Method for on-line measurement of polymer melt temperature and apparatus thereof

Patent metadata

Field	Value
Publication number	US-11752677-B2
Application number	US-202117226418-A
Country	US
Kind code	B2
Filing date	Apr 9, 2021
Priority date	Apr 9, 2020
Publication date	Sep 12, 2023
Grant date	Sep 12, 2023

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.

First claim

What is claimed is:

1. A method for on-line measurement of polymer melt temperature, comprising:
measuring, by an ultrasonic probe, ultrasonic sound velocity c of melt during injection molding on line;
measuring, by a pressure sensor, melt pressure P during injection molding on line, wherein the ultrasonic probe and the pressure sensor are arranged at a same cross section of the melt, wherein a sampling frequency of pressure or ultrasonic is higher than 250 MHz, and a signal preservation rate is higher than 20Sa/s, wherein an end of the ultrasonic probe fits and contacts a surface to be measured of a front mold by using a couplant, and another end of the ultrasonic probe is pressed tightly against and fixed onto inside of the mold, and wherein the pressure sensor is mounted into a mounting hole on a rear mold to measure a surface coplanar with a cavity surface; and
calculating, by a microprocessor, melt temperature T during injection molding by using a Newtonian-iterative numerical method according to a formula (1) as follows, and controlling, by the microprocessor, on-line quality of a molded product based on the melt temperature:
P=c 2 ( f ( T,P )− f ( T,P 0 ))  (1)

wherein f (T, P) and f (T, P 0 ) are respectively:

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Assignees

• Univ Zhejiang

Inventors

• Zhao Peng
• Zhang Jianfeng
• Ji Kaipeng
• Dong Zhengyang
• Xia Neng
• Zhou Hongwei
• Fu Jianzhong

Classifications

• B29C45/78 Primary

  of temperature · CPC title

• G01N29/024 Primary

  by measuring propagation velocity or propagation time of acoustic waves · CPC title

• G01N29/28

  providing acoustic coupling {, e.g. water (impedance matching G10K11/02)} · CPC title

• G01N29/4472

  Mathematical theories or simulation · CPC title

• G01K13/00

  Thermometers specially adapted for specific purposes · CPC title