JP2989083B2 - Extruder monitoring method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for monitoring an extruder, and more particularly to a novel improvement for monitoring a strand-like molten resin, a die and cooling water with a thermal imaging camera.

[0002]

2. Description of the Related Art In general, in a resin extrusion granulation method and apparatus in which a molten resin is extruded into a strand shape from a die of an extruder, cooled with cooling water, and granulated by a strand cutter device, the extruder and the strand cutter device are used. In order to maintain stable steady operation and to stabilize the quality of granulated resin products uniformly, it is necessary to always maintain a stable and homogeneous state of the strand-shaped molten resin extruded from the die of the extruder. There is. That is, it is necessary that a number of strands equal to the number of extrusion ports be extruded from a die having a plurality of extrusion ports with a constant thickness, and the resin temperature during extrusion and during cooling be constant. In order to achieve this object, the state of extrusion of the strand-like molten resin extruded from the die of the extruder is monitored, and the operating conditions are controlled so that the state of extrusion is always stable and constant. Conventionally, as a method and an apparatus for monitoring this type of extruder which has been used, generally, an image measurement is performed on an object to be measured by using an ITV camera or a color camera, and a background screen and a target screen are displayed using an image processing apparatus. It was separated and the strand-shaped molten resin was measured and monitored. As another conventional example using a background plate, for example, a configuration shown in FIG. 8 has been adopted.

[0003] In FIG. 8, reference numeral 1 denotes a cylinder 3 having a hopper 2, a plurality of heaters 4, 5, 6, 7, 9 provided on the cylinder 3, a die 10,
An extruder comprising a driving device 1A for driving a screw (not shown) in the cylinder 3;
Strand-like molten resin 4 extruded from the outlet 10a
Numeral 0 is configured to be supplied to the strand cutter 25 via each guide roller 22, 23, 24 of the cooling water tank 20 having the cooling water 21.

At a position below the exit 10a of the die 10, a background plate 26 having a plurality of colors having different brightness is provided vertically through a vertical wall 20a of the cooling water tank 20, and the upper side of the cooling water tank 20 is provided. In the position, an imaging camera 41 having a configuration in which the control device 42 is connected by a camera cable 43
Are arranged. Therefore, the background plate 26 is disposed at a position opposite to the strand-shaped molten resin 40 with respect to the imaging camera 41.

Next, the case where the strand-shaped molten resin 40 is actually measured in the above-described configuration will be described.
First, the background plate 26 is disposed at the exit 10a of the die 10, and a state (shown in FIG. 9) in which the plurality of strand-like molten resin portions 40A to 40F pass through the front side position of the background plate 26 is indicated by the imaging camera 41. The image signal is captured and taken into the control device 42 via the camera cable 43. In this case, the light-colored background portions 26A of the respective strand-shaped molten resin portions 40A to 40F
The difference between the dark background portion 26B and the dark background portion 26B can be clearly obtained as shown in FIGS.

[0006] Based on the image signal, the control device 42, as shown in FIG.
A and a difference between light and dark between the strand-shaped molten resin portions 40A to 40F are calculated to obtain a first light-dark signal (not shown), and the dark background portion 26B and the strand-shaped molten resin portions 40A to 40F are obtained.
A second light / dark signal (not shown) is obtained by calculating a light / dark difference from F.

By comparing these light / dark signals, as shown in FIG. 11 or FIG. 12, the density (light / dark) in the horizontal direction of the image is changed from the background color portion (light color background portion 26A or dark color background portion 26B) having a large difference. ) The number of difference gradients can be counted, and the number of strands can be measured.

Further, as shown in FIGS. 13 and 14, each of the above-described light and dark signals is compared, and the density in the horizontal direction of the image is determined from the background color portion (light background portion 26A or dark background portion 26B) having a large difference. The number of pixels at the difference center level (light / dark value of the center between the background color portion and the strand-shaped molten resin portions 40A to 40F) of the (light / dark) difference is counted, and each strand shape is calculated from a predetermined reference dimension (comparison value). 40A of molten resin
A width W of 40F is measured.

Therefore, by performing simple image processing using a simple image processing apparatus, the number of strands and the strand width can be measured and monitored.

[0010]

The conventional method and apparatus for monitoring an extruder are configured as described above, and therefore have the following problems. That is, in the two conventional methods described above, the monitoring performance is maintained at a certain level, but the outlet of the extruder and the cooling water tank are provided in the background of the strand-like molten resin, and these colors and light Due to the different reflections, separating the background screen and the target screen requires complicated arithmetic processing, which increases the size of the device.
Was expensive. In addition to the above-described conventional configuration, there is a method of individually monitoring the number and thickness (or width) of the strand-shaped molten resin, the die temperature, the resin temperature, the cooling water temperature, and the like. However, it has been extremely difficult to meet the demand for high performance in a small, simple configuration with a large monitoring device.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and in particular, a method and apparatus for monitoring an extruder in which a strand-like molten resin, a die, and cooling water are monitored by a thermal imaging camera. The purpose is to provide.

