Control device, extruder, control method, and computer program

Abstract

A control device 10 is provided with a control unit 11 and controls an extruder 1 provided with a cylinder 2, a first supply unit 8A for supplying recovered resin to the cylinder, a second supply unit 8B for supplying additive resin to the cylinder, a screw 3 rotatably disposed in the cylinder, and a drive unit 4 for rotationally driving the screw, the extruder 1 being configured to extrude recycled resin obtained by kneading the recovered resin and additive resin. On the basis of a detection value related to properties and condition of the recycled resin and detected from the extruder, the control unit adjusts the amount of the supplied additive resin by controlling the second supply unit.

Description

Control device, extruder, control method, and computer program

[0001] The present invention relates to a control device, an extruder, a control method, and a computer program for kneading resins.

[0002] Patent Document 1 describes a kneader that kneads recovered resin and additive resin to produce recycled resin. This kneader comprises a screw that is rotationally driven within a cylindrical cylinder, a supply unit that supplies recovered resin and two or more types of additive resin into the cylinder, a viscometer that measures the viscosity of the kneaded recycled resin in-line, and a control unit that controls the operation of the kneader. In this kneader, the control unit is configured to change the supply amount of each of the two or more types of additive resin based on the measured viscosity value of the kneaded recycled resin, so as to adjust the viscosity of the recycled resin to a target value.

[0003] International Publication No. 2024 / 048031

[0004] According to the technology described in Patent Document 1, the viscosity of the recycled resin is measured on the downstream side of the screw. Therefore, according to the technology described in Patent Document 1, a time lag occurs between the timing of supplying the additive resin and the timing of measuring the viscosity, and there is a possibility that time is required before the viscosity is adjusted to the target value. Further, according to the technology described in Patent Document 1, there is a possibility that the viscosity of the recycled resin that fluctuated during the time lag cannot be equalized.

[0005] An object of the present invention is to provide a control device, an extruder, a control method, and a computer program capable of speeding up the responsiveness of control for adding an additive resin to a recovered resin.

[0006] One aspect of the present disclosure is as follows: (1) A control device for controlling an extruder that extrudes a recycled resin obtained by kneading the recycled resin and the additive resin, the control device comprising a control unit, a cylinder, a first supply unit for supplying recovered resin to the cylinder, a second supply unit for supplying additive resin to the cylinder, a screw rotatably disposed in the cylinder, and a drive unit for rotationally driving the screw, wherein the control unit controls the second supply unit to adjust the amount of additive resin supplied based on a detection value relating to the properties of the recycled resin detected from the extruder. (2) The control device according to item (1), wherein the detection value relating to the properties of the recycled resin is a detection value detected from the drive unit. (3) The control device according to item (2), wherein the detection value relating to the properties of the recycled resin is at least one of a first detection value indicating the amount of power consumed, a second detection value indicating the current value, and a third detection value related to the load, all detected from the drive unit. (4) The control unit controls the second supply unit to adjust the amount of additive resin supplied so that the viscosity of the recycled resin becomes a predetermined value, as described in any of items (1) to (3). (5) The control unit controls the second supply unit to adjust the amount of additive resin supplied based on the detected value and a viscosity measurement value detected from an in-line viscometer located downstream of the extruder, as described in any of items (1) to (4). (6) The control unit controls the second supply unit to adjust the amount of additive resin supplied per unit time, as described in any of items (1) to (5). (7) The control unit controls the second supply unit to adjust the amount of additive resin supplied based on the detected value and the viscosity of the recycled resin corresponding to the detected value, which is obtained based on the detected value and a predetermined relationship between the detected value and the viscosity of the recycled resin, as described in any of items (1) to (6). (8) The control device according to item (5), wherein the control unit updates the relationship to reduce the error between the detected value, the viscosity of the recycled resin corresponding to the detected value obtained based on a predetermined relationship between the detected value and the viscosity of the recycled resin, and the viscosity measurement value.(9) The control device according to item (5) or (8), wherein the control unit adjusts control parameters for controlling the supply amount of the second supply unit to reduce the error between the detected value, the viscosity of the recycled resin corresponding to the detected value obtained based on a predetermined relationship between the detected value and the viscosity of the recycled resin, and the viscosity measurement value. (10) An extruder for extruding a recycled resin in which the recovered resin and the additive resin are kneaded, comprising: a control unit; a cylinder; a first supply unit for supplying recovered resin to the cylinder; a second supply unit for supplying additive resin to the cylinder; a screw rotatably disposed in the cylinder; and a drive unit for rotationally driving the screw, wherein the control unit controls the second supply unit to adjust the supply amount of the additive resin and adjust the viscosity of the recycled resin based on a detected value relating to the properties of the recycled resin. (11) The extruder according to item (10), comprising a die having a resin channel disposed downstream of the cylinder, wherein the die is configured to extrude the recycled resin in a strand shape from the outlet of the resin channel. (12) A control method for controlling an extruder that extrudes recycled resin, which is a mixture of the recycled resin and the additive resin, comprising a cylinder, a first supply unit for supplying recovered resin to the cylinder, a second supply unit for supplying additive resin to the cylinder, a screw rotatably disposed in the cylinder, and a drive unit for rotationally driving the screw, wherein a computer controls the second supply unit to adjust the amount of additive resin supplied based on detected values ​​relating to the properties of the recycled resin. (13) A computer program installed in a computer that controls an extruder which extrudes a recycled resin obtained by kneading the recycled resin and the additive resin, the extruder comprising a cylinder, a first supply unit for supplying recovered resin to the cylinder, a second supply unit for supplying additive resin to the cylinder, a screw rotatably disposed in the cylinder, and a drive unit for rotationally driving the screw, wherein the computer controls the second supply unit to adjust the amount of additive resin supplied based on detected values ​​relating to the properties of the recycled resin.

