| 摘要 |
<p>The appts. consists of a hollow, C-shaped frame made of sheet metal. The upper arm of the frame contains a grid on which the crucible is placed so the wax can run out of its spout; and in the upper arm is a fan and an electric heater generating a current of hot air which heats the crucible and melts the wax. The molten wax flows downwards into a metal dish resting on the lower arm of the frame and not exposed to the current of hot air; the metal dish may also be cooled. The underside of the upper arm of the frame pref. has a gap below the grid so the molten wax can flow downwards into the dish in which rapid cooling occurs. Used for mfg. lost wax castings, esp. in a dental laboratory. The wax is rapidly cooled so no noxious fumes are evolved; this means that a fume extn. duct is not required in the laboratory.</p> |
