JP3029184B2 - Extruder output measuring device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extruder for melting a polymer material and extruding the same into a die, and more particularly to an extruder measuring apparatus for measuring the amount of resin material extruded.

[0002]

2. Description of the Related Art Conventionally, in this type of measurement of the amount of extrusion, for example, Japanese Unexamined Patent Publication No.
As described in Japanese Unexamined Patent Publication No. 6 (1994), an average extrusion amount is calculated from the material weight of the hopper, and further, a target extrusion amount is calculated based on the dimensions (width, thickness), take-up speed, and material density of the prepared film. In some cases, the average extrusion rate is adjusted to the target extrusion rate.

[0003] Further, in order to stabilize the extruded amount, there is a type in which a gear pump is provided in a die head portion and the extruded amount is calculated backward from the discharged amount.

[0004]

As shown in FIG. 3, the actual amount of extrusion F is a steady state showing a static movement of the ordinary amount of extrusion.

[0005]

[Outside 1]

[0006] Although this is composed of the dynamic extrusion rate ΔF indicating the movement of the extrusion rate, the measurement of the extrusion rate described in the above publication can calculate only the static extrusion rate, and cannot calculate the dynamic extrusion rate. There was a problem. Also, in the above-described measurement of the extrusion amount, since the weight of the material on the hopper side is detected, even if the flow rate changes on the hopper side, the change takes at least several minutes to reach the die head portion. Due to the existence of such dead time, the extrusion amount measured on the hopper side is not the instantaneous value of the extrusion amount on the die head side at that time, so that there is a problem that the extrusion amount control lacks accuracy. In addition, it takes a long time to measure the extrusion amount to detect the dimensions of the produced film, making it difficult to measure in a short span, increases the amount of wasted material, and increases the production cost of the film. There was also a problem.

[0007] In addition, in the measurement of the extruded amount provided with a gear pump, since the temperature rise phenomenon often appears in the pump, if the molten material is thermally decomposed or undergoes other phenomena (for example, in the case of a material containing a foaming agent, it is fired. Phenomena etc.) may occur and there is a problem that it cannot be commercialized. The present invention has been made in view of the above problems, and an object of the present invention is to provide an extruder extruder measuring apparatus capable of measuring a static extruding amount and a dynamic extruding amount to accurately measure an extruding amount in a die head. And

[0008]

According to one aspect of the present invention, there is provided an extruder for melting a polymer material supplied to a hopper and extruding the same through a cylinder to a die head. An input amount detection unit including a weighing sensor for detecting an input amount of the polymer material, a first temperature detection unit including a heat sensor for detecting a temperature of the material, and a second unit including a heat sensor for detecting a temperature of the cylinder. A temperature detecting means, a rotation number detecting means for detecting a rotation number of a screw provided in the cylinder, and a pressure sensor for detecting a pressure of a polymer material in the cylinder. Pressure detecting means, second pressure detecting means comprising a pressure sensor for detecting the pressure of the polymer material in the die head, and an average extrusion amount based on the detected input amount. A first calculating means comprising a calculating unit for calculating a minute time extrusion amount based on the detected material temperature, cylinder temperature, screw rotation speed, and the amount of change in the polymer material pressure in the cylinder and the die head. An extruder comprising: a second calculating means including a calculating unit; and a third calculating means including a calculating unit configured to calculate the extruding amount of the extruder based on the calculated average extruding amount and minute time extruding amount. An output meter is provided.

According to a second aspect of the present invention, there is provided an extruder for melting a polymer material put into a hopper and extruding the same through a cylinder to a die head, wherein the first temperature detecting means comprises a heat sensor for detecting the temperature of the material. A second temperature detecting means including a heat sensor for detecting a temperature of the cylinder; a rotational speed detecting means including a rotational sensor for detecting a rotational speed of a screw provided in the cylinder; and a polymer material in the cylinder. A first pressure detecting means comprising a pressure sensor for detecting the pressure of the second material, a second pressure detecting means comprising a pressure sensor for detecting the pressure of the polymer material in the die head, and Calculating means comprising an arithmetic unit for calculating an average extrusion amount by using the above-mentioned detected material temperature, cylinder temperature, screw rotation speed, cylinder interior, and die head. A second calculating means including a calculating unit for calculating a minute time extrusion amount based on a change amount of the polymer material pressure, and an actual extrusion of an extruder based on the calculated average extrusion amount and the minute time extrusion amount. A third calculating means including a calculating unit for calculating the amount.

