JPH0639099B2 - Volume reduction device for waste synthetic resin - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

The present invention relates to a device for reducing the volume of waste synthetic resin so that it can be effectively reused.

[Prior art and problems]

Currently, a huge amount of used synthetic resin is generated. Moreover, its amount has increased significantly. Most of the used synthetic resins are incinerated for disposal. The waste synthetic resin incinerator has a short life, and the incineration cost is rising. Also, depending on the type of synthetic resin, it produces toxic gas when incinerated. Some of the used synthetic resin is used to mold recycled products. In order to reuse the waste synthetic resin, the dirty synthetic resin is washed, melted, molded into pellets, and reused. This method has a drawback that the processing cost for processing the waste synthetic resin into pellets becomes high. In order to effectively reuse a huge amount of waste synthetic resin, it is important to reduce the processing cost and volume. The volume-reduced waste synthetic resin can be remolded with a molding machine. An apparatus has been developed for pushing waste synthetic resin into a cylinder with a thin tip to reduce the volume (JP-A-61-82).
879). This volume reducing device heats the tip of the cylinder in order to melt the extruded waste synthetic resin by heat. In this volume reducing device, a waste synthetic resin is pushed into the cylinder by a piston, heated and melted at the tip, and pushed out from the cylinder 1 in a volume-reduced state. Furthermore, an apparatus for melting synthetic resin by self-heating has been developed (Japanese Utility Model Publication No. 62-22340). This device has a screw shaft in a cylinder that pushes out waste synthetic resin. The opening at the tip of the cylinder is narrowed down, and the synthetic resin is made to generate heat by friction heat in this part. The tip of the screw shaft is shaped so that the transfer amount of the synthetic resin is small so that the heat generation amount of the synthetic resin increases at the tip of the cylinder. The volume reducing device having this structure can reduce the heat energy for heating the cylinder. However, these volume reduction devices have a risk of exploding when using a synthetic resin having a high moisture content. The explosion is caused by the water contained in the waste synthetic resin being primarily vaporized and expanded in the cylinder. Therefore, there is a drawback that the volume of waste synthetic resin having a high water content cannot be safely reduced. In order to solve this drawback, the present inventor has formed a plurality of small drainage openings at the bottom of the cylinder so that the waste synthetic resin does not come out. This volume reducing device can drain the water contained in the waste synthetic resin from the drain port at the bottom of the cylinder. However, since the drainage port is opened to the passage of the waste synthetic resin, there is a drawback that it cannot be drained because it is clogged in a short time.
If the drain port is clogged, the vaporized vapor in the cylinder expands and explodes, creating an extremely dangerous condition. The present inventor further changed the shape of the drain port to a slit shape in order to solve this drawback. The slit-shaped drain port was opened by extending in a direction parallel to the screw axis. The drainage port having this shape is less likely to be clogged as compared with the drainage port having a large number of small holes, but the clogging cannot be resolved after a long time. The slit-shaped drainage port can reduce clogging to some extent by increasing the opening area. However, when the opening area of the drainage port is increased, the waste synthetic resin is easily pressed. For this reason, there is a drawback that it is clogged when operating for a long time. The present inventor managed to open drain holes of various shapes at the bottom of the cylinder in order to eliminate clogging of the drain holes. However, the drainage port of any shape could not eliminate the clogging caused by long-term operation. Therefore, the present inventor assumed all conditions in order to theoretically analyze the state in which the drainage port is clogged. As a result, it was clarified that the clogging of the drainage port was caused by the waste synthetic resin supplied to the cylinder being pumped by the fins of the screw shaft. That is, since the drainage port is opened at the transfer position of the waste synthetic resin that is pressure-fed by the fins, the waste synthetic resin and foreign matter under pressure are pressed into the opening of the drainage port. Become. In order to avoid this state, the present inventor opened a drain port on the rear side of the synthetic resin to be pumped. When we experimented with this volume reduction device, we succeeded in relieving the clogging of the drain port very effectively. Therefore, an important object of the present invention is to provide a volume reduction device for waste synthetic resin, which is capable of reducing the volume of waste synthetic resin having a high water content safely and efficiently.

