COLLAPSIBLE MATERIAL CONTAINING UNEXPANDED VERMICULITE PARTICLES , PLACEMENT RACK THAT BREAKS DOWN DURING INCINERATION AFTER PREDETERMINED TIME PERIOD, LOST-WAX MOLD, AND MOLD COLLAPSING METHOD

摘要

Disclosed is a collapsible material comprising a base formed of a hydrate of a hydraulic material (such as cement or gypsum) and unexpanded vermiculite particles dispersed in the base, wherein a coating film comprising at least any one of a hydrate of the hydraulic material, silica powder and dolomite is formed on the surface of the base, wherein the base is collapsed by use of thermal expansion of the unexpanded vermiculite particles. Further disclosed is a placement rack such as a fire grate for use in a cremation process, comprising the collapsible material as defined above, for placing an object to be incinerated thereon.