According to a third aspect of the present invention, the second calculating means calculates a minute time extrusion amount based on an autoregressive exogenous model, using a change amount of each event in consideration of the characteristics of the extruder as a variable.

[0011]

The static extruding amount is calculated from the detected material input amount, and the dynamic extruding amount is calculated from the detected material temperature, cylinder temperature, screw rotation speed, and the amount of change in the polymer material pressure in the cylinder and the die head. Is calculated, and the actual extrusion amount is obtained from the static extrusion amount and the dynamic extrusion amount.

According to a second aspect of the present invention, a static extrusion amount is calculated from the detected screw rotation speed instead of the material input amount, and the detected material temperature, cylinder temperature, screw rotation speed, the inside of the cylinder and the inside of the die head are calculated. The dynamic extrusion rate is calculated from the change in the polymer material pressure, and the actual extrusion rate is determined from the static extrusion rate and the dynamic extrusion rate. According to the third aspect, the dynamic extrusion rate is estimated by an autoregressive exogenous model using the material temperature, the cylinder temperature, the screw rotation speed, and the changes in the polymer material pressure in the cylinder and the die head as variables.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an extruder measuring apparatus for an extruder according to the present invention will be described with reference to FIGS. In creating the present invention, the inventor of the present application sets the temperature of a polymer material in a hopper, for example, a polyethylene material, the temperature of a cylinder, the rotation speed of a screw provided in a cylinder, and the resin in a cylinder. The pressure of the polymer material melted in the cylinder and the pressure of the resin in the die head provided at the outlet of the cylinder (hereinafter referred to as "extrusion pressure")
It was detected that such an event affected the throughput.

Therefore, in the present invention, the static extrusion rate is calculated from the flow rate of the polymer material, and the material temperature,
The dynamic extrusion rate is calculated from the cylinder temperature, the screw rotation speed, the resin pressure in the cylinder and the die head, and the actual extrusion rate is determined from the static extrusion rate and the dynamic extrusion rate. FIG. 1 is a block diagram showing a configuration of an extrusion amount measuring device according to the present invention. In the figure, a weighing sensor 20 such as a load cell is disposed on a hopper 11 of an extruder 10 to measure the flow rate of a polymer material, and a heat sensor 21 such as a thermocouple is disposed on a material.

[0015]

[Outside 2]

1 is connected to the ΔF calculation unit 27,
The data of the measured material temperature Tm is output to the ΔF calculation unit 27. The cylinder 12 includes a heat sensor 22 such as a thermocouple.
Is arranged to measure the cylinder temperature, and the pressure sensor 23 is arranged to measure the resin pressure in the cylinder 12. In addition, a rotation sensor 24 is provided on a screw motor 14 for driving the screw 13 in the cylinder 12 to rotate, and the rotation speed of the screw 13 is measured. The heat sensor 22, the pressure sensor 23, and the rotation sensor 24 are connected to the ΔF calculation unit 27, respectively, and measure the measured cylinder temperature Tc,
The data of the resin pressure Pc and the screw rotation speed N are output to the ΔF calculation unit 27.

In measuring the cylinder temperature, as shown in FIG.
When the screw 13 in the cylinder 12 has a tapered shape that gradually increases in diameter with respect to the flow direction of the resin, a position where the compression zone of the extruder 10 starts, that is, a position where the screw 13 starts to be tapered. Then, it was detected by an experiment that the material began to melt in earnest and became a melt, and that a change in temperature at this position had a large effect on the throughput. Therefore, in this embodiment, the heat sensor 22 is disposed at a position where the tapered portion of the screw 13 starts.

