Alkaline Phenolic Resin Self-hardening Sand


Overview of Self-hardening Alkaline Phenolic Resin Sand

In addition to alkaline phenolic resin self-hardening sand's fast speed and adjustable service time in a large range, it also has the following characteristics:

1. The basic phenolic resin binder is synthesized from phenol and formaldehyde and does not contain furfuryl alcohol. During the casting process, there are basically no defects of sulfur penetration and needle like pores in the surface layer of steel castings produced by furan resin.

2. In the process of sand mixing, molding, core making, pouring and sand cleaning, alkaline phenolic resin rarely releases toxic and pungent gases, which has no impact on the operating environment.

3. Alkaline phenolic resin is strongly alkaline, and the acid consumption value of raw sand is not high. Alkaline raw sand can be used, such as chromite sand in large steel castings.

 

Characteristics of Fused Ceramic Sand

The manufacturing method of fused ceramic sand is to select high-quality raw materials and place them in an electric furnace. When the molten liquid flows out of the furnace, it is blown away with compressed air flow. After cooling, spherical or nearly spherical particles are obtained with smooth surface.

As fused ceramic sand has the above excellent physical and chemical properties, it has obvious casting performance advantages over silica sand and other special casting sand.

1. The particle shape is spherical and the surface is smooth. Under the same strength requirements, the amount of resin can be reduced by 30-40% compared with the use of silica sand, and the air emission of mold / core sand can be greatly reduced.

2. It has high fire resistance and is neutral, and can be used for casting all kinds of casting alloys, including stainless steel, manganese steel and chromium steel.

3. It has good fluidity and is easy to fill. It can make sand cores with complex shape and small local cross-sectional area.

4. It has high strength, low crushing rate, high durability and high regeneration recovery rate, and the regeneration recovery rate is as high as 98%.

5. Fused ceramic sand has a low expansion coefficient, which can reduce casting defects such as veins caused by sand (expansion);

6. Environmental protection advantages: less casting waste (waste sand) and less waste gas are produced, which is known as the green casting material of the 21st century.

7. Fused ceramic sand also has the advantages of high thermal conductivity of core sand, good air permeability and good collapsibility after pouring.

 

Reclamation about Alkaline Phenolic Resin Self-hardening Sand

In addition to the excellent performance of fused ceramic sand, which makes the rapid development of alkaline phenolic resin self-hardening sand in the production of steel castings, the progress of used sand recycling technology is another key factor for the rapid development of this process. Because the alkaline phenolic resin film is a tough resin film, compared with furan self-hardening sand, the regeneration of used sand is very difficult and the regeneration efficiency is low. Over the years, the reclamation methods of used sand can be generally classified into wet, thermal and dry methods (mechanical methods). In addition to mechanical regeneration, there are often more than two combined regeneration methods. It has been found in a large number of studies and practical applications that ester hardened alkali phenolic resin sand is a kind of self-hardening sand that is relatively difficult to effectively regenerate. Its regeneration difficulty is second only to sodium silicate sand, and far more difficult than furan resin sand and PEP set sand. Its most obvious feature is that the strength of the recycled sand mold is getting lower and lower, resulting in mold fracture, mold collapse, difficulty in mold removal, or sand flushing and sand sticking of castings and other defects. After long-term production practice, mechanical regeneration has gradually become the mainstream process of alkaline phenolic resin self-hardening sand regeneration.

 

Benefit of Fused Ceramic Sand Applied in Alkaline Phenolic Resin Self-hardening Sand

The use of fused ceramic sand for molding and core making can greatly improve the dimensional accuracy of the core, and then improve the utilization rate of metal materials. Improve product quality, reduce welding repair rate, reduce scrap rate, and improve casting surface quality.

1. Significantly reduce raw sand consumption.

2. Significantly reduce the amount of binder.

3. Improve core accuracy and material utilization.

4. Improve the surface quality and reduce the workload of sand falling and cleaning.

5. Improve the quality of castings and reduce the production and quality cost of castings.

6. Reduce the emission of waste gas and sand, realize green production, improve the working environment, reduce dust etc.

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