Study of the Formation of Shell Sand Parts Used in the Shell Molding Process

M. I. ARANGUREN; J. BORRAJO; R. J. J. WILLIAMS

SAMPE Journal

Society for the Advancement of Material and Process Engineering.

Año: 1984 vol. 20 p. 18 - 23

0091-1062

Reprinted in SAMPE Quarterly, 16, 11-16, (1985) Abstract A model analyzing the formation of shell sand parts for the shell molding process is proposed and an approx. analytical solution for heat transport in a semi-infinite medium of variable thermal conductivity is developed. With this equation and a numerical solution of the mass balance, the shell thickness, defined as the region where the conversion of the thermosetting resin is greater than the gel value, may be calculated. Good agreement with experimental results is shown for a large range of wall temp., resin formulations and inversion times. The wall temp. and the required shell thickness are the most important parameters for varying the inversion time. Both initial temp. and hardener amount are not very relative to the cycle-time. Descriptors: Shell mold casting | Mathematical models | Foundry sands | Physical properties | Thermal conductivity | Foundry sand binders