JPH06190891A - Plasticization apparatus and plasticization method using the same - Google Patents

Abstract

PURPOSE:To achieve equipment downsizing and cost reduction, to make sealing inside a cylinder effective, to increase production of molded products, and to improve product quality by installing a rotary valve for feeding material connected closely to a cylinder with a screw inserted into the cylinder. CONSTITUTION:In a plasticization apparatus, a rotary valve 2 is connected to the outlet side of a hopper 1, to which a cylinder 4 is closely connected through a manifold 3. The rotary valve 2 is rotated by a driving motor 2a to feed material in the hopper 1 to the cylinder 4. A screw 5 rotated by a driving part 7 is inserted into the hollow part of the cylinder 4, and a rotation seal part 6, which prevents air inflow from the driving part 7 side, is installed close to the screw root part 5a. Since the cylinder 4 is always sealed by the rotary valve 2 in the plasticization apparatus, air inflow during deaeration is effectively prevented, and an optional amount of the material in an optional condition can be fed by the rotary valve 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasticizing apparatus for increasing the production amount and quality of molded articles by increasing the degree of vacuum inside a cylinder, and a plasticizing method using the apparatus.

[0002]

2. Description of the Related Art Presently, in a single-spindle or multi-spindle plasticizer used for plastic molding or the like, vent holes are provided in a cylinder, and deaeration of the inside of the cylinder is performed from these holes to thereby prevent inter-material and inter-material The quality of molded products is improved by removing the air, volatile substances and water contained in the product.
In this case, in order to effectively degas the material, it is necessary to seal the front side of the vent hole to prevent air from flowing from the outside to the inside of the cylinder during degassing. If the material supply side is not properly sealed, the air outside the cylinder will flow in from the material supply side, or the material inside the cylinder will be sucked through the vent holes, and the material will be effectively degassed. I can't.

Therefore, in the conventional plasticizing apparatus, as shown in FIG. 11, the vent hole 102 (vent portion) of the screw 101 is used.
A compression portion having a shallow screw groove is formed in a portion located closer to the front, and the material is filled in the cylinder 103 at the compression portion during the material transportation to seal the vent portion. In addition, Japanese Patent Publication Sho 45
As in the extruder disclosed in JP-A-27912,
There is also a configuration in which a separate movable valve device having a pressing valve that can be opened and closed by pressing force is provided in the feeder, and the hopper outlet is closed by this pressing valve to seal the material supply side. On the other hand, in the conventional plasticizing method, a constant amount of material is always supplied from the hopper into the cylinder regardless of the rotation speed of the screw in the plasticizing device.

[0004]

The above-mentioned conventional plasticizing apparatus has the following problems. That is, in the case where the compression portion is formed on the screw as the sealing means on the material supply side, the entire length of the screw becomes long only at the compression portion, and the entire apparatus becomes large and expensive. Further, in the case where the feeder is provided with a separate movable valve device, the structure of the feeder is complicated and the cost becomes high.

Further, in the conventional plasticizing method, a constant amount of material is supplied into the cylinder irrespective of the rotation speed of the screw. Therefore, when the rotation speed of the screw changes, the plasticizing device using the multi-screw screw is used. In the above, the supply of the material cannot correspond to the production amount of the molded product, resulting in excess and deficiency of the supplied material.
In particular, when the rotation speed of the screw is increased, the amount of material in the cylinder becomes insufficient, the production amount of the molded product decreases, and the quality of the molded product also deteriorates.

The present invention has been conceived in view of the above-mentioned problems, and a plasticizing device capable of effectively sealing the inside of a cylinder while reducing the size and cost of the device, and a screw. An object of the present invention is to provide a plasticizing method capable of supplying an appropriate amount of material according to the number of revolutions, increasing the production amount of a molded product and improving the quality.

[0007]

In order to achieve the above object, the plasticizing apparatus of the present invention is a rotary valve in which a screw is inserted into a cylinder and a powdery or granular material is supplied into the cylinder. , A structure in which the cylinder is hermetically connected, and an air suction pump is provided between the rotary valve and the cylinder as necessary, or an air vent hole is provided near the material supply part of the cylinder. is there.

