| 摘要 |
This invention relates to an improved method of installing an elongated heater such as a cartridge heater in a molding member such as an injection molding manifold member. First, a bore is drilled into an elongated portion of the manifold member to extend generally parallel to the hot runner passage extending through it and a filler duct is drilled from the top to intersect the bore along its length. The cartridge heater is then inserted into the bore and a filler tube with a base is set on the top in alignment with the filler duct. A brazing paste is then applied around the base of the filler tube and around the terminal portions of the cartridge heater extending from the bore. The manifold member is then heated in a vacuum furnace which brazes the filler tube in position and seals the outer end of the duct against leakage. A slug of copper is then inserted into the filler tube and the manifold member is again heated in the vacuum furnace sufficiently to cast the conductive copper to fill the space around the cartridge heater. The filler tube is then machined off to produce the finished manifold member. The copper fuses to the outer casing of the cartridge heater and the bore and together with the elimination of the insulative air space around the cartridge heater substantially improves heat flow and reduces the formation of hot spots which cause the heating element to burn out. In another embodiment, a tubular heater having two terminal portions is installed in a heater plate of a thermosetting mold with the terminal portions extending at opposite ends of the heater plate. |
