JP3703138B2 - Method for controlling molten resin temperature of screw type extruder and screw type extruder - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a molten resin temperature control method for a screw-type extrusion molding machine and a screw-type extrusion molding machine, and more particularly to a novel improvement for improving the product quality by controlling the temperature of a screw using a temperature measuring element for a screw. .
[0002]
[Prior art]
Conventionally, the structure shown in FIGS. 4 to 8 has been used as a screw-type extruder for synthetic resin materials.
That is, in FIG. 4, what is indicated by reference numeral 100 is a screw type extrusion molding machine, and this screw type extrusion molding machine 100 is capable of rotating the drive motor 12, the speed reducer 13 and the screw 14 from one end side of the gantry 11. The cylinders 15 that are provided are configured to be sequentially connected and arranged. Although one screw 14 is shown in FIG. 4, there are cases where two screws 14 are arranged in parallel. A control device 20 is provided adjacent to the gantry 11, and a temperature controller 23 connected to a cylinder temperature sensor 21 and an electromagnetic valve 22 described later is incorporated.
[0003]
The cylinder 15 includes a connecting cylinder 23, a raw material supply cylinder 25 having a raw material inlet 24, a plurality of temperature adjusting cylinders 26, and a front end cylinder 27 connected from the reduction gear 13 side, with through-holes arranged in a straight line. Yes. The connecting cylinder 23 is formed with a through-hole (not shown) for piping connected to a rotary joint 50 described later through the wall portion. In the raw material supply cylinder 25 and the temperature adjustment cylinder 26, a water-cooling cylinder jacket 31 is formed inside the wall. The water cooling jacket 31 is connected to the cooling water unit 16 by a supply pipe 32 and a return pipe 33. A solenoid valve 22 is provided in each branch pipe of the supply pipe 32 to each temperature adjustment cylinder 26. The temperature adjustment cylinder 26 is provided with a cylinder heater 40 on the outer periphery. The electromagnetic valve 22 and the cylinder heater 40 are connected to the control device 20. The temperature adjusting cylinder 26 and the tip cylinder 27 are provided with a cylinder temperature sensor 21 for measuring the temperature in the vicinity of the inner wall surface. Further, the tip cylinder 27 is provided with a resin temperature measuring body 28 that penetrates the wall portion and protrudes into the inner hole.
[0004]
In FIG. 5, the screw 14 is constituted by a screw shaft 41, a plurality of types and a plurality of types of screw segments 42, and a tightening nut 42a. The screw shaft 41 is inserted into the cylinder 15 and has a cross section perpendicular to the axis substantially a regular polygon.
[0005]
In FIG. 6, a screw hole 41a is formed in the screw shaft 41 of the screw 14 from the rear end on the reduction gear 13 side to the front end. Further, the screw shaft 41 is formed with a water supply hole 44 penetrating from the cooling water hole 41a to the outer periphery and a drainage hole 45 adjacent to the two axial directions. A discharge hole 43 is coaxially disposed on the outer periphery of the cooling water hole 41 a, and the discharge hole 43 communicates with the drain hole 45.
[0006]
The outer periphery of the screw shaft 14 where the water supply hole 44 and the drainage hole 45 are located is relatively rotatable in a watertight state, that is, for supplying cooling water to the screw 14 that is rotationally driven during operation. A rotary joint 50 is connected. The rotary joint 50 supplies and drains the cooling water while the screw 14 is rotating.
[0007]
The screw extruder 100 configured as described above operates as follows. First, the cylinder heater 40 of the cylinder 15 is energized to raise the temperature. Cooling water is supplied from the cooling water unit 16 to each cylinder jacket 31, and the cylinder heater 40 and the electromagnetic valve 22 are adjusted by the control device 20 as necessary. The temperature measured by the resin temperature measuring element 60 is adjusted to each temperature adjusting cylinder. It controls to become each predetermined temperature of 26. Next, the drive motor 12 is started, the screw 14 is driven to rotate through the speed reducer 13, and the synthetic resin material is supplied from the hopper 24 to the inner hole of the material supply cylinder 25. The synthetic resin raw material is sequentially transported in the distal direction by the transport action of the rotating screw 14. During this transportation, the synthetic resin material is kneaded and melted by the kneading action of the rotating screw 14 and the heating of the temperature adjusting cylinder 26 which has been heated. The molten synthetic resin material that has reached the tip of the cylinder 15 after the completion of the predetermined kneading is extruded from the tip cylinder 27 through the die 27a. The unmelted synthetic resin raw material supplied from the raw material inlet 24 is blocked by the ground seal 23a so as not to leak out toward the speed reducer 13.