Further, in order to improve the sealing property on the material supply side, a plurality of rotary valves are hermetically connected and stacked, and further, a plurality of rotary valves are hermetically connected via a connecting pipe, and the connecting pipe is connected. A suction pump that sucks the air in the connecting pipe to the outside is attached, and a plurality of rotary valves are hermetically connected via the material storage unit, and the suction that sucks air from the material storage unit to this material storage unit is performed outside. A pump is attached, or a plurality of rotary valves are arranged in multiple rows on the same rotary shaft and rotated by a single drive motor to supply the material into the cylinder.

As another means for further improving the sealing property on the material supply side, a shut-out valve is hermetically connected to the upper part of the rotary valve, and further,
A shut-out valve is hermetically connected to the upper part of the rotary valve via a connecting pipe, and a suction pump that sucks air from the connecting pipe to the outside is attached to this connecting pipe, or a material storage unit is installed on the upper part of the rotary valve. The shut-out valve is hermetically connected via the, and a suction pump for sucking air from the storage section to the outside is attached to the material storage section.

Further, the plasticizing method of the present invention using the above-mentioned plasticizing apparatus is a method for performing plasticizing while supplying a material by a rotary valve into a cylinder in which a screw is inserted, wherein the rotary valve is continuously connected. Material is supplied into the cylinder while rotating or intermittently rotating, or the rotational speed of the rotary valve is synchronized with the rotational speed of the screw, and an appropriate amount of material according to the rotational speed of the screw is supplied into the cylinder for plasticization. There is a way. In the present specification, air is a concept including general gases such as various gases including air.

[0011]

In the plasticizing device of the present invention having the above-mentioned structure, since the rotary valve having a high sealing property is used as the material supplying means, the seal in the cylinder can be surely performed without using a special screw or a sealing device. It is possible to increase the degree of vacuum in the cylinder by performing various operations and providing various deaerating means. Further, according to the plasticizing method of the present invention using the above-mentioned plasticizing device, it is possible to always supply an appropriate amount of material into the cylinder, and by removing the air between the materials supplied in the cylinder and in the material, The bulk density of the material can be increased.

[0012]

EXAMPLES Examples of a plasticizing apparatus and a plasticizing method using the apparatus according to the present invention will be described below with reference to the drawings. First, a single-screw screw plasticizing apparatus according to the first embodiment of the present invention will be described. FIG. 1 is a sectional view showing a plasticizing device according to this embodiment. In the figure, 1 is a hopper, and a rotary valve 2 is provided on the outlet side of the hopper 1.
Is connected. The outlet side of the rotary valve 2 is
It is hermetically connected to the cylinder 4 via the connecting pipe 3. The rotary valve 2 is rotated by a drive motor 2a and supplies the material in the hopper 1 to the cylinder 4.

A screw 5 which is rotated by a drive unit 7 is inserted in the hollow portion of the cylinder 4. Further, in the vicinity of the material supply portion of the cylinder 4 that is joined to the connecting pipe 3, that is, at a position facing the screw root portion 5a of the cylinder 4 in the present embodiment, an air vent hole for sucking the air in the cylinder 4 to the outside ( An air vent portion) 4a is provided. The number of the air vents 4a may be one or more, or part or all may be porous. Further, a rotary seal portion 6 for preventing the inflow of air from the driving portion 7 side is provided near the screw root portion 5a.

The drive unit 7 includes a detection unit 9 for detecting the rotation speed of the screw 5, and a control unit 10 for receiving the signal from the detection unit 9 and controlling the rotation speed of the drive motor 2a of the rotary valve 2. It is provided. These, the detection unit 9 and the control unit 1
0 will be described in detail in the examples of the plasticizing method described later. A heater 8 is provided on the peripheral surface of the cylinder 4, and heats the cylinder 4 to melt the material in the cylinder.

FIG. 2 is a sectional view showing a single screw type plasticizing apparatus according to the second embodiment of the present invention. In the plasticizing device of the present embodiment, the suction pipe of the suction pump 11 is connected to a part of the connecting pipe 3 that connects the rotary valve 2 and the cylinder 4, and the suction pump 11 allows the space between the materials in the connecting pipe 3 and It is configured to suck the air in the material. In the case of this embodiment, the air vent hole 4a provided near the material supply portion of the cylinder 4 can be omitted. According to the apparatus of the present embodiment, air between materials and in the material can be removed before the material is supplied to the cylinder.