[Means for Solving the Problems]

The waste synthetic resin volume reducing device of the present invention has the following configuration in order to achieve the above-mentioned object. The volume reduction device for waste synthetic resin comprises a cylinder 1 having a waste synthetic resin supply port 8 opened therein, a screw shaft 2 rotatably disposed in the cylinder 1, and a screw shaft 2 arranged in parallel with the screw shaft 2. A cutting member 10 arranged in the cylinder 1,
A cutting member 10 and a motor 4 for rotating the screw shaft 2 are provided. The cylinder 1 has an opening at the front end, and penetrates the closed rear portion to support the screw shaft 2 and the cutting member 10. The screw shaft 2 fixes a spiral fin 9 that transfers the supplied waste synthetic resin toward the tip. The cutting member 10 is provided with a ridge 11 which approaches the fin 9 of the screw shaft 2 and cuts the waste synthetic resin. Further, the cylinder 1 is located rearward of the waste synthetic tree supply port 8 and has a slit-shaped drain port 5 at the bottom thereof. The waste synthetic resin supplied to the supply port is cut by the screw shaft 2 and the cutting member 10, the water content of the waste synthetic resin is drained from the drain port 5, and the synthetic resin with the reduced water content is pumped to the front of the cylinder 1. Then, the volume is reduced.

[Action]

The volume reducing device of the present invention reduces the volume of the waste synthetic resin and discharges it under the following conditions. The waste synthetic resin supplied to the cylinder 1 is heated and melted in the cylinder 1, then reduced in volume, and extruded from the cylinder 1. However, the volume reducing device of the present invention does not necessarily completely melt the waste synthetic resin in the cylinder 1. This is because the volume of the waste synthetic resin can be sufficiently reduced even when the waste synthetic resin is in a semi-molten state or a partially molten state. The water supplied to the cylinder 1 together with the waste synthetic resin flows down to the bottom of the cylinder 1 and is drained from the drain port 5 opened at the bottom. The drain port 5 is opened at the rear part of the cylinder 1. In other words, the drain port 5 is opened on the side opposite to the transfer direction of the waste synthetic resin. Therefore, the waste synthetic resin that is cut by the cutting member 10 and the screw shaft 2 and is pressure-fed by the fins 9 is not pressed by the drainage port 5. Therefore, the volume reducing device of the present invention is
It is possible to prevent the waste synthetic resin and foreign matter from being pressed into the drainage port 5.

[Preferred embodiment]

