JP7544650B2 - Double-screw extrusion kneading device and double-screw extrusion kneading method - Google Patents

Description

The present invention relates to a double-screw extrusion kneading device and a double-screw extrusion kneading method.

In recent years, double-screw extruder kneaders equipped with at least two screws have come into widespread use as devices for kneading fillers or pigments into plastic sheets or films.

A double-screw extrusion kneader has at least several screws with helical grooves, a cylinder portion called a barrel in which the screws are housed, and a mechanism for rotating the screws. Double-screw extrusion kneaders are widely used in processes such as heating the barrel portion to plasticize plastic and extrude it, and compounding resin with fillers or pigments.

A double-screw extrusion kneader is equipped with a barrel with a cooling jacket (cooling water passage) inside the wall, and screws arranged in the screw housing of the barrel so that they can rotate in the same or opposite directions. By rotating the screws, materials such as resin are transported, mixed and/or kneaded, and extruded. When this double-screw extrusion kneader is in operation, a cooling water supply device is used to flow cooling water into the cooling jacket of the barrel to lower the temperature of the kneaded material and the barrel temperature.

The cooling water supply device of a double-screw extruder kneader includes a cooling water tank (sometimes called a reserve tank) that stores a fixed amount of cooling water, a circulation pump for supplying cooling water from the cooling water tank, and a heat exchanger (cooler) for lowering the temperature of the cooling water to a specified temperature. The cooling water from the cooling water tank is supplied to the cooling jacket of the barrel via the circulation pump and cooler, and is circulated so that it returns to the cooling water tank via the cooling jacket.

Patent Document 1 (JP Patent Publication 3-81129) discloses a heater device with a cooler in which one of a pair of block heaters heats up more quickly, enabling a stable supply of cooling water even if there is a temperature difference between the pair of block heaters.

The heater and cooler device described in Patent Document 1 is a heater and cooler device that controls the barrel of an extruder to a predetermined temperature, and is composed of a pair of semicircular heater blocks fixed to surround the barrel on either side, a cooler with multiple inverted U-shaped pipes arranged side by side within the heater blocks, a heater also located within the heater block with U-shaped sheathed wires arranged side by side, and a fixed throttle valve that branches off from the piping from the cooling water supply device and is connected between both water supply sides of the cooler of the pair of heater blocks.

Patent Document 2 (JP Patent Publication No. 2010-036557) discloses a method for supplying cooling water to a kneading extruder, which reduces the amount of dissolved oxygen in the cooling water supplied to the cooling jacket of the barrel of the kneading extruder, thereby preventing corrosion of the inner surface of the cooling jacket.

The cooling water supply method for a kneading extruder described in Patent Document 2 is a method for supplying cooling water from a cooling water tank to a cooling jacket of a barrel of the kneading extruder, and circulating the cooling water from the cooling jacket to the cooling water tank, and at the same time, supplying the cooling water with a reduced amount of dissolved oxygen to the cooling jacket. The method includes : supplying an inert gas to the cooling water tank configured as a closed container that isolates the inside from the atmosphere ; bringing the inert gas into contact with the cooling water in the cooling water tank and transferring the dissolved oxygen in the cooling water to the inert gas, thereby reducing the amount of dissolved oxygen in the cooling water in the cooling water tank; releasing the oxygen-containing inert gas separated from the cooling water from a space above the water surface in the cooling water tank to the outside of the tank through a gas release pipe that is provided in the cooling water tank and has a throttle section, and preventing the intrusion of air from the outside of the tank by the throttle section.

Patent document 3 (JP Patent Publication 10-337768 A) discloses a method for cooling a plastic melting cylinder that aims to realize a cooling system that does not cause cracks in the jacket or the like and reduces equipment and operating costs.

The method for cooling a plastic melting cylinder described in Patent Document 3 involves circulating a mixture of atomized water or oil and air as a cooling medium for the plastic melting cylinder through the medium path of the plastic melting cylinder to cool the plastic melting cylinder.

Japanese Patent Application Publication No. 3-81129 JP 2010-036557 A Japanese Patent Application Publication No. 10-337768

The technology described in Patent Document 1 describes a Y-type strainer. A typical Y-type strainer uses a stainless steel mesh to remove large foreign matter of 0.1 mm or more and several mm or less. Therefore, when the flow path is clogged, it is necessary to replace the member.
Furthermore, if even a rust particle of about 0.1 mm gets caught in the solenoid valve, the valve cannot be closed completely, causing the circulating cooling water to flow into the barrel, which in turn causes a cooling effect due to the large latent heat of the water, lowering the temperature of the barrel.
In this case, barrel temperature control works to compensate for the drop in barrel temperature, and even if the heater device attached to the barrel heats at 100% output, the temperature drop cannot be suppressed, or very large temperature fluctuations will occur, and in either case, the resin processing will essentially become unstable.