[0007] According to the present invention, the responsiveness of the control for adding additive resin to the recovered resin can be accelerated.

[0008] Figure 1 is a cross-sectional view showing the configuration of an extruder. Figure 2 is a block diagram showing the configuration of the extruder. Figure 3 is a block diagram showing the hardware configuration of the control device. Figure 4 is a diagram showing the relationship between viscosity and the power consumption of the drive unit. Figure 5 is a flowchart showing the processing flow of the control method executed in the control device. Figure 6 is a flowchart showing the processing flow of another control method executed in the control device.

[0009] Hereinafter, embodiments for carrying out this invention will be described illustratively with reference to the drawings. However, unless otherwise specifically stated, the dimensions, materials, shapes, relative arrangements, and other details of each component described in the following embodiments, as well as the various control procedures, control parameters, and target values, are not intended to limit the scope of this invention to those specific examples.

[0010] As shown in Figure 1, the extruder 1 is configured to knead resin and produce recycled resin. Some or all of the functions of the extruder 1 are controlled by a control device 10. The extruder 1 is equipped with a cylindrical cylinder 2. Inside the cylinder 2, a cylindrical (more specifically, columnar) internal space 2A is formed. The cylinder 2 is heated by a heater (not shown) to melt the resin being fed into it. Note that the shape of the internal space 2A of the cylinder 2 is not limited to a cylindrical shape and can be changed according to the shape or number of screws 3, etc.

[0011] The cylinder 2 has a first opening 2B that communicates with the outside on the upstream side (-x direction side) of the internal space 2A. The first opening 2B is formed above the cylinder 2 (+z direction). Upstream of the cylinder 2, a hopper 8 is provided to supply resin to the internal space 2A through the first opening 2B. The top of the hopper 8 is open to allow resin material to be fed in. The bottom of the hopper 8 is open to communicate with the first opening 2B. The hopper 8 is formed to guide the fed pelletized or crushed resin material into the inside of the cylinder 2.

[0012] Above the hopper 8 is a first supply unit 8A that supplies the recovered resin to the cylinder 2. The recovered resin is resin recovered from waste materials, and is, for example, resin fragments containing a mixture of thermoplastic resins such as polyethylene and polypropylene, which have been recovered from waste and separated after crushing by magnetic separation or specific gravity separation. The types and ratios of resin fragments contained in the recovered resin are unknown. Therefore, the viscosity of the recovered resin after it has been melted and kneaded is unknown. As described later, additive resins are added to the recovered resin to adjust its viscosity. The recovered resin is not particularly limited as long as it is resin recovered from waste materials, and may be post-consumer recycled material (PCR material) or post-industrial recycled material (PIR material; also called pre-consumer recycled material). Furthermore, in the following description, the resin obtained by processing the recovered resin for reuse will be referred to as "recycled resin".

