JP4056907B2 - Apparatus and method for supplying resin raw material for synthetic resin molding machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus for supplying a resin raw material to a synthetic resin molding machine, more specifically, a synthesis by a molding machine while quickly discharging water vapor and gas generated during heating and conveyance by a heating cylinder comprising a screw and a casing. The present invention relates to a supply device and a supply method that do not generate a silver strip or a cavity in a resin molded product.
[0002]
[Prior art]
In the production of synthetic resin molded products by injecting molten resin into a synthetic resin molding machine (extrusion molding machine, injection molding machine) while transporting and melting the resin raw material with a heating cylinder consisting of a screw and casing, In the casing of the heating cylinder that is the melting region, water vapor due to moisture adhering to the resin raw material, or decomposition gas or volatile gas due to the resin component (monomer, oligomer or solvent) is generated. If such water vapor and gas are not sufficiently removed before reaching the molding machine, silver strips and cavities and the like are generated in the synthetic resin molded product produced by the molding machine, causing a product defect.
[0003]
Patent Document 1 discloses a gas or moisture removing device for a synthetic resin molding machine so as not to cause such product defects. In Patent Document 1, an inner cylinder part (material introduction pipe) and an outer cylinder part (cylindrical lower body) surrounding the inner cylinder part (material introduction pipe) are provided at a resin raw material inlet (material supply inlet) of a heating cylinder constituting the molding machine. The heating cylinder is sucked and exhausted through the raw material charging port by a suction air source connected to the outer cylindrical portion while charging the resin raw material from the inner cylindrical portion to the heating cylinder.
[0004]
Patent Document 2 is a further improvement, in which undried resin pellets are supplied into a cylinder of an injection molding machine to perform the first injection, and the quality of the resin purge injected after a predetermined time has elapsed from the first injection. A method of performing injection molding by performing injection with an optimum deposition amount per unit shot obtained by inspection is disclosed.
[0005]
[Patent Document 1]
No. 7-2182
[Patent Document 2]
WO99 / 33630 gazette
[0006]
[Problems to be solved by the invention]
The gas, water vapor, etc. (hereinafter referred to as gas) removal device disclosed in Patent Document 1 is a gas generated in a casing when the resin raw material is heated and melted while being conveyed toward a molding machine by a heating cylinder. However, there are still problems to be solved as follows.
[0007]
That is, as the continuously supplied resin material is conveyed by the heating cylinder toward the injection port (nozzle) to the former molding machine, the inside of the casing of the heating cylinder is closed by the molten resin. Therefore, the gas generated in the front side portion is not sufficiently exhausted.
[0008]
Further, the behavior is such that the charged resin raw material once accumulates and stays in the vicinity of the resin raw material inlet and is then fed into the casing. FIG. 5 is a diagram for explaining such a phenomenon. In FIG. 5, the front end portion of the inner cylinder portion n is located at a substantially central portion of the raw material input port h. When the resin raw material p is continuously input from the inner cylindrical portion n, the raw material input port is as shown in the figure. While the resin raw material p is temporarily accumulated and stayed in the vicinity of h, it is fed to the front side by the screw s. For this reason, the inlet portion of the casing c may be clogged with the remaining resin material, and the exhaust from the outer cylinder portion g is mainly leaked air from the end portion of the screw as shown by the arrows in the figure. Thus, the exhaust efficiency of the front side portion of the casing c is reduced.
[0009]
As described above, if the exhaust in the casing is not sufficiently performed, the molten resin is injected into the molding machine while containing the gas, which causes the occurrence of silver strips and cavities, and product defects still occur. There was a thing. In addition, in the case of the method of Patent Document 2, since injection is always performed with an optimum deposition amount, such a problem does not occur, but it is necessary to perform resin purge many times for each molding process, and production efficiency is improved. There was a problem of getting worse.