The technology described in Patent Document 2 uses cooling water with reduced dissolved oxygen by bubbling an inert gas into normal industrial water. It is described as being able to suppress the occurrence of rust caused by oxidation even if the water evaporates in the barrel block, but normal industrial water contains various metal salts, including iron, and is therefore insufficient in preventing rust, resulting in an unstable state of resin processing.

Furthermore, the technology described in Patent Document 3 claims to use mist water or oil as the cooling medium, and further claims that if water is used, pure water or ion-exchanged water is preferable. However, when water is mistified, the latent heat per volume is very small, resulting in a small cooling effect. Furthermore, when mist oil is used, no latent heat or only a small latent heat can be expected, and in some cases the oil can deteriorate due to the heat of the barrel, turning into a tar-like substance and causing blockages in the pipes.

An object of the present invention is to provide a twin-screw extrusion kneading apparatus and a twin-screw extrusion kneading method which solve the above-mentioned problems, and which allows stable long-term machine operation for 5 to 10 years and stable production of a material to be kneaded simply by replacing the filter.
Another object of the present invention is to provide a twin-screw extrusion kneading apparatus and a twin-screw extrusion kneading method which prevent the occurrence of rust, prevent immobilization or sticking of solenoid valves, suppress blockages in piping, and enable stable long-term machine operation for five or ten years and stable formation of a material to be kneaded simply by replacing filters.

(1)
A double-screw extrusion kneading apparatus according to one aspect includes a double-screw extrusion kneading section that kneads the material to be kneaded, and a barrel temperature control section that adjusts the barrel temperature of the double-screw extrusion kneading section by a barrel cooling water circulation device and/or a heating device, in which the double-screw extrusion kneading section has a path from the upstream side to the downstream side of the material to be kneaded formed by a plurality of barrel block sections, and the barrel temperature control section controls heating and cooling for one or more of the plurality of barrel block sections, and the barrel cooling water circulation device includes a first path from the piping formed for each of the plurality of barrel blocks to a heat exchanger, a reserve tank, a circulation pump, a filter, and a solenoid valve, and a second path from the circulation pump, a water flow regulating valve, and a reserve tank.

In this case, since the barrel block in the double-screw extrusion kneading section is formed of multiple barrel block parts, the barrel temperature can be adjusted appropriately from the upstream side to the downstream side of the material to be kneaded. In addition, foreign matter that may adhere to the valve body of the solenoid valve can be removed by a filter. Furthermore, it is possible to reduce the load on the circulation pump by bypassing a part of the circulating water discharged from the circulation pump to the reserve tank via the water flow control valve, which is the second path.
In addition, by disposing a filter downstream of the circulation pump, the effect of pressure loss due to the filter can be reduced. As a result, the double-screw extrusion kneading apparatus can stably operate for a long period of time (5 to 10 years) and produce a stable material to be kneaded by simply replacing the filter.

(2)
In the twin-screw extrusion kneading apparatus according to a second aspect of the present invention, the screws of the twin-screw extrusion kneading section may have a segment configuration having one or a plurality of kneading sections.

In this case, since the double-screw extrusion kneading apparatus has one or more kneading sections, heat is likely to be generated in the vicinity of one or more kneading sections due to the application of strong shear force to the material to be kneaded. However, since the double-screw extrusion kneading apparatus of the present invention has multiple barrel block sections, the temperature can be adjusted individually, and the barrel block section corresponding to the one or more kneading sections that generate heat can be cooled.

(3)
The double-screw extrusion kneading apparatus according to the third invention may be such that, in the double-screw extrusion kneading apparatus according to one aspect and the second invention, the barrel block in the kneading section corresponds to a part of the multiple barrel block parts, and the barrel block other than the kneading section corresponds to another part of the multiple barrel blocks.

In this case, temperature control is performed only on a portion of the multiple barrel block sections near the kneading section where heat is likely to be generated due to the application of strong shear forces to the material being kneaded, and no control is performed on the other portions of the multiple barrel block sections, so temperature control can be kept to a minimum.

(4)
A twin-screw extrusion kneader according to a fourth aspect of the present invention is the twin-screw extrusion kneader according to any one of the aspects to the third aspect of the present invention, wherein a filter of the barrel cooling water circulator may have a filtration accuracy of 50 μm or less.

In this case, foreign matter adhering to the valve body of the solenoid valve can be removed by a filter, allowing for stable continuous operation of the double-screw extrusion kneading device.

(5)
The twin-screw extrusion kneader according to the fifth invention is the twin-screw extrusion kneader according to one aspect to the fourth invention, wherein in the barrel cooling water circulator, the cooling water supplied initially or when replacing the barrel cooling water circulator may be deionized water having a viscosity of 5 μS/cm or less.

