HOT RUNNER IN PLASTIC INJECTION MOLD NAMED MAINTAIN RUNNER

摘要

PROBLEM TO BE SOLVED: To keep the accuracy of a mold and to shorten a rising time at the time of molding while preventing the generation of trouble by using glass ceramics in a runner structure and suppressing the lowering of heat conductivity and the diffusion of use heat and supplying a current to the metal foil film on the surface of a runner to keep the temp. of a boundary by Joule heat.;SOLUTION: Glass ceramics are used in a cold runner form and plating is applied to the surface of a runner and a conductor is formed by etching and a current is supplied to the conductor to obtain Joule heat to keep the temp. of a resin. In a small-sized mold high in a shot speed, the temp. of a resin is kept without using a heater to mold the resin. In a large-sized mold low in a shot speed, the heater is used to prevent the lowering of the temp. of the resin. Since temp. rises for a short time from the shape of the heater and a heat conductive medium from aspect of a runner structure is unnecessary, rising is enabled at the time of retreat. A resin is easily removed when it is cured.;COPYRIGHT: (C)2000,JPO