JPH04226326A - Synthetic resin extrusion molding method - Google Patents

Abstract

PURPOSE:To provide the extrusion molding method in which the blending ratio of a new raw material resin, a waste material and a plasticizer can be controlled smoothly without any trouble corresponding to the variation when the waste material to be used is varied to a large extent. CONSTITUTION:A new raw material resin, a waste material, a plasticizer and an additive are fed into a feed opening 17a of an extruder 17 and extrusion molded into the film shape. A lug waste material 23a is crushed by a crusher 22 and stored in a waste material primary feeder 10 and a waste material secondary feeder 12. The weight of both the materials is measured and the values are input into a main computer 1. The blending ratio of the respective materials is decided according to the total amount of the waste material in the waste material primary feeder 10 and the waste material secondary feeder 12 by the main computer 1. A motor 15 of a resin feeder 14 and a motor 13 of the waste material secondary feeder 12 are operated through a computer 2a for resin and a computer 2 for feeding the waste material based on the command of the computer 1 and issued correspondingly to the decided blending ratio, and also a motor 7 of a plasticizer pump 8 and a motor 4 of an additive pump 5 are operated.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention uses new raw material resin, waste material, and plasticizer as raw materials, supplies these raw materials to an extruder to melt and extrude them, and supplies the extruded molten raw materials to a die using a melt pump. The present invention relates to a synthetic resin extrusion molding method for obtaining molded articles.

0002

[Prior Art] This type of molding method is used, for example, in the production of plasticized resin films, to cut off both edges of the film extruded from a die and to remove edge waste material that is generated when forming the film into a film of a predetermined width. It is used when collecting and reusing.

[0003] In this case, the blending ratio of the new raw material resin, waste material, and plasticizer must be controlled depending on the amount of waste material used. Furthermore, in order to keep the thickness of the film constant, it is necessary to control the pressure of the molten raw material discharged from the extruder within a predetermined range.

Conventionally, as a method for performing such control,
A method disclosed in Japanese Patent Publication No. 60-31649 is known. In this conventional method, the mixing ratio of new raw material resin, waste material, and plasticizer is determined in advance, and the waste material is directly supplied to the extruder. The amount of waste material supplied is measured and subtracted from the predetermined total amount of raw materials supplied to the extruder to adjust the amount of new raw material resin and plasticizer supplied.

[0005] Regarding the pressure of the molten raw material, the total amount of raw material supplied to the extruder is slightly increased so that the pressure of the molten raw material does not become low, and if the pressure of the molten raw material becomes too high, the melt pump The molten raw material is discharged from the molten raw material discharge port in the passage between the two through the control valve and regulated.

[0006]

[Problem to be Solved by the Invention] However, with such conventionally known control methods, when the production of waste material fluctuates significantly due to a significant change in product size or a failure in the waste material system, the raw material The metering device is unable to quickly follow this process, causing problems in film production itself.

[0007] Furthermore, if the pressure of the molten raw material becomes too high, the control valve opens and a portion of the molten raw material is discharged from the outlet, resulting in a loss of raw material and requiring time and effort to dispose of the discharged raw material.

[0008] This invention solves the above-mentioned problem, and its purpose is to adjust the blending ratio of new raw material resin, waste material, and plasticizer even if the waste material used changes significantly. It is an object of the present invention to provide a synthetic resin extrusion molding method that can be controlled smoothly and without any trouble. Another object of the present invention is to provide a synthetic resin extrusion molding method in which the pressure of the molten raw material discharged from an extruder can be controlled without discharging the molten raw material to the outside.

[0009]

[Means for Solving the Problems] The synthetic resin extrusion molding method according to claim 1 uses a new raw material resin, waste material, and a plasticizer as raw materials, and melt-extrudes the raw materials by supplying the raw materials to an extruder.
In a synthetic resin extrusion molding method in which a molded product is obtained by supplying an extruded molten raw material to a die using a melt pump, there are a step of supplying waste material to an extruder via a waste material primary feeder and a waste material secondary feeder; The mixing ratio of new raw material resin, waste material and plasticizer is determined according to the amount of waste material in the primary feeder, and the process of supplying a predetermined amount of raw materials to the extruder according to the determined mixing ratio, and the extruder and melting process. measuring the pressure of the molten raw material between the melt pump and the melt pump, and driving and controlling the melt pump so that this pressure becomes a predetermined pressure;
includes.