In the measurement of the resin pressure in the cylinder 12, when the screw 13 has a tapered shape as shown in FIG. 1, the starting position of the metering zone of the extruder, that is, the taper of the screw 13 The department is over,
Since the flow of the resin is stabilized at the position where the flat portion starts, it was detected by an experiment that the change in pressure at this position greatly affected the extrusion amount. Thus, in this embodiment, the pressure sensor 23 is disposed at a position where the tapered portion of the screw 13 ends.

Since the cylinder temperature and the resin pressure are affected by the shape of the screw as described above, it is desirable to detect the optimum arrangement position by experiment or the like according to the shape of the screw. In addition, a pressure sensor 25 is disposed in the die head 15 at the outlet of the cylinder 12 to measure the extrusion pressure in the die head 15. The pressure sensor 25 calculates ΔF
It is connected to the calculation unit 27 and outputs data of the measured extrusion pressure Pd to the ΔF calculation unit 27.

[0020]

[Outside 3]

The flow rate data FH output from the sensor 20
Is obtained by a predetermined number, and the following equation (1) is obtained.

[0022]

(Equation 1)

[0023]

[Outside 4]

That is, it is output to the F calculation unit 28 as the static extrusion amount. ΔF calculation unit 27 includes heat sensors 21 and 22;
Five variables (material temperature Tm, cylinder temperature Tc, resin pressure Pc, screw rotation speed N, and extrusion pressure P) output from the pressure sensor 23, the rotation sensor 24, and the pressure sensor 25.
The time series data of d) is fetched, and an autoregressive exogenous (hereinafter, referred to as “ARX”) model is expressed by the following equation (2) using these time series data.

[0025]

(Equation 2)

[0026]

[Outside 5]

The reference numeral 28 can be constituted by a CPU. Next, the parameters a1, b1, c1, d1, e1, and f1 are estimated by the following five-input one-output primary system. First, ΔF (i) = a1ΔF (i−1) + b1ΔTc (i−1) + c1ΔTm (i−
1) + d1ΔPc (i-1) + e1ΔPd (i-1) + f1ΔN (i-1) + V
(i)

[0028]

(Equation 3)

## EQU1 ## here,

[0030]

(Equation 4)

Then, equation (3) becomes:

[0032]

(Equation 5)

And the estimated value is

[0034]

(Equation 6)

## EQU1 ## The error V is

[0036]

(Equation 7)

This is multiplied by the transpose of V, V ^T, to give

[0038]

(Equation 8)

## EQU1 ## You can minimize the error by the V ^T V minimized. Therefore, each parameter a
Partial differentiation is performed on 1, b1, c1, d1, e1, and f1. Since the above partial differentiation is the same for each parameter, the case of a1 and f1 is shown here as a representative.

[0040]

(Equation 9)

## EQU1 ## Expanding equation (4),

[0042]

(Equation 10)

-(Ya1z1-b1z2-c1z3-d1z4
−e1z5−f1z6) ^T z1 + (ya1z1−b1z2−c1)
z3-d1z4-e1z5-f1z6) T (-z1) = 0 , and the thus the equation becomes (y-a1z1-b1z2-c1z3 -d1z4-e1z5-f1z6) T z1 = 0 ... (6). Similarly, parameters b1, c1, d1, e1, f1
The partial differential with respect to, (y-a1z1-b1z2- c1z3-d1z4-e1z5-f1z6) T z2 = 0 ... (7) (y-a1z1-b1z2-c1z3-d1z4-e1z5-f1z6) T z3 = 0 ... (8 ) (y-a1z1-b1z2- c1z3-d1z4-e1z5-f1z6) T z4 = 0 ... (9) (y-a1z1-b1z2-c1z3-d1z4-e1z5-f1z6) T z5 = 0 ... (10) (y- a1z1-b1z2-c1z3-d1z4- e1z5-f1z6) T z6 = 0 ... it is (11). Next, when these equations (6) to (11) are synthesized,

[0044]

[Equation 11]

Is as follows. Here, when transposition is performed with [z1... Z6] = z, the above equation (12) becomes

[0046]

(Equation 12)

Is as follows. Since z and y are experimental data, the parameters a1, b1, c1, d1, e1, and f1 can be calculated. Further, the first-order or higher-order parameters (ai, bi, ci, di, ei, fi, where i> 1) shown in equation (2) can be calculated in the same manner. Note that the above parameter estimation is generally known in the ARX model.