[0013] The first supply unit 8A has a storage unit 8A1 for temporarily storing the recovered resin before supplying it. The storage unit 8A1 has a stirrer 8A2 for distributing the recovered resin. The stirrer 8A2 is configured to stir the recovered resin when it falls from the storage unit 8A1. The stirrer 8A2 is composed of dry blenders such as a tumble mixer, V-blender, ribbon blender, double-roll mixer, shaker, and buffer tank with internal rotor blades. The stirrer 8A2 is configured to drop the fragments of the stirred recovered resin downwards from below.

[0014] A second supply unit 8B is located above the hopper 8 to supply additive resin to the cylinder 2. The additive resin includes a low-viscosity resin (first additive resin) to reduce the viscosity of the recovered resin and a high-viscosity resin (second additive resin) to increase the viscosity of the recovered resin. Both the first and second additive resins have known melt flow rates (MFRs) that indicate viscosity or fluidity, and their viscosities or MFRs are different from each other.

[0015] The first and second additive resins are resins that are added to and mixed with the recovered resin to adjust the viscosity of the recovered resin to a predetermined range (target value). The first and second additive resins may be the same type of resin as the resin contained in the recovered resin (in this embodiment, polyethylene or polypropylene). The first and second additive resins may be other resins as long as they can adjust the viscosity or MFR of the recovered resin.

[0016] The second supply unit 8B includes a first additive resin supply unit 8C for supplying the first additive resin and a second additive resin supply unit 8D for supplying the second additive resin. The first additive resin supply unit 8C includes a storage unit 8C1 for storing pelletized first additive resin and a stirrer 8C2 for stirring the first additive resin. The second additive resin supply unit 8D includes a storage unit 8D1 for storing pelletized second additive resin and a stirrer 8D2 for stirring the second additive resin.

[0017] Hopper 8 is shared by the first supply unit 8A and the second supply unit 8B, and simultaneously supplies the recovered resin, the first additive resin, and the second additive resin into the cylinder 2. There may be two or more hoppers 8 for the first supply unit 8A and the second supply unit 8B. Additives such as stabilizers, antioxidants, and nucleating agents, reinforcing fiber materials such as glass fibers, carbon fibers, and organic fibers, rubber and / or talc, and fillers such as calcium carbonate may be supplied to hopper 8. Since the change in viscosity due to the addition of a certain amount of these fillers, etc. is within the range that can be predicted by known theoretical or empirical formulas, the supply of these additives, etc. does not make the viscosity of the resulting recycled resin unpredictable. The first supply unit 8A and the second supply unit 8B are controlled by the control device 10 as described later.

[0018] Cylinder 2 has a lid portion 2D that closes the upstream side of the internal space 2A. On the downstream (+x direction) side of cylinder 2, there is a resin outlet 2C formed with a conical surface such that its diameter decreases towards the downstream side of the internal space 2A. The downstream side of the resin outlet 2C is open. Downstream of the resin outlet 2C is a filtration section 6 that removes foreign matter contained in the kneaded recycled resin. The filtration section 6 filters the kneaded resin composition.

[0019] The filtration section 6 is composed of a filter that removes foreign matter such as soil and / or sand contained in the recovered resin. The filtration section 6 suppresses the incorporation of foreign matter into the recycled resin. Any filter can be used in the filtration section 6 as long as it can filter the resin and remove foreign matter. Downstream of the filtration section 6 is an extrusion section 5 that extrudes the kneaded recycled resin.

[0020] An internal space 5A is formed inside the extrusion section 5. A gear pump 5B capable of extruding recycled resin downstream is located in the internal space 5A. By using the gear pump 5B, the amount of resin discharged in the extrusion section 5 can be accurately measured, improving the accuracy of calculating the viscosity of the recycled resin. A die 7 is provided downstream of the extrusion section 5 to extrude the recycled resin into the external space. A resin channel 7A is formed in the die 7 through which the extruded recycled resin flows.

[0021] The resin channel 7A is a channel through which the recycled resin extruded from the extrusion section 5 flows in a molten state. The resin channel 7A may be provided with a heater (not shown) for heating the recycled resin to keep it flowing. The resin channel 7A is provided with a viscometer K1 for detecting the viscosity of the recycled resin. The viscometer K1 is, for example, an in-line viscometer that takes at least a portion of the recycled resin kneaded by the extruder 1 and measures its viscosity. The viscometer K1 may be composed of other sensors that can detect the viscosity of the recycled resin obtained by melt-kneading by the extruder 1. The resin channel 7A has multiple holes at its outlet and is configured to extrude the recycled resin in multiple strands.