[0010] Furthermore, the synthetic resin extrusion molding method according to claim 2 uses new raw material resin, waste material, and plasticizer as raw materials, supplies these raw materials to an extruder and melt-extrudes them, and converts the extruded molten raw materials into a molten product. In a synthetic resin extrusion molding method in which a molded product is obtained by feeding a molded product to a die using a pump, there is a step in which waste material is fed to an extruder via a waste material primary feeder and a waste material secondary feeder, and a waste material primary feeder and a waste material secondary feeder. The mixing ratio of new raw material resin, waste material, and plasticizer is determined according to the total amount of waste material accumulated in both of include.

[0011]

[Operation] According to the invention described in claim 1, the waste material is the waste material 2.
Before being supplied to the extruder by the secondary feeder, the waste material is temporarily stored in the primary feeder, and the amount stored there is measured. The blending ratio of the new raw material resin, waste material, and plasticizer is determined based on these two stored amounts, and a predetermined amount of the raw material is supplied to the extruder by the waste material secondary feeder according to the blending ratio. The pressure of the molten raw material discharged from the extruder is based on the raw material pressure measured between the extruder and the melt pump, and the melt pump is driven to keep the pressure within a predetermined range. controlled.

[0012] Furthermore, according to the invention as claimed in claim 2, the waste material is passed through the waste material primary feeder and the waste material 2 before being fed to the extruder.
Both waste materials are stored in both secondary feeders, where the storage amounts of both waste materials are measured. Then, the blending ratio of the new raw material resin, waste material, and plasticizer is determined based on the total amount of both of these stored quantities, and a predetermined amount of raw material is supplied to the extruder by the waste material secondary feeder according to the blending ratio. . Therefore, even if the amount of waste material used fluctuates significantly, it is possible to feed the waste material to the extruder using the surplus material stored in the waste material secondary feeder, and the blending ratio can be adjusted smoothly in response to the fluctuations. It can be changed.

[0013] Moreover, the waste material is transferred to the waste material primary feeder and the waste material 2 feeder.
Since waste material is stored in both secondary feeders, when the amount of waste material in the waste material secondary feeder falls to the level required for filling,
It becomes possible to make a filling request to the next feeder. Therefore, when the amount of waste material generated is constant, the amount of waste material fed to the extruder by the waste material secondary feeder can be set to a constant value, thereby reducing the number of changes in the blending ratio of new raw material resin, waste material, and plasticizer. It can be reduced.

Furthermore, the raw material thus supplied to the extruder is kneaded and melted in the extruder and extruded to the melt pump, but in this case, the molten raw material between the extruder and the melt pump is By measuring the pressure and adjusting the drive of the melt pump to keep the pressure of the molten raw material within a predetermined range based on the measured pressure, the pressure of the molten raw material can be reduced without discharging any of the molten raw material to the outside. controlled.

[0015]

EXAMPLES (Example 1) Hereinafter, an example of the invention as claimed in claim 1 will be described in the case where a plasticized polyvinyl butyral film is extruded.

FIG. 1 shows the overall configuration of an extrusion molding apparatus for producing a film, FIG. 2 shows a schematic cross-section of the edge crusher in the apparatus shown in FIG. 1, and FIG. 3 shows the control of raw material supply to the extruder. A schematic flowchart is shown.

The extrusion molding apparatus shown in FIG. 1 includes an extruder 17, a gear pump 18 which is a melt pump connected to the tip of the extruder 17, a wide slit die 20 connected to the gear pump 18, and an ear crusher 22. ing. The extruder 17 is equipped with a screw 171 inside and a heater (not shown) outside, and the screw 171 is connected to a transmission device 161.
It is rotationally driven by a motor 16 via.

The supply port 17a of the extruder 17 is supplied with polyvinyl butyral, which is a new raw material resin, waste materials, plasticizers, and additives. Polyvinyl butyral is motor 15
The resin is supplied from a resin feeder 14 driven by. The motor 15 is operated based on instructions from the main computer 1, and the amount of resin supplied by the resin feeder 14 per unit time is fed back to the main computer 1.

