MOLDING MATERIAL Russian patent published in 1999 - IPC

FIELD: foundry; applicable in preparation of raw sand-clay mixture with carbon-containing materials. SUBSTANCE: molding material contains, wt.%: bitumen with softening temperature of 125-135 C determined by ring and ball method 12.0-20.0; carbon 2.0-5.0; bentonite 5.0-15.0; the balance, ground coal. Use of claimed molding material provides for the following properties of molding mixtures: compression strength 0.95-1.1 kgf/sq. cm; rupture strength in zone of moisture condensation 0.28-0.kgc/cm² kgf/sq.cm; thermal stresses 5.9-6.4 kgf/sq/cm. EFFECT: reduced tendency to caking, improved casting surface quality and sanitary conditions of labour and ecology. 1 tbl