| 摘要 |
A barrel (11a, 11b) adapted for use in a plastics machine, has an inner layer of insulating ceramic (13a, 13b) disposed over and around the barrel along its length to form an insulated barrel, a wire layer (16, 16b) including a plurality of heating coils (17, 17b) of alloy resistance wire wound around the insulated barrel under tension in a spiral fashion, the wire layer also providing additional termination coils (18, 18b) near opposite ends of the barrel for making electrical contact with a source of electrical power to heat the barrel, and a top layer (19, 19b) of an electrically insulating ceramic disposed over the heating coils A method of making a barrel with a heater, comprises spraying a layer (12, 12b) of a metal bonding alloy over a portion of the barrel to be heated. |