In this case, the cooling water supplied initially or when replacing the equipment is deionized water with a viscosity of 5 μS/cm or less, which can prevent precipitation in the piping. In particular, if the cooling water initially supplied to the barrel cooling water circulation system is deionized water with a viscosity of 5 μS/cm or less, precipitation in the piping can be prevented for 5 to 10 years, even if the viscosity gradually changes to 5 μS/cm or more during continuous operation.

(6)
The sixth aspect of the present invention relates to a double-screw extrusion kneader, and in the double-screw extrusion kneader according to the fifth aspect of the present invention, a pressure gauge is provided in the first path, and the pressure gauge includes at least a first pressure gauge and a second pressure gauge, and the first pressure gauge may be provided upstream of the filter and the second pressure gauge may be provided downstream of the filter.

In this case, the pressure difference between the first and second pressure gauges can be used to determine whether the filter is clogged, making it easy to know when it is time to replace the filter.

(7)
A double-screw extrusion kneading method according to yet another aspect includes a double-screw extrusion kneading process in which a path is formed from the upstream side to the downstream side of the material to be kneaded using a plurality of barrel block sections to knead the material to be kneaded, and a barrel temperature control process in which the barrel temperature in the double-screw extrusion kneading process is adjusted by a barrel cooling water circulation process or a heating process, wherein the barrel temperature control process controls heating and cooling for one or more of the plurality of barrel block sections, and the barrel cooling water circulation process includes a first circulation process in which cooling water is supplied into piping formed for each of the plurality of barrel block sections via a circulation pump, a filter, and an electromagnetic valve, and circulated to a heat exchanger and a reserve tank, and a second circulation process in which cooling water from the circulation pump is circulated to the reserve tank via a water flow control valve.

In this case, since the barrel block in the double-screw extrusion kneading section is formed of multiple barrel block parts, the barrel temperature can be adjusted appropriately from the upstream side to the downstream side of the material to be kneaded. In addition, foreign matter that may adhere to the valve body of the solenoid valve can be removed by a filter. Furthermore, the load on the circulation pump can be reduced by using a water flow control valve to balance the flow rate of the first circulation process with the bypass amount of the second circulation process.
That is, by using the water flow control valve to bypass the discharge water from the circulation pump to the reserve tank, it is possible to prevent the circulation pump from operating at a high load even if the solenoid valve in the barrel cooling water circulation process is fully closed for a long time. Also, by placing a filter downstream of the circulation pump, the effect of pressure loss due to the filter can be reduced. As a result, the double-screw extrusion kneading apparatus can stably operate for a long period of time, for 5 to 10 years, and produce a stable kneaded material, simply by replacing the filter.

FIG. 1 is a schematic diagram showing an example of a double-screw extrusion kneading apparatus according to an embodiment of the present invention. FIG. 1 is a schematic diagram showing an example of a double-screw extruder kneader. FIG. 2 is a schematic diagram showing an example of the relationship between a plurality of barrel blocks and a barrel temperature controller in a double-screw extrusion kneader according to the present embodiment. FIG. 4 is a diagram showing an example of a control flow of a temperature control unit. FIG. 11 is a schematic diagram showing another example of the relationship between a plurality of barrel blocks and a barrel temperature controller in a double-screw extrusion kneader according to the present embodiment. FIG. 2 is a schematic diagram showing another example of a double-screw extrusion kneading apparatus according to the present embodiment.

The following describes an embodiment of the present invention with reference to the drawings. In the following description, identical parts are given the same reference numerals. Furthermore, when the reference numerals are the same, their names and functions are also the same. Therefore, detailed descriptions thereof will not be repeated.

(Embodiment)
Fig. 1 is a schematic diagram showing an example of a double-screw extrusion kneader 100 according to the present embodiment, and Fig. 2 is a partially enlarged schematic diagram showing an example of a double-screw extrusion kneader 200. Fig. 3 is a schematic diagram showing an example of the relationship between a plurality of barrel block sections 230a, -, 230i according to the present embodiment and a barrel temperature controller 300 in the double-screw extrusion kneader 100.
FIG. 4 is a diagram showing an example of a control flow of the temperature control unit 500, FIG. 5 is a schematic diagram showing another example of the relationship between the multiple barrel block sections and the barrel temperature controller 300 in the double-screw extrusion kneading apparatus 100 according to this embodiment, and FIG. 6 is a schematic diagram showing another example of the double-screw extrusion kneading apparatus 100 according to this embodiment.

(Two-screw extrusion kneading apparatus 100)
As shown in FIG. 1, the twin-screw extrusion kneading apparatus 100 mainly includes a twin-screw extrusion kneader 200 and a barrel temperature controller 300 .

