Present Situation and Development of Resin Binder
The foundry industry is undergoing technological transformation in many aspects, and its development speed in the past two decades is faster than ever before. In particular, the application of resin binder technology has made great progress in ensuring the dimensional accuracy of castings, improving the surface quality of castings, reducing scrap, saving man-labor hours, improving labor productivity, reducing the labor intensity of workers, and recycling molding sand. In order to ensure the quality of steel castings and meet the needs of the market, many manufacturers have introduced PEP-SET.
Precautions for Treatment of Pep-set Resin
1. The entire PEPSET resin system is alkaline. Therefore, compared with furan resin, the adv value of the original sand used for PEPSET resin sand can be slightly larger, which can be within the range of 6(max).
2. in production, it requires the moisture content of raw sand ≤ 0.2%
3. Effect of Reclaimed Sand on the Properties of Pep-set Resin Sand
① ignition loss is the approximate standard to measure the residual amount of hardened binder in organic sand mold. The ignition loss of reclaimed sand shall be less than 1.5%.
② Micro powder content: a large part of the micro powder contained in reclaimed sand is the resin film peeled off during sand regeneration. It will greatly deteriorate the properties of molding sand and increase the defects such as porosity and sand sticking of castings. It should be removed by dust removal system as far as possible.
4. PEPSET resin is very sensitive to temperature and should have a suitable ambient temperature to ensure that the resin temperature is between 15 ~ 30 ℃. The sand temperature should also be controlled at 15 ～ 30 ℃.
Characteristics of Fused Ceramic Sand
1. Round solid ball shape, saving binder addition
2. High refractoriness and service temperature
3. Good air permeability
4. Lower thermal expansion rate and thermal conductivity
5. Easily reclaimed and lower breakage rate
Pep-set Advantages as Below
Using PEPSET resin sand instead of sodium silicate sand can produce castings with high dimensional accuracy and complex shape, and its performance can fully meet the production requirements.
In order to reduce the gas evolution of molding sand and reduce porosity defects, fused ceramic sand with clean and round surface should be selected.
Pep-set uses special tooling to control the sand iron ratio within a certain range, avoiding problems such as large sand consumption, increased cost and difficult crushing caused by too large sand box.
The combination of fused ceramic sand and PEP-set resin has successfully completed many representative casting products, such as wear-resistant steel combination bucket teeth, ultra-low carbon stainless steel casting guide shell, power station valve body, etc.