[0008]
Further, at the time after the drive motor 12 is activated, the cooling water is continuously supplied from the water supply pipe 44 a via the rotary joint 50. This cooling water is supplied from the rotary joint 50 to the cooling water hole 41a through the water supply hole 44 of the screw shaft 41, and then flows backward through the discharge hole 43 on the outer periphery of the cooling water hole 41a. It is discharged to the outside through the joint 50. That is, the cooling water cools the screw shaft 41 from the inner peripheral surface while backflowing the inner peripheral surface of the cooling water hole 41a and the discharge hole 43, and thus cools the screw 14 from the inside.
[0009]
Inside the cylinder 15, the synthetic resin raw material generates heat when it is melted by being sheared by the screw 14 that is driven to rotate, and there is a possibility that the temperature rises above a predetermined controlled temperature of the temperature adjusting cylinder 26. is there. In response to such an abnormal temperature rise of the synthetic resin raw material, the temperature from the inside of the screw 14 and the temperature in the vicinity of the inner wall surface of the temperature adjusting cylinder 26 by the cylinder temperature sensor 21 and the kneading by the resin temperature sensor 28 are mixed. By controlling the cylinder heater 40 and the electromagnetic valve 22 based on the measurement result of the melted synthetic resin raw material temperature, the temperature during and after the kneading of the cylinder 15 is controlled to be a predetermined temperature.
[0010]
[Problems to be solved by the invention]
Since the conventional screw type extruder and its temperature control method are configured as described above, the following problems exist.
That is, it cannot be said that the synthetic resin raw material is always filled and transported in the cylinder, and the temperature detection accuracy of the synthetic resin raw material is low in the resin temperature sensor provided near the inner wall surface in the cylinder wall. Therefore, it is difficult to control the melting temperature of the synthetic resin raw material with high accuracy. For example, when kneading a low melting point synthetic resin raw material such as an EVA resin raw material or a coating raw material, temperature control in the low temperature region is very difficult. is there. As a result, stable operation could not be continued and it was difficult to ensure uniform product quality. Although the cooling water is constantly passed through the screw shaft to suppress the temperature rise due to the shear heat generation of the synthetic resin raw material, the temperature of the screw shaft itself is not measured and controlled.
[0011]
The present invention has been made to solve the above-described problems, and in particular, the temperature of the screw is detected by a screw temperature sensor provided on the screw to control the temperature of the screw. An object of the present invention is to provide a method for controlling the temperature of a molten resin in a screw-type extruder and a screw-type extruder that can improve product quality by temperature control.
[0012]
[Means for Solving the Problems]
The method of controlling the molten resin temperature of a screw type extruder according to the present invention includes a long cylindrical cylinder (15) having a temperature measuring element (21) for a cylinder, and an internal portion of the cylinder (15) that is rotatably driven. Synthetic resin raw material by means of a screw (14) that has a plurality of cooling water holes (41a, 41aA, 41aB) formed coaxially on the shaft and that allows the cooling water to be passed and discharged through the rotary joint (50). using melt-kneading screw type extruder (100), distribution in different lengths located along the axial direction of Oite the screw (14) in the vicinity of the surface of the screw shaft (41) of the screw (14) Detected temperature signals detected by a plurality of screw temperature detectors (200 to 200b) provided are opposed to each other via a wireless transmission means from a transmission head portion (202) provided at an end portion of the screw shaft (41). in particular to the input temperature controller (23) of the output head controller from (203) (20) Converting mechanism for controlling the passing water amount of the cooling water in said screw (14), and passed through the cooling water to the inside wall of the cylinder (15) to cool the cylinder (15), said cylinder (15) Heated by a cylinder heater (40) provided on the outer periphery, and measured the temperature of the inner wall of the cylinder (15) or the vicinity thereof by the cylinder temperature sensor (21) , and based on the temperature, the temperature controller (23 ) by controlling the temperature of the cylinder (15), a method for controlling the temperature of said synthetic resin material, also screw-type extruder according to the present invention, the detected temperature from the measuring cylinder Yutakatai (21) controller using a temperature controller (20) of the elongated tubular shape to control the temperature by (23) the cylinder (15) and the cylinder rotates drivably inserted rotary joint therein in (15) (50) the screw (14) which is to be passed through and discharge the cooling water through the In a screw-type extruder for melting and kneading synthetic resin raw materials, a cylinder jacket (31) and a cylinder heater (40) provided in the cylinder (15) and an inner wall of the cylinder (15) or protruding from the inner wall A resin temperature sensor (28) and a plurality of cooling water holes formed coaxially in the screw (14) for passing and draining the cooling water through the rotary joint (50) (41a, 41aA, 41aB) and a plurality of screw temperature sensors (200 to 200b) disposed at different lengths along the axial direction in the vicinity of the surface of the screw shaft (41) of the screw (14). ), A transmission head part (202) provided at an end of the screw shaft (41) and connected to each of the temperature measuring elements (200 to 200b ) for each screw, and facing the transmission head part (202) Each detected temperature signal from each of the temperature measuring elements (200 to 200b) provided is sent to the transmission head unit (202 ) And an output head for receiving via the wireless transmission means (203) from measurement for the cylinder Yutakatai (21), measuring resin Yutakatai (28) and the measuring screw for Yutakatai (200 ~ 200b) The detected temperature signal is input to the temperature controller (23) via the output head part (203), and the temperature of the synthetic resin raw material is controlled .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of a method for controlling a molten resin temperature of a screw extruder according to the present invention and a screw extruder according to the present invention will be described with reference to the drawings. In addition, about the same or equivalent part as a prior art example, the description is abbreviate | omitted using the same code | symbol, and only a different part is demonstrated.
