Furan resin for casting steel
Nitrofuran resin is not suitable for steel castings, especially large steel castings and alloy steel castings.
Characteristics of furan resin
1. High final strength
Low volume and low cost
2. Fast curing speed
Fast curing speed of resin can shorten production cycle and improve production efficiency.
3. Environmental protection
The free formaldehyde content of resin is very low, less than 0.05%, only 20% of the industry standard, and the amount of resin added is low, which greatly reduces the environmental pollution and significantly improves the working conditions of workers.
4. No need to add silane in core molding
5. Can improve casting quality and yield and reduce cost
The reduction of resin content will reduce the air output of mold and core, which is beneficial to reduce or eliminate the defects of pores in castings.Due to the fast curing speed, the addition of curing agent decreases correspondingly, which can alleviate the defects of S and spheroidization on the surface of the casting.
1. Sand mixing technology
The amount of resin added is generally 0.7-1.5% (accounts for sand weight), and the amount of curing agent added is generally 30-70% (accounts for resin weight). Sand and curing agent are first mixed with continuous or intermittent sand mixer, and then mixed with resin. The sand mixing time is generally 5-60 seconds.
2. Selection of resin content
As the indexes of sand shape, grain size, mud content and so on used by various manufacturers are quite different, and the weight and complexity of mold and core are different, the addition amount of resin should be based on the principle of meeting the production needs, and the addition amount of resin should be reduced as far as possible on the premise that the strength meets the production requirements.
3. Control of demoulding time
Control the appropriate demoulding time (generally 10-40 minutes), premature demoulding will produce adhesive mold or even bad, core or collapse box;If it is too late, it will be difficult to release and even damage the mold, core or model.
4. Curing speed control
Curing speed is too slow, increase the amount of curing agent (generally not more than 70%) or change curing agent with faster curing speed;Curing speed is too fast, and the addition of curing agent should be reduced (generally no less than 30%) or replaced with curing agent with slower curing speed.