MOLDING SAND APPROPRIATE FOR THE FABRICATION OF CORES AND MOLDS

摘要

The molding sand comprises hollow microspheres of aluminum silicate, preferably with an aluminum content between 15 and 45% by weight, a wall thickness between 3 and 10% of the particle diameter and a particle size between 10 and 350 mu m. These sands are useful to manufacture low density cores with good "veining" and penetration characteristics, moreover maintaining the mechanical properties of the core obtained. These cores are useful in the manufacture of iron casting.