JPH0630752B2 - Volume reduction device for waste synthetic resin - Google Patents

Description

Detailed Description of the Invention

TECHNICAL FIELD 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 in a reduced volume state. The volume reducing device of this structure requires a large amount of thermal energy to heat the cylinder to a high temperature. Therefore, the running cost becomes high. As a volume reducing device for solving this drawback, a device for melting synthetic resin by self-heating has been developed (Jitsuko Sho 62-22).
340). 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, it is difficult to efficiently reduce the volume of all thermoplastic waste synthetic resins. The reason is that the calorific value fluctuates significantly depending on the type of synthetic resin and the water content. The present inventor has developed a volume reducing device of Japanese Patent Application No. 1-199917 (see Japanese Patent Application Laid-Open No. 3-65284) for the purpose of solving this drawback. The volume reducing device includes a cylinder including a pushing cylinder and a volume reducing cylinder. The push cylinder has a built-in screw shaft for supplying the supplied waste synthetic resin to the volume reduction cylinder. The volume reduction cylinder has a built-in taper shaft that heats the synthetic resin supplied here to reduce the volume. The volume reduction cylinder is provided with a tapered heat generation volume reduction opening whose cross-sectional area increases toward the opening end. The taper shaft also has a taper shape that becomes thicker in the extrusion direction so that a heat-reduction gap can be formed between the taper shaft and the heat generation-reduction opening. The surface of the taper shaft is provided with a ridge for rubbing the synthetic resin. This volume reducing device reduces the volume of waste synthetic resin under the following conditions. Waste plastic is supplied to the push cylinder. The synthetic resin sent into the pushing cylinder is sent forward by the screw shaft. The waste synthetic resin sent to the volume-reducing cylinder is rubbed in the heat-reduction gap between the heat-reduction volume opening and the taper shaft and self-heats. The waste synthetic resin self-heats in the heating volume reduction gap because it is rubbed in a pressed state by the rotating tapered shaft. The volume reducing device of this structure has a feature that the volume can be efficiently reduced because the volume of the waste synthetic resin can be reduced by self-heating. However, the volume reducing device having this structure has a drawback that it is extremely difficult to adjust the heating volume reduction gap. The reason is that the volume reduction state and processing capacity of the synthetic resin fluctuate significantly depending on the heating volume reduction gap. That is, when the heating volume reduction gap is narrowed, the waste synthetic resin is strongly pressed and the amount of heat generation increases. On the contrary, if the heating volume reduction gap is adjusted to be wide, the pressing frictional force of the waste synthetic resin is reduced and the amount of heat generation is reduced. To increase the amount of heat generated,
When the heating volume reduction gap is narrowed, the amount of the synthetic resin that is reduced in volume and extruded decreases, and the processing capacity decreases. It is necessary to adjust the heating volume reduction gap to an interval at which the supplied waste synthetic resin is sufficiently heated and reduced in volume, and moreover, a large amount of waste synthetic resin can be efficiently volume-reduced. Unfortunately, the volume reducing device of this structure has a drawback that the optimum value of the heating volume reduction gap varies depending on the amount of waste synthetic resin supplied to the pushing cylinder. This makes it difficult to adjust the heating volume reduction gap.
The amount of heat generated varies depending on the amount of waste synthetic resin input because the waste synthetic resin supplied to the cylinder pushes out the synthetic resin in the heating volume reduction gap. When a large amount of waste synthetic resin is supplied to the cylinder, this pushes out the synthetic resin in the volume reducing cylinder, and the synthetic resin is discharged from the volume reducing cylinder in a short time. Therefore, the volume reduction cylinder cannot sufficiently reduce the volume of the synthetic resin. On the contrary, when the amount of waste synthetic resin supplied to the pushing cylinder becomes small, the synthetic resin of the volume reduction cylinder is not pushed out and the volume reduction cylinder is rubbed and heated to a high temperature for a long time, and the temperature of the heating volume reduction gap becomes too high. There are drawbacks. The present invention was developed to further solve this drawback. An important object of the present invention is to uniformly heat the supplied waste synthetic resin to reduce it regardless of the supply amount of the waste synthetic resin. It is to provide a volume reduction device that can be accommodated.