In addition, a different part is a structure which has the temperature measuring body for screws which detects the temperature of the supply shaft structure of the cooling water in the screw 14, and the screw 14. FIG.
[0014]
In FIG. 1, the screw shaft 41 of the screw 14 is formed with a non-penetrating cooling water hole 41a in the shaft core portion from the rear end to the front end of the drive motor 12 side. Unlike the conventional case, the cooling water holes 41 a are formed with double and triple cooling water holes 41 a A and 41 a B coaxially and communicate with the discharge holes 43. These cooling water holes 41a to 41aB are communicated with the plurality of water supply holes 44 from the rotary joint 50 and the respective electromagnetic valves 44B, and are individually opened and closed by the control device 20 to open the respective cooling water holes 41a. , 41aA, 41aB can be selectively controlled.
The cooling water discharged from each of the cooling water holes 41a, 41aA, 41aB is collected or discharged from the common discharge hole 43 through the drain hole 45 through the rotary joint 50.
[0015]
The screw shaft 41 of the screw 14 is provided with a plurality of screw temperature measuring bodies 200, 200a, 200b (the number is arbitrary) near the surface thereof, and each of the screw temperature measuring bodies 200, 200a, 200b is respectively It is arrange | positioned at different length positions along an axial direction, and it is comprised so that the temperature detection of a different length position can be performed.
[0016]
Each of the temperature measuring elements 200, 200a, 200b for the screw is connected to a transmission head portion 202 provided at the end of the screw shaft 41 via the wiring 201, and each of the temperature measuring elements 200, 200a, 200b for the screw is connected. The detected temperature signal is transmitted from the transmission head unit 202 to the output head unit 203 arranged oppositely via known electromagnetic means or non-contact wireless transmission means such as infrared rays.
[0017]
The detected temperature signals output from the output head unit 203 are input to the temperature controller 23 of the control device 20, and the detected temperature signals are input to the temperature controller 23 in real time while the screw 14 is rotating. can do.
[0018]
Next, the operation will be described. First, cooling water is supplied through the rotary joint 50 at a time after the drive motor 12 is activated. This cooling water is sent to each cooling water hole 41a, 41aA, 41aB according to opening / closing of each electromagnetic valve 44B, and is collected or discharged from the rotary joint 50 to the outside through the drain hole 45 from the discharge hole 43.
[0019]
That is, the cooling water cools the screw 14 heated from the inside by the shear heat generation of the synthetic resin raw material while flowing from the cooling water holes 41a, 41aA, 41aB to the discharge hole 43.
[0020]
During this time, the temperature measuring elements 200, 200a, 200b provided at three locations measure the temperature of each position of the screw 14, and each detected temperature signal is transmitted from the transmission head unit 202 through the output head unit 203 to the temperature controller. 23, the opening and closing of each solenoid valve 44B is controlled, and the screw 14 is controlled to a desired set temperature. That is, by controlling the temperature of the screw 14 from the inside of the screw 14, the temperature of the synthetic resin material that is transported and kneaded while being in contact with the screw 14 is controlled. Therefore, the screw-type extrusion molding machine 100 uses the temperature controller 23 of the controller 20 to control the solenoid valve based on the measurement data of the cylinder temperature sensor 21, the resin temperature sensor 28, and the screw temperature sensors 200 to 200b. 44B and the cylinder heater 40 are controlled to maintain the desired temperature during and after the kneading of the synthetic resin material to be kneaded and melted.
[0021]
【The invention's effect】
Since the method for controlling the molten resin temperature of the screw extruder and the screw extruder according to the present invention are configured as described above, the following effects can be obtained.
