A study in using rice husk as an additive to cast polyurethane resin in silicone vacuum casting

Abstract

Among the most commonly used Rapid Tooling Technology is silicon rubber mould whereby rapid prototyped product is used as the master pattern in making silicon rubber mould to cast polyurethane resins similar to injection molding process. However, this technique has high cost since the resins is expensive, not to mention the cost for mould making. This paper presents the usage of rice husk as an additive to resins in order to reduce the resin usage and production cost. Results showed that regardless of resins type and mixing ratio, addition of rice husks to resins can reduce resins usage up to 96% and curing time up to 66%. Parts produced using rice husk additive is porous due to resin expansion, and thus has light weight and low hardness compare to resins without rice husks addition.