(Two-screw extrusion mixer 200)
As shown in Figures 1 and 2, a double-screw extrusion kneader 200 according to this embodiment includes a drive unit 210, two screws 220, a plurality of barrel block sections 230a...230i, piping P230a...P230i connected to each of the plurality of barrel block sections, barrel heating devices H230a...H230i connected to each of the plurality of barrel block sections, piping P230a...P230i, solenoid valves 240a...240i, needle valves 250a...250i, a water collection manifold 260, and a water supply manifold 270.

In addition, the twin-screw extrusion kneader 200 is illustrated as a twin-screw extrusion kneader equipped with two screws 220. Note that the twin-screw extrusion kneader 200 according to the present invention is not limited to having two screws 220, but is a multi-screw extrusion kneader having any number of screws, such as three, four, six, etc., arranged in parallel or on a circumference.

(Screw 220)
As shown in Fig. 2, a screw 220 of a double-screw extrusion mixer 200 is provided with a kneading section 221. The kneading section 221 is provided with a frictional portion in a part of the spiral groove of the screw, or with a spiral groove portion partially in the reverse screw direction, in order to increase the dispersion efficiency or distribution efficiency for plasticizing or compounding the material to be kneaded.
In the kneading section 221 or in the vicinity of the kneading section 221, heat is generated due to a strong shear force being applied to the material to be kneaded, and the temperature of the material to be kneaded rises.
Moreover, the screw 220 is connected in parallel to the driving device 210 and is provided so as to be rotatable around the axis of the screw 220 .
In this embodiment, the case where two kneading sections 221 are provided has been described, but the present invention is not limited to this, and one or n (n is an integer) may be provided. Furthermore, the distribution efficiency may be further improved by disposing a segment (mixing segment) having a notched reverse-thread spiral groove downstream of the kneading section, and heat is generated continuously in the kneading section due to the occurrence of a shear flow or elongation flow when the resin passes through the notched section.

(Multiple barrel block portions 230a, ..., 230i)
Next, the multiple barrel block portions 230 a to 230 i form a path for the material to be mixed by the multiple screws 220 from the upstream side to the downstream side.
As shown in Fig. 3, the pipes P230a, ..., P230i are provided inside each of the barrel block parts 230a, ..., 230i so as to go around the corresponding paths of the barrel block parts 230a, ..., 230i. Although Fig. 3 shows one round, the number of rounds is not limited to two, three, or any other number of times. In addition, the paths may be created by linearly penetrating the barrel at a position avoiding the screw path and intersecting the multiple through paths, and by sealing the part from the outside of the barrel to the intersection with a plug as necessary.

The multiple barrel block sections 230a, ..., 230i in this embodiment are generally set to a temperature within the range of about 100°C to 350°C. For example, in the case of nylon 6 resin, it is generally set to about 250°C, and in the case of PET resin, it is generally set to about 280°C. Therefore, when the temperature of the multiple barrel block sections 230a, ..., 230i exceeds the set temperature due to shear heat generated by the kneaded material such as plastic, water is passed through the above-mentioned pipes P230a, ..., P230i to control it. This control will be described later.

The cooling water that is passed through vaporizes immediately due to the heat of the multiple barrel block parts 230a, ..., 230i as described above, and the large latent heat acts to lower the temperature of the multiple barrel block parts 230a, ..., 230i. In this case, if various metals, etc. are dissolved as ions in the cooling water that is passed through, they will precipitate as salt on the walls of the pipes P230a, ..., P230i, causing accumulation on the inner walls of the pipes P230a, ..., P230i, or if the cooling water contains any dissolved matter, they will precipitate as scale, causing blockage of the pipes P230a, ..., P230i.

In addition, in the multiple barrel block portions 230a, . . . , 230i in this embodiment, the portion into which the screw 220 is inserted has a special steel material with high wear resistance and/or corrosion resistance inserted as a sleeve, or the surface is hardened.
However, in the multiple barrel block portions 230a, ..., 230i, the portions into which the screw 220 is not inserted are often made of general steel, and corrosion occurs on the surfaces of the pipes P230a, ..., P230i due to the cooling water or the steam generated by the cooling water.
Then, rust due to corrosion gradually occurs. If rust occurs and rust particles get mixed into the cooling water and are caught between the closing surfaces of the solenoid valves 240a, 240i, a small amount of cooling water continues to flow into the barrel block portions 230a, 230i, causing a phenomenon in which temperature control becomes ineffective. In this embodiment, a filter 340, which will be described later, is provided to prevent this phenomenon.