[0012]

SUMMARY OF THE INVENTION An extruder monitoring method according to the present invention is directed to a forceps method for an extruder, wherein a strand-like molten resin extruded from a die of the extruder is monitored by an imaging camera. As the extruded state of the strand-shaped molten resin is monitored using a thermal imaging camera, the extruded state of the strand-shaped molten resin is determined by the number of strand-shaped molten resin, thickness (or width), temperature, die temperature, and die temperature. This is a method of simultaneously monitoring a plurality of temperatures of the heater for cooling and the temperature of the cooling water. Further, the monitoring device of the extruder according to the present invention is a monitoring device of the extruder, which is configured to monitor the strand-like molten resin extruded from the die of the extruder with the imaging camera, and a thermal imaging camera as the imaging camera, A control device connected to the thermal imaging camera, and a display device and a processing device connected to the control device,
The thermal imaging camera is configured to simultaneously monitor a plurality of the number, thickness (or width), temperature, die temperature, die heater temperature, and cooling water temperature of the strand-shaped molten resin. .

[0013]

In the extruder monitoring method and apparatus according to the present invention, a thermal imaging camera is installed on the resin outlet side of the die, and thermal images of the strand-like molten resin, the die and the cooling water are taken. The resin temperature of the strand-like molten resin, the die temperature, and the die heater temperature are measured from the heat distribution of the thermal image in the vicinity of the resin outlet of the extruder taken. Further, the number of strands, the strand width, and the temperature of the cooling water can be measured from the heat distribution of the thermal image of the cooling water tank captured.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a method and apparatus for monitoring an extruder according to the present invention will be described below in detail with reference to the drawings.
The same or equivalent parts as those in the conventional example will be described with the same reference numerals. FIG. 1 is a block diagram showing a monitoring device for an extruder according to the present invention, FIG. 2 is an enlarged configuration diagram showing a resin outlet side of the die in FIG. 1, FIG. 3 is an image diagram showing a thermal image taken, and FIG. 5 is a characteristic diagram showing the density and frequency of the AA portion of FIG. 5, FIG. 5 is a characteristic diagram showing the density distribution on the horizontal line of the AA portion of FIG. 3, and the density and the frequency of the BB portion of FIG. FIG. 7 is a characteristic diagram showing a frequency distribution, and FIG. 7 is a characteristic diagram showing a density distribution on a horizontal line of a BB portion in FIG.

In FIG. 1, reference numeral 1 denotes a cylinder 3 having a hopper 2, a plurality of heaters 4, 5, 6, 7, 9 provided in the cylinder 3, a die 10,
An extruder comprising a driving device 1A for driving a screw (not shown) in the cylinder 3;
The strand-like molten resin 40 extruded from the resin outlet 10a of the first strand 10 through the respective guide rollers 22, 23, and 24 of the cooling water tank 20 having the cooling water 21.
Is configured to be supplied.

At a position above the cooling water tank 20, a thermal imaging camera 41A having a configuration in which a control device 42 is connected by a camera cable 43 is provided.
2 is provided with a display device 45 for inputting the video signal 44 and a processing device 47 for transmitting and receiving the signal 46. The die 10 has a plurality of bolts 10A to 1A.
0F.

Next, a case will be described in which the number of strands, strand width, resin temperature, die temperature, heater temperature, cooling water temperature and the like of the strand-shaped molten resin are actually measured in the above-described configuration. First, the strand-like molten resin 40 extruded from the resin outlet 10a of the die 10 of the extruder 1
Each of the strand-shaped molten resin portions 40A to 40C is cooled by the cooling water 21 in the cooling water tank 20 and then pelletized by the strand cutter 25 through the guide rollers 22, 23 and 24 as shown in FIGS. The molten resin 31 is cut into a shape.

Next, FIG. 4 shows AA of the thermal image 100 of FIG.
FIG. 5 is a diagram showing a relationship (histogram) between the density and the frequency of each part, showing the frequency of the resin outlet 10a, the frequency of the strand-like molten resin parts 40A to 40C, and the frequency of the heater 9 from the left side. FIG. 5 is a diagram showing the density distribution on the horizontal line of the AA portion of the thermal image 100.
, The concentration of the resin outlet 10a, and the center is the concentration of the three strand-like molten resin portions 40A to 40C. In the state described above, FIG. 3 measured by the thermal imaging camera 41A
From the temperature signal of the die 10 of the thermal image 100 and the temperature signal of each of the strand-shaped molten resin portions 40A to 40C, as shown in FIG. 4, by counting the number of density (temperature) difference gradients in the horizontal direction of the image, The number of strands can be measured.