[0010]
The present invention has been made in view of the above circumstances, and exhausts the gas generated in the casing of the heating cylinder quickly and without stagnation, resulting in poor quality such as silver stripes and cavities in the product by the molding machine. An apparatus and method for supplying a resin raw material for a synthetic resin molding machine that is not allowed to be provided.
[0011]
[Means for Solving the Problems]
  In order to solve the above problems, a resin raw material supply apparatus for a synthetic resin molding machine according to the invention of claim 1 is a resin raw material installed at a raw material inlet of a heating cylinder of a synthetic resin molding machine comprising a clew and a casing. In the raw material charging port, a raw material charging inner cylinder portion and an exhaust outer cylinder portion surrounding the inner cylindrical portion and connected to the suction device are connected in series. Provided with means for sucking and transporting resin raw material deposited at the raw material inlet and recycling it to the upstream side of the raw material supply line constituting the above supply deviceA damper is provided on the inner cylinder part, an air release valve in the inner cylinder part is provided between the damper and the inner cylinder part, and is collected in the middle of the suction line in the suction device. And a means for recycling is constituted by the damper, the air release valve, the suction line, and the collector.
[0012]
According to such a configuration, the gas generated in the casing of the heating cylinder is sequentially discharged by the suction device, so that no gas stays in the molten resin that causes a silver strip or a cavity. And, since this suction device is equipped with means for sucking and transporting the resin raw material deposited at the raw material inlet and recycling it to the upstream side of the supply line constituting the supply device, the resin raw material deposited at the raw material inlet is Accordingly, the resin material is not blocked in the vicinity of the material inlet, and the discharge of the gas generated in the casing is not delayed. Moreover, since the resin raw material removed here is recycled and reused upstream of the supply line constituting the supply device, it is very efficient without waste. Moreover, since the suction device for exhausting the inside of the heating cylinder also serves as a suction air source for air transportation for recycling, the entire resin raw material supply line is compactly configured without increasing its size.
[0014]
  And the means for recycling configured as described above is claimed.2And a control means for controlling the opening and closing of the damper and the air release valve. The control means closes the damper and opens the air release valve after the resin material is completely charged into the heating cylinder. It is characterized by being controlled.
[0015]
In the recycling means configured as described above, when the damper is closed and the air release valve is opened after the resin raw material is charged into the heating cylinder, the air flowing from the air release valve becomes the carrier gas. Then, the resin raw material deposited in the vicinity of the raw material inlet is sucked and air-transported through the suction line and collected by the collector. The collected resin raw material is recycled to the upstream side of the raw material supply line and reused.
[0016]
  A discharge port of a resin material supply machine is continuously provided on the damper.3), And the damper is opened at least when the feeder is operated.4In addition, a charge tank constituting the end of the raw material supply line is installed on the feeder, and a second raw material that can be hermetically shut off from the upstream raw material supply line at the upper raw material input port of the charge tank. The damper is provided (claim)5It is desirable to configure.
[0017]
  If comprised in this way, the resin raw material supplied from a raw material supply line will be once stored in a charge tank, and will be injected | thrown-in to the said raw material inlet, after that the discharge amount is adjusted with the said feeder. The second damper is opened when the resin raw material is charged and stored in the charge tank.6However, when producing a resin molded product while feeding the resin raw material to the raw material inlet of the molding machine superheating cylinder by the raw material feeder, the damper under the feeder is opened and the second damper is closed. Thus, the upstream material supply line is hermetically cut off. Therefore, when exhausting the casing by the suction device, there are few leaks, and the decompression and exhausting in the casing can be performed efficiently.
[0018]
  Claim7The invention according to claim 1 to claim 16In any one of the inventions, the suction device includes means for pulsating suction air. If such a pulsating means is employed, the clogging or bridging of the resin raw material does not occur in the casing due to the pulsating operation of the exhaust flow, and the gas generated on the front side is discharged quickly and without stagnation. In particular, this exhaust flow has a larger pulsating action energy than steady exhaust, so even if there is a tendency for resin material blockage or bridging in the casing, it will collapse and obstruction or bridging will occur. It is prevented.