[0022] A cylindrical screw 3 is inserted into the internal space 2A of the cylinder 2. Two or more screws 3 may be arranged in parallel. The screw 3 is rotatably positioned within the cylinder. Fins 3A extending spirally in the direction of the axis 3S are formed on the outer wall of the screw 3. The screw 3 has a shaft 3D aligned with the direction of the axis 3S. The shaft 3D is rotatably supported by the lid portion 2D. The shaft 3D is connected to a drive unit 4 that generates rotational driving force.

[0023] The drive unit 4 rotates the screw 3 via the shaft 3D. The drive unit 4 includes, for example, a motor (not shown) that serves as a drive source, and a reduction gear (not shown) that reduces the rotational output of the motor and increases the torque to output rotational driving force. The drive unit 4 operates according to a set output. The drive unit 4 may be controlled by a control device 10. The control device 10 may be configured to control the extruder 1 to rotate the screw 3 and extrude the recycled resin, which is a mixture of recovered resin and added resin. The drive unit 4 may be controlled by a control device other than the control device 10.

[0024] With the above configuration, the extruder 1 is supplied with recovered resin from the first supply unit 8A and with additive resin from the second supply unit 8B. The recovered resin and additive resin are supplied into the cylinder 2 via the hopper 8. The recovered resin and additive resin melt inside the heated cylinder 2. The molten recovered resin and additive resin fill the space between the screw 3 and the inner wall of the cylinder 2. When the screw 3 is rotated by the drive unit 4, the recovered resin and additive resin are guided by the fins 3A and pumped downstream, and kneaded.

[0025] The kneaded resin is extruded downstream from the resin outlet 2C and passes through the filtration section 6. After passing through the filtration section 6, the kneaded resin has foreign matter removed and flows into the downstream extrusion section 5. The kneaded resin is pushed into the downstream resin flow path 7A by the gear pump 5B of the extrusion section 5. The kneaded resin flows through the resin flow path 7A and is extruded from the downstream outlet as multiple strands of recycled resin.

[0026] As shown in Figure 2, the control device 10 includes a control unit 11 that controls the extruder 1 and a storage unit 12 that stores data and computer programs necessary for control.

[0027] Figure 3 is a block diagram showing the hardware configuration of the control device 10. As shown in Figure 3, the control device 10 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, storage 104, an input unit 105, a display unit 106, and a communication interface (I / F) 107. Each component is connected to the others via a bus 108 so as to be able to communicate with each other.

[0028] The CPU 101 is a central processing unit that executes various programs and controls various parts. Specifically, the CPU 101 reads a program from the ROM 102 or storage 104 and executes the program using the RAM 103 as a working area. The CPU 101 controls each of the above components and performs various calculations according to the program recorded in the ROM 102 or storage 104. In this embodiment, the control program for the extruder 1 is stored in the ROM 102 or storage 104.

[0029] ROM 102 stores various programs and data. RAM 103 temporarily stores programs or data as a working area. Storage 104 is composed of a storage device such as an HDD (Hard Disk Drive), SSD (Solid State Drive), or flash memory, and stores various programs including the operating system, and various data. Note that storage 104 is not necessarily built into the control device 10; for example, it may be a portable storage device that can be attached to or detached from the control device 10, or an external cloud server may be used as the storage device.

[0030] The input unit 105 includes a pointing device such as a mouse and a keyboard, and is used for various types of input.

[0031] The display unit 106 is, for example, a liquid crystal display and displays various information. The display unit 106 may also function as an input unit 105 by employing a touch panel system.

[0032] The communication interface 107 is an interface for communicating with other devices, and standards such as Ethernet®, FDDI, 4G, 5G, and Wi-Fi® can be used.

[0033] The control unit 11 is composed of at least one hardware processor, such as a CPU 101. The storage unit 12 is composed of a computer-readable non-temporary storage medium, such as a storage device 104.

