Formula of water-based dip-coating coating special for precoated sand

Abstract

The invention provides a formula of a water-based dip-coating coating special for precoated sand. The formula comprises refractory aggregate, a bonding agent, a suspending agent, a surface active agent and a carrier. The refractory aggregate comprises mullite, iron oxide red, kunzite and ball clay powder. The bonding agent comprises polyvinyl alcohol and silica gel. The suspending agent compriseslithium-based bentonite and aluminum-magnesium silicate. The surface active agent comprises a water-based antifoaming agent, a wetting agent and a penetrant. By means of the water-based coating prepared through the formula, the surface quality of sand cores cast through the precoated sand is obviously improved, and the surfaces of the sand cores are smooth and low in roughness; and meanwhile the wetting agent is added into the formula, the surface tension of the coating can be reduced, and the adhesive force of the water-based coating can be improved.

Description

technical field [0001] The invention relates to the technical field of coated sand casting coatings, in particular to a formulation of a special water-based dipping coating for coated sand. Background technique [0002] At present, in the molding and core preparation process, due to the good formability of the coated sand, the high strength of the sand core, the clear outline, the high dimensional accuracy, and the ability to manufacture the most complex shell cores, it has developed rapidly at home and abroad. Now, coated sand has been widely used in automobiles, diesel engines, hydraulic parts and other industries, and can meet the production requirements of various complex precision castings. [0003] The characteristics of coatings for coated sand shell cores are: (1) Due to the fine particle size of the shell core sand: generally 70 / 140, and strong surface hydrophobicity, the coating has strong permeability. At the same time, the shape of the shell core is complex and t...

AI Technical Summary

Problems solved by technology

[0005] (1) Zircon powder of up to 30% is used. my country’s zircon powder resources are scarce, and most of them rely on imports, which are expensive, resulting in limited sources of raw materials for coatings and increased costs;

[0006] (2) If polyvinyl alcohol organic binder is used alone, the high-temperature strength of the coating is low, and the coating's ability to resist sand sticking and sand resistance is poor