[0019]
  Claim8The present invention relates to a method of supplying a resin raw material for a synthetic resin molding machine using the supply device, wherein the resin raw material is introduced into a raw material introduction port while the casing of the heating cylinder is sucked and decompressed by a suction device. After the charging is completed, the resin raw material deposited on the raw material inlet is sucked and transported by the suction device and recycled to the upstream side of the supply line constituting the supply device.
[0020]
  Then, the suction and transportation of the resin raw material deposited on the raw material charging port is performed by closing the damper provided between the inner cylinder portion and the upper material discharging machine outlet after the resin raw material charging is completed. This is done by opening the air release valve of the cylinder part.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an overall configuration diagram showing a resin raw material supply system to a synthetic resin molding apparatus in which the present invention is adopted, and FIG. 2 is a schematic enlarged longitudinal sectional view of a main part of the first embodiment in the system. is there.
[0022]
In FIG. 1, reference numeral 1 denotes a main hopper for storing synthetic resin pellets as a main raw material of the present system, and a screw feeder (main raw material feeder) 1a for discharging the raw material is attached to the lower end thereof. Reference numeral 11 denotes a weighing hopper that quantitatively measures the main raw material discharged from the main hopper 1 by the load cell 11a together with the recycled raw material described later. Although not shown in the figure, a colorant can be appropriately added to the weighing hopper 11.
[0023]
Reference numeral 12 denotes an air transportation line, and the resin raw material weighed by the weighing hopper 11 is pneumatically transported from the suction cylinder 11 b at the lower end of the weighing hopper 11 along the air transportation line 12 and collected by the suction hopper 2. . 13 is a pneumatic blower for air transportation, and 13a is a filter. In the figure, the suction air from the suction blower 13 is discharged to the atmosphere, but the downstream side of the suction blower 13 is connected to the air transport line 12 via a three-way valve and a heat exchanger, and airflow mixing / preliminary heating is performed. It is also possible to constitute an air circulation system for temperature. In this way, the resin raw material collected in the suction hopper 2 is preliminarily heated in the suction hopper 2 by contact with heated air. Reference numeral 21 denotes a level sensor that detects whether or not the resin raw material in the suction hopper 2 has reached a predetermined amount.
[0024]
A charge tank 3 is connected to the lower end of the suction hopper 2 via a second damper 31 (upper damper) operated by an air cylinder 31a, and the resin raw material collected in the suction hopper 2 is the damper 31. Is opened into the charge tank 3 from the upper end raw material inlet 32. Reference numeral 33 denotes a level sensor that detects whether or not the resin material in the charge tank 3 has reached a predetermined amount. The damper 31 is configured to hermetically shut off the charge tank 3 and its upstream supply line.
[0025]
At the lower end of the charge tank 3, a screw feeder (raw material supply machine) 4 that is rotationally driven by a variable speed motor 41 is installed. Further, a discharge port 43 that leads to an inner cylinder portion 5 to be described later of the screw feeder 4 Via a damper 42 (lower damper) operated by an air cylinder 42 a, it is connected to double cylinders 5 and 6, which will be described later, and connected to a raw material inlet 70 of the synthetic resin molding machine 7. As shown in FIG. 2, the synthetic resin molding machine 7 includes a heating cylinder 71 including a screw 71a and its casing 71b, a hydraulic cylinder 72 that moves the screw 71a forward, a motor 73 that rotates the screw 71a, and The heater 74 is provided around the casing 71b, and an injection or extrusion mold 75 is disposed in close contact with the tip nozzle portion 71c of the heating cylinder 71.
