Abstract

Greensand sand is one type of wet-molding sand, that’s usually used for metal casting. The quality of molding sand is one factor among others that important for good quality of casting products. There is one method to improve the quality of greensand by adding tapioka starch. The addition from tapioca starch can increase the toughness so the sand is more easily formed without fall-apart. To find out the effect of adding tapioca starch, this research was done by adding variations from 0% - 1.5% tapioca starch with an interval of 0.125% for each addition, and molding sand testing including : Sand characterization, mechanical testing compactability, permeability, moisture Content. Testing using SEM, roughness test, and gap analysis is performed as additional testing aimed at verifying the success of this research. Greensand in Polman Bandung has the optimal composition of 1.0% tapioca starch and the mechanical properties decreased by more than 1%. The results of this reserach can be used to improve the mechanical properties and strength of greensand in Polman Bandung. Beside that, this research can be useful for reference about the effect of tapioca as additive on greensand.

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