Study on the feasibility of alternatives for phenolic resins used in sand casting

ABSTRACT Phenolic resins are in-organic polymers with properties that make them high-strength binders with great potential for modification. The base-catalyzed phenol-formaldehyde resins provide the desired hardness to the core avoiding sand slipping on the surface. A modified resol type phenolic resin is developed for this study with minimum ingredients to compare it with existing recipes in the literature. A batch of cores was prepared with the standard 1-inch cross-section briquettes (dog-bone) with modified resol and cured through hot-curing process. Hardness and ultimate tensile strength values of these cores were compared with previous data present in literature. The average hardness as well the tensile strength from modified resol was higher than the cores from previous hot coating resol recipes and the gas-set cores present in the literature. Furthermore, the surface roughness of the cores was examined through Atomic Force Microscopy (AFM), and the ten-point height (Rz) value was lower than existing recipes.