The waste material primary feeder 10 is equipped with a cyclone 9 on its upper part, and the cyclone 9 has a first duct 91,
Ear crusher 22 via blower 21 and second duct 92
is connected to the bottom end of the As shown in FIG. 2, the selvage crusher 22 has an inlet at the top for receiving the cut film selvage 23a, a rotary slitter 222 below which cuts the selvedge into thin strips, and a rotary slitter 222 that cuts the selvedge into strips into squares. A rotary cutter 223 that cuts the waste material into chips of the shape, and a rotary cutter 224 that further crushes the waste material that was not cut completely by the rotary cutter 223 and remained in the form of threads.
and a screen 225 for dropping waste materials cut into small pieces to a predetermined size, and a drop port 226 below the screen 225.
The second duct 92 is connected to the second duct 92, and the side opposite to the second duct 92 is configured to be able to suck in outside air.

In FIG. 2, 227 is a fixed blade facing the rotary cutter 223, and 228 is a fixed blade facing the rotary cutter 224. Scrap wood 1
In the secondary feeder 10, the weight of waste material in the primary waste material feeder 10 is measured by a weight measuring device 101, and this measured value is input to the ear collection computer 2. Further, the motor 13 that drives the waste material secondary feeder 12 is operated based on instructions from the stub collection computer 2, and the amount of waste material supplied per unit time in the waste material secondary feeder 12 is fed back to the stub collection computer 2.

The plasticizer is stored in a tank 6, and is pumped into the extruder 1 by a plasticizer pump 8 driven by a motor 7.
7 is supplied to the supply port 17a. The additive is stored in a tank 3, and is supplied to the extruder 17 supply port 17a by an additive pump 5 driven by a motor 4. Motors 7 and 4 that drive pumps 8 and 5 are operated based on instructions from main computer 1, respectively.

The gear pump 18 is rotationally driven by a motor 19. The motor 19 is operated based on instructions from the main computer 1. A pressure sensor S is provided in the flow path between the extruder 17 and the gear pump 18, and the output of this sensor S is input to the main computer 1.

The main computer 1 and the ear collection computer 2 are connected so that they can communicate with each other. A method of extrusion molding a plasticized polyvinyl butyral film using the extrusion molding apparatus according to claim 1 configured as described above is as follows.

Initially, based on instructions from the main computer 1 which operates according to a predetermined program, the drive motor 15 of the resin feeder 14 is started, and the drive motor 7 of the plasticizer pump 8 and the additive pump 5 are started. The drive motors 4 of 1 and 4 are started to operate respectively, and polyvinyl butyral is supplied from the resin feeder 14.
The plasticizer in the plasticizer tank 6 is pumped from the pump 8 to the pump 5.
From then on, the additives in the additive tank 3 are transferred to the extruder 1.
7 to the supply port 17a.

In the extruder 17, the screw 171 is rotated by the motor 16 in advance, and the heater is energized to knead and melt the supplied raw materials (resin, plasticizer, and additives), and the extruder 17 and supplies the molten raw material to the gear pump 18.

The gear pump 18 is started to rotate in advance by a motor 19 before the molten raw material arrives, and the molten raw material extruded from the extruder 17 is forced into the wide slit die 20. In this way, the film 23 is melt-extruded and molded into a sheet from the die 20. The extruded film 23 is separated into both ears 23a by an ear slitter (not shown).
are cut continuously along the length. In this way, a film of a predetermined width and thickness is manufactured.

The removed ears 23a are guided to the ear crusher 22, where they are cut into strips with a width of 4 mm by the rotary slitter 222, and then cut into strips with a width of 4 mm by the rotary cutter 223. Chop into pieces. The thread-like portion that could not be cut by the rotary cutter 223 is further crushed by the lower rotary cutter 224. Out of the waste materials crushed in this way, those of a predetermined size are passed through the screen 225.
The waste material is lowered to the lower region 226 through the waste material feeder 10, and guided to the cyclone 9 of the waste material primary feeder 10 by the action of the blower 21 which has been started in advance. The waste material that reaches the cyclone 9 and is chopped into pieces falls within the cyclone 9 and is collected in the primary waste material feeder 10. The waste material in the waste material primary feeder 10 is transferred to the waste material secondary feeder 12 by the operation of the motor 11.
supplied to The waste material in the waste material secondary feeder 12 is supplied to the extruder 17 by operating the motor 13 based on instructions from the waste material collection computer 2.