(Barrel heating device H230a, ..., H230i)
3, barrel heating devices H230a to H230i are provided on the peripheral walls of the barrel block portions 230a to 230i, respectively. The barrel heating devices H230a to H230i are turned ON (heating)-OFF (non-heating) in accordance with a control signal from the barrel temperature controller 300.

(Water supply manifold 270)
Next, as shown in FIG. 2, needle valves 250a to 250i and solenoid valves 240a to 240i are provided in the pipes P230a to P230i extending from the water supply manifold 270 to the plurality of barrel block portions 230a to 230i, respectively.

(Needle valves 250a, ..., 250i)
In this embodiment, needle valves 250a to 250i are used as shown in Fig. 2, but the present invention is not limited thereto, and any other valve or water flow control valve may be used as long as it is a valve that can be used at an intermediate opening degree such as a globe valve or a butterfly valve. In this embodiment, a needle valve is used, which is particularly easy to finely adjust the flow rate among globe valves. In this embodiment, the needle valve 250a is provided, but the needle valve 250a may or may not be provided at the most upstream part of the kneading process, which corresponds to the raw material inlet.

(Solenoid valves 240a, ..., 240i)
The solenoid valves 240 a to 240 i according to this embodiment are turned ON (fully open)-OFF (fully closed) in accordance with a control signal from the barrel temperature controller 300 .
The solenoid valves 240a, . . . , 240i may be of a type that is normally closed (normally closed, energized open) without a control signal, or of a type that is normally open (normally open, energized closed). In other words, as long as the control signal can be used to achieve ON (fully open) or OFF (fully closed), there is no problem with any type of structure. In this embodiment, the solenoid valve 240a is provided, but the most upstream portion of the kneading process may or may not be provided with the solenoid valve 240a. In other words, cooling water may be constantly circulated through the most upstream portion of the kneading process, which serves as the raw material inlet.

(Water collecting manifold 260)
As shown in FIGS. 1 and 2, a water collection manifold 260 is disposed downstream of the pipes P230a, ..., P230i of the multiple barrel block portions 230a, ..., 230i.

(Barrel Temperature Controller 300)
Next, the barrel temperature controller 300 will be described. As shown in Figures 1, 2, and 3, the barrel temperature controller 300 includes a reserve tank 310, a circulation pump 320, a strainer 330, a filter 340, a heat exchanger 350, a flow rate control valve 360, temperature measurement units 370a to 370i, a pressure gauge 380, a pipe P300, and a temperature control unit 500 for one or more barrel block units 230a to 230i.
As shown in FIG. 3, the temperature control unit 500 receives temperature information from the temperature measurement units 370a to 370i and controls the solenoid valves 240a to 240i, the needle valves 250a to 250i, and the barrel heating devices H230a to H230i.
In this embodiment, the path including the reserve tank 310, the circulation pump 320, the strainer 330, the filter 340, the piping P230a, ..., P230i, and the heat exchanger 350 is called the first path (first circulation process), and the path including the reserve tank 310, the circulation pump 320, the flow control valve 360, and the heat exchanger 350 is called the second path (second circulation process).

In this embodiment, the needle valves 250a, 250i, the barrel heating devices H230a, 230i, and the pipes P230a, 230i are described as being included on the double-screw extrusion kneader 200 side, but they may also be arranged to be included on the barrel temperature controller 300 side.

The detailed control method of the temperature control unit 500 will be described later. In this embodiment, the temperature measurement units 370a, . . . 370i are preferably thermocouples or resistance temperature detectors.

(Materials for the reserve tank 310, the pipe P300, and the pipes P230a, ..., P230i)
In this embodiment, the reserve tank 310, the piping P300, and the piping P230a to P230i are preferably made of brass and/or stainless steel in consideration of corrosion such as rust. In this embodiment, the reserve tank material, the straight piping section, and joints such as elbows are made of stainless steel, and copper pipes are bent between the solenoid valve and the barrel's water supply side connection port, and between the barrel's water discharge side connection port and the water collection manifold.
In the present embodiment, the capacity of the reserve tank 310 may be 20 L or more and 50 L or less, or 30 L or more and 40 L or less. The cooling water in the reserve tank 310 is often at or below 80 degrees, and is preferably maintained within the range of 40 C or more and 60 C or less.
In addition, a ventilation pipe may be installed in the reserve tank 310 to release pressure within the tank, and the ventilation pipe may be equipped with a separate filter to prevent the intrusion of dust, dirt, and even small insects.
Furthermore, the reserve tank 310 can be equipped with a thermometer that displays the temperature of the circulating water, or a liquid level gauge or the like, to further improve usability.

(Circulation pump 320)
In this embodiment, a centrifugal pump (cascade pump) is used as the circulation pump 320. From the viewpoint of cost and/or long-term reliability, it is desirable to use a centrifugal pump (cascade pump).
The circulation pump 320 is not particularly limited as long as it can provide a water flow, and specifically, it may be an axial flow pump, a piston (plunger) pump, a gear pump, or the like.

