Paste additive for lost foam casting coating and preparation method

Abstract

The invention discloses a paste additive for a lost foam casting coating and a preparation method. The paste additive comprises the following components in parts by weight: suspending agent, 16 to 20 parts of sodium tripolyphosphate, 12 to 16 parts of dextrin, 11 to 15 parts of CMC (carboxy methylated cellulose) powder, 9 to 13 parts of waste paper fiber, 6 to 9 parts of polyvinyl alcohol, 3 to 5 parts of fatty alcohol ether sodium sulfate, 6 to 8 parts of polyoxyethylene polyoxypropylene pentaerythritol ether, and 220 to 300 parts of water, wherein the suspending agent is prepared by compounding 55 to 60 parts of rectorite, 36 to 41 parts of sodium-based bentonite, and 27 to 32 parts of sepiolite. The paste additive has the advantages that the paste additive and fire-refractory aggregate can be mixed at one time, and be stirred, so as to prepare the lost foam casting coating for casting alloys, and the paste additive is suitable for manufacturing at various production sites of lost foam coatings for casting enterprises. The lost foam coating prepared by the additive has the characteristics of good suspending property and smearing property, high coating strength, and the like.

Description

technical field [0001] The invention relates to a paste additive for lost foam coating and a preparation method thereof, belonging to the field of molding materials for casting. Background technique [0002] The lost foam casting process is to make a casting model with polystyrene foam, and then paint a special lost foam paint on the model. After air drying, bury the model in dry sand, and then vacuumize to form the strength of the sand mold, and pour the metal liquid. , A method of obtaining castings after cooling. All kinds of steel castings, iron castings and non-ferrous alloy castings produced by the lost foam casting process have smooth surfaces, high dimensional accuracy, and more and more applications. One of the most critical technologies of lost foam casting is lost foam coating. Without good lost foam coating, castings will collapse and be scrapped during pouring, or castings will have defects of sticky sand and pores, which will lead to increased scrap rate and l...

AI Technical Summary

Problems solved by technology

The quality of the lost foam coating produced in this way is not guaranteed, and problems such as poor suspension stability of the coating, easy precipitation, uneven coating, cracking of the coating, and poor air permeability often occur.

[0004] Most of the existing additives for commercial lost foam coatings are powders, which are mixed with a few powders such as a single powder suspending agent, powder binder, powder thickener, etc., and the performance is not complete. Without special process or equipment refining, it is impossible to fully tap the properties of various materials. The production method is the same as that of general lost foam coatings. It is also poured into a mixer with refractory aggregate and carrier and stirred. The obtained lost foam coatings There are also performances such as poor suspension stability, easy precipitation and hardening, poor coating and hanging properties, and unstable quality