[0048]

[Outside 6]

Next, the operation of the extrusion amount measuring apparatus shown in FIG. 1 will be described with reference to the flowchart of FIG. First, A
The parameters and order of the RX model are set, and the sampling time for the static extrusion amount and the sampling time for the dynamic extrusion amount are set (step 101). Usually, the sampling time of the static extrusion amount is longer than the sampling time of the dynamic extrusion amount, so that it is set to a multiple.

Next, it is determined whether or not the above parameters are reset (step 102). Here, for example, when measuring the extrusion amount of a material having a different material, the accuracy of the measurement of the extrusion amount is improved by newly setting the parameter according to the material. Here, when the above parameters are to be reset, the process returns to step 101 and resets.

[0051]

[Outside 7]

The F operation unit 27 starts sampling each data, and determines whether or not the set sampling time has been reached (step 103). Each time the set sampling time is reached, each sensor 20 to 25

[0053]

[Outside 8]

If the pulling time has not been reached, F
The calculation unit 28 calculates the actual extrusion amount F from the dynamic extrusion amount ΔF input from the ΔF calculation unit 27. The operation of measuring the extrusion amount is repeatedly performed, for example, until an end instruction is given from the operator. Therefore, in this embodiment,
Since the extruded amount at the die head is calculated from the static extruded amount, which is the average value of the extruded amount, and the dynamic extruded amount every minute time, the actual extruded amount can be accurately measured.

Further, in this embodiment, since the extrusion amount is measured by using the time series data of a plurality of variables which affect the extrusion amount, the change in the extrusion amount can be measured at any time, and the waste associated with the measurement can be measured. Time can be reduced. Further, in this embodiment, since the extrusion amount is obtained by using the ARX model, the causal relationship between the past state of each variable (the past state not only one step before but also several steps before) and the extrusion amount is determined. Can be detected.

In this embodiment, the static extrusion amount is calculated from the flow rate of the material. However, the present invention is not limited to this. For example, the static extrusion amount can be calculated from the screw rotation speed N. In this case, the following equation

[0057]

(Equation 13)

From this, it is possible to calculate the static extrusion amount.

[0059]

As described above, according to the first aspect of the present invention, in an extruder in which a polymer material charged into a hopper is melted and extruded to a die head via a cylinder, the polymer material charged into the hopper is charged. Charging amount detecting means for detecting an amount, first temperature detecting means for detecting a temperature of the material, second temperature detecting means for detecting a temperature of the cylinder, and rotation of a screw provided in the cylinder Rotation number detecting means for detecting the number, first pressure detecting means for detecting the pressure of the polymer material in the cylinder, second pressure detecting means for detecting the pressure of the polymer material in the die head, First calculating means for calculating an average extrusion amount based on the detected input amount, and the detected material temperature, cylinder temperature, screw rotation speed, polymer material pressure in the cylinder and in the die head. A second calculating means for calculating a minute time extrusion amount based on the change amount; and a third calculating means for calculating an extrusion amount of the extruder based on the calculated average extrusion amount and the minute time extrusion amount. Therefore, it is possible to measure the static extrusion amount and the dynamic extrusion amount to measure the accurate extrusion amount at the die head.