(Filter 340)
The filter 340 is composed of a housing portion made of stainless steel and/or resin and a filter cartridge that actually performs filtration.
The filter cartridge according to the present embodiment may be a wound filter, a pleated filter, a nonwoven fabric filter, a sponge filter, or the like.
The filter 340 according to the present embodiment uses a wound filter as a filter cartridge.
The present embodiment is not like the Y-type strainer of Patent Document 1. Generally, Y-type strainers are generally made of punched metal with a size of millimeters inside, or stainless steel mesh with openings of several mm or more. In other words, they are used to remove large foreign objects.

On the other hand, the filtration accuracy of the filter cartridge in this embodiment must be 50 μm or less, and 20 μm or less is more preferable. This is because even if a particle such as a rust grain of about 0.1 mm is caught between the solenoid valves 240a, ..., 240i, the water stop valve or valve body cannot be completely closed, and the cooling water flows into the multiple barrel block parts 230a, ..., 230i, causing a problem that the cooling effect of the large latent heat of the cooling water causes a drop in the temperature of the multiple barrel block parts 230a, ..., 230i.

In order to compensate for the drop in temperature of the multiple barrel block portions 230a, ..., 230i, the temperature control portion 500 operates, and even if the barrel heating devices H230a, ..., H230i attached to the multiple barrel block portions 230a, ..., 230i heat at 100% output, it may be difficult to suppress the temperature drop, or there may be a problem that the temperature fluctuation is very large and the resin processing becomes essentially unstable.
Thus, if the filtration accuracy exceeds 50 μm, it is insufficient to capture fine particles, and fine particles that have passed through filter 340 may become caught in the water stopping surface or valve body of solenoid valves 240 a to 240 i, causing malfunctions. There is no particular limit to the lower limit of the filtration accuracy, but if the filtration accuracy is too low, clogging may occur quickly, increasing the frequency of maintenance, or the supply pressure may need to be set high, increasing the load on circulation pump 320.

Further, the location of filter 340 in the path of barrel temperature controller 300 is not particularly limited, but a position after the outlet of circulation pump 320 is preferable as a position of the path that can maintain the heat resistance and filtration pressure of the material of filter 340. By providing filter 340 near the downstream of circulation pump 320, pressure loss due to filter 340 can be suppressed.
Furthermore, in this embodiment, the location where the filtration flow rate can be increased and efficient filtration can be performed is the downstream side of the first path from the outlet of heat exchanger 350, reserve tank 310, and circulation pump 320 to strainer 330 and pressure gauge 380, and is also the part where no pressure loss of the filter is added in order to eliminate the load on circulation pump 320 in the second path, so it is placed in the position shown in Figure 1.

(Heat exchanger 350)
The heat exchanger 350 according to this embodiment is of a sealed type, such as a plate type or a shell-and-tube type, taking into consideration contamination from the outside world.
The cooling medium for the heat exchanger 350 itself may be a gas such as air or a liquid such as water. In particular, water, which has a large heat capacity, may be preferably used as the cooling water. Furthermore, the cooling medium may be drinking water or industrial water in a one-way manner, or circulating cooling water combined with a cooling tower or the like.

(Flow Control Valve 360)
In this embodiment, the flow rate control valve 360 is used to adjust the circulation rate of the cooling water flowing through the first and second paths. In a state where most of the solenoid valves 240 are closed and the total amount of water passing through the barrel is reduced, reducing the bypass rate through the second path reduces the amount of water discharged from the circulation pump and at the same time increases the pressure, increasing the torque of the electric motor driving the circulation pump. Therefore, it is essential to open the flow rate control valve 360 and circulate the cooling water through the second path of the reserve tank 310, the circulation pump 320, the strainer 330, the flow rate control valve 360, and the heat exchanger 350. Furthermore, if the electric motor is operated in a high torque state for a long period of time, it may cause the motor to burn out in the worst case.
In addition, considering that there is not much need for fine flow rate adjustment, an inexpensive gate valve is used as the flow rate adjustment valve 360. Note that, without being limited to a gate valve, any valve such as a globe valve or a ball valve may be used. Note that, in this embodiment, the flow rate adjustment valve 360 is adjusted so that the pressure on the pressure gauge 380 does not exceed 0.4 MPa during the initial barrel temperature rise (basically, when the solenoid valve is fully closed).

