the soundness of mold cavity was positively correlated with the strength and moldability of green sand. Meanwhile, the compressive strength was closely correlated with the soundness of mold cavity. For green sand with the diluted core sand, the soundness of mold cavity did not correlated with shear strength and moldability, but negatively correlated with the compressive strengt?1 of green sand.
The soundness of mold cavity Draft Jolt and squeeze molding machine