摘要 |
A foundry mold member made from a plurality of sand particles bound together with a binder which is concentrated at the contact points between contiguous sand particles and consists essentially of gelatins having a Bloom rating less than about 175 Bloom grams. The sand particles are first coated with a sol of the gelatin, cooled to ambient temperature and conditioned to a prescribed water content necessary to effect migration of the gelatin to the interparticle contact points upon heating of the coated particles in a pattern mold. <IMAGE> |