JPH0449443B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to a plastic molding machine, in which a virgin material and a pulverized reduced material can be mixed while being transported and fed to a hopper of a molding machine by closed-loop air suction transport. This invention relates to a method and device for mixed transportation of materials.

PRIOR TECHNOLOGY A method of manufacturing a plastic molded article by mixing a virgin material and a pulverized reduced material has been known for a long time. After the pulverized and reduced materials are individually weighed using a weighing machine, they are mixed using a mixer and pneumatically transported to a molding machine in an open loop.

Problems to be Solved by the Invention However, the following problems have been pointed out in the conventional method as described above.

First, since a weighing machine and a mixer must be installed in the middle of the material transport pipeline, the equipment becomes large and expensive.

Second, when changing the type of plastic molded product to be manufactured, the material remaining in the mixer must be removed and replaced one by one, which is time-consuming and reduces factory productivity. ing.

Thirdly, because of the open-loop air suction type transportation system, when the air forcibly sent out by the blower is released to the outside, dust is scattered, making the environment unsanitary.

Fourthly, since the blower is operated to introduce outside air into the transport pipe, there is a problem that the dew point within the transport pipe becomes non-uniform and the mixed material reabsorbs moisture.

The technical object of the present invention is to solve the above-mentioned problems that the conventional methods had.

Concrete Means for Solving the Problems The concrete means provided as the method of the present invention for solving the above-mentioned problems are carried out using a mixed transportation device for plastic molding materials that is proposed at the same time. It is.

Here, the mixed transport device for plastic molding materials includes a blower installed at the end of a degassing pipe connected to a degassing port of the hopper of the molding machine, in order to degas and reduce the pressure inside the hopper, and this blower and the above-mentioned a material transport conduit provided between the suction ports of the hopper and provided with at least one set of material supply units combining a pulverized reduced material supply unit and a virgin material supply unit; and the at least one set of material supply units. means for individually and synchronously controlling the amount of material supplied from each of the material supply units, the control means comprising:
It is characterized in that the material is continuously supplied in a fixed quantity from the main material supply unit, and the material is intermittently supplied in a fixed quantity from the material supply unit which is the compounded material.

Furthermore, in the method of the present invention, in the mixed transportation device for plastic molding materials characterized by the above-described configuration, when the blower is operated, the molded product to be manufactured is transported from either one of the set of material supply units. It is characterized in that while the corresponding main material is continuously supplied in a fixed quantity, the other supply unit intermittently supplies a fixed quantity of the compounding material.

Effect of the Invention In the method of the present invention, when a closed-loop air-suction type plastic molding materials mixing transportation device is operated, the main material is continuously supplied in a fixed amount, while the blended material is intermittently supplied in a fixed amount and sent into the transportation pipe. Because it is a thing,
Since the main material and the compounded material are dispersed and mixed while being transported at high speed in the transport pipe, a uniform mixed material can be obtained.

Moreover, because of this effect, there is no need for a special measuring machine or mixer, and the mixing ratio of the materials can be arbitrarily set simply by individually controlling the amount of materials supplied from each material supply unit.

Effects of the Invention According to the present invention, since it has the above-mentioned features, there is no need for a weighing machine or an expensive mixer, and
Since the device can be simplified, the material transport and mixing device can be constructed at low cost.

In addition, even if the plastic molded product to be manufactured is changed during manufacturing, there is no need to replace the materials, and this can be done simply by changing the supply amount from each set material supply unit. Therefore, there is an advantage that productivity within the factory can be significantly improved without requiring any effort.

Furthermore, the mixed transportation of materials is carried out by a closed-loop air suction transportation method, so the air containing dust inside the hopper, which is deaerated by the blower, is circulated within the closed loop without being released to the outside. , the scattering of dust to the surrounding area is almost eliminated, and a sanitary environment can be maintained.

In addition, since the mixed material is transported by circulating air in a closed loop without introducing outside air, the dew point in the circulation pipe remains almost constant.
The problem of re-absorption of moisture by the material transported in the material transport pipe can also be solved.

Embodiment of the Invention FIG. 1 is a schematic diagram of an embodiment of the apparatus of the present invention.

1 is a molding machine, 2 is a hopper, 6 is a material transport pipe 10 is a blower, A is a pulverized reduced material supply unit, and B is a virgin material supply unit.

As shown in the figure, this material transport device operates a blower 10 to deaerate the molding machine 1 and transfer the materials supplied from each of the pulverized reduced material supply unit A and the virgin material supply unit B to the molding machine. 1. It is forcibly transported to 1.

To explain the structure of each part of such a material transport device, the hopper 2 has a structure that is sealed with a lid to maintain airtightness, and a cylindrical filter 7 is provided inside the hopper 2. The mixed material sucked in through the suction port 5 is temporarily stored inside the cylindrical filter 7, and then passed through the material discharge port 9 at the lower end to the molding machine.
The air that flows into the hopper 2 together with the mixed material is passed through a cylindrical filter 7 and degassed and circulated through a deaeration port 3.

