The advantages and disadvantages of furan resin self-hardening sand of iron castings

Furan resin self-hardening sand named from furan no-bake process, it takes furan resin as adhesion agent and mixes with catalyzer to produce sand molds, the sand molds can concrete under room temperature.

The advantages of furan resin sand

1. The sizes of metals castings are accurate, the outline of the metal castings is clear, the surface of the metal castings is smooth, the appearance quality is good and the micro-structure is compact.

2. The sand molds do not need to be oven dry, so it shortens the period of production and save energy.

3. Because there is no oven dry, so the sand molds are compact, and reduce the intensity of labor.

The disadvantages of furan resin sand

1. High requirement for the quality of the raw materials.

2. There is stimulating gas during molding and pouring.

3. The cost of resin sand is high, and should be considered comprehensively.

The production processes of furan resin sand

1. The choice of raw materials

A. The requires of sand. The content of SiO2 should be high, the content of mud and the value of acid should be low.

B. Furan resin. The casting foundries should choose the resin with few or without nitrogen based on the technique demand and the structures of the metal castings.

C. Solidification agent. Generally, we should use organic sulfuric acid solution.

D. Annexing agent. Adding some annexing agents can improve the property furan resin self-hardening sand; increase the intensity of resin sand.

2. The reuse of furan resin self-hardening sand

The old sand can be used again; it can control the volume of sand and increase the quality of resin sand castings, we can take the following measures to acquire high quality regeneration sand.

A. Regulate the temperature of sand.

It is the key of furan resin self-hardening sand, if the temperature can be controlled well, we can increase the production rate and reduce the defects and cost, improves the work conditions.

B. The quality index of regeneration sand.

Controlling the value of acid consumption, PH and lossonignition is very important in furan resin self-hardening sand it can reduce the defects of castings and.

3. Mixed Processes

After China enter WTO, the casting export is increasing very fast, at the same time, the requirements of castings in international markets are higher, because the furan resin adhesion agent is used widely in the sand cast, and the quality of castings has been improved obviously, it brings distinguish economic effects, so it has been universally acknowledged by metal foundries.

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