FIG. 3 is a sectional view showing a twin-screw type plasticizer according to a third embodiment of the present invention. The plasticizing device of this embodiment is installed in the cylinder 4 in a state where two screws 5 and 5 (only one screw is shown) are meshed with each other. Further, a vent hole 4b is provided in the upper part of the cylinder 4 for sucking volatile substances, moisture, etc. generated from the air and the material in the cylinder 4 to the outside. Also in this embodiment, the air vent hole 4a can be omitted.

In the plasticizing apparatus of the first, second and third embodiments having such a structure, the rotary valve 2 constantly seals the inside and the outside of the cylinder 4,
Effectively prevent the inflow of air from the material supply side during degassing. Therefore, air can be effectively sucked from the suction pump 11 and air, volatile matter, moisture, etc. can be effectively sucked from the air vent hole 4a and / or the vent hole 4b, and the degassing effect of the material in the cylinder 4 is improved. Further, by using the rotary valve, the material can be supplied in any manner such as continuous or intermittent manner and in any amount. Further, when the plasticizing device has a multi-screw screw, the rotation of the screw and the rotation of the rotary valve can be synchronized to appropriately supply the material in an amount corresponding to the screw rotation.

According to these plasticizing devices of this embodiment, unlike the conventional plasticizing devices, the compression portion is not formed in the screw and the feeder is not provided with a movable valve device having a complicated structure. Can seal well. Therefore, the entire length of the screw can be shortened to reduce the size and cost of the entire apparatus, and the feeder structure can be simplified.

In the first, second and third embodiments described above, the material is supplied into the cylinder by a single rotary valve, but in order to further improve the sealing property on the material supply side, The material may be supplied by a plurality of stacked rotary valves, or the material may be supplied by providing a shutout valve on the upper part of the rotary valve. Hereinafter, examples of these plasticizing devices will be described.

FIG. 4 is a partial sectional view showing a plasticizing device according to a fourth embodiment of the present invention. The plasticizing device of this embodiment is
Between the hopper 1 and the connecting pipe 3, two rotary valves 21,
22 is directly airtightly connected and laminated. According to this embodiment, since the two rotary valves are laminated, the sealability between the outside and the inside of the cylinder 4 can be further improved, and air between the materials in the cylinder 4 and air inside the material can be removed. You can do your mind more effectively. The plasticizing device of this embodiment can be implemented by either a single screw type or a twin screw type plasticizing device.

FIG. 5 is a partial sectional view showing a plasticizing device according to a fifth embodiment of the present invention. The plasticizing device of this embodiment is
A suction pipe of a suction pump 31 similar to that of the second embodiment in which two rotary valves 21 and 22 are hermetically connected to each other via a connecting pipe 30 and air is sucked from the connecting pipe 30 to the outside. Are connected. According to this embodiment, the air between and in the material can be removed before the material is fed into the cylinder 4.

FIG. 6 is a partial sectional view showing a plasticizing device according to a sixth embodiment of the present invention. The plasticizing device of this embodiment is
The two rotary valves 21 and 22 are hermetically connected to each other via the material storage unit 40, and
In addition, a suction pipe of a suction pump 41 for sucking air from the material storage unit 40 to the outside is connected to the outside. According to this embodiment, the material supplied from the hopper 1 is once stored in the material storage unit 40, and degassed by the suction pump 41 for a certain period of time. Therefore, before supplying the material into the cylinder 4, the air between the material and the air inside the material can be more surely removed, so that the bulk density of the material can be increased. Further, in the present embodiment, the air vent portion 4a has the following configuration. That is, the wall of the cylinder 4 in the vicinity of the material supply unit has a double cylinder structure including a heating cylinder 4c that is an outer cylinder and a gas permeable cylinder 4d that is an inner cylinder, and the suction pump 42 allows air from the inside of the cylinder 4 to flow outside. It is configured to suck. With such a configuration, air between materials in the cylinder 4 and air in the material can be effectively degassed, and
The bulk density of the material can be higher. In addition, the air vent 4a having the double cylindrical structure is not provided, and the material storage 4
It can be sufficiently used as a plasticizing device having only a structure in which the suction pipe of the suction pump 41 is connected to 0.