[0034] The control unit 11 is configured to control at least the second supply unit 8B to supply the additive resin into the cylinder 2. When the control unit 11 controls the components of the extruder 1 other than the second supply unit 8B, it is configured to control the drive unit 4 to rotate the screw 3, control the first supply unit 8A and the second supply unit 8B to supply the recovered resin and the additive resin into the cylinder 2, and control the extrusion unit 5 to extrude the recycled resin in which the recovered resin and the additive resin have been kneaded.

[0035] The control unit 11 acquires detection values ​​related to the properties of the recycled resin detected by the detection unit S provided in the extruder 1. The detection unit S detects detection values ​​that correlate with the properties of the recycled resin, such as the power consumption of the drive unit 4, the current value, and the load. The detection unit S may be composed of various sensors that detect the target detection value, or it may acquire a control signal capable of calculating the detection value. The detection unit S may detect any detection value as long as it is capable of detecting a detection value that correlates with the properties of the resin (excluding viscosity).

[0036] As shown in Figure 4, for example, there is a correlation between the viscosity of the recycled resin and the power consumption of the drive unit 4, where power consumption increases with increasing viscosity. Based on this, for example, a calculation formula (1) is set that shows the relationship between the viscosity (η) of the recycled resin and the power consumption (E) of the drive unit 4. η = a + bE (1) where a and b are constants. The calculation formula is set in advance based on experimental results. The calculation formula may also be set in real time based on detected values. The calculation formula may be set using any detected value related to the properties of the recycled resin, such as current value, load, etc., not just the power consumption of the drive unit 4. The calculation formula is set in advance or in real time to show the relationship between detected values ​​related to the properties of the recycled resin and viscosity. Here, an example of calculation formula (1) being a linear equation is shown, but the relationship between the viscosity (η) of the recycled resin and the power consumption (E) of the drive unit 4 in calculation formula (1) may be linear or nonlinear. The calculation formula (1) may use any relational expression as long as it is possible to calculate the relationship between the viscosity (η) of the recycled resin and the power consumption (E) of the drive unit 4.

[0037] The control unit 11 estimates viscosity from a calculation formula using at least one of the following: a first detection value indicating power consumption detected from the drive unit 4, a second detection value indicating current value, and a third detection value related to the load. Based on the detection values ​​related to the properties of the recycled resin detected from the detection unit S, the control unit controls the second supply unit 8B to adjust the supply amount of additive resin and adjust the viscosity of the recycled resin. The control unit 11 controls the second supply unit 8B to adjust the supply amount of additive resin so that the viscosity of the recycled resin reaches the target value. The control unit 11 controls the second supply unit 8B to adjust the supply amount of additive resin per unit time.

[0038] For example, when the viscosity of the recycled resin is to be lowered, the control unit 11 controls the first additive resin supply unit 8C to increase the supply amount of the first additive resin and controls the second additive resin supply unit 8D to decrease the supply amount of the second additive resin. For example, when the viscosity of the recycled resin is to be increased, the control unit 11 controls the first additive resin supply unit 8C to decrease the supply amount of the first additive resin and controls the second additive resin supply unit 8D to increase the supply amount of the second additive resin.

[0039] The control unit 11 may determine whether the viscosity of the recycled resin extruded from the extruder 1 is the desired viscosity based on the viscosity measurement value detected by the viscometer K1 located downstream of the extruder 1. The control unit 11 may also further perform feedback control or feedforward control to adjust the supply amount of additive resin by controlling the second supply unit so that the viscosity of the recycled resin extruded from the extruder 1 becomes the target value, based on the viscosity measurement value. The control unit 11 may update the parameters included in the calculation formula to reduce the error between the viscosity measurement value and the viscosity calculation value calculated by the calculation formula. For example, the least squares method or robust estimation method may be used to adjust the parameters, but any calculation method that can reduce the error may be used. The control unit 11 may adjust the control parameters for controlling the supply amount of the second supply unit 8B to reduce the error between the viscosity measurement value and the viscosity calculation value calculated by the calculation formula.

[0040] For example, if the viscosity detected by the viscosity measurement is higher than the viscosity calculation value (target value) calculated by the calculation formula, the control unit 11 adjusts the control parameters of the first additive resin supply unit 8C to increase the supply amount of the first additive resin. For example, if the viscosity detected by the viscosity measurement is lower than the viscosity calculation value (target value) calculated by the calculation formula, the control unit 11 adjusts the control parameters of the second additive resin supply unit 8D to increase the supply amount of the second additive resin. Here, the target value may be not only one viscosity calculation value, but also a numerical range that includes the viscosity calculation value.