Furthermore, a blower 10 for deaerating and reducing the pressure inside the hopper 2 and a bag filter 11 for removing dust are provided at the end of the deaeration pipe 4, and the blower 10 and the material transport pipe 6 are connected to the air supply pipe 12. The pipes are connected together to form a closed loop pipe as a whole.

The pulverized reduced material supply unit A and the virgin material supply unit B are provided in series in the material transport pipe 6, and both have bases 14 and 1 equipped with constant-speed rotary valves 13 and 16 as metering mechanisms.
7 (in the embodiment, a caster 20 is provided at the bottom to make it movable), and a crusher 15 and a material storage tank 18 are mounted on the top of each base 14 and 17, respectively. It is becoming.
Both of these material supply units A and B are detachable and replaceable from the transport pipe 6, and the rotation times of the rotary valves 13 and 16 are individually controlled by a control means. . In the embodiment, the material supply units A and B are provided with through passages 21 and 22 that penetrate horizontally in their respective bases 14 and 17, and a portion of these through passages 21 and 22 are connected to the rotary valves 13 and 16, respectively. The opening end of each of the through passages 21 and 22 is provided with a one-touch coupler 8, so that the opening end of the transport conduit 6 can be connected to the opening end of the transport pipe 6 for replacement with one touch.

At least one set of such material supply units A and B is provided, with the pulverized and reduced material supply unit A and the virgin material supply unit B being one set. ，
It is constructed by mounting different types of crushers 15 and virgin material storage tanks 18 containing different types of virgin pellets on the top of the plastic molding 17. , it is possible to supply virgin materials in fixed quantities.

In the embodiment, these different types of material supply units A and B are respectively A, A', B, B',
B'' indicates that the virgin material supply unit has the function of drying the material, and B' indicates the unit that has the function of dehumidifying the material.
B''.

FIG. 2 is an embodiment of the hardware configuration of the control means configured using a microcomputer, and M _A , M _B , 10 are the drive motors of the rotary valve 13 of the pulverized and reduced material supply unit A, respectively;
Rotary valve 1 of virgin material supply unit B
6 shows a drive motor and a blower, and 23 shows a level detector provided on the base of the molding machine 1.

Here, geared motors and step motors are suitably employed as actuators for rotationally controlling the rotary valves 13 and 16 of each material supply unit A and B used in the present invention, but in particular a step motor is employed. Needless to say, in some cases, the mixing ratio of the main material and compounding material can be adjusted with high precision.

FIG. 3 is a system diagram of the control procedure when implementing the method of the present invention.

In the data input routine, the supply amount is set for each of the virgin material unit and pulverized reduced material unit A and B within one batch transportation time according to the mixing ratio (for example, weight ratio) of the main material and compounded material. Enter the data necessary to do so.

In other words, the injection amount S for one shot of the molding machine 1
(g), unit weight of virgin material V (g), unit weight of pulverized reduced material C (g), mixing ratio of virgin material
VR (%), and in the case of pulverized reduced material, the ratio VC (%) is input.

In the next material supply amount setting routine, the rotation control times t and T of the rotary valves 13 and 16 of each material supply unit A and B within one batch transportation time are calculated based on the data input in the data input routine. (see Figure 4 above). For example, when the virgin material is the main material and the pulverized reduced material is the compounded material, the rotary valve 16 provided on the virgin material supply unit B side is rotated intermittently within the rotation control time T. The rotary valve 13 of the pulverized reduced material supply unit A
It is obtained by calculating the rotation control time t.

FIGS. 5a and 5b show the rotary valves 13 and 16 of each of material supply units A and B within one batch transportation time calculated in the material supply amount setting routine.
This is an explanatory diagram showing a comparison of the rotation control times T and t, and by changing the size of t with respect to a constant size of T, the mixing ratio of the compounded material to the main material can be arbitrarily changed. It can be seen that it can be defined (FIG. 5c shows an example in which t is made smaller than T for reference).

In this way, the rotation control times t and T of the rotary valves 13 and 16 of each material supply unit A and B are controlled.
After this is calculated, the mixed transport of materials is controlled. That is, control signals based on the calculated rotation control times t and T are applied to the driver circuits 24 and 24 of the rotary valves 13 and 16 of each material supply unit A and B, respectively.
25 (see Figure 2), and the driver circuit 2
In steps 4 and 25, the rotary valves 13 and 16 are controlled to rotate synchronously and individually in accordance with such control signals to carry out the method of the present invention, and plastic molded articles are continuously manufactured by the molding machine 1.

FIG. 6 is a timing chart illustrating the operation of the control system when implementing the method of the present invention using the apparatus of the present invention.