FIG. 7 is a partial sectional view showing a plasticizing device according to a seventh embodiment of the present invention. The plasticizing device of this embodiment is
In the material supply path 60 in which the inlet side is hermetically connected to the hopper 50 and the outlet side is hermetically connected to the cylinder 4,
Three rotary valves 23, 24, 25, which are rotated by a single drive motor 20a, are arranged in multiple rows on the same rotary shaft, and the cylinder 4 is provided near the outlet side of the material supply passage 60. As a material extruding means to the screw feeder 70 rotated by a drive motor 70a
Is attached. According to this embodiment, three rotary valves 23, 24, 25 are arranged in multiple rows and
A screw feeder 7 is used as a material extruding means for the cylinder 4.
Since 0 is attached, the degree of vacuum in the cylinder 4 is improved, air between the materials in the cylinder 4 and air in the material can be effectively degassed, and further, the supply amount of the material is increased. You can

When the heat of the heater 8 (see FIGS. 1 to 3) provided on the discharge port side of the cylinder 4 is transferred to the rotary valves 23, 24, 25 via the cylinder 4, the material supply passage 6 is formed.
The material inside 0 may melt and the sealing properties of the rotary valves 23, 24, 25 may deteriorate. Therefore, in this embodiment, a cooling unit 80 that circulates a coolant 81 such as water is provided on the peripheral surface of the cylinder 4 on the material supply side.
The cooling unit 80 prevents the heat of the heater 8 and the like from being transferred to the rotary valves 23, 24, 25, and improves the sealing performance of the rotary valves 23, 24, 25. In addition, such a cooling unit 80 is not limited to the present embodiment, and the same effect as that of the present embodiment can be obtained even if the cooling unit 80 is provided in the cylinder 4 of the plasticizing device according to the first to sixth embodiments described above.

FIG. 8 is a partial sectional view showing a plasticizing device according to an eighth embodiment of the present invention. The plasticizing device of this embodiment is
A ball valve 26 as a shut-out valve and a rotary valve 22 are directly airtightly connected and laminated between the hopper 1 and the connecting pipe 3. The ball valve 26 is rotated by 90 degrees by a motor 27 driven by a signal from the controller 10 to change its position, and the material is repeatedly supplied and shut off. According to this embodiment, since the ball valve 26 and the rotary valve 22 are laminated, the cylinder 4
The outer and inner sealing properties of the
The air between the materials in the cylinder 4 and the air in the material can be degassed more effectively, and it is particularly suitable for supplying the powdery material. In addition, the plasticizing apparatus of the present embodiment is a single screw type,
It can be carried out in either of the twin-screw type plasticizers.

FIG. 9 is a partial sectional view showing a plasticizing apparatus according to the ninth embodiment of the present invention. The plasticizing device of this embodiment is
The ball valve 26 and the rotary valve 22 are hermetically connected to each other via a connecting pipe 30, and the connecting pipe 30 is provided with a suction pipe of a suction pump 31 for sucking air from the connecting pipe 30 to the outside. It is connected. According to this embodiment, the air between and in the material can be removed before the material is fed into the cylinder 4.

FIG. 10 is a partial sectional view showing a plasticizing apparatus according to the tenth embodiment of the present invention. In the plasticizing device of this embodiment, the ball valve 26 and the rotary valve 22 are connected to the material storage unit 4.
It is configured such that they are hermetically connected to each other via 0, and a suction pipe of a suction pump 41 similar to the second embodiment that sucks air from the material storage unit 40 to the outside is connected to the material storage unit 40. As the shut-out valve 26, a butterfly valve, a slide valve or the like can be used instead of a ball valve.

