Study On The Combined Process Of Alkaline Phenolic Resin

Alkaline phenolic resin sand casting is of a smooth surface, high dimensional accuracy, and high efficiency of shape. Meanwhile it does not contain N, P, S and other harmful elements. With the good production environment, the foundry industry is recognized as more environment-friendly modeling materials, meeting with the trend of green cast. However, when poured castings, the surface of alkali phenolic resin sand set off a chemical reaction, forming an inert film to reduce the performance of the old sand and the impact of recycling old sand. Therefore, the regeneration experiments of alkali phenolic resin sand has some practical significance.This article summarizes the characteristics of the alkali phenolic resin old sand, hot, wet and vibration characteristics of regeneration, which also analyse the characteristics. Phenolic resins are organics and combustible, and the inert film surface of which can be removed by thermal regeneration to improve the performance of reclaimed sand. The effect of regeneration of old sand alkali phenolic resin is depend on different temperature:if the temperature is too low, it can’t remove the inert film; if temperature is too high, it will increase the production costs and make the dispersed old sand sintered together again. Therefore, this paper carried out the experiment on the temperature effects and the phenolic resin sand regeneration, which determines the 400℃,10min experimental parameters.Alkali phenolic resins are resole resin solution under strongly basic catalyzed conditions by condensation of phenol and formaldehyde resin, therefore, water-soluble is relatively good, which can be regenerated by a wet method. The test can be carried out by Homemade wet lab regeneration equipment, orthogonal experiments are carried out. Analyzing emphatically the time, changing the number of sand-water ratio of four factors’influence on the regeneration intervals. Effect size obtained as follows:* Change number> sand-water ratio> Time> ventilation interval. Then find the optimal parameters for each influencing factors.Regeneration is under the effect of vibration vibration force, the use of shear force sand and grit, sand and remove inert membrane between the inner wall surface of the sand, the sand surface morphology and performance close to the original sand regeneration methods. Taking laboratory-made double plastid Asian resonance vibration recycling machine for sand regeneration treatment, through ball and sand mass ratio, frequency, amplitude, regeneration time four factors and three levels orthogonal experiment results. Experimental results show that the impact of the double factors plastid Asian resonance vibration sand reclamation machine regeneration of descending order:frequency, amplitude, regeneration time, balls and sand quality ratio. The optimal process parameters are obtained through experimentClay content, go mud rate were measured to different processes of sand after regeneration. The results showed that after sand reclamation process, its mud volume have different degrees of decline. The highest rate was 85.1% to the mud. The surface morphology by scanning electron microscopy reclaimed sand was observed, observation result further validate the effectiveness of the for the combined regeneration process.The compressive strength is as the primary measure of reuse. Experimental results of the compressive strength of sand show that:new sand strength (0.468MPa)> Hot+wet sand regeneration joint strength (0.452MPa)>+thermal vibration joint reclaimed sand strength (0.428MPa)> thermal reclaimed sand strength (0.305 MPa)> old sand strength (0.051MPa), combined with hot+wet sand reclaimed sand strength can reach 96.6% of new sand intensity values, while the thermal regeneration+vibration joint strength is 91.5% of sand new intensity values.