(Cooling Water in Barrel Temperature Controller 300)
It is essential that the water initially supplied to the barrel temperature controller 300 or the water supplied during replacement for maintenance is deionized water that does not contain any foreign microparticles or dissolved salts. Specifically, the electrical conductivity must be 5 μS/cm or less as a guideline for not dissolving salts, and more preferably 2 μS/cm or less.
In addition, when the amount of water circulating through the barrel cooling water circulation device decreases due to long-term use, it is also possible to additionally supply deionized water with an electrical conductivity of 5 μS/cm or less, more preferably 2 μS/cm or less. To remove fine particles, raw water before ion exchange is filtered with a filter of 20 μm or less, or more preferably raw water that has been treated with a reverse osmosis (RO) membrane is deionized. If water with an electrical conductivity of more than 5 μS/cm is used, it is likely to induce the generation of salt and even rust during barrel cooling.

(Barrel Temperature Controller 300)
Next, the operation of the barrel temperature controller 300 in the double-screw extrusion kneader 100 will be described.
4, as an initial operation, the temperature control unit 500 turns on (operates) the circulation pump 320 (step S1). As a result, the cooling water stored in the reserve tank 310 is circulated by the circulation pump 320 through a second path consisting of the pipe P300, the strainer 330, the flow rate control valve 360, and the heat exchanger 350.

Next, the temperature control unit 500 acquires the temperatures measured by the temperature measuring units 370a, ..., 370i provided for each of the barrel block sections 230a, ..., 230i (step S2), compares the temperature of each of the barrel block sections 230a, ..., 230i with the set target temperature, and performs calculations according to the deviations obtained by the comparison (step S3).

If the calculated temperature is lower than the set temperature (COLD in step S3), the temperature control unit 500 turns on (ON: heats) the corresponding parts of the barrel heating devices H230a, ..., H230i provided in the corresponding multiple barrel block sections 230a, ..., 230i (step S4).
After the process of step S4, the temperature control unit 500 returns to step S2 and repeats the process.

Furthermore, if the temperature control unit 500 determines based on the calculation result that the temperature is the same as the set temperature (NONE in step S3), the temperature control unit 500 returns to step S2 and repeats the process.
Furthermore, when the temperature control unit 500 determines based on the calculation result that the temperature is higher than the set temperature (HOT in step S3), the temperature control unit 500 turns on (ON: permitted passage, open) the corresponding parts of the solenoid valves 240a, ..., 240i and needle valves 250a, ..., 250i provided in the corresponding multiple barrel block portions 230a, ..., 230i (step S5).
As a result, the cooling water circulating through the second passage is forced to flow into the first passage.
After performing the process of step S5, the temperature control unit 500 returns to step S2 and repeats the process.

As a result, the cooling water passes from the water supply manifold 270 through the needle valves 250a, ..., 250i and the corresponding parts of the solenoid valves 240a, ..., 240i, and flows through the pipes P230a, ..., P230i of the multiple barrel block sections 230a, ..., 230i, thereby enabling temperature control of the multiple barrel block sections 230a, ..., 230i.

In addition, PID control is used as the control in the temperature control unit 500 according to this embodiment. However, this is not limited to PID control, and ON-OFF control or the like may be used. In addition, in this embodiment, one temperature control unit 500 controls multiple barrel block units 230a, to, 230i, but this is not limited to this, and as shown in FIG. 5, multiple temperature control units 500a, to, 500i may be provided, and one temperature control unit 500 may be provided in a one-to-one relationship with any one of the multiple barrel block units 230a, to, 230i.

In addition, if all of the solenoid valves 240a, . . . , 240i are closed, the flow rate of the cooling water required for circulation becomes extremely small, which causes a problem of placing a very large load on the circulation pump 320. Therefore, in the double-screw extrusion kneading apparatus 100 of this embodiment, a second path is provided to return the cooling water directly to the reserve tank 310.
1, a configuration may be adopted in which the second path returns the refrigerant from the downstream side of the flow rate adjustment valve 360 directly to the reserve tank 310 without passing through the heat exchanger 350.

(First pressure gauge 380a and second pressure gauge 380b)
As shown in FIG. 6, a first pressure gauge 380a and a second pressure gauge 380b may be provided instead of the pressure gauge 380 in FIG.
In this case, if the pressure difference between the first pressure gauge 380a and the second pressure gauge 380b is large, it is possible that the filter 340 is clogged, and therefore maintenance can be easily performed.

In addition, some of the materials to be mixed in the double-screw extrusion kneader 200 in this embodiment are glass fibers, color pigments, and inorganic powders, which are mixed into the other part of the materials to be mixed, which is resin, using the double-screw extrusion kneader 200.