[0026]
The resin material P input from the material input port 70 is heated and melted by the heater 74 while being fed in the casing 71b toward the nozzle portion 71c by the rotation of the screw 71a. The molten resin is compressed with high density in the vicinity of the nozzle portion 71c at the tip. Thereafter, the operation of the ram 72 a of the hydraulic cylinder 72 causes the screw 71 a to move to the left in FIGS. 1 and 2, whereby molten resin is injected from the nozzle portion 71 c and injected into the core of the mold 75. After cooling and curing, the mold 75 is removed and the synthetic resin molded product is taken out.
[0027]
The double cylinder includes an inner cylinder part 5 for raw material charging and an exhaust outer cylinder part 6 surrounding the inner cylinder part 5. The inner cylinder part 5 is connected to the discharge port 43 of the screw feeder 4 via a damper 42, and the resin raw material discharged from the screw feeder 4 passes through the inner cylinder part 5 and is formed from the raw material input port 70 through the molding machine. The heating cylinder 71 is charged. The raw material charging port 70 is provided with detecting means (level sensor) 51 for detecting whether or not the resin raw material is deposited in the vicinity thereof. The level sensor 51 will be described later.
[0028]
The exhaust outer cylinder portion 6 is disposed so as to surround the inner cylinder portion 5, and a lower end opening portion thereof communicates with the raw material charging port 70. A suction port 61 is provided in the middle of the outer cylinder portion 6. A suction line 80 is connected to the suction port 61 by a pipe, and a collector 83 is disposed in the middle of the suction line 80, and the primary side of the collector 83 is exhausted via a pulsation generator 82. A suction blower 81 is connected by piping. Two dampers 84 a and 84 b that are operated by an air cylinder are provided at the upper and lower sides of the lower discharge cylinder 84 of the collector 83. The pulsation generator 82 is composed of a valve body that is operated by a continuously rotating motor (not shown). By alternately opening and closing the suction line 80 as the valve body rotates, the suction air flow in the suction line 80 is given strength. As a result, the suction airflow is pulsated. By the pulsating suction devices 81 and 82, the inside of the heating cylinder 71 of the molding machine is depressurized to about 600 torr.
[0029]
Thus, when the screw feeder (raw material feeder) 4 is operated with the upper damper 31 closed and the lower damper 42 opened, the resin raw material P in the charge tank 3 is transferred to the outlet 43 and the inner cylinder portion 5. Further, the raw material is introduced into the heating cylinder 71 of the molding machine 7 through the raw material introduction port 70. The charged resin material P is sequentially fed to the front side of the casing 71b by the rotation of the screw 71a, and is heated and melted by the heater 74 during this feeding.
[0030]
Since the suction blower 81 is connected to the exhaust outer cylinder part 6 through the suction port 61, the inside of the outer cylinder part 6 is filled when the resin material is charged and the resin material in the casing 71b is fed. , The inside of the casing 71b is sucked under reduced pressure through the raw material inlet 70, and the gas generated in the casing 71b is sequentially discharged. At this time, since the damper 31 hermetically shuts off the charge tank 3 and the supply line upstream thereof, there is no leakage at this portion, and vacuum suction is efficiently performed.
[0031]
In addition, since the pulsation is applied to the suction airflow by the pulsation generator 82, a large working energy is expressed by the pulsation compared to the steady exhaust, and the molten resin is blocked or bridged in the casing 71b of the heating cylinder 71. Even if there is a tendency to occur, it is destroyed and its occurrence is prevented in advance. Accordingly, a gap through which gas can flow is always formed in the casing 71b, and even if there is a slight leak from the screw end, the gas generated along with the melting of the resin at the front side in the casing 71b is sequentially and efficiently discharged. The
[0032]
On the other hand, an air introduction port 52 is formed on the side wall of the cylindrical portion between the lower damper 42 and the inner cylinder portion 5, and an air release valve 53 that is operated by an electromagnetic valve is connected to the atmosphere introduction port 52 by piping. ing. The atmospheric release valve 53, the lower damper 42, the suction line 80 and the collector 83 (including the suction blower 81) constitute a means 8 for recycling the deposited resin material.