Embodiments of the present invention will be described below with reference to the drawings. However, the embodiments shown below exemplify a volume reducing device for embodying the technical idea of the present invention, and the volume reducing device of the present invention is configured with materials, shapes, structures, and arrangements of components. It is not specific to the structure below. The volume reduction device of the present invention has various modifications within the scope of the claims. Further, in this specification, for easy understanding of the claims, the numbers corresponding to the members shown in the examples are referred to as "Claims of the claims" and "Means for solving the conventional problems. It is added to the members shown in "Column" and "Column of action and effect". However, the members shown in the claims are not limited to the members of the embodiment. 1 and a perspective view of FIG. 2 show a waste synthetic resin volume reducing device, which includes a cylinder 1, a screw shaft 2 rotatably disposed in the cylinder 1, and the screw shaft 2. And a drive motor for rotating the. The cylinder 1 includes a volume reduction cylinder 1A that heats and reduces the volume of the waste synthetic resin, and a pushing cylinder 1B that press-fits the waste synthetic resin into the volume reduction cylinder 1A. The pushing cylinder 1B is connected to the tip of the volume reducing cylinder 1A, and the pushing cylinder 1B and the volume reducing cylinder 1A are connected in series. The pushing cylinder 1B press-fits the supplied waste synthetic resin into the volume reduction cylinder 1A. The pushing cylinder 1B is opened upward, and the waste synthetic resin supply port 8 is opened. Inside the pushing cylinder 1B, the screw shaft 2 with the fin 9 and the cutting member 10 are arranged side by side in the same horizontal plane. Therefore, the push-in cylinder 1B is formed in a tubular shape capable of accommodating two shafts in parallel. The screw shaft 2 with the fin 9 is rotatably arranged inside the pushing cylinder 1B. The screw shaft 2
The waste synthetic resin, which is rotated by the motor 4 and sent from the supply port 8 to the pressing cylinder 1B, is pressure-fed. Therefore,
The fin 9 fixed to the surface of the screw shaft 2 has a spiral shape. The cutting member 10 cuts the waste synthetic resin supplied from the supply port 8 into small pieces. The waste synthetic resin is sandwiched between the cutting member 10 and the fins 9 of the screw shaft 2. Therefore, on the surface of the cutting member 10, a plurality of ridges 11 extending vertically is formed.
Is provided, and the entire shape is processed into a spline shape. The tip edge of the convex shape 11, in other words, the top edge of the mountain portion of the ridge 11 is in contact with or extremely close to the tip edge of the fin 9 of the screw shaft 2. Fin 9 of screw shaft 2
And the ridge 11 of the cutting member cuts the supplied waste synthetic resin. Although not shown, the cutting member may be a spline-like member having a large number of short ridges arranged in a staggered pattern extending in the axial direction. The cutting member 10 cuts by sandwiching the waste synthetic resin between the cutting member 10 and the fin 9 of the screw shaft 2. Therefore, the cutting member 10
Are rotated opposite to the screw shaft 2. In the volume reducing device shown in FIG. 1, the cutting member 10 and the screw shaft 2 are rotated in opposite directions via a gear 12. The waste synthetic resin cut into small pieces is pressed into the volume-reducing cylinder 1A by the spiral fins 9 of the screw shaft 2. The inner shape of the pressing cylinder 1B is such that the tips of the fins 9 of the screw shaft 2 and the edges of the ridges of the cutting member 10 are, for example,
It is processed into a shape that approaches 0.1 to 5 mm. As described above, the volume reducing device that cuts the waste synthetic resin supplied by the cutting member 10 and supplies the waste synthetic resin to the volume reducing cylinder 1A can directly supply the waste synthetic resin having a long string shape, a sheet shape, a bag shape, or the like. The feature is that waste synthetic resins of various shapes can be efficiently rubbed in the next step. Push-in cylinder 1B provided at the rear of cylinder 1
Has a drain port 5 opened rearward of the supply port 8. The drain port 5 is opened at the bottom of the pushing cylinder 1B.
The rear end portion of the pushing cylinder 1B is shown in FIG.
In the pushing cylinder 1B shown in this figure, the rear end opening of the cylinder 1 is closed by a back plate 14. The drain port 5 is opened between the back plate 14 and the pushing cylinder 1B, and the drain port 5 is provided at the rear end of the cylinder 1. Back plate 14
Is screwed to a flange provided on the outer periphery of the rear end of the cylindrical push cylinder 1B to close the rear end of the push cylinder 1B. A screw shaft passing through the back plate 14 is rotatably supported on the back plate 14. FIG. 4 shows a rear view of the pushing cylinder 1B in which the drain port 5 is opened. Push cylinder 1 shown in this figure
The flange of B has a groove 15 on the surface closed by the back plate in order to provide the drain port 5 at the rear part. The groove 15 is provided so as to communicate with the inner surface of the cylinder 1. The pushing cylinder 1B shown in FIG. 4 has a screw shaft 2 and a cutting member built therein in parallel to each other. Therefore, the pushing cylinder 1B is provided with two grooves 15. One groove 15
Communicates with the inner surface of the cylinder containing the screw shaft 2.
The other groove 15 communicates with the inner surface of the cylinder containing the cutting member. The groove 15 penetrates the bottom of the pushing cylinder 1B and is connected to the outside. The width of the groove 15 determines the opening lateral width of the drainage port 5. Groove 15