[0041] In the above description, an example was shown in which the control unit 11 estimates viscosity from a calculation formula using at least one of a first detected value indicating the amount of power consumed, a second detected value indicating the current value, and a third detected value related to the load, all of which are detected by the drive unit 4. However, the present invention is not limited to this, and the control unit 11 may estimate the viscosity of the recycled resin from the detected value based on the detected value relating to the properties of the recycled resin and a predetermined relationship between the detected value and the viscosity of the recycled resin. For example, the predetermined relationship between the detected value and the viscosity of the recycled resin may be in the form of a data table or in the form of a learning model obtained by machine learning or the like.

[0042] Furthermore, the control unit 11 may update the aforementioned relationship so as to reduce an error between the viscosity of the recycled resin estimated from the detected value and the viscosity measurement value obtained by the viscometer K1, based on a predetermined relationship between the detected value relating to the property of the recycled resin and the viscosity of the recycled resin. In one example, when a data table is used as the aforementioned relationship, the data in the data table may be updated. In another example, when a learned model obtained by machine learning is used as the aforementioned relationship, the learned model may be updated by performing machine learning using the viscosity measurement value.

[0043] The control unit 11 may aggregate parameters of the data table or the learned model from a plurality of other extruders 1 to generate a database. The control unit 11 may execute machine learning using the database to update the learned model. The database may be provided to other control devices connected to other extruders 1, or may be updated by other control devices.

[0044] FIG. 5 shows a processing flow of the control method for the extruder 1 executed by the control device 10. The control method for the extruder 1 is executed based on a computer program installed in a computer mounted on the control device 10. When the control device 10 controls the entire extruder 1, the computer program causes the control unit 11 (processor) to execute the following processes.

[0045] The control unit 11 controls the first supply unit 8A to supply recovered resin to the cylinder 2 (S100). The control unit 11 controls the second supply unit 8B to supply additive resin to the cylinder 2 (S102). The control unit 11 controls the drive unit 4 to rotationally drive the screw 3 rotatably disposed in the cylinder 2 (S104). Based on the detected value relating to the property of the recycled resin, the control unit 11 controls the second supply unit 8B to adjust the supply amount of the additive resin, thereby adjusting the viscosity of the recycled resin (S106). The control unit 11 controls the extrusion unit 5 to extrude the recycled resin obtained by kneading the recovered resin and the additive resin from the downstream side of the screw 3 (S108).

[0046] When the control device 10 controls the second supply unit 8B of the extruder 1, the computer program causes the control unit 11 (processor) to execute the following processing. In this case, the extruder 1 operates based on a preset operation, and the control unit 11 is configured to control the second supply unit 8B based on a detection value related to properties of the recycled resin.

[0047] As shown in FIG. 6, the control unit 11 acquires a detection value related to properties of the recycled resin from the extruder 1 in a state where the recovered resin and the additive resin are charged into the cylinder 2 and kneaded by the screw 3 (S200). Based on the detection value, the control unit 11 calculates a control value for the second supply unit 8B corresponding to a supply amount of the additive resin, outputs a control signal to the second supply unit 8B, and causes the second supply unit 8B to perform an operation based on the control value (S202). In this case, the control unit 11 may directly operate the second supply unit 8B based on the control signal, or may only output the control signal.

[0048] As described above, according to the control device 10, by estimating the viscosity of the recycled resin using a detection value such as power consumption of the drive unit 4, a time lag between the timing of supplying the additive resin and the timing of measuring the detection value can be reduced, and the responsiveness of the control for adding the additive resin to the recovered resin can be improved. According to the control device 10, feedback control or feedforward control of the second supply unit 8B can also be performed based on the detection value of the viscometer K1 provided on the downstream side of the cylinder 2. According to the control device 10, parameters such as an arithmetic expression for calculating the viscosity of the recycled resin are adjusted and / or updated based on the viscosity measurement value obtained by the viscometer K1, whereby an error between the actual viscosity of the recycled resin and an estimation result can be reduced. According to the control device 10, a control parameter of the second supply unit 8B is adjusted based on the viscosity measurement value obtained by the viscometer K1, whereby an error between the viscosity of the recycled resin and a calculation result can be reduced.

