US 11,752,677 B2Granted

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

AssigneeZhejiang University

InventorsPeng Zhao, Jianfeng Zhang, Kaipeng Ji, Zhengyang Dong, Neng Xia, Hongwei Zhou, Jianzhong Fu

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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.

Claims6

Dependent claims

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=c2(f(T,P)−f(T,P0)) (1)
wherein f (T, P) and f (T, P0) are respectively:
f
⁢
(
T
,
⁢
P
)
=
1
[
b
1
⁢
⁢
m
+
b
2
⁢
⁢
m
⁡
(
T
-
b
5
)
]
⁢
{
1
-
C
⁢
⁢
ln
⁡
[
1
+
P
b
3
⁢
⁢
m
⁢
e
[
-
b
4
⁢
⁢
m
⁡
(
T
-
b
5
)
]
]
}
f
⁢
(
T
,
P
0
)
=
1
[
b
1
⁢
⁢
m
+
b
2
⁢
⁢
m
⁡
(
T
-
b
5
)
]
⁢
{
1
-
C
⁢
⁢
ln
⁡
[
1
+
P
b
3
⁢
⁢
m
⁢
e
[
-
b
4
⁢
⁢
m
⁡
(
T
-
b
5
)
]
]
}
wherein:
P0 is 1 standard atmospheric pressure, while C, b1m, b2m, b3m, b4m, and b5 are constant coefficients.

139 more elements

An apparatus for on-line measurement of the polymer melt temperature, comprising:

an ultrasonic probe, configured to perform on-line measurement of ultrasonic sound velocity c of melt during the injection molding process;
a pressure sensor, configured to perform on-line measurement of pressure P of the melt during the injection molding process, 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 wherein 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
a microprocessor configured to receive signals from the ultrasonic probe and the pressure sensor to output numeral values of the ultrasonic sound velocity c and the pressure P, obtain the polymer melt temperature T according to a formula:
P=c2(f (T, P0)−f(T, P0)), and control on-line quality of a molded product based on the polymer melt temperature;
wherein f (T, P) and f (T, P0) are respectively:
f
⁡
(
T
,
P
)
=
1
[
b
1
⁢
m
+
b
2
⁢
m
(
T
-
b
5
)
]
⁢
{
1
-
C
⁢
ln
[
1
+
P
b
3
⁢
m
⁢
e
[
-
b
4
⁢
m
(
T
-
b
5
)
]
]
}
f
⁡
(
T
,
P
0
)
=
1
[
b
1
⁢
m
+
b
2
⁢
m
(
T
-
b
5
)
]
⁢
{
1
-
C
⁢
ln
[
1
+
P
0
b
3
⁢
m
⁢
e
[
-
b
4
⁢
m
(
T
-
b
5
)
]
]
}
wherein:
P0 is 1 standard atmospheric pressure, while C, b1m, b2m, b3m, b4m, and b5 are constant coefficients.

123 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/226,418Filed 9 Apr 2021
Priority: CN 202010276363.39 Apr 2020
Published: US 2021/0316489 A114 Oct 2021
Granted: 12 Sep 2023
Term ends: Not estimatedThe source records don’t support an estimate.

Classification15 codes

B29C 45/78
Measuring, controlling or regulating: of temperature
G01K 11/24
Using measurement of acoustic effects: of the velocity of propagation of sound
G01K 13/026
For measuring temperature of moving fluids or granular materials capable of flow: of moving liquids
G01N 29/228
Details , e.g. general constructional or apparatus details: related to high temperature conditions