Suitability of Yellow Dextrine as a Core Binder

Abstract

Dextrine belongs to e class of cereal binders and is Dextrine commonly used as binders in foundry Moulding sands. is manufactured by the degradation of corn starch in its dry state, by the application of heat and chemicals. The chemicals most commonly used are weak aqueous mineral acid s usually sprayed on the dried starch. The acidified starch is then subjected to torrefaction or roasting process, Different properties in the dextrine are obtained by varying the amounts of acid, the temperature of roasting, and the length of exposure to heat. Dextrines are obtainable with different degrees of water solubility, the highest water solubility percentage being in the neighborhood of 95 percent. This type of dextrin imparts a high hardness to the outer skin of the core and a soft center whereas the dextrine having low water solubility of about 10 percent imparts a uniform hardness throughout t the core cross-section.