Full-Scale Air Emissions Monitoring and Casting Quality Demonstration of a Hybrid Hydrolyzed Collagen–Alkali Silicate Core Binder

Abstract

When comparing a novel collagen and alkali silicate core binder system to a conventional phenolic urethane binder system during full-scale trials, the phenolic urethane incurred a 33.3 % higher emissions rate than did the novel binder system. This was chronicled during several hours of stack tests in a full-scale trial demonstration of 3500 novel cores at a high-volume automotive ductile iron foundry. Baseline phenolic urethane emissions were determined immediately prior to running the collagen and alkali silicate cores, when making an identical casting. Approximately 10 % of the demonstration iron castings were inspected for defects, of which none (0 %) were scrapped on account of core-related defects. Also, the novel core’s shakeout was complete. These favorable results were achieved with humidity-free storage of the cores over the 10 days that the cores were made. These novel demonstration cores required somewhat longer curing time in the core-making machine, than did conventional phenolic urethane cores; and this curing rate was influenced by air flow and pressure into the core box. Also, tensile specimen tests of the collagen and alkali silicate-adhered system were higher than that of the conventional phenolic urethane system. When exposed to high humidity levels (80–95 % relative humidity) for prolonged periods of time (10 days), the collagen and alkali silicate-adhered tensile specimens degraded in terms of tensile strength and scratch hardness. These losses mostly rebounded when the tensile specimens were re-dried.