[Means for solving conventional problems]

The waste synthetic resin volume reducing device of the present invention has the following configuration in order to achieve the above-mentioned object. (A) The volume reducing device includes a cylinder 1. (B) The cylinder includes a push-in cylinder 1B for supplying waste synthetic resin and a volume reduction cylinder 1A for heating the supplied waste synthetic resin by frictional heat to reduce the volume. (C) The pushing cylinder 1B has a built-in screw shaft 5 for transferring the supplied waste synthetic resin to the volume reducing cylinder 1A. (D) The volume-reducing cylinder 1A is connected to the tip of the push-in cylinder 1B so as to heat and reduce the volume of the synthetic resin sent from the push-in cylinder 1B. (E) The volume-reducing cylinder 1A is provided with a tapered heat-generating volume-reducing opening 7 whose cross-sectional area increases toward the opening end. (F) A taper shaft 6 is arranged inside the heat generation and volume reduction opening 7. (G) The taper shaft 6 has a taper shape that gradually becomes thicker in the extruding direction of the waste synthetic resin so that a heat-reduction space can be formed between the taper shaft 6 and the inner surface of the heat-generation volume-reduction opening 7. . (H) On the outer periphery of the taper shaft 6, a plurality of ridges 13 are provided extending in the axial direction so that the synthetic resin can efficiently generate heat by frictional heat. (I) The ridge 13 is inclined with respect to the axial direction of the taper shaft 6 in order to control the delivery amount of the synthetic resin that has been heated and reduced in volume. When the inclination angle of the ridge 13 is large, the synthetic resin in the heating volume reduction gap is promptly sent out. On the other hand, when the angle of inclination of the ridge 13 is small, the stagnation time of the synthetic resin in the heating volume reduction gap becomes long. In the heating volume reduction gap, the stagnation time of the synthetic resin may be too long or, conversely, too short. If it is too long, the processing capacity of the waste synthetic resin will decrease, and if it is too short, the volume of the waste synthetic resin will not be sufficiently reduced. The angle of inclination of the taper axis of the ridge with respect to the axial direction is the first
As shown in the drawing, in the plan view of the taper shaft 6 in which the ridge 13 is located right above, it is the angle at which the ridge 13 and the central axis intersect. The inclination angle of the ridge 13 is preferably adjusted in the range of 1 to 15 degrees in consideration of the processing capacity of the synthetic resin and the volume reduction state. (J) The ridge 13 is inclined in a direction in which the taper shaft 6 rotates to push out the synthetic resin so that the synthetic resin whose volume has been reduced can be forcibly pushed out from the heating volume reduction gap by the rotation thereof. . (K) The taper shaft 6 is connected to the base so as to be movable in the axial direction via the tailstock 3 so that the heating volume reduction gap can be adjusted.

[Operation effect]

