JP2010188546A - Method and apparatus for controlling processing amount of extruder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To secure the quality of pellets by variably controlling the amount of a molten resin supplied from a storage tank to an extruder. <P>SOLUTION: In a method and a constitution, a synthetic resin raw material is supplied from the storage tank (9) to the raw material supply opening (7) of a cylinder (2) through a gate valve (8), melted, and kneaded by a screw (3) rotated/driven in the cylinder (2). When the synthetic resin raw material is extruded in the shape of a cord from the tip of the cylinder (2) through a die (11), the kneading state of the synthetic resin raw material is adjusted by adjusting the number of revolutions of the screw (3), and the amount of the synthetic resin raw material supplied from the storage tank (9) into the cylinder (2) is adjusted by adjusting the opening of the gate valve (8). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an extruder throughput control method and apparatus, and more particularly to a novel improvement for variably controlling the amount of molten resin supplied from a storage tank to an extruder.

  In general, synthetic resin raw materials produced by a synthesizer are generally screw-type extrusions that have a main component of a cylinder with a rotationally driven screw inserted for the purpose of removing volatile components, improving quality, or homogenizing the raw materials. The mixture is melt kneaded by a machine (hereinafter abbreviated as “extruder”). The melted and kneaded synthetic resin raw material in a high-temperature melt state is extruded into cooling water from a large number of die holes provided at the tip of the cylinder in the form of a strand so that it can be easily handled as a raw material. Is granulated into pellets.

  When the synthetic resin raw material in a molten state is directly supplied from the synthesis apparatus to the extruder, the synthetic resin raw material is first supplied to a storage tank provided connected to the raw material supply port of the cylinder of the extruder. The A gate valve is usually provided between the storage tank and the raw material supply port. When the extruder is operated, the gate valve is fully opened, and the molten synthetic resin raw material supplied from the synthesizer is supplied from the storage tank to the extruder. Is continuously fed to.

The throughput of the extruder is substantially proportional to the number of rotations of the screw. Further, the operation of the extruder is operated so as to keep the storage amount (upper surface level) of the synthetic resin raw material in the raw material storage tank constant. During steady operation of the extruder, the supply amount of the synthetic resin raw material to be supplied may fluctuate and the level of the storage tank may fluctuate. In such a case, change the screw speed of the extruder, i.e., if the level drops, lower the screw speed to reduce the throughput, and if the level rises, increase the screw speed. By increasing the processing amount, the supply amount from the storage tank to the extruder changes, and a predetermined constant level is secured and maintained in the storage tank.
Since the above-mentioned conventional methods are generally used in the in-house technology as a common technique, no patent application has been filed, and no particular patent document is disclosed.

  Since the conventional throughput control method and apparatus for an extruder are configured as described above, the following problems exist. That is, in the case of an extruder in which a gate valve having only a valve opening or closing function is provided between the storage tank and the raw material supply port of the extruder, the steady product quality of the pellets to be granulated is In some cases, it could not be obtained.

  In other words, only changing the screw speed of the extruder corresponds to the fluctuation factors of the operating state, so changing the screw speed directly changes the throughput of the extruder. The extrusion speed of the string-like raw material extruded from the die changes. As a result, the shape, that is, the length of the pellets that are granulated by the cutter device that is operating in a steady state changes, and pellets having different shapes (product quality related to the shape) may be granulated.

  In addition, changing the rotational speed of the screw changes the kneading state or filling rate of the raw material in the cylinder, changes the action of removing volatile components, improving the quality, or homogenizing the raw material. Different pellets could be granulated.

