Resin material mixing and supply device

Abstract

To provide a resin material mixing and feeding device that is configured to: reduce a burden of cleaning work by streamlining a transport path of a resin material; reduce a burden of managing work by supplying only a required amount of mixed material; prevent excessive drying by routing recycled material so that the material does not pass through a dryer; and further improve a quality of a molded product.SOLUTION: A resin material mixing and feeding device 1 comprises: a drying unit 5 for drying a virgin material; a first weighing unit 11; a dry weighing device 2 having a first tank 13; a granulation unit 6 for granulating recycled material; a second weighing unit 12; a granulation weighing device 3 having a second tank 14; a stirring unit 8 for stirring the dried virgin material and the recycled granulated material to obtain a mixed material and supplying the mixed material to a molding machine 50; a transport unit 9; and a control unit 7. An outlet of the first tank 13 and the second tank 14 are connected by a first pipe 31, and an outlet of the second tank 14 and the stirring unit 8 are connected by a second pipe 32.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a resin material mixing and supplying device. [Background technology]

[0002] An injection molding machine (hereafter referred to as molding machine) is a device that produces molded products by repeating a molding cycle in which heated and molten resin material is injected into a mold and cooled and solidified, and is capable of mass-producing molded products with complex shapes in a short period of time. Resin materials include virgin materials that are in the stage before being heated and melted, and recycled materials that consist of sprues, runners, etc. Nowadays, it is becoming common to mix virgin materials and recycled materials in a certain ratio and supply them to the molding machine to produce the molded product, depending on the quality required for the product.

[0003] Conventionally, devices have been proposed that weigh virgin material and recycled material and supply them to a hopper of a molding machine (Patent Document 1: Japanese Patent Laid-Open Publication No. 8-207042, Patent Document 2: Japanese Patent Laid-Open Publication No. 2003-089113). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 8-207042 [Patent Document 2] JP 2003-089113 A Summary of the Invention [Problem to be solved by the invention]

[0005] Conventionally, virgin materials were transported to a mixer through the first pipeline, granulated recycled materials were transported to a mixer through the second pipeline, the mixed materials mixed in the mixer were transported to a dryer through the third pipeline, the mixed materials dried in the dryer were transported to a mixer through the fourth pipeline, and the mixer supplied them to a molding machine. Because of the complicated structure with four pipelines, cleaning these pipelines was cumbersome. In addition, when production was finished, the mixed materials remaining in the dryer had to be stored as surplus materials, and the management work until the production of molded products using the stored mixed materials began was cumbersome. Furthermore, since drying recycled materials in a dryer results in excessive drying, it has recently been discovered that molding defects such as yellowing caused by excessive drying of recycled materials can become a quality issue as the quality level required for molded products improves. [Means for solving the problem]

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and has an object to provide a resin material mixing and supplying device configured to reduce the burden of cleaning work by streamlining the transport path for resin material, reduce the burden of managing surplus material by supplying only the required amount of mixed material, and prevent excessive drying by routing recycled material through a route that does not pass through a dryer, thereby further improving the quality of molded products.

[0007] The solution disclosed below as one embodiment solves the above problem.

[0008] The resin material mixing and supplying device of the present invention comprises a drying unit for drying virgin material, a drying and weighing machine having a drying unit for drying virgin material, a first weighing unit for weighing the dry virgin material, and a first tank for storing the weighed first transport amount of the dry virgin material, a granular cutting and weighing machine having a granular cutting unit for cutting recycled material, a second weighing unit for weighing the granular recycled material, and a second tank for storing the weighed second transport amount of the granular recycled material, a mixing unit for mixing the dry virgin material and the granular recycled material to form a mixed material and supplying it to a molding machine, a transport unit for supplying the dry virgin material and the granular recycled material to the mixing unit, and a control unit for controlling adjustment of the first transport amount and the second transport amount, and is characterized in that the outlet of the first tank and the second tank are connected to a first pipe for transporting the dry virgin material, and the outlet of the second tank and the mixing unit are connected to a second pipe for transporting the granular recycled material and the dry virgin material.

[0009] With this configuration, the number of pipes can be streamlined from four to two, greatly reducing the burden of cleaning work. Virgin and recycled materials are weighed out separately, and the required amount is mixed and supplied as a mixed material, minimizing excess mixed material and greatly reducing the burden of management work. Moreover, excessive drying of recycled materials can be prevented, further improving the quality of molded products.