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 pushing cylinder 1B is
The screw shaft 5 of the pushing cylinder 1B feeds the volume reduction cylinder 1A. The waste synthetic resin sent to the volume-reducing cylinder 1A is rubbed in the heating volume-reducing gap and heated and melted. In the heating volume reduction gap, the waste synthetic resin self-heats and the volume is reduced. This is because the self-heating of the waste synthetic resin is rubbed by the convex strip of the rotating taper shaft while being pressed against the inner surface of the heat-reduction opening. However, the volume reduction device of the present invention does not necessarily need to completely melt the waste synthetic resin in the heating volume reduction gap. 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 waste synthetic resin whose volume has been reduced in the heating volume reduction gap is extruded from the heating volume reduction gap by the ridge 13 of the taper shaft 6. This is because the ridge 13 is inclined in the direction in which the synthetic resin in the heating volume reduction gap is pushed out by the rotation of the taper shaft 6. As described above, the volume reduction device for waste synthetic resin according to the present invention has a tapered heating volume reduction gap that increases in the direction in which the synthetic resin is sent out. Then, the volume-reduced synthetic resin is forcibly pushed out from the heating volume-reduction gap by the ridge 13 of the taper shaft 6. That is, the ridges 13 provided on the surface of the taper shaft 6 cause the waste synthetic resin supplied to the heating and volume-reducing gap to self-heat by frictional heat, and further, the volume-reduced waste synthetic resin is forcibly discharged in order. ing. The volume reduction device capable of heating, reducing the volume and extruding the waste synthetic resin in this state has the feature that the supplied waste synthetic resin can be uniformly reduced in volume and discharged. It is the ridge 13 of the taper shaft 6.
However, the discharge amount of waste synthetic resin can be controlled. In other words, even if the supply amount of the waste synthetic resin changes, the heating and volume reducing conditions in the heat reducing volume of the waste synthetic resin are less likely to change. The synthetic resin of the heating volume reduction gap,
The conventional volume reducer, which is pushed and discharged by the synthetic resin supplied one after another, changes when the supply amount of waste synthetic resin changes,
The time to pass through the heating volume reduction gap changes. When the time for passing through the heating volume reduction gap changes, the waste synthetic resin is changed in heating and volume reduction conditions. The volume reduction device that changes the heating and volume reduction conditions cannot uniformly reduce the volume of the waste synthetic resin that is supplied, and the adjustment of the heat volume reduction gap that determines the volume reduction state of the waste synthetic resin is extremely difficult. It gets harder. However, the volume reducing device of the present invention can uniformly reduce the volume of the supplied waste synthetic resin and discharge it regardless of the supply amount of the waste synthetic resin, so that it is easy to adjust the heating volume reduction gap and reduce the heating volume. The gap can be adjusted to an ideal state. Since the heating volume reduction gap can be adjusted to an ideal state for volume reduction of waste synthetic resin, it also realizes the feature of increasing the processing efficiency of waste synthetic resin.