  In the extruder throughput control method according to the present invention, a synthetic resin raw material is supplied from a storage tank to a raw material supply port of a cylinder of the extruder through a gate valve, and melt-kneaded by a screw that is rotationally driven in the cylinder. In the processing amount control method of the extruder that is extruded in a string shape from the tip of the cylinder through a die, the rotational speed of the screw is adjusted to adjust the kneading state of the synthetic resin material, and the opening of the gate valve is adjusted. It is a method of variably controlling the supply amount of the synthetic resin raw material that is adjusted and supplied from the storage tank into the cylinder, and the detection of the opening degree of the gate valve is a sliding amount of the valve element provided in the gate valve And a gate valve driving device is connected to the gate valve, and the position detection sensor and the gate valve driving device are connected to the gate valve. The gate valve driving device is a method in which a control device is connected, and a method in which a vent port is provided on the upstream side of the raw material supply port of the cylinder, and the throughput control device for an extruder according to the present invention is The synthetic resin raw material is supplied from the storage tank to the raw material supply port of the cylinder of the extruder through the gate valve, melted and kneaded by a screw that is driven to rotate in the cylinder, and formed into a string from the tip of the cylinder through a die. In the throughput control device of the extruder to be extruded, the rotational speed of the screw is adjusted to adjust the kneading state of the synthetic resin raw material, and the opening of the gate valve is adjusted and supplied from the storage tank into the cylinder The amount of the synthetic resin raw material to be supplied is variably controlled, and the opening degree of the gate valve is detected by a slice of a valve body provided in the gate valve. A configuration in which a position detection sensor for detecting the amount is used, a gate valve driving device is connected to the gate valve, and a control device is connected to the position detection sensor and the gate valve driving device. In addition, a vent port is provided on the upstream side of the raw material supply port of the cylinder.

Since the throughput control method and apparatus of the extruder according to the present invention are configured as described above, the following effects can be obtained.
That is, a synthetic resin raw material is supplied from a storage tank to a raw material supply port of a cylinder of an extruder through a gate valve, melted and kneaded by a screw that is driven to rotate in the cylinder, and is formed in a string shape from a tip of the cylinder through a die In the method of controlling the throughput of the extruder to be extruded, the kneading state of the synthetic resin raw material is adjusted by adjusting the rotational speed of the screw, and the opening of the gate valve is adjusted to enter the cylinder from the storage tank. Since the supply amount of the synthetic resin raw material to be supplied is variably controlled, it is possible to suppress fluctuations in the linear velocity of the resin at the die, and it is possible to obtain pellets of good quality.
Further, the opening degree of the gate valve is detected by a position detection sensor provided in the gate valve for detecting the sliding amount of the valve body, and the supply amount of the molten resin is controlled by the opening degree, and the screw rotation speed is detected. By changing, the resin filling rate in the cylinder can be changed.
Further, the bench port is positioned upstream of the gate valve, and the resin filling rate in the cylinder is changed and maintained, so that the molten resin can be sufficiently deaerated.

It is a block diagram of the throughput control method and apparatus of the extruder by this invention.

  It is an object of the present invention to provide an extruder throughput control method and apparatus that variably control the amount of molten resin supplied from a storage tank to an extruder.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of an extruder throughput control method and apparatus according to the present invention will be described with reference to the drawings.
In FIG. 1, what is indicated by reference numeral 1 is an extruder, and this extruder 1 is continuously arranged on the rear end side of the cylinder 2, the screw 3 inserted into the cylinder 2 and driven to rotate, and the cylinder 2. The speed reducer 4 that rotationally drives the screw 3, the variable speed motor 5, and the motor drive device 6 are configured.

  In the cylinder 2, a raw material supply port 7 is formed on the rear end side, which is the upstream side, and a storage tank 9 is connected to the raw material supply port 7 via a gate valve 8, and a die is connected to a front end opening 10 of the cylinder 2. 11 is provided. The gate valve 8 includes a gate valve driving device 12 that opens and closes a valve body (not shown), a control device 13 that adjusts the opening degree of the valve body, and a position detection sensor 14 that detects the opening degree of the valve body. .

Next, the operation will be described.
A high-temperature melted synthetic resin raw material is directly supplied to the storage tank 9 from a device (not shown). The synthetic resin raw material is supplied from the storage tank 9 through the gate valve 8 into the cylinder 2 from the raw material supply port 7.

  The screw 3 is rotationally driven by a variable speed motor 5 via a speed reducer 4. The synthetic resin raw material supplied from the raw material supply port 7 into the cylinder 2 is kneaded by the screw 3 and sequentially transferred toward the distal end. While the inside of the cylinder 2 is transferred from the raw material supply port 7 to the tip, the synthetic resin raw material is kneaded by the screw 2 to remove volatile components, improve quality, or homogenize.

