Lost foam paint and method for producing the same

Abstract

The invention discloses an expendable pattern casting (EPC) coating and a method for producing the same. The EPC coating comprises a refractory aggregate, a bonding agent, a suspending agent, a wetting agent, a defoaming agent, an addition agent and a dispersing agent, wherein the refractory aggregate comprises high aluminum powder, quartz powder and olivine powder; the bonding agent comprises B01 water soluble resin or polyvinyl alcohol resin aqueous solution, polyvinyl acetate emulsion, bentonite and sodium hexametaphosphate; the suspending agent comprises sodium carboxymethyl cellulose; the wetting agent comprises tween or / and span; the defoaming agent comprises monobasic alcohol octanol; the addition agent comprises sodium carbonate, cryolite and ferric oxide powder; and the dispersing agent is water. The EPC coating has the advantages that by selecting proper coating components and adjusting the contents thereof, and selecting a proper mixing process, the normal temperature and high temperature strengths, the suitable high temperature air permeability, and the excellent flow parallel and suspension properties and the brushability for a coating layer are completely satisfied. The coating is applicable to gray cast iron pieces with different brands, and particularly the coating layer sheds off automatically and gradually in the cooling process of a cast after pouring and mold dismantling so that the surface of the cast is bright and clean, and the process for cleaning the cast is greatly simplified and saved.

Description

technical field [0001] The invention belongs to the engineering field of auxiliary materials for casting, and specifically relates to a lost foam coating and a manufacturing method thereof. Background technique [0002] Lost foam casting coating is one of the two key technologies of lost foam casting process. The performance of the coating directly affects the quality of the casting, which is significantly different from the traditional sand casting coating. The main purpose of traditional sand casting coatings is to prevent castings from mechanical sand sticking and chemical sticking sand, while coatings for lost foam casting have an important role in forming and maintaining casting cavities in addition to the above two functions, so it must have a high Excellent room temperature strength, high temperature strength and suitable high temperature air permeability. [0003] Although the lost foam casting process has developed rapidly since its inception, the coating technolo...

AI Technical Summary

Problems solved by technology

[0003] Although the lost foam casting process has developed rapidly since its inception, the coating technology has been plagued by the fact that it is difficult to greatly improve the casting yield. The main reason is that the quality of the coating cannot meet the requirements of the lost foam casting process.

One is that the strength at room temperature does not meet the requirements, and the shape is deformed and the coating is damaged during molding, so that the casting is scrapped; the other is that the high-temperature strength is low, and the casting cavity collapses, damages, and paint peeling occurs during pouring, so that the casting is scrapped; the third is that the coating is not suitable. High temperature air permeability, too high air permeability will cause the cavity to collapse, and too low air permeability will cause casting defects such as pores, wrinkled skin, and slag inclusions

Chinese patent 02100867.1 discloses a special coating for water-based lost foam casting. In the coating, washing powder is used as a foaming agent to see that the coating has wettability. operate