Conversion of an Investment Casting Sprue Wax to a Pattern Wax by Chemical Agents

In this research, the properties of a commercial investment casting sprue wax (B97) were modified to improve its properties so it can be used as a pattern wax in investment casting. For this purpose, some colloids (gum arabic, pectin, agar, polyvinylpyrrolidone-40, polyvinylpolypyrrolidone, alginic acid, cellulose, carboxymethyl cellulose, silicon, tannic acid, saponin), some surface active agents (sodium dodecyl sulfate, sorbitane oleostearate, glycerine), and activated charcoal and palmitic acid were used as additives or fillers. The effect of these chemicals on the surface roughness, solidification shrinkage, apparent viscosity, hardness, tensile strength, and wettability of B97 wax were investigated. These additives modified the properties of B97 sprue wax to such an extent that it had properties superior to those of a commercial investment casting pattern wax (B140).