A kind of preparation method of water-based spray coating for large iron castings

Abstract

The invention relates to a production method of a fireproof coating for a sand mould casting and particularly relates to a preparation method of a water-base spraying coating for a large-size iron casting, which is used for a large-size thick-wall iron casting and is suitable for a spraying coating process. The method comprises the following steps: adding water into a high-speed dispersion kettle; starting electric agitation; slowly adding hydroxypropyl methyl cellulose; after adding the material, continuing to agitate; adding sodium pentachlorophenate, an organic silicon de-foaming agent and an activating agent into the dispersion kettle; starting the electric agitation and slowly adding attapulgite into the dispersion kettle while keeping high-speed agitation; after adding the material, dispersing; sequentially adding PVA (Polyvinyl Acetate), ethyl silicate and aluminum sulfate into the dispersion kettle; after adding the material, dispersing; sequentially adding bauxite and sillimanite into the dispersion kettle under an agitating state; after adding the material, finishing dispersion; discharging and packaging. The production method provided by the invention is unique in raw materials and process, high in environmental protection coefficient, excellent in coating rheological property and good in spraying performance; the coating is easy to sinter and is particularly suitable for the large-size iron casting.

Description

technical field [0001] The invention relates to a production method of a refractory coating for sand casting, in particular to a method for preparing a large-scale thick-walled iron casting water-based spray coating suitable for a spray coating process. Background technique [0002] Foundry coating is a very important material in the foundry industry, which has a great influence on the appearance quality and internal quality of castings. Casting coatings can be divided into brush coatings, flow coatings, dip coatings and spray coatings according to their application methods, and correspondingly there are brush coatings, flow coatings, dip coatings and spray coatings. Flow coating and dip coating are only suitable for small and medium-sized parts, and the efficiency of brushing is too low. For the production of large parts, it is an inevitable trend to choose spray coating. [0003] However, there are currently few researches and developments on spray coatings in China, espe...

AI Technical Summary

Problems solved by technology

[0003] However, there are currently few researches and developments on spray coatings in China, especially spray coatings for large iron castings, and there are a series of problems in production operations. The smell is very strong; the anti-sand sticking performance of the coating is poor, it is not easy to sinter, and cannot meet the anti-sand sticking requirements of large castings; due to the high surface tension of the coating, it is difficult to guarantee the coating hangability of the coating, there are many drip marks, and the coating is uneven , affecting the surface quality of castings; the paint spraying performance is poor

[0004] So far there is no way to overcome the above drawbacks