Moldable compound for making heat-insulating riser jackets (insulating riser sleeve) or insulating pads.
In contrast to exothermic compounds (exothermic mixtures) which self-heat as a result of an aluminothermic reaction, insulating compounds first absorb heat from the liquid metal used to fill the mold until reaching equilibrium temperature; from this moment on, they protect the liquid casting metal against further heat losses for a certain time. Therefore, riser sleeves made of insulating compounds delay the beginning of solidification, promote seal-feeding and increase yields.
Insulating compounds may also be used as a powder to cover risers. They are spread over the open risers, protecting the metal contained in the riser against heat emission.
In addition, there are insulating compounds used for heat insulation at the back of furnaces.