As described above, in the twin-screw extrusion kneading device 100 according to the present invention, the twin-screw extrusion kneader 200 is formed of a plurality of barrel block parts 230a, 230i, so that the barrel temperature can be adjusted appropriately from the upstream side to the downstream side of the material to be kneaded. In addition, foreign matter adhering to the valve bodies of the solenoid valves 240a, 240i can be removed by the filter 340. Furthermore, even if the amount of cooling water in the reserve tank 310 is small, the flow rate adjustment valve 360 is used to circulate the cooling water to the second path, so that the load on the circulation pump 320, which is normally operating, can be suppressed. As a result, the twin-screw extrusion kneading device 100 can stably operate for long periods of time, such as five or ten years, and can stably form the material to be kneaded, simply by replacing the filter 340.

The double-screw extrusion mixer 200 according to the present invention corresponds to the "double-screw extrusion mixer section", the temperature control section 500 corresponds to the "barrel temperature control section", the multiple barrel block sections 230a, ..., 230i correspond to the "multiple barrel block sections", the circulation pump 320 corresponds to the "circulation pump", the heat exchanger 350 corresponds to the "heat exchanger", the reserve tank 310 corresponds to the "reserve tank", the strainer 330 corresponds to the "strainer", and the flow rate control valve 360 corresponds to the "water flow control valve". valve", filter 340 corresponds to the "filter", pressure gauge 380 corresponds to the "pressure gauge", solenoid valves 240a, ..., 240i correspond to the "solenoid valve", piping P230a, ..., P230i correspond to the "piping formed for each of the multiple barrel blocks", multi-screw extrusion kneading device 100 corresponds to the "multiple-screw extrusion kneading device", screw 220 corresponds to the "screw", kneading section 221 corresponds to the "kneading section", and cooling water corresponds to the "cooling water".

The above describes an embodiment of the present invention, but the present invention is not limited to the above embodiment and can be modified and implemented in various ways within the scope of the claims.

REFERENCE SIGNS LIST 100 Twin-screw extrusion kneading device 200 Twin-screw extrusion kneader 220 Screw 230a, ~, 230i Multiple barrel block sections 221 Kneading section 240a, ~, 240i Solenoid valve 310 Reserve tank 320 Circulation pump 330 Strainer 340 Filter 350 Heat exchanger 360 Flow rate control valve 380 Pressure gauge 380a First pressure gauge 380b Second pressure gauge 500 Temperature control section P230a, ~, P230i Piping

Claims (6)

A double-screw extrusion kneading section for kneading the material to be kneaded;
A barrel temperature control unit that adjusts the barrel temperature of the double-screw extrusion kneading section by a barrel cooling water circulator and/or a heater,
In the double-screw extrusion kneading section, a path of the material to be kneaded from the upstream side to the downstream side is formed by a plurality of barrel block sections,
The barrel temperature control unit controls heating and cooling of one or more of the plurality of barrel block units,
the barrel cooling water circulation device includes a first path extending from a pipe formed for each of the barrel block portions to the pipe via a heat exchanger, a reserve tank, a circulation pump, a strainer, a filter , and an electromagnetic valve, and a second path extending from the circulation pump to the circulation pump via the strainer, the water flow control valve , and the reserve tank ,
The filter has a filtering accuracy of 50 μm or less . The twin-screw extrusion kneading device according to claim 1, wherein the screw of the twin-screw extrusion kneading section is configured as a segment having one or more kneading sections. 3. The double-screw extrusion kneading apparatus according to claim 2, wherein the barrel block in the kneading section corresponds to a part of the plurality of barrel block parts, and the barrel block other than the kneading section corresponds to the other part of the plurality of barrel block parts . 4. The biaxial extrusion kneader according to claim 1, wherein the cooling water supplied to the barrel cooling water circulation device at the beginning or when the cooling water is replaced is deionized water having a viscosity of 5 μS/cm or less. A pressure gauge is provided in the first passage,
the pressure gauge includes at least a first pressure gauge and a second pressure gauge;
The first pressure gauge is provided upstream of the filter,
The double-screw extrusion kneader according to claim 1 , wherein the second pressure gauge is provided downstream of the filter. A double-screw extrusion kneading process in which a path from the upstream side to the downstream side of the material to be kneaded is formed by a plurality of barrel block portions, and the material to be kneaded is kneaded;
A barrel temperature control step of adjusting the barrel temperature in the double screw extrusion kneading step by a barrel cooling water circulation step or a heating step,
The barrel temperature control step controls heating and cooling of one or more of the barrel block portions,
The barrel cooling water circulation process includes a first circulation process of supplying the cooling water into pipes formed in each of the barrel block portions through a circulation pump, a strainer, a filter , and an electromagnetic valve, and circulating the cooling water to a heat exchanger and a reserve tank;
a second circulation step of circulating the cooling water from the circulation pump to the reserve tank through the strainer and the water flow control valve ;
The method for kneading by double-screw extrusion , wherein the filter has a filtering accuracy of 50 μm or less .