Method of making catalyst cured resin-coated sand cores

Abstract

A resin coated sand is blown into a core box to form an uncured core with a desired packing density. The core box has one or more inlets to permit ingress of gases and one or more outlets to permit egress of only gases. A non-catalyzing gas is passed through the defined sand core in the core box to create a first effluent and the hydrocarbon content in such first effluent that was exposed to the uncured resin of the sand core is measured. A catalyst carrying gas (nitrogen) is injected into the inlets to pass through the defined sand core within the core box for polymerizing the resin and thence exit from the outlets as a second effluent. The hydrocarbon content of the second effluent is continuously measured (i.e. non-dispersive infrared spectroscopy system). When the hydrocarbon content decreases to approximately the hydrocarbon content of the first effluent, the core box is opened to remove the sand core in a consistently cured condition.