| 摘要 |
An electrically heated nozzle device for plastic molding or die casting equipment having a novel casing with an integral heater core, and means to seal the casing for retaining the heater core in place and to electrically insulate the electrical heating element from the casing and prevent loss of thermal transmitting packing contained in the casing, which is structured to receive the heater core in the area close to its passage for carrying molten material to be molded or cast in a forming cavity, and which may be shaped. The casing may also include a probe for a thermocouple or a thermocouple well for sensing temperature; and the method includes the steps of arranging an unsheathed electric heating element in a bore formed in the nozzle casing in proximity to its molding material orifice, filling the bore with heat transmitting electrical insulation embedding an electric heating element, compacting the insulation about the heating element and in the bore to eliminate air voids, and sealing the bore. The method may also include the steps of assembling in the nozzle casing a body of relatively flexible green ceramic particles impregnated in heat dissipatable material and embedding a resistance wire heating element in the body, heating the assembly to bake out the heat dissipatable material and sinter the ceramic particles together, and compacting the assembly to eliminate air voids therein and between the casing and said assembly. Also disclosed herein in a heater body embodying modified features of the invention.
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