Depth determines the vertical width of the drainage port 5. The drainage port 5 has a width of 20 to 200 mm and a width of 1 to 15 mm, for example. In the pushing cylinder 1B of this shape, the drain port 5 can be opened on the inner surface of the cylinder by fixing the back plate to the flange. Since the drainage port 5 is opened on the inner surface of each of the cylinders in which the screw shaft 2 and the cutting member are incorporated, the drainage port 5 has a feature that water can be efficiently drained from the bottoms of the two cylinders. By the way, the volume reducing device of the present invention is characterized in that the drain port 5 is provided at the rear of the supply port 8 of the cylinder 1. This is because the waste synthetic resin that is pressure-fed by the fins 9 is not pressed into the drain port 5. The ideal opening position of the drain port 5 is the final end of the cylinder 1, as shown in FIG. However, it goes without saying that the drain port 5 can be sufficiently used even if it is opened slightly forward from the final end. The volume reduction cylinder 1A in which the waste synthetic resin is press-fitted in the pushing cylinder 1B is a cylinder 1 in which the volume of the waste synthetic resin is reduced.
Discharge from. The volume-reduction cylinder 1A has a tapered heat-reduction volume opening 7 whose cross-sectional area increases toward the open end so that the heat generation state can be adjusted depending on the type of waste synthetic resin. The heat-reduction volume opening 7 extends in the axial direction to form a groove (not shown).
Is provided. The provision of the groove prevents the waste synthetic resin from slipping and reduces the rotation of the synthetic resin by the screw shaft 5. The waste synthetic resin that does not rotate integrally with the screw shaft 5 at the heat generation reduction opening 7 is rotated by the rotating screw shaft 5.
And self-heats efficiently. A taper shaft 6 is built in the volume reduction cylinder 1A. The taper shaft 6 is connected to the tip of the screw shaft 2. The taper shaft 6 is connected to the tip of the screw shaft 2 so as to be movable in the axial direction. At the center of the taper shaft 6, a square hole into which the screw shaft 2 is inserted is provided. The tip of the screw shaft 2 has a prismatic shape that can be slidably inserted into the square hole. The prism of the screw shaft 2 is inserted into the square hole of the taper shaft 6, and the taper shaft 6 is rotated by the screw shaft 2. When the taper shaft 6 moves in the axial direction, the depth at which the prism is inserted into the square hole changes. The taper shaft 6 is linearly connected to the screw shaft 2. On the surface of the taper shaft 6, a ridge 13 is provided extending in the axial direction. The ridges 13 reduce the slip of waste synthetic resin. Therefore, the tapered shaft 6 having the ridge 13
Has the feature that it can efficiently rub waste synthetic resin and self-heat. That is, a groove is provided in the heat generation and volume reduction opening 7, and the tapered shaft 6
If the ridges 13 are provided on the, the waste synthetic resin can be most efficiently reduced in volume by self-heating. The ridges provided on the surface of the taper shaft may be arranged such that the short ridges 13 are extended in the axial direction and are apart from each other, as shown in FIG. The taper shaft 6 is supported by the tailstock 3 so as to be movable in the axial direction of the screw shaft 2. The taper shaft 6 moves in the axial direction together with the tailstock 3. Therefore, the tapered shaft 6 is rotatably supported by the tailstock 3 but does not move in the axial direction. A shaft protruding from the tip of the tapered shaft 6 is supported by the tailstock 3 via a bearing. The tailstock 3 can be moved in the axial direction of the volume reduction cylinder 1A,
In addition, it is attached to the base so that it can be fixed at the moving position. The tailstock 3 moves the taper shaft 6 in the axial direction to adjust the gap between the taper shaft 6 and the volume reduction cylinder 1A. When the tailstock 3 is brought close to the cylinder 1 and the taper shaft 6 is pushed deeply into the volume-reducing cylinder 1A, the gap between the taper shaft 6 and the volume-reducing cylinder 1A becomes narrow. On the contrary, tailstock 3
Is separated from the cylinder 1, the gap between the taper shaft 6 and the volume reducing cylinder 1A becomes wider. When the gap between the taper shaft 6 and the volume-reducing cylinder 1A becomes narrow, the waste synthetic resin is rubbed against each other while being strongly pressed in the narrow gap. Therefore, the amount of heat generated is increased, and the waste synthetic resin having a high melting temperature or the waste synthetic resin having a high water content can be completely melted at a higher temperature. If the gap between the taper shaft 6 and the volume reducing cylinder 1A is adjusted to be wide, the pressing force of the waste synthetic resin becomes weak and the amount of heat generation becomes small. Therefore, this state is optimal for treating waste synthetic resin having a low melting temperature or a low water content.
In this state, the amount of synthetic resin discharged per unit time increases. Therefore, the gap between the taper shaft 6 and the volume-reducing cylinder 1A is adjusted to the optimum heat generation amount and treatment amount in consideration of the type of synthetic resin supplied and the water content. The volume reducing device shown in FIG. 1 does not require a heating means such as a heater because the volume of the synthetic resin can be reduced by self-heating. However, the structure for reducing the volume of the waste synthetic resin of the present invention is not specified to that shown in FIG. It goes without saying that a heater can also be used to reduce the volume of waste synthetic resin.