  The synthetic resin raw material that has reached the tip of the cylinder 2 is fed into a plurality of strings from the tip opening 10 through the die 11 by pressure due to the transfer action of the screw 3, and is sent to a cutter device (not shown) to be pelletized. .

  In the above-described operation, the screw 3 is rotationally driven by the variable speed electric motor 5 whose electric motor driving device 6 adjusts the rotational speed. Further, the gate valve 8 is driven by the control device 13 based on the detection data of the position detection sensor 14, and the opening degree of the gate valve 8 is adjusted. Further, a vent port 15 is provided on the upstream side of the raw material supply port 7 of the cylinder 2, and degassing can be sufficiently performed by changing or maintaining the resin filling rate in the cylinder 2.

The opening degree of the gate valve 8 is detected by the position detection sensor 14 and is input to the control device 13, and the supply amount of the synthetic resin raw material to the extruder 1 changes as the opening degree of the gate valve 8 changes. The motor driving device 6 adjusts the rotational speed of the variable speed motor 5 to an appropriate value as necessary in the direction of maintaining the product quality of the pellets to be granulated.
As described above, the control device 13 and the electric motor drive device 6 and the system related to the granulating device exchange data with each other and make adjustments in conjunction with each other, thereby relating to the shape and physical properties of the pellet to be granulated. A program is set in advance so that product quality can be easily maintained in a steady state.

DESCRIPTION OF SYMBOLS 1 Extruder 2 Cylinder 3 Screw 4 Reducer 5 Variable speed motor 6 Motor drive device 7 Raw material supply port 8 Gate valve 9 Storage tank 10 Tip opening 11 Die 12 Gate valve drive device 13 Control device 14 Position detection sensor

Claims (8)

  Synthetic resin raw material is supplied from the storage tank (9) through the gate valve (8) to the raw material supply port (7) of the cylinder (2) of the extruder (1), and is rotated in the cylinder (2). In a method for controlling the throughput of an extruder that is melt-kneaded by a screw (3) and extruded from the tip of the cylinder (2) through a die (11) into a string shape, the rotational speed of the screw (3) is adjusted. In addition to adjusting the kneading state of the synthetic resin raw material, the amount of the synthetic resin raw material supplied from the storage tank (9) into the cylinder (2) is variably controlled by adjusting the opening of the gate valve (8). A method for controlling the throughput of an extruder.   The opening degree of the gate valve (8) is detected by a position detection sensor (14) provided in the gate valve (8) for detecting a sliding amount of the valve body. Extruder throughput control method.   A gate valve driving device (12) is connected to the gate valve (8), and a control device (13) is connected to the position detection sensor (14) and the gate valve driving device (12). The processing amount control method of the extruder according to claim 1 or 2.   The throughput control of the extruder according to any one of claims 1 to 3, wherein a vent port (15) is provided upstream of the raw material supply port (7) in the cylinder (2). Method.   Synthetic resin raw material is supplied from the storage tank (9) through the gate valve (8) to the raw material supply port (7) of the cylinder (2) of the extruder (1), and is rotated in the cylinder (2). In a throughput control device of an extruder that is melt-kneaded by a screw (3) and extruded from the tip of the cylinder (2) through a die (11) into a string shape, the rotational speed of the screw (3) is adjusted. In addition to adjusting the kneading state of the synthetic resin raw material, the amount of the synthetic resin raw material supplied from the storage tank (9) into the cylinder (2) is variably controlled by adjusting the opening of the gate valve (8). A throughput control device for an extruder characterized by the above.   The opening degree of the gate valve (8) is detected by a position detection sensor (14) provided in the gate valve (8) for detecting a sliding amount of the valve body. Extruder throughput control device.   A gate valve driving device (12) is connected to the gate valve (8), and a control device (13) is connected to the position detection sensor (14) and the gate valve driving device (12). The throughput control apparatus of the extruder of Claim 5 or 6.   The throughput control of an extruder according to any one of claims 5 to 7, wherein a vent port (15) is provided on the upstream side of the raw material supply port (7) in the cylinder (2). apparatus.

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