When the waste material starts to be supplied to the supply port 17a of the extruder 17 in this way, the supply port 17a of the extruder 17
The raw materials supplied to a are polyvinyl butyral, plasticizers, additives and waste materials. Thereafter, as long as the waste material is supplied, the film 23 will be formed while reusing this waste material.

[0029] Furthermore, the waste material primary feeder 10 and the waste material 2
In order to prevent blocking of waste material in the next feeder 12, the duct 91, the duct 92, the waste material primary feeder 10
, the waste material secondary feeder 12, the cyclone 9, etc. are preferably jacketed and cooled by passing cold water through them to cool the waste material.

The blending proportions of polyvinyl butyral, plasticizer, additives and waste materials constituting the raw materials are determined as follows. That is, the weight of the waste material accumulated in the waste material primary feeder 10 is measured by the measuring device 101, and the result is sent to the main computer 1 via the ear collection computer 2.
The main computer 1 determines the blending ratios of polyvinyl butyral, plasticizers, additives, and waste materials according to a predetermined program based on the weight of the waste material, and based on this determination, the motor 1 of the resin feeder 14
5. Plasticizer pump motor 7 and additive pump motor 4
and the ear collection computer 2.
The motor 13 of the waste material secondary feeder 12 is operated via. The amount of resin supplied per unit time in the resin feeder 14 is fed back to the main computer 1, and corrected so that polyvinyl butyral is supplied based on the determined blending ratio. Further, by feeding back the amount of waste material per unit time supplied from the waste material secondary feeder 12 to the ear collection computer 2, correction is made so that the waste material supply is performed based on the determined blending ratio.

The motor 15 of the resin feeder 14, the motor 7 of the plasticizer pump 8, the motor 4 of the additive pump 5, and the motor 13 of the secondary waste material feeder 12 are operated according to the weight of the waste material stored in the primary waste material feeder 10. The extruder 17 is operated so as to achieve the blending ratio of the raw materials determined based on this, and the total amount of raw materials supplied to the supply port 17a of the extruder 17 is always a predetermined amount.

[0032] The mixing ratio of the waste material is determined by, for example, measuring the amount of waste material stored in the waste material primary feeder in 2 kg increments, and if the amount of waste material stored is 0 to 2 kg, the amount of waste material is 0% of the total amount of raw material supplied. If the storage amount is 2 to 4 kg, waste wood should be 1%,
When the amount of waste material stored is 4 to 6 kg, the amount of waste material is 2%, and when the amount of waste material stored is 20 to 22 kg, the amount of waste material is determined to be 10%.

In this case, when the mixing ratio of waste material changes, for example from 1% to 2%, from 2% to 3%, and conversely from 3% to 2%, the main computer 1 and the ear collection computer 2 By employing delay compensation or feedforward control in communication, the blending ratio can be changed even more smoothly. The delay compensation measures the amount of polyvinyl butyral supplied per unit time and determines the target amount of waste material supplied by the main computer 1. Although this control may be used at all times, it is only used when the ratio is changed. You may. By performing such control, even if waste material transportation suddenly stops, the proportion of waste material in the blending ratio smoothly shifts to 0%, so that no problem occurs in film production.

The procedure for determining the blending ratio explained above is illustrated in the flowchart of FIG. 3. In addition, in the synthetic resin extrusion molding method of the invention according to claim 1, in the extrusion molding method as described above, the pressure of the molten raw material in the passage between the extruder 17 and the gear pump 18 is detected by the pressure sensor S. Then, while inputting the sensor output to the computer 1, the rotation speed of the pump motor 19 is controlled so that the pressure is within a predetermined range. As a result, variations in the thickness of the resulting film 23 are reduced. Note that the method of controlling the pressure of the molten raw material is not limited to the above method,
Other known methods can also be employed.

(Example 2) Next, an example of the invention as claimed in claim 2 will be described in the case where a plasticized polyvinyl butyral film is extruded.

FIG. 4 shows the overall configuration of an extrusion molding apparatus for producing a film, and FIG. 5 shows a schematic flowchart for controlling the supply of raw materials to the extruder. Note that in FIG. 4, the same components as in the first embodiment described above are given the same reference numerals.