Preferred 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. The volume reduction device for waste synthetic resin shown in the schematic sectional view of FIG. 2 and the perspective view of FIG. 3 includes a cylinder 1 composed of a pushing cylinder 1B and a volume reducing cylinder 1A, and a screw arranged in the pushing cylinder 1B. Axis 5
And a taper shaft 6 connected to the tip of the screw shaft 5.
And a motor 4 for rotating the drive shaft 2. The volume reduction cylinder 1A heats the waste synthetic resin to reduce its volume. The waste synthetic resin is supplied to the pushing cylinder 1B.
The pushing cylinder 1B press-fits the waste synthetic resin into the volume reducing cylinder 1A. The pushing cylinder portion 1B is connected to the tip of the volume reducing cylinder 1A. Push cylinder part 1B
And the volume reduction cylinder 1A are connected in series. The volume reduction cylinder 1A heats and reduces the volume of the waste synthetic resin and discharges it. An exothermic volume reduction opening 7 is opened in the volume reduction cylinder 1A. The heat generation reduction opening 7 is formed in a tapered shape whose cross-sectional area increases toward the opening end. The heat generation and volume reduction opening 7 having this shape has a feature that the waste synthetic resin can be efficiently reduced in volume, and the heat generation state can be adjusted depending on the type and the amount of water of the supplied waste synthetic resin. A cross-sectional view of the heat-reduction volume opening 7 is shown in FIG. As shown in this figure, the heat generation reducing opening 7 has a plurality of grooves 14
Is provided. The groove 14 is provided on the inner surface of the heat generation reduction opening 7 so as to extend in the axial direction. Five to fifty grooves 14 are provided on the inner surface of the heat generation and volume reduction opening 7. The depth and width of the groove 14 are designed in the range of 1 to 10 mm. As shown in FIG. 4, the cross-sectional shape of the groove 14 may be semicircular in cross section, or may be square or trapezoidal although not shown. In this way, the heat generation reducing opening 7 provided with the groove 14 is provided.
Can efficiently self-heat by reducing the slip of waste synthetic resin. By the way, this volume reduction device ideally completely melts and reduces the volume of the waste synthetic resin, but it is not always necessary to heat the waste synthetic resin to a melting temperature or higher to completely melt it. 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. A taper shaft 6 is provided in the heat generation and volume reduction opening 7 of the volume reduction cylinder 1A. The taper shaft 6 is connected to the tip of the drive shaft 2 and is rotated by the drive shaft 2. The surface of the tapered shaft 6 is provided with four ridges 13 extending in the axial direction. The ridges 13 rub the waste synthetic resin fed into the heating volume reduction gap to reduce the volume, and forcibly discharge the reduced volume. The ridge 13 is inclined with respect to the axial direction of the taper shaft 6. The inclination angle determines the discharge state of the synthetic resin whose volume has been reduced in the heating volume reduction gap. When the inclination angle is large, the synthetic resin in the heating volume reduction gap is quickly discharged. Therefore, the capacity of the waste synthetic resin for volume reduction is increased. On the contrary, when the inclination angle is small, the passage time of the synthetic resin in the heating volume reduction gap becomes long. Therefore, the volume of the waste synthetic resin can be reduced sufficiently at a high temperature. The inclination angle of the ridge 13 is adjusted to an optimum value in consideration of the processing capacity of the waste synthetic resin and the volume reduction state. The inclination angle is usually 1 to 15 degrees, preferably 2-1
Designed in the 0 degree range. Further, in the inclined ridges 13, the taper shaft 6 rotates,
Forcibly discharge the synthetic resin from the heating volume reduction gap. For this reason, as shown in FIG. 1, the inclination direction of the ridges 13 is designed so that the synthetic resin is forcibly discharged from the heating volume reduction gap when rotated from the taper shaft 6. Further, FIG. 5 shows the cross-sectional view shape of the ridge 13. The ridges 13 shown in this figure include a front side surface 13A and a rear side surface 1
The slope is different from that of 3B, and the front side surface 13A is a slope having a gentle upward slope, and the rear side surface 13B is a descending surface having a steeper downward slope than the front side surface 13A. The front side surface 13A has a curved surface shape with a gradually increasing gradient. Preferably, the front side surface 13A of the ridge has a curved surface that curves with a predetermined radius of curvature. The length L of the inclined portion of the front side surface 13A of the ridge is adjusted to an optimum value in consideration of the height H of the ridge. The ratio of the length L of the inclined portion to the height H of the ridge is usually adjusted in the range of 0.3 ≦ L / H ≦ 5, preferably 0.5 ≦ L / H ≦ 3. Further, the height H of the ridge gradually decreases toward the tip of the tapered shaft 6, but is designed to be 3 to 40 mm at the highest portion. The ridges provided on the surface of the taper shaft may be arranged such that the short ridges 14 are extended in the axial direction and are slightly separated, as shown in FIG. It is also possible to provide 3 to 10 ridges on the surface of the tapered shaft. The taper shaft 6 is connected to the tip of the drive shaft 2 so as to be movable in the axial direction. Therefore, a square hole into which the drive shaft 2 is inserted is provided at the center of the tapered shaft 6. The tip of the drive shaft 2 has a prismatic shape that can be slidably inserted into the square hole. The prism of the drive shaft 2 is inserted into the square hole of the tapered shaft 6,
