Abstract: The present disclosure discloses a method for on-line measurement of the polymer melt temperature, comprising: on-line measurement of ultrasonic sound velocity c of melt in an injection molding process, on-line measurement of melt pressure P in the injection molding process, and obtaining melt temperature T in the injection molding process by formula (1). The present disclosure also discloses an apparatus for on-line measurement of the polymer melt temperature. The method and the apparatus provided in the present disclosure may enable on-line and in-situ characterization of the melt density and further enable on-line quantitative measurement of the melt quality. Compared with infrared measurement methods, the method provided herein is significantly reduced in cost, which is of great significance to theoretical researches of crystallization process and shear heating.

Abstract: The present invention discloses a ultrasonic method for indirectly measuring a pressure of a cavity of an injection molding machine, comprising: emitting ultrasonic wave to each pull rod along an axial direction of the pull rod respectively at the same time, detecting an ultrasonic wave echo time difference of each pull rod, and obtaining an average pressure inside a cavity of the injection molding machine. By the detection method and detection device of the present invention, the pressure inside the cavity may be detected in a certain state, the pressure inside the cavity in the injection molding process may be detected in real time, and the detection process is simple and the accuracy is high.

Abstract: The present disclosure discloses a method for on-line measurement of the polymer melt temperature, comprising: on-line measurement of ultrasonic sound velocity c of melt in an injection molding process, on-line measurement of melt pressure P in the injection molding process, and obtaining melt temperature T in the injection molding process by formula (1). The present disclosure also discloses an apparatus for on-line measurement of the polymer melt temperature. The method and the apparatus provided in the present disclosure may enable on-line and in-situ characterization of the melt density and further enable on-line quantitative measurement of the melt quality. Compared with infrared measurement methods, the method provided herein is significantly reduced in cost, which is of great significance to theoretical researches of crystallization process and shear heating.

Abstract: The present invention discloses a ultrasonic method for indirectly measuring a pressure of a cavity of an injection molding machine, comprising: emitting ultrasonic wave to each pull rod along an axial direction of the pull rod respectively at the same time, detecting an ultrasonic wave echo time difference of each pull rod, and obtaining an average pressure inside a cavity of the injection molding machine. By the detection method and detection device of the present invention, the pressure inside the cavity may be detected in a certain state, the pressure inside the cavity in the injection molding process may be detected in real time, and the detection process is simple and the accuracy is high.