With the new FEEDEX NF1 range of exothermic feeders for aluminum, the application of exothermic powders to boost the feeding effect in the riser is unnecessary.
The use of insulating feeders - based on fibres or spheres and bonded with inorganic or organic resin binders - is common practice in aluminum foundries.
If the insulating property of the sleeve is not sufficient, or if the size of the sleeve is limited, then exothermic riser powders may need to be applied to avoid shrinkage defects in the casting. These powders start an exothermic reaction when coming into contact with liquid aluminum and provide energy to the melt in the feeder to slow down solidification.
With the use of FEEDEX NF1 exothermic feeders, the use of riser powders can be avoided. The sleeve ignites within 30 seconds of coming into contact with molten aluminum and the steady and long-lasting exothermic reaction significantly delays solidification of the metal in the sleeve, ensuring excellent feed performance.
The FEEDEX NF1 concept delivers:
- High exothermicity with improved feeding performance
- Exceedingly high strength
- Minimized fettling costs when used in combination with breaker cores
- Easy and quick knock-off of the sleeve and riser stub
- Reduced process variation
- Lower emissions