Study On New Type Low Furfuryl Alcohol And High-active Furan Resin And Its Curing Agent

Since the late 1950s, no-bake furan resin sand in the foundry production gradually popularized. So far, furan resin is the largest condensation resin in foundry production use. Our country no-bake furan resin product quality has come close to foreign industrialized countries to the similar product level.On the average level at home, however, there are still many problems in no-bake furan resin sand technology. Firstly, the production cost high, because of furfuryl alcohol addition amount is very high in furan resin synthesis process, due to the existing production techniques restrictions. Secondary, deteriorating operating environment, because of the content of free formaldehyde is high. Thirdly, low production efficiency, furan resin and its curing agent active low, and the rate of curing slower.With this background, combined with actual production needs, this research develop new type low furfuryl alcohol high-active furan resins and its matching curing agent. Through a lot of in-depth system of experiments, developed new type low furfuryl alcohol high-active furan resins and its curing agent successfully. The main contents of this paper were as follows:Firstly, optimal synthesis parameters of urea-formaldehyde furan resin (Nitrogen 3%) using DMAIC model of six sigma; Content of free formaldehyde dropped down to only about 0.05% and other properties unchanged by using PVA and C,and finally furfuryl alcohol content reduced by 10%～15% than the similar furan resins, because of furan resin was modified by acetone.Secondary, molecular structure design of new type highly active non-nitrogen furan resin, and pointed out the main raw materials used in selecting the compound and quality requirements. The molecular structure of this new type resin containing more active hydrogen, phenolic hydroxyl, hydroxyl methyl, hydroxy and ester group, the resin has many advantages including high hardening speed, high initial tensile strength and final strength, low free formaldehyde content, and so on.Thirdly, a new design for formula and synthesis process of non-nitrogen furan resin using IDDOV model of Six Sigma for the first time. Furfuryl alcohol content of the new resin is about 68.5%～72%, furfuryl alcohol content reduced by 13%～25% than the similar furan resins. The new synthesis process has many advantages including substantially reduced energy consumption and secondary pollution, maximum reduces operating worker's Labor intensity, and so on.Fourthly, with the lower sulphonated temperature (80℃) and shorter sulphonated time (3h) during xylene sulfonic acid synthesis process, and has good sulphonated effect. The curing agent can satisfy new high-active furan resin requirements, resin content accounted for the original sand quality only about 1.0%, curing agent consumption accounts for 30%～50% of resin quality, can meet modeling and core making requirements in various weather conditions.Fifth, results of different temperature and time of synthesis of xylene sulfonic acid are good by using infrared spectra (IR) analysis, low-temperature and short time of synthesis conditions are reasonable, and the practice also proved its superiority. In addition, with series of molecular structures of reaction liquid produced gradually meet the design requirements, verify the molecular design of furan resin rationality and validity.Sixth, the development of the new low furfuryl alcohol high-active furan resin and curing agent has been applied in practical production, and the effect is very good.