According to the plasticizers of the fourth to tenth embodiments, the material supplying means for the cylinder 4 is formed by laminating a plurality of rotary valves 21, 22 (23, 24, 25). Alternatively, since the shut-out valve 26 is laminated on the rotary valve 22, the sealability of the cylinder 4 can be further improved, and
It is possible to more effectively deaerate the air between the materials in the cylinder 4 and in the material. In addition, the suction pump 31
When (41, 42) is attached, it is possible to reliably remove air between the materials before the supply and inside the materials. And the deaeration of the air in the material can be performed more effectively.

Next, an embodiment of a plasticizing method using the plasticizing apparatus according to the above-mentioned first to tenth embodiments will be described. The plasticizing method according to this embodiment includes a rotary valve 22.
Is continuously or intermittently rotated to supply an arbitrary amount into the cylinder 4 for plasticization, or the rotational speed of the rotary valve 22 is synchronized with the rotational speed of the screw 5 to obtain an appropriate amount according to the rotational speed of the screw 5. This is a method of supplying the above material into the cylinder 4 for plasticization.

1 and 2, description will be given of a case where the rotational speed of the rotary valve is synchronized with the rotational speed of the screw 5 to supply the material and plasticize it. The synchronization of the screw 5 and the rotary valve 2 is performed by the detection unit 9 and the control unit 10 provided in the drive unit 7. That is, the detection unit 9
Detects the number of rotations of the screw 5 and outputs a signal to the control unit 10. The control unit 10 rotates the drive motor 2a based on the signal from the detection unit 9 to rotate the rotary valve 2 to rotate the number of rotations of the screw 5. The rotation speed corresponds to. As a result, the rotation speeds of the screw 5 and the rotary valve 2 are synchronized, and when the rotation speed of the screw 5 changes, the rotation speed of the rotary valve 2 also changes, so that an appropriate amount of material according to the rotation speed is always stored in the cylinder 4. Is supplied to.

Further, since the inside of the cylinder 4 is sealed by the rotary valve 2, when the present plasticizing method is carried out by using the plasticizing apparatus of the first embodiment, the air is removed from the air vent hole 4a of the cylinder 4 through the material. The air mixed in the air is effectively sucked, and the air flows in the cylinder 4, and the material flows well into the cylinder 4 by the flow of the air. As a result, the bulk density of the material in the cylinder 4 is increased, the material is reliably and smoothly supplied, and variations in the discharge amount are eliminated. Further, when the present plasticizing method is carried out using the plasticizing apparatus of the second embodiment, the bulk density of the material is increased by removing air from the material before feeding. Further, when the present plasticizing method is carried out by using the plasticizing apparatus of the third embodiment, air, volatile matter, moisture and the like are sucked from the vent hole 4b provided in the upper part of the cylinder 4 to cause impurities in the cylinder 4. Degassing effectively and increasing the bulk density of the material. Furthermore, when this plasticizing method is carried out by using the plasticizing apparatus of the fourth to seventh embodiments, since the sealing property on the material supply side is high, the bulk density of the material in the cylinder 4 is further increased.

According to the plasticizing method of the present embodiment as described above, an appropriate amount of material corresponding to the rotation speed of the screw 5 is supplied into the cylinder 4, and at the same time, the effective removal based on the high sealability of the rotary valve is performed. By virtue of the vapor action, the material in the cylinder 4 is always made to have a high bulk density, and impurities (air, volatile matter, moisture, etc.) between and in the material are removed to increase the production amount of the molded product and to improve the quality. Enable improvement.

This plasticizing apparatus and the plasticizing method using this apparatus have deep valleys of the screw like the twin screw type,
It works particularly well when the material is only in the lower part of the cylinder.

The plasticizing apparatus of the present invention and the plasticizing method using the apparatus are not limited to the above embodiments. For example, the plasticizing device of the present invention is not limited to the above-mentioned single-screw type or twin-screw type, and may be changed to a multi-screw type having two or more screws. In this case, as in the plasticizing device of the second embodiment, the cylinder 4
If the vent hole 4b is provided in the upper part of the, the impurities in the cylinder 4 can be effectively degassed. Of course, this vent hole can be provided in a uniaxial type plasticizing device. Also,
The plasticizing apparatus and the plasticizing method of the present invention can be widely applied to plasticize various materials such as powder and particles.