Further, the number of pixels at the difference center level (temperature value at the center between the die 10 and the strand-like molten resin portions 40A to 40C) of the density (temperature) difference in the horizontal direction of the image shown in FIG. 5 is counted and set in advance. The width dimension W of each of the strand-shaped molten resin portions 40A to 40C can be measured from the set reference dimension (comparison value).

FIG. 6 is a diagram showing a relationship (histogram) between the density and the frequency of the BB portion of the thermal pixel 100. The frequency of the cooling water 21 and the strand-like molten resin portions 40A to 40A-4 are shown from the left side.
The frequency of 0C is shown. FIG. 7 shows a thermal image 100.
3A and 3B are diagrams showing the concentration distribution on the horizontal line of the B-B portion, where both ends are the concentration of the cooling water 21 and the center is the concentration of the three strand-like molten resin portions 40A to 40C. Also, as shown in FIGS. 6 and 7, the cooling water tank 2
The number of strands and the width W of each of the strand-like molten resin portions 40A to 40C located in the cooling water 21 in FIG.
The measurement can be performed in the same manner as in the case of FIG.

Further, the temperature of the strand-like molten resin 40, the temperature of the resin outlet 10a, the temperature of the heater 9 wound around the die 10, and the temperature of the cooling water 21 are also shown in FIG. By processing, it can be easily obtained as shown in FIG. 5 and FIG. In the above-described embodiment, the case where the density is detected has been described. However, it goes without saying that the temperature can be detected and used instead of the density.

[0022]

The method and apparatus for monitoring an extruder according to the present invention are configured as described above, so that the following effects can be obtained. That is, since the strand-like molten resin extruded from the die of the extruder and its peripheral portion are monitored by the thermal imaging camera, by processing the thermal image obtained by the thermal imaging camera, the strand-like molten resin is processed. The number of strands and width (thickness), die temperature, heater temperature and cooling water temperature can be measured and monitored simultaneously,
A simple and inexpensive small monitoring device can be obtained without using a complicated configuration as in the related art.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an entire extruder monitoring device according to the present invention.

FIG. 2 is an enlarged configuration diagram showing a periphery of a die of FIG. 1;

FIG. 3 is a thermal image of FIG. 2 captured by a thermal imaging camera.

FIG. 4 is a characteristic diagram showing a relationship between density and frequency on line AA in FIG. 3;

FIG. 5 is a characteristic diagram showing a density distribution along the line AA in FIG. 3;

FIG. 6 is a characteristic diagram showing a relationship between density and frequency on line BB in FIG. 3;

FIG. 7 is a characteristic diagram showing a density distribution along line BB in FIG. 3;

FIG. 8 is a configuration diagram showing the entire monitoring device of a conventional extruder.

FIG. 9 is an enlarged configuration diagram showing the strand-like molten resin of FIG. 8;

FIG. 10 is a distribution diagram showing the relationship between the density and the frequency of the image of FIG. 9;

FIG. 11 is a distribution diagram showing a relationship between density and frequency in FIG. 10;

FIG. 12 is a distribution diagram showing a relationship between density and frequency in FIG.

FIG. 13 is a concentration distribution diagram of each strand-like molten resin portion.

FIG. 14 is a concentration distribution diagram of each strand-like molten resin portion.

[Explanation of symbols]

Reference Signs List 1 extruder, 9 heater, 10 dies, 20 cooling water tank, 21 cooling water, 40 strand molten resin, 41A
Thermal imaging camera, 42 control unit, 45 display.

Continuation of front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B29C 47/00-47/96

Claims (2)

(57) [Claims] 1. A method of monitoring a molten resin extruded from a die (10) of an extruder (1) using an imaging camera, the method comprising the steps of: 41A) using the strand-like molten resin
While monitoring the extrusion state of (40), the number, thickness (or width) of the strand-like molten resin (40),
A method for monitoring an extruder, comprising simultaneously monitoring a plurality of temperatures among a temperature, a temperature of a die (10), a temperature of a die heater, and a temperature of cooling water. 2. A monitoring device for an extruder, wherein a strand-like molten resin (40) extruded from a die (10) of an extruder (1) is monitored by an imaging camera. (41A), a control device (42) connected to the thermal imaging camera (41A), and a display device (45) and a processing device (47) connected to the control device (42), Thermal imaging camera (41A), strand-like molten resin (40)
Monitoring of the extruder characterized by simultaneously monitoring a plurality of the number, thickness (or width), temperature, temperature of the die (10), temperature of the die heater and temperature of the cooling water. apparatus.