Since this second embodiment has many parts that overlap with the first embodiment described above, only the different parts will be explained in detail. As in Example 1, extruder 1
Polyvinyl butyral, which is a new raw material resin, waste materials, plasticizers, and additives are supplied to the supply port 17a of No. 7, and the polyvinyl butyral is supplied from a resin feeder 14 driven by a motor 15. The amount of resin supplied per unit time by the resin feeder 14 is determined by the main computer 1 through the resin supply computer 2a.
will be fed back to.

[0038] The ear waste material crushed by the ear crusher 22 is
The waste material is stored in both the waste material primary feeder 10 driven by the motor 11 and the waste material secondary feeder 12 driven by the motor 13, and is supplied from the waste material secondary feeder 12 to the supply port 17a of the extruder 17. The motor 13 is operated based on instructions from the waste material supply computer 2, and the amount of waste material supplied per unit time by the waste material secondary feeder 12 is fed back to the main computer 1 through the waste material supply computer 2.

In the waste material primary feeder 10, the waste material 1
The weight of waste material in the next feeder 10 is measured by a gravity measuring device 101, and the value is input into the main computer 1. Further, in the waste material secondary feeder 12, the weight of waste material in the waste material secondary feeder 12 is measured by the gravity measuring device 102, and the value is inputted to the main computer 1 through the waste material supply computer 2.

[0040] In addition, most of the extrusion molding equipment is the same as in Example 1.
It has a similar configuration. A method of extrusion molding a plasticized polyvinyl butyral film using the extrusion molding apparatus configured as described above is as follows.

Initially, based on instructions from the main computer 1 which operates according to a predetermined program (the main computer 1 and the resin supply computer 2a
are connected to each other so as to communicate with each other), the drive motor 15 of the resin feeder 14 is started, and the drive motor 7 of the plasticizer pump 8 and the additive pump 5 are started.
The drive motors 4 of 1 and 2 are started to operate respectively, thereby supplying polyvinyl butyral from the resin feeder 14, the plasticizer from the plasticizer tank 6 from the pump 8, and the additive from the additive tank 3 from the pump 5. It is supplied to the supply port 17a of the extruder 17.

In the extruder 17, the screw 171 is rotated by the motor 16 in advance, and the heater is energized to knead and melt the supplied raw materials (resin, plasticizer, and additives), and the extruder 17 and supplies the molten raw material to the gear pump 18.

The gear pump 18 is started to rotate in advance by the motor 19 before the molten raw material arrives, and the molten raw material extruded from the extruder 17 is forced into the wide slit die 20. In this way, the film 23 is melt-extruded and molded into a sheet from the die 20. The extruded film 23 is separated into both ears 23a by an ear slitter (not shown).
are cut continuously along the length. In this way, a film of a predetermined width and thickness is manufactured.

The removed ears 23a are guided to the ear crusher 22, where they are cut into square chips by a rotary slitter and a rotary cutter, and then dropped through a screen and passed through a blower that has been started in advance. At 21, the waste material is guided to the cyclone 9 of the primary feeder 10. The waste material that has reached the cyclone 9 falls through the cyclone 9 and is stored in the waste material primary feeder 10. Further, a part of the waste material in the primary waste material feeder 10 is supplied to the secondary waste material feeder 12 by the operation of the motor 11, and is also stored in the secondary waste material feeder 12. The waste material in the waste material secondary feeder 12 is collected by operating the motor 13 based on instructions from the main computer 1 (the main computer 1 and the waste material supply computer 2 are connected to each other so as to communicate with each other). ,
It is supplied to the supply port 17a of the extruder 17.

In this case, when the amount of waste material in the primary waste material feeder 10 and the waste material secondary feeder 12 reaches a certain amount or more, the supply of waste material to the supply port 17a of the extruder 17 is started. Then, when the amount of waste material in the secondary waste material feeder 12 falls to the filling request level, a filling request is made to the primary waste material feeder 10. Waste material primary feeder 10
When this filling request is received, a portion of the waste material is supplied to the waste material secondary feeder 12 until the filling completion level is reached, and then the feeding is stopped until the next filling request is made.

