CN1102606A - Foundry method - Google Patents

Abstract

The new-type casting technology features use of wet coated sand and polyethene foam plastic or wax mould. At first, said mould is put in moulding box, into which wet coated sand is filled then. After baking for 15-60 min. at 100-300 deg.C, the mould is gasified and the sand is solidified to become hard casting proplasm. Pouring molten metal in it can form needed casting. Its advantages include high productivity, no need of expensive mould and apparatus, and high precision and fineness of casting.

Description

Foundry method

The present invention relates to a kind of novel casting method, more precisely with the precoated sand crab process, the advantage of disappearance mould and three kinds of casting methods of dewax comprehensively is the novel casting method of one.

Precoated sand crab process, casting method with the vanishing pattern, methods such as lost wax process are adopted in hot investment casting at present usually.Though the precoated sand crab process is easy to operate, the production efficiency height, shell mould intensity height, cast(ing) surface is bright and clean, and sand removal is easy, but needs special equipment and metal die, equipment investment is big, metal die expense costliness also needs to make up and could form complete casting mold behind the mould assembly and cast, and causes the casting dimension error easily.Though casting method with the vanishing pattern is simple to operate, sand removal does not easily need the molding mould assembly, production casting dimension accuracy height, but the residue during owing to cast after the gasification of plastics mould is difficult to get rid of, and causes casting surface defect easily, only is suitable for producing the better simply foundry goods of some shapes.Though lost wax process production casting dimension accuracy height, any surface finish, and can produce various complicated precision castings, and its technical process need be smeared refractory material from level to level, and is bothersome time-consuming, complicated operation, and the production cycle is long.

Purpose of the present invention is exactly the shortcoming that overcomes above-mentioned several castings, collection precoated sand crab process, casting method with the vanishing pattern, the advantage of lost wax process is an one, a kind of not only production casting dimension accuracy height is provided, any surface finish, and easy to operate, with short production cycle, sand removal precoated sand disappearance easily formwork type method, but this method hand moulding, but also machine moulding can be cast the complicated precision castings of various materials.

The objective of the invention is to realize by following content.Precoated sand disappearance formwork type method of the present invention is to use a kind of wet film coating sand and directly adopts the polystyrene foam plastics mould of casting method with the vanishing pattern or the wax-pattern of lost wax process; at first mould is placed in the sandbox; and then above-mentioned wet film coating sand is filled out case enrich; put it into subsequently in 100-300 ℃ the baking oven heated baking 15-60 minute; the gasification of being heated of foamed plastics or wax-pattern; wet film coating sand then is heated and solidify to form hard thermosetting housing; it is the shelly casting mold; molten metal is poured in it, form required foundry goods.The manufacturing of employed wet film coating sand of the present invention obtains by following method, roughing sand is heated to 100 ℃, remove moisture content, after roughing sand moisture content is less than 1%, roughing sand is positioned over mixed grind in the puddle mixer of room temperature, in mixed grind, adds resin compound, the addition of resin compound is the heavy 1-4% of roughing sand, after being mixed, add urotropine firming agent (as hexa) again, the addition of curing agent is the heavy 5-20% of resin compound, pour out kolleroang after being mixed, make to obtain wet film coating sand, described resin compound comprises phenolic resins 58-85%(percentage by weight), epoxy resin 3-17%, organic ester 3-10%, organosilicon 5-15%, starch 0.5-1%, clay 0.1-0.5%, potter's clay 0.1-0.5%, graphite powder 0.3-1%.Described this wet film coating sand has good wet strength, mouldability and flowability, and the long effect of depositing is arranged, its curing rate is faster than the gasification rate of polystyrene foam plastics or wax-pattern.

The invention has the advantages that easy to operate, the production efficiency height, with short production cycle, sand removal is convenient, need not use expensive metal die and equipment, the casting dimension accuracy height, any surface finish, environmental pollution is little, shell mould can long-term storage, but hand moulding, but also machine moulding can be produced the various precision castings of must mixing.

Claims (1)

1, a kind of novel casting method is characterized in that using a kind of wet film coating sand and directly adopts polyethylene foams mould or wax-pattern; At first mould is placed in the sandbox, then wet film coating sand being filled out case enriches, put it into subsequently in 100-300 ℃ the baking oven heated baking 15-60 minute, the gasification of being heated of foamed plastics or wax-pattern, wet film coating sand then is heated and solidify to form hard thermosetting housing, be the shelly casting mold, again molten metal poured in it, form required foundry goods.