[0033]
That is, after the raw material supply device 4 completes the introduction of the resin raw material from the raw material input port 70 into the heating cylinder 71 of the molding machine 7, the lower damper 42 is closed and the air release valve 53 is opened. A large amount of air flows in from 52, and this becomes a carrier gas, and the resin raw material P deposited near the raw material charging port 70 is sucked from the suction port 61 of the cylindrical portion 6, and is transported by air through the suction line 80 and is collected. It is collected by 83. Therefore, since the next raw material charging / molding process is executed in the state where the resin raw material is not accumulated near the raw material charging port 70, the resin 71 is not blocked in the casing 71b of the molding machine 7. The gas is discharged quickly.
[0034]
Next, the operation control of each part will be described with reference to the operation time chart of FIG. 3 and the control block diagram of FIG. In FIG. 3, as a previous step, the air transport suction blower 13 is activated by the detection signal of the level sensor 21 of the suction hopper 2, and a predetermined amount of resin raw material already measured by the measurement hopper 11 is sucked as will be described later. Pneumatically transported from the cylinder 11b and collected by the suction hopper 2. If the level sensor 21 generates a full signal, the suction blower 13 stops. These operations are performed based on the detection signal of the level sensor 21 independently of the following steps. During this time, the upper damper 31 is closed, and is hermetically shut off from the charge tank 3 and below.
[0035]
At the start of the molding process, the molding machine 7 is in a standby state in which the holding pressure in the previous process is released and the mold is clamped after demolding. In this state, the hydraulic cylinder 72 is unloaded but the ram 72a is In the extended state, the screw 71a is thus waiting in the forward position within the casing 71b. Further, the exhaust suction blower 81 is always on. When the lower damper 42 is closed and the upper damper 31 is opened, the resin material in the suction hopper 2 is charged into the charge tank 3 by natural fall. When the level sensor 33 in the charge tank 3 generates a full signal, the upper damper 31 is closed and the lower damper 42 is opened. The lower damper 42 is closed when the upper damper 31 is opened, and the inside of the heating cylinder 71 of the molding machine 7 is maintained in a reduced pressure state when the resin raw material is charged into the charge tank 3. The
[0036]
In this state, the charging of the resin raw material P to the molding machine 7 and the preparation for the molding process are completed. When the measurement start signal sw1 is issued from the molding machine 7 (t0), the motor 73 of the molding machine 7 is turned on, and the screw 71a starts to rotate in the direction A in FIG. After a short time t1, the feeder (screw feeder) 4 is turned on and its operation starts. The delay time t1 is set as a time sufficient to feed the resin material P deposited near the material input port 70 of the molding machine 7 to the front side in the heating cylinder 71. If it is demonstrated that the resin raw material does not accumulate near the raw material inlet 70, the delay time t1 is not particularly required.
[0037]
As described above, the resin raw material P charged by the operation of the feeder 4 is sequentially fed to the front side in the heating cylinder 71, but depending on the discharge amount from the feeder 4, the resin raw material P is placed near the raw material inlet 70. Raw materials may accumulate and stay. When the level sensor 51 provided in the vicinity of the raw material inlet 70 detects this deposited resin, a signal is generated, and the feeder 4 is thereby stopped. Since the rotation of the screw 71 a continues while the feeder 4 is stopped, the deposited resin is fed to the front side in the heating cylinder 71. Thereafter, when there is no more resin material accumulated, the level sensor 51 generates no signal, and the operation of the feeder 4 is resumed in response to this.
[0038]
This is repeated until the measurement completion signal sw2 is issued from the molding machine 7 (t2). As described above, since the operation of the feeder 4 is controlled based on the output signal of the level sensor 51, the resin raw material accumulation in the vicinity of the raw material inlet 70 is suppressed, and the closed state in which the exhaust in this vicinity is inhibited. Is less likely to occur. Therefore, the gas generated on the front side of the heating cylinder 71 is sequentially discharged from the outer cylinder portion 6 through the suction port 61 and from the suction blower 81, and there is no generation of silver stripes or cavities due to the gas staying in the molten resin. High quality molded products are produced.
