Special paint for evaporative pattern cast iron and manufacturing method of special paint

Abstract

The invention relates to special paint for evaporative pattern cast iron and a manufacturing method of the special paint. The special paint comprises the following components: 45-55 parts of bauxite, 30-35 parts of spar powder, 3-7 parts of mica powder, 10-14 parts of kieselguhr, 1-2 parts of attapulgite, 1.5-2.5 parts of sodium bentonite, 1-2 parts of meerschaum, 1.5-2.5 parts of artificial starch, 0.05-0.1 part of hydroxyethyl cellulose, 2-4 parts of emulsion powder, 0.2-0.4 parts of sodium carbonate, 0.1-0.3 part of antifoaming agent, 0.1-0.3 part of surfactant and water with the weight accounting for 35-45% of the total weight of the other components. The thickness of a single coated coating of the paint is between 0.55mm and 0.7mm; and coating can ensure no flowing, and prevent exposure of a facade and cracks of a corner. The coating with the appropriate thickness is good in air permeability, and the paint is particularly suitable for castings with complicated inner cores, such as thin-wall gray iron castings with complicated inner cavities, like an engine body, a cylinder cover and a vent pipe.

Description

technical field [0001] The invention relates to a coating and a manufacturing method thereof, in particular to a special coating for lost foam cast iron and a manufacturing method thereof. Background technique [0002] Traditional casting coatings only play a barrier role between castings and molds to prevent sand sticking. However, ordinary casting coatings are prone to sand sticking due to poor adhesion, low strength, poor fire resistance, and large gas generation at high temperatures. , Trachoma, porosity, carbon residue and other defects. Sand sticking in castings is because the coating does not effectively block and isolate, or the chemical reaction between the coating and the high-temperature metal liquid occurs. [0003] The lost foam coating is the isolation layer between the molding sand and the foam mold. The finer the refractory material used for the coating, the thicker the coating is, and the casting is not easy to stick sand. However, thick coating and fine m...

AI Technical Summary

Problems solved by technology

[0004] In addition, the uniformity of the coating is also very important. Most foreign coatings have poor thixotropy (referring to force, stirring, and shear thinning) and tend to flow, which makes the surface coating thickness of the casting uneven, and even some facades flow to reveal white mold. , it is also necessary to repaint the paint