According to a second aspect of the present invention, there is provided an extruder for melting a polymer material charged into a hopper and extruding the same through a cylinder to a die head, wherein the first temperature detecting means for detecting the temperature of the material; Temperature detecting means for detecting the temperature of the screw, rotational speed detecting means for detecting the rotational speed of a screw provided in the cylinder, and first pressure detecting means for detecting the pressure of the polymer material in the cylinder. Second pressure detecting means for detecting the pressure of the polymer material in the die head, first calculating means for calculating an average extrusion rate based on the detected screw rotation speed, and the detected material temperature. A second calculating means for calculating a minute time extrusion amount based on a change amount of a polymer material pressure in a cylinder temperature, a screw rotation speed, a cylinder and a die head, and the calculated average extrusion. And a third calculation means for calculating the actual extrusion rate of the extruder based on the minute time extrusion rate,
Since the static extrusion amount is calculated from the detected screw rotation speed instead of the material input amount, the accurate extrusion amount at the die head can be measured also in this case.

According to the third aspect, the second calculating means calculates the minute time extruded amount based on the autoregressive exogenous model using the change amount of each event in consideration of the characteristics of the extruder as a variable. Can be measured at any time.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an extrusion amount measuring device according to the present invention.

FIG. 2 is a flowchart for explaining the operation of the extrusion amount measuring device shown in FIG.

FIG. 3 is a diagram showing a change with time of an actual extrusion amount.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Extruder 11 Hopper 12 Cylinder 13 Screw 14 Screw motor 15 Die head part 20 Weighing sensor 21, 22 Heat sensor 23, 25 Pressure sensor 24 Rotation sensor 26-28 Calculation part

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-61-141526 (JP, A) JP-A-64-90721 (JP, A) JP-A-2-137911 (JP, A) JP-A-3-107 261539 (JP, A) JP-A-5-96608 (JP, A) JP-A-5-131521 (JP, A) JP-A-5-192989 (JP, A) JP-A-5-329911 (JP, A) JP-A-5-329916 (JP, A) JP-A-7-285164 (JP, A) JP-A-3-26151539 (JP, A) JP-A-5-329916 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B29C 47/00-47/96

Claims (3)

(57) [Claims] 1. An extruder for melting a polymer material charged into a hopper and extruding the polymer material into a die head through a cylinder, wherein a charging amount detecting means for detecting a charging amount of the polymer material charged into the hopper; First temperature detecting means for detecting the temperature of the material, second temperature detecting means for detecting the temperature of the cylinder, rotational speed detecting means for detecting the rotational speed of a screw provided in the cylinder, First pressure detecting means for detecting the pressure of the polymer material in the cylinder, second pressure detecting means for detecting the pressure of the polymer material in the die head, and average extrusion based on the detected input amount A first calculating means for calculating the amount, and a minute time extrusion based on the detected material temperature, cylinder temperature, screw rotation speed, and the amount of change in the polymer material pressure in the cylinder and the die head. And a third calculating means for calculating an actual extruding amount of the extruder based on the calculated average extruding amount and minute time extruding amount. Machine for measuring the extrusion amount of the machine. 2. An extruder for melting a polymer material charged into a hopper and extruding the polymer material into a die head via a cylinder, wherein first temperature detecting means for detecting the temperature of the material, and detecting the temperature of the cylinder A second temperature detection unit, a rotation speed detection unit for detecting a rotation speed of a screw provided in the cylinder, a first pressure detection unit for detecting a pressure of a polymer material in the cylinder, and the die head Second pressure detecting means for detecting the pressure of the polymer material in the first, first calculating means for calculating an average extrusion amount based on the detected screw rotation speed, and the detected material temperature and cylinder temperature A second calculating means for calculating a minute time extrusion amount based on the amount of change in the polymer material pressure in the cylinder and the die head in the screw rotation speed, and the calculated average extrusion amount and the minute amount. Extrusion rate measuring apparatus of an extruder, characterized in that a third calculation means for calculating the actual extrusion rate of the extruder based on the time the extrusion rate. 3. The method according to claim 2, wherein the second calculating means calculates a minute time extrusion amount based on an autoregressive exogenous model, using a change amount of each event in consideration of characteristics of the extruder as a variable. Item 3. An apparatus for measuring an extrusion amount of an extruder according to Item 1 or 2.