[0010] It is preferable that the conveying unit and the stirring unit are connected to a suction pipe for sucking air, and the control unit transports the recycled material to the stirring unit and then controls the transport of the dried virgin material. With this configuration, a single conveying unit can handle the air suction of the entire device, making it a rational configuration.

[0011] The mixing unit is preferably provided with a glass tube for supplying the mixed material to the molding machine and a sensor for detecting the amount of the mixed material in the glass tube, and the control unit is preferably configured to control the transport of the recycled material and the dried virgin material until the amount of the mixed material reaches the set level when the control unit receives a detection signal from the sensor and determines that the amount of the mixed material falls below a set level. With this configuration, the mixed material required for production can be easily supplied to the molding machine in a reasonable amount without interruption.

[0012] The granular cutting unit is provided with a surplus material discharge section, and the surplus material discharge section preferably has a door that opens under the weight of the surplus material among the recycled materials to discharge the surplus material outside the machine. With this configuration, it is possible to prevent a load from being applied to the granular cutting blade and supply only the required amount of granular cut recycled material, thereby reducing the burden of managing the surplus material, extending the life of the granular cutting blade, and reducing the burden of maintenance work. Effect of the Invention

[0013] According to the resin material mixing and supplying device of the present invention, the transport path for the resin material is streamlined, thereby significantly reducing the burden of cleaning work, the required amount of mixed material is continuously supplied, thereby reducing the burden of managing surplus material, and the route for recycled material does not pass through the dryer, thereby preventing excessive drying and further improving the quality of the molded product. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing the layout of a resin material mixing and supplying device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing the piping configuration of the resin material mixing and supplying device according to this embodiment. [Diagram 3] 3A to 3D are schematic external views showing an example of the operation of the surplus material discharge section according to this embodiment. [Figure 4] FIG. 4 is a flow chart showing an example of the operation procedure of the resin material mixing and supplying device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] An embodiment of the present invention will be described in detail below with reference to the drawings. As shown in FIG. 1 and FIG. 2, the resin material mixing and supplying device 1 is configured by combining a drying and weighing machine 2, a granular cutting and weighing machine 3, and a stirring unit 8. The drying and weighing machine 2 dries a pellet-shaped virgin material 41 to produce a dried virgin material. The granular cutting and weighing machine 3 granulates a regenerated material 42 such as a sprue or a runner to produce a granular regenerated material. The stirring unit 8 stirs the dried virgin material and the granular regenerated material to produce a mixed material, and supplies the mixed material to a molding machine 50. The resin material mixing and supplying device 1 is configured not to control the molding machine 50, and includes a control unit 7 configured to control each device independently of the molding machine 50. The control unit 7 is provided in the drying and weighing machine 2 as an example. The resin material mixing and supplying device 1 includes a conveying unit 9 that supplies the dried virgin material and the granular regenerated material to the stirring unit 8, respectively. The conveying unit 9 is provided in the drying and weighing machine 2 as an example. In addition, in all the drawings for explaining the embodiments, the same reference numerals are given to members having the same functions, and repeated explanations thereof may be omitted.

[0016] The drying and weighing machine 2 is configured by connecting a drying unit 5, a first weighing unit 11, and a first tank 13, and has a control unit 7 and a transport unit 9 built in. The drying unit 5 sucks up the pellet-shaped virgin material 41 stored in the material tank 36 with an attached hopper, drops it from the hopper into a drying container, and dehumidifies and dries it with dry air from a heater in the drying container to produce dry virgin material. The first weighing unit 11 weighs the dry virgin material by rotating a screw a predetermined number of times with a motor. The first tank 13 stores the first transport amount of the dry virgin material weighed by the first weighing unit 11.

[0017] The granular material measuring machine 3 is configured by connecting a granular material measuring unit 6, a second measuring unit 12, and a second tank 14. The granular material measuring unit 6 cuts the regenerated material 42 into granular material. The second measuring unit 12 measures the granular material by rotating the screw a predetermined number of times using a motor. The second tank 14 stores the second transport amount of the granular material measured by the second measuring unit 12.

[0018] The mixing unit 8 mixes the dry virgin material and the granular recycled material to produce a mixed material 43, which is then supplied to the molding machine 50. The conveying unit 9 uses suction air to supply the dry virgin material and the granular recycled material to the mixing unit 8. The mixing unit 8 is a suction-type fine powder removal hopper, or what is known as a helical hopper.

