Process for fabricating low nitrogen furan resin for steel casting

Abstract

The invention relates to a manufacture method of furan resin used for steelcasting, in particular to a manufacture technology of low nitrogen furan resin used for steelcasting. The optimum formula is: 8 to 9 shares of formaldehyde (36.5 percent ), 3 to 5 shares of carbamide, no less than 85 shares of furfuryl alcohol, 40 percent of NaOH solution, 10 percent of hydrochloric acid solution, 0.2 percent of silane coupling agent; the invention comprises the following steps: feeding material, increasing temperature by heating, dehydration, synthesizing, discharging material, packing and warehousing; the invention uses the unique technology to achieve good performances that free formaldehyde of low nitrogen furan resin used for steelcasting is less than 0.1 percent, the tensile strength for 24 hours is more than 2.2MPa, the using time is more than 30 minutes, and the nitrogen content is less than 1.4 percent.

Description

technical field [0001] The invention relates to a production method of furan resin for steel casting, in particular to a production process of low nitrogen furan resin for steel casting. Background technique [0002] At present, the known resin sand binders for casting are mainly furan resins, which can be divided into high-nitrogen furan resins, medium-nitrogen furan resins, low-nitrogen furan resins and nitrogen-free furan resins according to their nitrogen content. For its special casting requirements, low-nitrogen and nitrogen-free resins are generally used. The current low-nitrogen and nitrogen-free resins for steel casting mainly have the following defects: the free formaldehyde content of the resin is high, which is released in large quantities during use, seriously polluting the working environment and harming the health; Castings produce pores; the higher the urea content in the resin, the higher the strength and the lower the product cost, but the amount of gas ge...

AI Technical Summary

Problems solved by technology

The current low-nitrogen and nitrogen-free resins for steel casting mainly have the following defects: the free formaldehyde content of the resin is high, which is released in large quantities during use, seriously polluting the working environment and harming the health; Castings produce pores; the higher the urea content in the resin, the higher the strength and the lower the product cost, but the amount of gas generated by the resin at high temperature is also large, and the possibility of defects such as pores and pinholes in the casting is also greater; the resin can be The use time is short, the final strength is low, and it cannot meet the requirements of the casting process