Preparation method of high temperature resistant dope for lost foam

Abstract

The invention relates to a preparation method of high temperature resistant dope for lost foam. The invention comprises the following components by weight percent: 2 to 3 fire clay, 25-50 black charcoal ash, 5 to 6 hard charcoal ash and 10 polyvinyl acetate emulsion, which are mixed to obtain a condensate. Water is added to the condensate according to the weight proportion of 1 to 5-20. The water and the condensate are mixed evenly and the dope is prepared. The invention adopts water as solvent, which is non-toxic, tasteless and has no pollution. The black charcoal ash, the hard charcoal ash, the polyvinyl acetate emulsion anti-burnt-on sand and the fire clay can resist the high temperature of more than 1500 degrees centigrade. The dope manufactured through the method has good suspension property and a compact high-strength coating can be formed on the surface of a foam plastic mould. The disposable falling off percentage of the dope layer of casting finished products is improved further, the surface is smooth and the pass percent is increased greatly. The invention has the advantages of simple brushing process, good quality and easy technology. The cost of the invention is lower than the cost of the traditional like dope on condition that the surface of the casting does not adhere to sand and the surface finish degree of the casting is ensured.

Description

technical field [0001] The invention relates to a preparation method of a casting coating, in particular to a preparation method of a high-temperature-resistant coating for lost foam. Background technique [0002] In the molding of large-scale castings, lost foam casting is a commonly used process. When using foam plastic models to make molds, it is necessary to coat the outer surface of the foam plastic models with paint to overcome the loss of casting sand and the large number of pores on the surface of castings. defect. The quality of lost foam castings mainly depends on the coating. If the coating cannot withstand the high temperature and impact of molten steel, it will cause problems such as molding sand falling off, resulting in product quality problems. In the lost foam casting industry, commonly used coatings are alcohol coatings and water-based coatings. However, the coatings on the market are expensive, and the process is not easy to master, resulting in high pro...

AI Technical Summary

Problems solved by technology

However, the coatings on the market are expensive, and the process is not easy to master, resulting in high production costs and prolonged production cycles.