| 摘要 |
PURPOSE:To reduce the time for curing sand and to mold efficiently a core by using molding sand added with a self-curing binder to mold said core, and permeating compressed air through the sand to evaporate the moisture in the sand. CONSTITUTION:Plural vent holes 3 are penetrated and punched in mating patterns 1a, 1b. Molding sand S added and mixed with a binder contg. a water soluble crosslinking agent such as a saccharide and a methylolurea or methylolmelamine and a catalyst for reaction, etc. such as an org. acid, inorg. acid, etc. is packed in the cavity part thereof. The pattern 1 is upset, and the other pattern 1b is parted therefrom. The one pattern 1a is placed on a receiving plate 5 provided with an air discharging hole 5a in such a way that the recess 4 of the pattern 1 faces downward. A cover member 7 is airtightly put on the cover 1 and compressed air kept at an ordinary temp. is supplied thereon. The compressed air flows through the inside of the sand S to assist evaporation of moisture and to accelerate the curing of the sand S. The core free from strength deterioration and deformation is thus molded. |