Through such operations, a considerable amount of waste material is stored in the waste material secondary feeder 12 with a margin, and when the amount of waste material generated is constant, the total amount of waste material from the waste material primary feeder and the waste material secondary feeder is becomes constant, and it becomes possible to set the amount of waste material supplied to the extruder by the waste material secondary feeder to be constant. In addition, when determining the blending ratio of new raw material resin, waste material, and plasticizer only according to the amount of waste material in the primary waste material feeder 10, even when the amount of waste material generated is constant, the amount of waste material in the primary waste material feeder is constant. Instead, waste material 2
The amount of waste material fed to the extruder by the next feeder fluctuates, which increases the number of changes in the blending ratio of new raw material resin, waste material, and plasticizer.

When the waste material starts to be supplied to the supply port 17a of the extruder 17 in this way, the supply port 17a of the extruder 17
The raw materials supplied to a are polyvinyl butyral, plasticizers, additives and waste materials. Thereafter, as long as the waste material is supplied, the film 23 will be formed while reusing this waste material.

The blending proportions of polyvinyl butyral, plasticizer, additives and waste materials constituting the raw materials are determined as follows. That is, the waste materials stored in the primary waste material feeder 10 and the waste materials stored in the secondary waste material feeder 12 are measured by gravity measuring instruments 101 and 102, respectively, and the results are input into the main computer 1. In the main computer 1, the waste material primary feeder 1
The blending proportions of polyvinyl butyral, plasticizers, additives, and waste materials are determined according to a predetermined program according to the total amount of waste materials in 0 and waste materials in the secondary waste material feeder 12, and this determined blending ratio is determined. Based on the instructions of the main computer 1 according to the proportion, the resin computer 2
a and the waste material supply computer 2 to the motor 15 of the resin feeder 14 and the motor 13 of the secondary waste material feeder 12.
At the same time, the motor 7 of the plasticizer pump 8 and the motor 4 of the additive pump 5 are operated. Instructions to each motor are given at the same time.

Motor 15 of resin feeder 14, motor 13 of waste material secondary feeder 12, motor 7 of plasticizer pump 8
, the motor 4 of the additive pump 5 is connected to the waste material primary feeder 10
The operation is performed so as to achieve the blending ratio of raw materials determined based on the total amount of waste materials stored in the secondary waste material feeder 12, and the total amount of raw materials supplied to the supply port 17a of the extruder 17 is always predetermined. drive in such a way that the amount of

In addition, in this example, in addition to the new raw material resin, waste material, and plasticizer, the supply amount of additives also depends on the total amount of waste material stored in the waste material primary feeder and the waste material secondary feeder. However, when no additive is added, or when the amount of additive added is extremely small, the motor 15, The motor 7 and the motor 13 may also be controlled.

[0051] The mixing ratio of the waste materials is determined by, for example, measuring the total amount of stored waste materials stored in the primary waste material feeder and the secondary waste material feeder in 1 kg increments, and if the amount of stored waste materials is 0 to 1 kg, the raw material is 0% of the total supply amount is waste wood, and the amount of waste material stored is 1 to 2 kg.The amount of waste material is 1%, and the amount of waste material stored is 2 to 2 kg.
For 3 kg, waste material is 2%, ...the amount of waste material stored is 20~2
For 1 kg, it is determined that the waste material is 20%.

In this case, if each raw material supply device is selected and used so that the response speed of each raw material supply device is almost the same, for example, from 1% to 2%, from 2% to 3%, from 3% to When the blending ratio of waste materials changes from 2% to 2%, the blending ratio can be changed smoothly. therefore,
There is no need to correct the actual supply amount by employing delay compensation or feedforward control in communication between each computer, and the control software becomes simpler.

[0053] In addition, for example, 5 to 2
If you use a highly responsive device that stabilizes in about 0 seconds, you can change the ratio at a large pitch. therefore,
It is also possible to respond to sudden size changes or fluctuations in the amount of waste material supplied from offline with a small storage amount.

Furthermore, when using high-response equipment, in addition to the changes based on the above levels, for example, from 1% to 3%.
%, 3% to 5%, 5% to 3% and so on.
By programming the rate to change at twice the pitch, the response to changes in the amount of waste material used can be further improved, allowing for a smaller storage amount.

The procedure for determining the blending ratio explained above is illustrated in the flowchart of FIG. 5. Also, in the synthetic resin extrusion molding method of the invention as claimed in claim 2, the pressure of the molten raw material in the passage between the extruder 17 and the gear pump 18 is detected by the pressure sensor S. Then, while inputting the sensor output to the computer 1, the rotation speed of the pump motor 19 is controlled so that the pressure is within a predetermined range. As a result, variations in the thickness of the resulting film 23 are reduced. Note that the method of controlling the pressure of the molten raw material is not limited to the above method,
Other known methods can also be employed.

