Seiko Koki Kabushiki Kaisha

Toshihide Kasuga

Hiraku Shindo

Susumuhide Onuma

Kiyomitsu Noguchi

Takashi Hanyuda

The present invention relates to a hot runner probe having a shell-shaped probe body having a molten resin flowing surface which is combined to form a single unit with a ceramic heater wherein the ceramic heater is covered by the heater pattern that consists of high electric-resistance metal and has made the temperature gradient at the tip part higher than that at the center part, and then is insulation-baked. The present invention also relates to high-accuracy injection molding using the hot runner probe under the proper and ideal temperature distribution, by applying the ceramic heater, which is provided with temperature gradients, to the increase and decrease of resistance values due to temperature changes by the one circuit control means.

Hot runner probe and its equipment

A method of injection molding of polyethylene terephthalate resin which includes a process to heat and melt polyethylene terephthalate resin by means of plasticizing system, and inject the molten polyethylene terephthalate resin under a desirable injection molding pressure from nozzle part 8 through manifold part 9 and runner part 1 into cavity 4, and at the same time of the injection molding, to perform the opening and closing motion of gate 3 part by melting or solidifying the solidified or molten polyethylene terephthalate resin remaining at the gate 3 part by means of the intermittent temperature control apparatus 7 made of a platinum wire provided with along the vicinity of the gate 3, so as to produce the moldings removing the residual sprue at the gate 3 part. By the present invention, the polyethylene terephthalate resin which is very difficult to process by injection molding, is produced as moldings not accompanying a whitening phenomenon but of a high quality with superior transparency.

Growing community of inventors

Kaminoyama, Japan

Toshihide Kasuga