[0039]
The resin raw material P charged as described above is heated and melted by the heater 74 while being sequentially fed to the front side of the casing 71b of the heating cylinder 71 by the feeding action accompanying the rotation of the screw 71a. The reaction force is applied to the heating cylinder 71 as the molten resin is pumped to the inner side of the casing 71b. At this time, since the hydraulic cylinder 72 is in an unloaded state, the ram 72a is retracted by this reaction force. When the ram 72a is degenerated and a position sensor (not shown) installed at a predetermined position is operated, a measurement completion signal sw2 is transmitted (t2), and based on this, the motor 73 of the molding machine 7 is turned off and supplied soon. The machine 4 also stops.
[0040]
Thereafter, the hydraulic cylinder 72 of the molding machine 7 is operated, and the ram 72 a is expanded and one shot of molten resin staying at the tip of the heating cylinder 71 is injected from the nozzle 71 c and injected into the mold 75. The pressure holding state (the hydraulic cylinder 72 is in the operating state) is maintained for a predetermined time, and then the operation of the hydraulic cylinder 72 is released to bring it into a no-load state before cooling and demolding.
[0041]
Simultaneously with the transmission of the weighing completion signal sw2, the operation of the screw 71a and the feeder 4 is stopped simultaneously. At this time, since a slightly larger amount of resin material (for example, about 51 to 53 g if one shot is 50 g) is pre-weighed and temporarily stored in the charge tank 3, the screw 71 a and When the feeder 4 is stopped, excess resin material P accumulates and stays at the material inlet 70.
[0042]
Therefore, when the lower damper 42 is closed and the atmosphere release valve 53 is opened, the suction blower 81 is always turned on, so that a large amount of air flows from the atmosphere release valve 53 through the atmosphere introduction port 52 into the inner cylinder. To do. The inflowing air serves as a carrier gas, sucks the accumulated resin material, and is transported by air through the suction port 61 provided in the outer cylinder portion 6 and is collected by the collector 83. At this time, the upper damper 84a provided in the discharge cylinder 84 of the collector 83 is closed, and the lower damper 84b is opened. Therefore, the collected resin material is stored in the collector 83. When collecting and collecting this deposited resin. The pulsation device is preferably stopped.
[0043]
Thereafter, it is determined that all the accumulated resin has been collected and recovered by no signal from the level sensor 51 (after a predetermined time has elapsed by setting a timer), the atmosphere release valve 53 is closed and the lower damper 42 is opened. . Subsequently, the upper damper 84a provided in the discharge cylinder 84 is opened, the lower damper 84b is closed, and the recovered resin in the collector 83 is transferred into the discharge cylinder 84 between the dampers 84a and 84b. . Thereafter, the upper damper 84a is closed, the lower damper 84b is opened, and the recovered resin in the discharge cylinder 84 is dropped onto the weighing hopper 11. Such a damper operation makes it possible to collect and discharge the deposited resin while maintaining the reduced pressure state in the molding machine 7, and is extremely effective in improving the efficiency of the raw material supply and the molding process. It is.
[0044]
In parallel with the dropping of the recovered resin onto the weighing hopper 11, the screw feeder (main raw material supply machine) 1 a of the main hopper 1 is operated to feed the main raw material into the weighing hopper 11. In this weighing hopper 11, the recovered resin and the main raw material are combined and weighed until reaching a predetermined amount set slightly larger than one shot as described above, and when the predetermined amount is reached, the main raw material is signaled by the signal of the load cell 11a. The feeder 1a stops and enters a standby state for the next process.