[0019] The mixing unit 8 is provided with a glass tube 33 as a passage for supplying the mixed material 43 dropped from the hopper body to the molding machine 50, and a sensor 34 for detecting the amount of the mixed material 43 in the glass tube 33. One example of the sensor 34 is a capacitance-type proximity sensor. When the control unit 7 receives a detection signal from the sensor 34 and determines that the amount of the mixed material 43 has fallen below a set level, the control unit 7 controls the transport of the virgin material 41 and the recycled material 42 to the mixing unit 8 until the amount of the mixed material 43 reaches the set level.

[0020] The conveying unit 9 and the agitation unit 8 are connected to a suction pipe 35 for sucking air. The suction pipe 35 is a suction hose, and the suction air is sucked in the direction of the arrow a1. The outlet of the first tank 13 and the second tank 14 are connected to a first pipe 31 for transporting dry virgin material. The first pipe 31 is the dry virgin material transport hose, and the material is pressure-fed by the dehumidified air in the drying unit 5 in the direction of the arrow b1 and is simultaneously transported to the second tank by the suction air. The outlet of the second tank 14 and the agitation unit 8 are connected to a second pipe 32 for transporting the granulated recycled material and the dry virgin material. The second pipe 32 is the mixed material transport hose, and the material is pressure-fed by the dehumidified air in the drying unit 5 in the direction of the arrow b2 and is simultaneously transported by the suction air. Here, the control unit 7 is configured to transport the granulated recycled material to the agitation unit 8 in response to condition input from the touch panel 7a, and then control the transport of the dry virgin material to the agitation unit 8.

[0021] The dry weighing machine 2 is provided with an air switching valve 37 for exhaust. In this embodiment, by switching the air switching valve 37, the dehumidified air in the drying unit 5 is put into the measured first tank 13 and the dried virgin material is pumped out at the same time as the material is transported. This prevents the material from remaining in the first tank 13 and the second tank 14, and the measured first transport amount of the dried virgin material can be supplied to the stirring unit 8 in an accurate amount. In addition, in this embodiment, the control unit 7 controls the dehumidified air in the drying unit 5 to be put into the measured first tank 13 and the second tank 14 and the dried virgin material is pumped out at the same time as the material is transported. This prevents the material from remaining in the first tank 13 and the second tank 14, and the measured second transport amount of the dried virgin material can be supplied to the stirring unit 8 in an accurate amount. Therefore, the mixed material 43 mixed in the stirring unit 8 at an accurate ratio can be sent to the molding machine 50 in an accurate amount.

[0022] As shown in FIG. 3A to FIG. 3D, the granular cutting and weighing machine 3 has an excess material discharge section 21 disposed obliquely downward on the slope of the discharge tank 6b below the processing section in which the granular cutting blade 6a is disposed in the granular cutting unit 6. The excess material discharge section 21 includes a guide 21b that is formed by processing sheet metal and bent on the lower surface, left side surface, and right side surface to prevent the excess material from scattering, and a door 21a that is processed by processing sheet metal into an L-shape. The door 21a is supported on a shaft near the upper surface of the guide 21b so that it can swing in the front-rear direction. As shown in FIG. 3A and FIG. 3D, the door 21a swings forward and opens due to the weight of the excess material of the recycled material 42, thereby discharging the excess material outside the machine. Then, as shown in FIG. 3B and FIG. 3C, when the excess material is discharged outside the machine, the door 21a swings backward and closes. According to this configuration, the load on the granular cutting blade 6a can be prevented and only the required amount of granular recycled material can be supplied, which reduces the burden of managing surplus material, extends the life of the granular cutting blade 6a, and reduces the burden of maintenance work.

[0023] 4 is a flow chart showing an example of the operation procedure of the resin material mixing and supplying apparatus 1 according to this embodiment. The operation procedure of the resin material mixing and supplying apparatus 1 will now be described.

[0024] In step S1, the operator specifies the weighing conditions of the resin material from the touch panel 7a. After the weighing conditions of the resin material are specified, the process proceeds to step S2. In step S2, the control unit 7 determines whether the amount of the mixed material 43 is less than the set level based on a detection signal from the sensor 34 arranged in the glass tube 33. If the amount of the mixed material 43 is less than the set level, the process proceeds to step S3. In step S3, the control unit 7 transmits a weighing start command for the dried virgin material 41 to the dry weighing machine 2, and then transmits a weighing start command for the regenerated material 42 to the granular weighing machine 3. The weighing condition for the virgin material 41 is the weighing time for the dried virgin material stored in the first tank 13. The weighing condition for the regenerated material 42 is the weighing time for the granular regenerated material stored in the second tank 14.