【The invention's effect】

The volume reducing device of the present invention has a feature that it effectively prevents clogging of a drainage port that removes water contained in waste synthetic resin and can efficiently reduce the volume of waste synthetic resin. This is because the device of the present invention can cut waste synthetic resin into small pieces with the screw shaft and the cutting member, and effectively drain the contained water from the drain port to reduce the volume. The device that cuts waste synthetic resin into small pieces and reduces the volume has the feature that the synthetic resin can be efficiently reduced in volume, but the small synthetic resin tends to clog the drainage port. Although it is possible to make the drainage outlet larger so as to be less likely to be clogged, the large drainage outlet cannot be made larger because there is a drawback that the synthetic resin cut into small pieces leaks. Small drains tend to be clogged with chopped synthetic resin. The volume reducing device of the present invention is provided with a slit-like drainage port behind the supply port of the cylinder in order to eliminate clogging of the small cut synthetic resin. Since this drainage port is located at a position opposite to the direction in which the waste synthetic resin is transferred, the waste synthetic resin that is cut into small pieces and pressure-fed by the screw shaft is not forcibly pressed and clogged. Therefore, the volume reducing device of the present invention has a feature that the clogging of the drainage port can be effectively eliminated and the water content of the waste synthetic resin can be effectively removed. Further, in the volume reducing device of the present invention, even if the small cut synthetic resin is moved to the position where the drainage port is closed, the fins provided on the screw shaft can easily remove the synthetic resin from the opening. This is because the fins of the rotating screw shaft do not transfer synthetic resin, foreign matter, etc. toward the drain port, but move in a direction crossing the opening of the drain port. The waste synthetic resin from which water has been removed at the drainage port is efficiently heated and melted in the cylinder to be reduced in volume. Waste synthetic resin containing a large amount of water needs to be vaporized and heated to a volume reduction temperature. The temperature at which the volume of waste synthetic resin can be reduced is 1.
50 ° C to 250 ° C, which is higher than the boiling point of water. Therefore, the waste synthetic resin is heated to the volume-reducing temperature by boiling the contained water. The thermal energy required to boil water is extremely large compared to the thermal energy required to heat waste synthetic resin to the volume reduction temperature. The heat energy required to heat 1 g of synthetic resin is only 0.2-0.5 calories. The thermal energy required to vaporize 1g of water is
There are also 540 calories. If the volume is reduced by heating in a cylinder without sufficiently separating water from the waste synthetic resin, not only the volume reduction efficiency is remarkably lowered, but also water is vaporized and expanded at one time to explode. The volume reduction efficiency decreases because a large amount of heat energy is required to vaporize the water content. Further, the explosion in the cylinder occurs temporarily when a waste synthetic resin having a high water content is added. In the state where the volume of waste synthetic resin having a low water content is continuously reduced, the temperature in the cylinder is maintained at 150 ° C to 250 ° C, which is higher than the boiling point of water. In this state, when a large amount of water is supplied together with the waste synthetic resin into the cylinder heated to a high temperature, the water vaporizes and expands in an instant. When water vaporizes, its volume expands 1000 times. An explosion in the cylinder will cause serious damage to the cylinder and internal parts, and will also cause a serious danger by spraying from the synthetic resin supply port of the cylinder. However, since the volume reducing device of the present invention drains the water supplied to the cylinder from the drain port to reduce the volume of the waste synthetic resin, there is no danger of explosion and the waste synthetic resin can be efficiently reduced in volume. .

[Brief description of drawings]

1 and 2 are a schematic sectional view and a perspective view of a waste synthetic resin volume reducing apparatus according to an embodiment of the present invention, FIG. 3 is a sectional view showing a rear end portion of a cylinder, and FIG. 4 is a cylinder. FIG. 5 is a rear view showing the rear end, and FIG. 5 is a side view showing another embodiment of the tapered shaft. 1 …… Cylinder 1A …… Volume reduction 1B …… Pushing cylinder 2 …… Screw shaft 3 …… Tailstock 4 …… Motor 5 …… Drainage port, 6 …… Taper shaft 7 …… Volume reduction Opening, 8 ... Supply port 9 ... Fin, 10 ... Cutting member 11 ... Projection strip, 12 ... Gear 13 ... Projection strip, 14 ... Rear plate 15 ... Groove

Claims (1)

[Claims] 1. A cylinder 1 in which a waste synthetic resin supply port 8 is opened, a screw shaft 2 rotatably disposed in the cylinder 1, and a cylinder 1 parallel to the screw shaft 2 in the cylinder 1. A cutting member 10 provided,
It is equipped with a cutting member 10 and a motor 4 for rotating the screw shaft 2, and the screw shaft 2 penetrates the rear part of the cylinder 1 in which the tip of the cylinder 1 is opened and closed.
And a cutting member 10 are supported, and a spiral fin 9 for transferring the supplied waste synthetic resin toward the tip is fixed to the screw shaft 2, and the cutting member 1
0 is provided with a ridge 11 that approaches the fins 9 of the screw shaft 2 and cuts the waste synthetic resin. Further, the cylinder 1 is located rearward of the waste synthetic resin supply port 8 and At the bottom, there is a slit-shaped drainage port 5, the waste synthetic resin supplied to the supply port is cut by the screw shaft 2 and the cutting member 10, and the water content of the waste synthetic resin is drained from the drainage port 5 to contain the water content. Cylinder 1 with reduced plastic
A volume reduction device for waste synthetic resin that is configured to be pumped forward to reduce the volume.