[0045]
When the upper damper 31 is in the open state and the resin raw material is charged into the charge tank 3, the raw material level in the suction hopper 2 may drop, and the level sensor 21 may emit an empty signal (raw material request signal). At this time, the upper damper 31 is closed and the lower damper 42 is opened, and the air transport blower 13 is operated, and each resin raw material is transported to the suction hopper 2 and collected in the same manner as described above. It is also possible to repeat this until the level sensor 33 of the charge tank 3 generates a full signal and to configure the operation sequence so as to prepare for the next molding step.
[0046]
FIG. 4 shows a control block for executing the above-described operation, and the CPU 9 as the control means manages the above-described operation sequence. The CPU 9 operates the air transport blower 13 in response to the raw material request signal from the level sensor 21, and opens the upper damper 31 in response to the raw material request signal from the level sensor 33, and accordingly instructs the opening / closing of the lower damper 42. Furthermore, control is performed so that the feeder 4 is operated in response to the measurement start signal sw1 of the molding machine 7 and the feeder 4 is stopped in response to the measurement completion signal sw2. At this time, the above-described operation control of the feeder 4 is performed in combination with the raw material presence / absence signal of the level sensor 51 provided at the raw material inlet 70.
[0047]
In addition, the CPU 9 executes opening / closing control of the air release valve 53, operation control of the exhaust suction blower 81, operation control of the screw feeder 1a in the raw material hopper 1, operation control of the load cell 11a, control of opening / closing of the dampers 84a and 84b, and the like. Needless to say. The operation control of the hydraulic cylinder 72 and the motor 73 of the molding machine 7 is performed by a control sequence unique to the molding machine (not shown). In the resin raw material supply system of the present invention, the measurement start signal sw1 and the measurement from the molding machine 7 are measured. The completion signal sw2 is input and the above operation control is performed.
[0048]
In addition, this invention is not limited to the resin raw material supply system in the said embodiment, Needless to say, unless it deviates from this invention, it is applied also to another supply system. Moreover, as each level sensor 21, 33, 51, the well-known sensor employ | adopted for granular material processing systems, such as a contact-type sensor, a resistance type sensor, a distance sensor, a photoelectric sensor, a beam sensor, is used. Furthermore, although the example of the screw feeder was shown as the feeder 4, a rotary valve and other feeders can also be adopted. In addition, the damper 42 is regarded as the feeder 4 without using these electric feeders, and this opening and closing is controlled. You may make it do.
[0049]
【The invention's effect】
  As described above, claims 1 and8According to the invention, since the gas generated in the casing of the heating cylinder is sequentially discharged by the suction device, the gas does not stay in the molten resin which causes silver strips and cavities. And, since this suction device is equipped with means for sucking and transporting the resin raw material deposited at the raw material inlet and recycling it to the upstream side of the supply line constituting the supply device, the resin raw material deposited at the raw material inlet is Therefore, the clogged state with the resin raw material in the vicinity of the raw material inlet is not generated, and the discharge of the gas generated in the heating cylinder is not delayed.
[0050]
Moreover, since the resin raw material removed here is recycled to the upstream side of the supply line constituting the supply device, there is no waste and it is extremely efficient. Moreover, since the suction device for exhausting the inside of the heating cylinder also serves as a suction air source for air transportation for recycling, the entire resin raw material supply line is compactly configured without increasing its size. As described above, when the present invention is employed in a resin raw material supply system of a synthetic resin molding machine, a high-quality molded product free from silver stripes and cavities can be efficiently produced.
[0051]
In particular,Claims 1, 2 and 8If this invention is adopted, the deposited resin can be recycled very simply and efficiently by operating the damper and the air release valve. Claims3-6If a damper that hermetically shuts off is provided between the supply system parts as in the invention of this invention, and the damper is automatically controlled to open and close according to the supply process, the exhaust efficiency by the suction exhaust device is reduced. In addition, the resin raw material supply and the resin molding can be performed more efficiently.