[0049] This application claims priority based on Japanese Patent Application No. 2025-054362 filed on March 27, 2025, and the contents described in the claims, specification and drawings of the Japanese patent application are incorporated herein by reference.

[0050] 1 Extruder, 2 Cylinder, 3 Screw, 4 Drive unit, 8A First supply unit, 8B Second supply unit, 10 Control device, 11 Control unit

Claims

1. A control device for controlling an extruder that extrudes a recycled resin obtained by kneading the recycled resin and the recycled resin, the extruder comprising a control unit, a cylinder, a first supply unit for supplying recovered resin to the cylinder, a second supply unit for supplying additive resin to the cylinder, a screw rotatably disposed within the cylinder, and a drive unit for rotationally driving the screw, wherein the control unit controls the second supply unit to adjust the amount of additive resin supplied based on detected values ​​relating to the properties of the recycled resin detected from the extruder.

2. The control device according to claim 1, wherein the detected value relating to the properties of the recycled resin is a detected value detected by the drive unit.

3. The control device according to claim 2, wherein the detected value relating to the properties of the recycled resin is at least one of a first detected value indicating the amount of power consumed detected from the drive unit, a second detected value indicating the current value, and a third detected value relating to the load.

4. The control device according to claim 1 or 2, wherein the control unit controls the second supply unit to adjust the amount of the additive resin supplied so that the viscosity of the recycled resin becomes a predetermined value.

5. The control device according to claim 1 or 2, wherein the control unit controls the second supply unit to adjust the amount of additive resin supplied based on the detected value and the viscosity measurement value detected from an in-line viscometer located downstream of the extruder.

6. The control device according to claim 1 or 2, wherein the control unit controls the second supply unit to adjust the amount of additive resin supplied per unit time.

7. The control device according to claim 1 or 2, wherein the control unit controls the second supply unit to adjust the amount of the additive resin supplied based on the detected value and the viscosity of the recycled resin corresponding to the detected value, which is obtained based on the detected value and a predetermined relationship between the detected value and the viscosity of the recycled resin.

8. The control device according to claim 5, wherein the control unit updates the relationship to reduce the error between the detected value, the viscosity of the recycled resin corresponding to the detected value obtained based on a predetermined relationship between the detected value and the viscosity of the recycled resin, and the viscosity measurement value.

9. The control device according to claim 5, wherein the control unit adjusts control parameters for controlling the supply amount of the second supply unit so as to reduce the error between the detected value, the viscosity of the recycled resin corresponding to the detected value obtained based on a predetermined relationship between the detected value and the viscosity of the recycled resin, and the viscosity measurement value.

10. An extruder comprising a control unit, a cylinder, a first supply unit for supplying recovered resin to the cylinder, a second supply unit for supplying additive resin to the cylinder, a screw rotatably disposed within the cylinder, and a drive unit for rotationally driving the screw, wherein the extruder extrudes a recycled resin obtained by kneading the recovered resin and the additive resin, the control unit controlling the second supply unit to adjust the amount of additive resin supplied and adjust the viscosity of the recycled resin based on detected values ​​relating to the properties of the recycled resin.

11. The extruder according to claim 10, comprising a die having a resin channel disposed downstream of the cylinder, wherein the die is configured to extrude the recycled resin in a strand-like manner from the outlet of the resin channel.

12. A control method for controlling an extruder that extrudes a recycled resin obtained by kneading the recycled resin and the additive resin, the extruder comprising a cylinder, a first supply unit for supplying recovered resin to the cylinder, a second supply unit for supplying additive resin to the cylinder, a screw rotatably disposed within the cylinder, and a drive unit for rotationally driving the screw, wherein a computer controls the second supply unit to adjust the amount of additive resin supplied based on detected values ​​relating to the properties of the recycled resin.

13. A computer program installed on a computer that controls an extruder which extrudes a recycled resin obtained by kneading the recycled resin and the additive resin, the extruder comprising a cylinder, a first supply unit for supplying recovered resin to the cylinder, a second supply unit for supplying additive resin to the cylinder, a screw rotatably disposed within the cylinder, and a drive unit for rotationally driving the screw, wherein the computer controls the second supply unit to adjust the amount of additive resin supplied based on detected values ​​relating to the properties of the recycled resin.

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