[0056]

[Effects of the Invention] As described above, according to these invented methods, a new raw material resin, waste material, and plasticizer are used as raw materials, the raw materials are melted and extruded with an extruder, and the extruded molten raw materials are extruded with a melt pump. In the synthetic resin extrusion molding method, which obtains molded products by feeding it to a die, new raw material resins,
The blending ratio of waste material and plasticizer can be smoothly changed in response to the above changes and fluctuations. In addition, the pressure of the molten raw material discharged from the extruder is determined by driving the melt pump to keep the pressure within a predetermined range based on the raw material pressure measured between the extruder and the melt pump. Since it is controlled and no molten raw material is discharged to the outside, there is an advantage that there is no raw material loss and no effort is required to dispose of the discharged raw material.

Furthermore, according to the method of the invention according to claim 2,
The waste material is not directly fed to the extruder, but is first
The waste material is stored in the secondary feeder and the secondary feeder, and the storage amount of each is measured here, and depending on the total amount of waste material,
The blending ratio of new raw material resin, waste material, and plasticizer is determined, so even if the amount of waste material fluctuates significantly due to a major change in product size or a failure in the waste material system, the amount of raw material will be adjusted accordingly. The blending ratio can be smoothly controlled. Therefore, the raw material dispensing device can follow this smoothly, and there will be no trouble at all in extrusion molding.

Moreover, by accumulating waste material in both the waste material primary feeder and the waste material secondary feeder, when the amount of waste material generated is constant, the amount of waste material fed to the extruder by the waste material secondary feeder can be set to be constant. This makes it possible to reduce the number of changes in the blending ratio of new raw material resin, waste material, and plasticizer.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of the inventive method according to claim 1.

2 is a schematic cross-sectional view of the ear crusher in the apparatus shown in FIG. 1; FIG.

FIG. 3 is a schematic flowchart of controlling the supply of raw materials to an extruder in the method of the invention according to claim 1.

FIG. 4 is a schematic explanatory diagram of the inventive method according to claim 2.

FIG. 5 is a schematic flowchart of controlling the supply of raw materials to an extruder in the method of the invention according to claim 2.

[Explanation of symbols]

1 Main computer 2 Ear collection computer or waste material supply computer 2a Resin supply computer 5 Additive pump 8 Plasticizer pump 10 Waste material primary feeder 12 Waste material secondary feeder 14 Resin feeder 17 Extruder 18 Melt pump 20 Die 22 Ear crusher S pressure sensor

Claims (3)

[Claims] Claim 1: Using new raw material resin, waste material, and plasticizer as raw materials, supplying these raw materials to an extruder and melt extrusion,
In a synthetic resin extrusion molding method in which a molded product is obtained by supplying an extruded molten raw material to a die using a melt pump, there are a step of supplying waste material to an extruder via a waste material primary feeder and a waste material secondary feeder; The mixing ratio of new raw material resin, waste material and plasticizer is determined according to the amount of waste material in the primary feeder, and the process of supplying a predetermined amount of raw materials to the extruder according to the determined mixing ratio, and the extruder and melting process. measuring the pressure of the molten raw material between the melt pump and the melt pump, and driving and controlling the melt pump so that this pressure becomes a predetermined pressure;
A synthetic resin extrusion molding method including. [Claim 2] Using new raw material resin, waste material, and plasticizer as raw materials, supplying these raw materials to an extruder and melt extrusion,
In a synthetic resin extrusion molding method in which a molded product is obtained by supplying an extruded molten raw material to a die using a melt pump, there are a step of supplying waste material to an extruder via a waste material primary feeder and a waste material secondary feeder; The mixing ratio of new raw material resin, waste material, and plasticizer is determined according to the total amount of waste material accumulated in both the primary feeder and waste material secondary feeder,
A synthetic resin extrusion molding method including the step of supplying a predetermined amount of raw materials to an extruder according to the determined blending ratio. 3. The synthetic resin according to claim 2, comprising the step of measuring the pressure of the molten raw material between the extruder and the melt pump, and driving and controlling the melt pump so that this pressure becomes a predetermined pressure. Extrusion method.