As can be seen from FIG. 6, in the method of the present invention,
The material sent out from each material supply unit A, B is transported intermittently every batch transport time, and the supply/stop of this material is controlled by the rotary valves 13, 16 of each material supply unit A, B. This is done by synchronously turning ON and OFF rotation control t and T. In addition, a material level detector 23 provided in the molding machine 1 determines whether the mixed material stored in the hopper 2 exceeds a predetermined upper limit level or not, and continues supplying if the mixed material does not exceed the upper limit level. A signal is output to the CPU, and when the mixed material stored in the hopper 2 exceeds a predetermined upper limit level, a supply stop signal is output to the CPU.

In the embodiment, as shown in FIG. 2, the material level detector 23 is constructed using a capacitive level switch, and when the mixed material reaches the upper limit level, the contact is closed and the CPU A supply stop signal is output by outputting an L level signal to. On the other hand, in the CPU, material level detector 2
3, and if this signal is a supply continuation signal, a pulse signal corresponding to the calculated rotation control time t, T is sent to the driver circuit 24 of each rotary valve 13, 16. 25, the rotation of each rotary valve 13, 16 is controlled to continue supplying the material, but when a supply stop signal is output from the material level detector 23, transportation of the next batch is stopped. .

With this method, the transportation of one batch will not be interrupted during transportation, and each material supply unit A and B will continue to individually supply materials according to the preset mixing ratio. Therefore, there is no possibility that the quality of the molded product will vary due to a difference in the mixing ratio during manufacturing.

Moreover, the blower 10 used to transport the mixed material to the molding machine 1 via the transport pipe 6 is
In order to prevent clogging due to the mixed material remaining in the transport pipe 6, pre-blowing and post-blowing are operated before and after controlling the rotation of the rotary valves 13 and 16. This is possible by providing .

When the blower 10 reaches a predetermined air volume, the rotary valves 13 and 16 of each material supply unit A and B are controlled to rotate synchronously, so that each material is sucked through the transport pipe 6 and mixed with each other. It reaches molding machine 1.

In the present invention, in the flow of suction air generated when the molding machine 1 is degassed in the closed loop pipeline, the main material is continuously supplied in a fixed quantity into the transport pipeline, and the blended material is intermittently supplied in a fixed quantity. Therefore, the main material and the compounded material can be continuously transported to the molding machine 1 while being uniformly mixed, and plastic molded products with particularly high productivity and little variation in quality can be continuously manufactured.

In addition, since the mixed transportation of materials is carried out in a closed loop, the air containing dust inside the hopper, which is deaerated by a blower, is circulated within the closed loop without being released to the outside, so that the surrounding dust is removed. There is almost no scattering and a sanitary environment can be maintained.

Furthermore, since the air is circulated in a closed loop without letting outside air flow in, the dew point in the circulation pipe remains almost constant, which eliminates the problem of re-absorption of moisture by the material being transported through the material transport pipe. can also be resolved.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of an embodiment of the apparatus of the present invention, FIG. 2 is a hardware configuration diagram showing an embodiment of the control means,
FIG. 3 is a diagram showing the control flow of the method of the present invention, and FIG.
The figure is a flowchart of the data input routine and the material supply amount setting routine, Figure 5 is a comparison diagram of the rotation control time of the rotary valve of each material supply unit, and Figure 6 is a diagram of the control operation when implementing the method of the present invention. It is an explanatory diagram. Explanation of the symbols: In the figures, 1 is a molding machine, 2 is a hopper, 10 is a blower, A is a pulverized and reduced material supply unit, 13 is a rotary valve thereof, B is a virgin material supply unit, and 16 is a rotary valve.

Claims (1)

[Scope of Claims] 1. A blower for deaerating and reducing the pressure inside the hopper is provided at the end of a deaeration pipe line connected to a deaeration port of a hopper of a molding machine, and between this blower and a material suction port of the hopper, Mixed transport of materials for plastic molding, comprising connecting material transport pipes provided with at least one set of material supply units that are a combination of a pulverized reduced material supply unit and a virgin material supply unit to form a closed loop pipe. A method of mixing and transporting plastic molding materials using a device, in which when the blower is operated, the main material corresponding to the molded product to be manufactured is continuously supplied from one of the set of material supply units. 1. A method for mixing and transporting materials for plastic molding, characterized in that a material to be a compounding material is intermittently supplied in a fixed quantity from another supply unit while the other supply unit supplies the material in a fixed quantity. 2. A blower installed at the end of the deaeration pipe connected to the deaeration port of the hopper of the molding machine to degas and depressurize the inside of the hopper; and a pulverization reduction device provided between the blower and the suction port of the hopper. A material transport conduit comprising at least one set of material supply units that is a combination of a material supply unit and a virgin material supply unit, and a supply of material supplied from each material supply unit of the at least one set of material supply units. The control means includes means for individually and synchronously controlling the amount of materials, and the control means continuously supplies a fixed amount of the material from the main material supply unit, while the material is supplied from the material supply unit for the compounded material. A mixed transportation device for plastic molding materials, characterized in that the device is configured to supply a fixed amount intermittently.