(1) A screw in a screw type kneading extruder is provided with screw temperature measuring elements at a plurality of positions in the axial direction in the screw shaft, and the temperature in the vicinity of the screw surface is measured. Even when the inside of the cylinder is transported and kneaded and melted in an unfilled state, the temperature of the synthetic resin material that is transported and kneaded while being in contact with the screw can be measured with high accuracy.
(2) A plurality of cooling water holes are formed in the screw shaft of the screw in the screw type extrusion molding machine, the temperature can be finely adjusted, and the temperature control of the synthetic resin raw material can be performed with high accuracy.
(3) Accordingly, it is possible to easily ensure uniform product quality without stopping the screw and lowering the rotational speed of the screw due to an increase in the molten resin temperature.
[Brief description of the drawings]
FIG. 1 is a cross-sectional configuration diagram showing a main part of a screw-type extruder according to the present invention.
2 is a cross-sectional view showing the main part of FIG.
3 is a cross-sectional view of the entire length of the screw of FIG.
FIG. 4 is a cross-sectional configuration diagram showing a conventional screw type extrusion molding machine.
FIG. 5 is a cross-sectional view showing the screw of FIG.
6 is a cross-sectional configuration diagram illustrating a main part of FIG. 4;
7 is a cross-sectional view of the main part of FIG.
FIG. 8 is a detailed configuration diagram showing the rotary joint of FIG. 6;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 14 Screw 15 Cylinder 20 Control apparatus 21 Cylinder temperature measuring element 23 Temperature controller 28 Resin temperature measuring element 31 Cylinder jacket 40 Cylinder heating heater 41 Screw shaft 41a, 41aA, 41aB Cooling water hole 44 Water supply hole 44B Solenoid valve 45 Drain hole DESCRIPTION OF SYMBOLS 50 Rotary joint 100 Screw type extrusion molding machine 200-200b Temperature measuring body for screws 202 Transmission head part 203 Output head part

Claims (2)

A long cylindrical cylinder (15) having a temperature measuring element (21) for cylinder and a plurality of cooling water holes (41a, 41aA ) inserted into the cylinder (15) so as to be rotationally driven and coaxially formed therein. , 41aB) , and using a screw type extrusion molding machine (100) that melts and kneads the synthetic resin raw material with a screw (14) that allows cooling water to pass through and discharge through the rotary joint (50). screw (14) of the screw shaft (41) measuring a plurality of screw Oite the near the surface along the axial direction of the screw (14) disposed in different lengths positions from each other of Yutakatai by (200～200B) The detected temperature signal is adjusted from the transmission head unit (202) provided at the end of the screw shaft (41 ) to the control device (20) from the opposed output head unit (203) via the wireless transmission means. controls the passing water amount of the cooling water in said screw (14) by entering into a vessel (23), Wherein by cooling water to pass therethrough the wall of serial cylinders (15) cylinder (15) is cooled, the said cylinder with heating by the cylinder heater provided on the outer periphery of the cylinder (15) (40) (15) the temperature of the inner wall or near the measured by the cylinder temperature detector (21), wherein controlling the temperature of the cylinder (15) by the temperature controller (23) based on said temperature, the temperature of the synthetic resin raw material A method for controlling the temperature of a molten resin in a screw-type extrusion molding machine, characterized in that: A long cylindrical cylinder (15) that adjusts the temperature with the temperature controller (23) of the control device (20) using the temperature detected from the temperature measuring element (21) for the cylinder, and rotates in this cylinder (15) In the screw type extrusion molding machine that melts and kneads the synthetic resin raw material by a screw (14) that is inserted so as to be drivable and that allows cooling water to be passed and discharged through the rotary joint (50) , the cylinder (15) cylinder jacket provided in (31) and the cylinder and heater (40), said cylinder inner wall or Yutakatai measuring resin which protrudes from the inner wall (15) and (28), said screw (14) A plurality of cooling water holes (41a, 41aA, 41aB) that are formed coaxially with each other and allow the cooling water to flow and drain through the rotary joint (50) , and a screw shaft (41 ) of the screw (14). ) Are arranged at different lengths along the axial direction in the vicinity of the surface. And measuring a number of screw Yutakatai (200 ~ 200b), the screw shaft transmission head portion provided at an end portion connected to said Yutakatai measuring for each screw (200 ~ 200b) of (41) and (202), output for receiving via the wireless transmission means each detected temperature signal from the provided opposite to the transmission head portion (202) measuring for each screw Yutakatai (200 ~ 200b) from the transmission head (202) A head portion (203) ,
The cylinder temperature detector (21), measuring resin Yutakatai (28) and the measuring screw for Yutakatai (200 ~ 200b) detected temperature signal is the output head portion (203) said temperature controller through from ( 23. A screw type extrusion molding machine that is inputted to 23) and is configured to control the temperature of the synthetic resin raw material .

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