超音波による溶融樹脂温度の測定
Temperature Measurement of a Molten Resin in an Injection Molding Machine by Using an Ultrasonic Technique
西脇信彦・今野政昭・崔 愛玲・堀 三計
Nishiwaki, Nobuhiko / Konno, Masaaki / Cui, Ailing / Hori, Sankei
Up to now, a number of CAE mold design software packages for simulating an injection molding process have been developed. For most of such software, it is necessary to know accurately the temperature of the resin injecting into the mold. It is, however, not very easy to measure the temperature due to heat generation caused by the shear flow between the resin and the thermocouple. A non-contact measuring method has been developed by using an infrared technique, but the infrared radiation is generated not only from the molten resin, but also from the surrounding solid surface. Moreover, the emissivity of the molten resin cannot be easily measured.
In this study, a method of measuring the molten resin temperature by using an ultrasonic technique has been developed. The temperature of the molten resin is related to the pressure and sound velocity, and the pressure is easily and exactly measured. Therefore, the temperature of the molten resin flowing through the nozzle and the barrel can be measured.
Key words: Molten resin / Temperature / Non-contact measuring method / Ultrasonic wave / Nozzle