[0025] In step S4A, the dry weighing machine 2 receives a command to start weighing the virgin material 41, and proceeds to step S5A. In step S5A, the dry weighing machine 2 weighs the dry virgin material, sets it as a first transport amount, and stores it in the first tank 13. Then, in step S6A, the dry virgin material metering timer is up, and the dry virgin material metering screw stops.

[0026] In step S4B, the granular weighing machine 3 receives a command to start weighing the recycled material 42 and proceeds to step S5B. In step S5B, the granular weighing machine 3 breaks the recycled material 42 into pieces, weighs the broken recycled material, and stores it in the second tank 14 as a second transport amount. Then, in step S6B, the broken recycled material metering timer is up, and the broken recycled material metering screw stops.

[0027] When the weighing timer set values ​​of the dry weighing machine 2 and the crushed material weighing machine 3 have elapsed, the control unit 7 sucks and transports the crushed material recycled material and the dry virgin material to the agitation unit 8 using suction air from the transport unit 9 in step S7.

[0028] In the above embodiment, an example has been described in which granular recycled material is transported, followed by transporting dry virgin material, which is then stirred in the stirring unit 8 to produce a mixed material and supplied to the molding machine 50. The mixing ratio of the dry virgin material to the granular recycled material can be set to any ratio, for example 9:1, and for example 8:2. In addition to the above, at the start of molding, the first material transport to the molding machine 50 can be transported only with dry virgin material, and the second and subsequent material transports to the molding machine 50 can automatically transport mixed material at the set mixing ratio.

[0029] According to the resin material mixing and supplying device 1 of this embodiment, the burden of cleaning work can be significantly reduced by streamlining the transport path of the resin material. In addition, since the required amount of mixed material can be supplied without interruption, the burden of managing surplus material can be reduced. Moreover, by using a route for recycled material that does not pass through a dryer, excessive drying can be prevented, and the quality of the molded product can be further improved. The present invention is not limited to the above-described examples, and various modifications can be made without departing from the scope of the present invention. [Explanation of symbols]

[0030] 1 Resin material mixing supply device 2 Dry weighing machine 3 Grain cutting weighing machine 5 Drying Unit 6 Grain cutting unit, 6a Grain cutting blade, 6b Discharge tank 7 Control unit, 7a Touch panel 8 Mixing Unit 9. Transport Unit 11 First weighing unit 12 Second weighing unit 13. First Tank 14 Second Tank 21: surplus material discharge section, 21a: door, 21b: guide 31 1st pipe 32 2nd pipe 33 Glass Tube 34 Sensors 35 Suction tube 36 Material Tank 37 Air switching valve 41 Virgin material 42 Recycled materials 43 Mixed materials 50 Molding machine

Claims

1. the drying and weighing machine having a drying unit for drying virgin material, a first weighing unit for weighing the dry virgin material, and a first tank for storing a weighed first transport amount of the dry virgin material; a granulation measuring machine having a granulation unit for granulating recycled material, a second weighing unit for weighing the granulation recycled material, and a second tank for storing a weighed second transport amount of the granulation recycled material; a mixing unit for mixing the dry virgin material and the granulation recycled material to form a mixed material and supplying the mixed material to a molding machine; a transport unit for supplying the dry virgin material and the granulation recycled material to the mixing unit; and a control unit for controlling adjustment of the first transport amount and the second transport amount, wherein a first pipe for transporting the dry virgin material is connected to an outlet of the first tank and the second tank, and a second pipe for transporting the granulation recycled material and the dry virgin material is connected to an outlet of the second tank and the mixing unit. A resin material mixing and supplying device characterized by the above.

2. The conveying unit and the agitating unit are connected to a suction pipe for sucking air, and the control unit is configured to transport the granular recycled material to the agitating unit and then to control the transport of the dry virgin material.

2. The resin material mixing and supplying device according to claim 1 .

3. The mixing unit is provided with a glass tube for supplying the mixed material to the molding machine and a sensor for detecting the amount of the mixed material in the glass tube, and the control unit is configured to control the transport of the granulated recycled material and the dry virgin material until the amount of the mixed material reaches the set level when the control unit receives a detection signal from the sensor and determines that the amount of the mixed material has fallen below a set level.

3. The resin material mixing and supplying device according to claim 1 or 2,

4. The granulation unit is provided with a surplus material discharge section, and the surplus material discharge section has a door that opens due to the weight of the surplus material among the recycled materials to discharge the surplus material outside the machine.

4. The resin material mixing and supplying device according to claim 1,

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