[0052]
  Further claims7If the pulsating means as in the invention according to the invention is employed, the resin raw material is not blocked or bridged in the heating cylinder due to the pulsating operation of the exhaust flow, and the gas generated at the front side is discharged quickly and without stagnation. In particular, this exhaust flow has a larger pulsating action energy than steady exhaust, so even if there is a tendency for resin material to clog or bridge within the casing, it will break down and blockage or bridge will occur. Combined with the effect of preventing the deposition of the resin raw material at the raw material inlet, the gas generated in the casing is quickly discharged, and the production of a higher quality molded product is promised. is there.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing a resin raw material supply system to a synthetic resin molding apparatus in which the present invention is employed.
FIG. 2 is a schematic enlarged longitudinal sectional view of a main part of the embodiment in the system.
FIG. 3 is an operation time chart for the embodiment of the present invention.
FIG. 4 is a block diagram of the same control.
FIG. 5 is an explanatory view showing the behavior of a resin raw material in a conventional heating cylinder.
[Explanation of symbols]
3 Charge tank
31 Second damper (upper damper)
4 Raw material feeder
42 Damper (lower damper)
43 outlet
5 Inner cylinder for raw material input
53 Air release valve
6 Exhaust cylinder
7 Synthetic resin molding machine
70 Raw material inlet
71 Heating cylinder
71a screw
71b casing
74 Heater
8 Recycling means
80 Suction line
81 Suction device
82 Pulsation device
83 Collector

Claims (8)

A resin raw material supply device installed at a raw material inlet of a heating cylinder of a synthetic resin molding machine comprising a screw and a casing,
The raw material charging port is continuously connected with a raw material charging inner cylinder portion and an exhaust outer cylinder portion surrounding the inner cylindrical portion and connected to the suction device, and the resin deposited on the raw material charging port by the suction device. Equipped with means for sucking and transporting the raw material and recycling it upstream of the raw material supply line that constitutes the above-mentioned supply device ;
A damper is provided on the inner cylinder part, an air release valve in the inner cylinder part is provided between the damper and the inner cylinder part, and a collector is provided in the middle of the suction line in the suction device. An apparatus for supplying a resin raw material for a synthetic resin molding machine , wherein the damper, the air release valve, the suction line and the collector constitute the means for recycling . In claim 1 ,
The recycling means further includes a control means for controlling the opening and closing of the damper and the air release valve. The control means closes the damper and opens the air release valve after completion of charging the resin material into the heating cylinder. An apparatus for supplying a resin raw material for a synthetic resin molding machine, characterized in that it is controlled as described above. In claim 1 or 2,
A resin raw material supply apparatus for a synthetic resin molding machine, wherein a discharge port of a resin raw material supply machine is connected to the damper. In claim 3 ,
The apparatus for supplying a resin raw material for a synthetic resin molding machine, wherein the damper is opened at least when the feeder is operated. In claim 4 ,
A charge tank that constitutes the end of the raw material supply line is installed on the feeder, and a second damper that can be hermetically shut off from the upstream raw material supply line is installed at the upper end raw material inlet of the charge tank. An apparatus for supplying a resin raw material for a synthetic resin molding machine. In claim 5 ,
The apparatus for supplying a resin material for a synthetic resin molding machine, wherein the second damper is opened only when the resin material is charged into a charge tank. In any one of Claims 1 thru | or 6 .
The apparatus for supplying a resin raw material for a synthetic resin molding machine, wherein the suction device includes means for pulsating suction air. A method of supplying a resin raw material to a raw material inlet of a heating cylinder of a synthetic resin molding machine comprising a screw and a casing,
The resin material is introduced into the raw material inlet while the casing is sucked and depressurized by the suction device, and after this charging is completed, the resin raw material deposited in the raw material inlet is sucked and transported by the suction device, thereby constituting the supply device recycled to the upstream side of the supply line to be,
The suction transportation of the resin raw material deposited on the raw material charging port is performed by closing the damper provided between the inner cylinder part and the upper material discharging machine outlet after the resin raw material has been charged. A method for supplying a resin raw material for a synthetic resin molding machine, which is performed by opening an air release valve .

Images