PURPOSE:To provide a rigid low-cost model less liable to thermal deformation by a method wherein a surface layer made of silicone rubber or the like is lined with a mixture of glass fibers or the like and styrene resin or the like characterized by heat insulating property, rigidity, and reduced microwave energy loss. CONSTITUTION:A model 1 comprises a surface layer 2 (10mm thick) made, for example, of silicone rubber and backed with a back-face layer 3 consisting of a mixture of 90 parts of epoxy resin and 10 parts of glass fibers. Shell sand 4 or the like containing 1% of a dielectric substance to be molded is charged in the mold 1 and hardened by self-heating under irradiation of microwaves. By this, the amount of silicone rubber used in the model is reduced by a factor of about 1/5, the cost of the model is reduced, and the thermal deformation of the model surface layer 2 is minimized.
展开▼