[0035]

As described above, according to the plasticizing apparatus of the present invention, the degree of vacuum inside the cylinder can be increased while reducing the size of the apparatus. Further, according to the plasticizing method of the present invention, it is possible to supply an appropriate amount of material, and it is possible to increase the production amount and quality of molded articles.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a plasticizing device using a single screw according to a first embodiment of the present invention.

FIG. 2 is a vertical sectional view showing a plasticizing device using a single screw according to a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view showing a plasticizing device using a multi-screw screw according to a third embodiment of the present invention.

FIG. 4 is a partial sectional view showing a plasticizing device according to a fourth embodiment of the present invention.

FIG. 5 is a partial sectional view showing a plasticizing device according to a fifth embodiment of the present invention.

FIG. 6 is a partial sectional view showing a plasticizing device according to a sixth embodiment of the present invention.

FIG. 7 is a partial sectional view showing a plasticizing device according to a seventh embodiment of the present invention.

FIG. 8 is a partial sectional view showing a plasticizing device according to an eighth embodiment of the present invention.

FIG. 9 is a partial sectional view showing a plasticizing device according to a ninth embodiment of the present invention.

FIG. 10 is a partial sectional view showing a plasticizing device according to a tenth embodiment of the present invention.

FIG. 11 is a vertical cross-sectional view showing a plasticizing device according to a conventional example.

[Explanation of symbols]

 1, 50 ... Hopper 2, 21, 22, 23, 24, 25 ... Rotary valve 26 ... Shut-out valve 3, 30 ... Connection pipe 4 ... Cylinder 4a ... Air vent hole 4b ... Vent hole 5 ... Screw 5a ... Screw root portion 6 ... Rotary seal part 7 ... Drive part 8 ... Heater 9 ... Detection part 10 ... Control part 11,31,41,42 ... Suction pump 40 ... Material storage part 70 ... Screw feeder 80 ... Cooling part

Claims (13)

[Claims] 1. A plasticizing device, characterized in that a screw is inserted into a cylinder, and a rotary valve for supplying a material into the cylinder is hermetically connected to the cylinder. 2. The plasticizing device according to claim 1, wherein a suction pump for sucking air to the outside is attached between the rotary valve and the cylinder. 3. The plasticizing device according to claim 1, wherein an air vent is provided near the material supply section of the cylinder. 4. The plasticizing device according to claim 1, wherein a screw having two or more axes is inserted into the cylinder, and a vent hole is provided in an upper portion of the cylinder. 5. The plasticizing device according to claim 1, wherein the plurality of rotary valves are laminated and provided. 6. The plasticizing device according to claim 5, wherein a plurality of rotary valves are hermetically connected via a connecting pipe, and a suction pump for sucking air from the connecting pipe to the outside is attached to the connecting pipe. 7. The plasticizing device according to claim 5, wherein a plurality of rotary valves are hermetically connected via a material storage unit, and a suction pump for sucking air from the material storage unit to the outside is attached to the material storage unit. . 8. A plurality of rotary valves are arranged in multiple rows on the same rotary shaft and are rotated by a single drive motor,
The plasticizing device according to claim 5, wherein the material is supplied into the cylinder. 9. The plasticizing device according to claim 1, wherein a shut-out valve is hermetically connected to the upper portion of the rotary valve. 10. The plasticization according to claim 9, wherein a shutout valve is hermetically connected to an upper portion of the rotary valve via a connecting pipe, and a suction pump for sucking air from the connecting pipe to the outside is attached to the connecting pipe. apparatus. 11. A shutout valve is hermetically connected to an upper portion of the rotary valve via a material storage section, and
The plasticizing device according to claim 9, wherein a suction pump that sucks air from the storage unit to the outside is attached to the material storage unit. 12. A method of plasticizing while supplying a material by a rotary valve into a cylinder in which a screw is inserted, wherein the material is supplied to the cylinder while continuously or intermittently rotating the rotary valve. A plasticizing method characterized by plasticizing. 13. A method of performing plasticization while supplying a material by a rotary valve into a cylinder having a screw inserted therein, wherein the rotational speed of the rotary valve is synchronized with the rotational speed of the screw to obtain the rotational speed of the screw. A plasticizing method characterized by supplying a suitable material into a cylinder for plasticizing.