The taper shaft 6 is rotated by the drive 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 drive shaft 2. The taper shaft 6 is supported by the tailstock 3 so as to be movable in the axial direction of the drive shaft 2. The taper shaft 6 moves in the axial direction together with the tailstock 3. Therefore, the taper shaft 6
Is rotatably supported on 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. By the way, the volume reduction device for waste synthetic resin of the present invention reduces the volume by causing the synthetic resin to generate heat by itself.
A does not necessarily require a heating means such as a heater, but it goes without saying that a heater can be provided in this portion. Volume reduction cylinder 1A even if equipped with a heater
Since the waste synthetic resin self-heats, the heating capacity of the heater can be reduced. The pushing cylinder portion 1B is connected to the volume reducing cylinder 1A. The pushing cylinder portion 1B is opened upward, and the waste synthetic resin supply port 8 is opened. Inside the pushing cylinder portion 1B, the screw shaft 5 and the rotary cutter 10 are arranged side by side in the same horizontal plane. Therefore, the pushing cylinder portion 1B is formed in a tubular shape capable of accommodating two shafts. The screw shaft 5 is rotatably arranged inside the pushing cylinder portion 1B. The screw shaft 5 is the motor 4
The waste synthetic resin that has been rotated by and is sent from the supply port 8 to the pressing cylinder portion 1B is pressure-fed. Therefore, a spiral fin 9 is provided on the surface of the screw shaft 5. Rotary cutter 1 arranged parallel to the screw shaft 5
In No. 0, the waste synthetic resin supplied from the supply port 8 is cut into small pieces with the screw shaft 5 and pressure-fed to the volume reducing cylinder 1A. Therefore, a plurality of ridges 11 are provided on the surface of the rotary cutter 10 so as to extend vertically, and the entire shape is processed into a spline shape. The tip edge of the ridge 11, in other words, the top edge of the mountain portion of the ridge 11, is the screw shaft 5
The tip of the fin 9 comes into contact with or is extremely close to the fin 9, and the waste synthetic resin is sandwiched between the fin 9 of the screw shaft and the ridge 11 of the rotary cutter for cutting. Although not shown, the rotary cutter 10 may have a plurality of short ridges extending in the axial direction and arranged in a zigzag pattern instead of a spline shape. The rotary cutter 10 is rotated in the opposite direction with respect to the screw shaft 5 so as to cut the waste synthetic resin by sandwiching it with the screw shaft 5. In the volume reducing device shown in FIG. 2, the rotary cutter 10 and the screw shaft 5 are rotated in opposite directions via a gear 12. The inner shape of the pushing cylinder portion 1B is processed such that the fin tips of the screw shaft 5 and the ridge tip edges of the rotary cutter 10 approach, for example, 0.1 to 5 mm. As described above, the pushing cylinder portion 1B having the rotary cutter 10 parallel to the screw shaft 5 cuts the supplied waste synthetic resin into small pieces and pressure-feeds them to the volume reducing cylinder 1A. It has the feature that waste synthetic resin such as shapes can be supplied as it is, and various shapes of waste synthetic resin can be efficiently rubbed in the next step. However, depending on the type and shape of the waste synthetic resin, a rotary cutter is not always necessary, and the screw shaft and the cylindrical pushing cylinder part with a small clearance can also be used to send the waste synthetic resin to the volume reduction cylinder under pressure. Is. The rear end of the screw shaft 5 is connected to the reduction motor 4 and driven to rotate. By the way, at the rear end of the pushing cylinder part, at the bottom,
Preferably, a drain port (not shown) is opened. When the drain port is opened here, when the waste synthetic resin having a high moisture content is supplied, the moisture contained in the synthetic resin is removed, and the synthetic resin having a low moisture content can be supplied to the volume reducing cylinder.

[Brief description of drawings]

FIG. 1 is a plan view of a taper shaft used in a volume reducing device according to an embodiment of the present invention, and FIGS. 2 and 3 are sectional views and perspective views of the volume reducing device showing an embodiment of the present invention. Figure, 4th
FIG. 5 is a cross-sectional view of the volume-reducing cylinder and the tapered shaft, FIG. 5 is an enlarged cross-sectional view of the heating volume-reducing gap, and FIG. 6 is a side view showing another embodiment of the tapered shaft. 1 ... Cylinder, 1A ... Volume reduction cylinder, 1B ... Pushing cylinder, 2 ... Drive shaft, 3 ... Tailstock, 4 ... Motor, 5 ... Screw shaft, 6 ... Tapered shaft, 7 ... … Heat generation reduction opening, 8… Supply port, 9… Fin, 10… Rotary cutter, 11… Projection, 12… Gear, 13… Projection, 13A… Front side, 13B… Rear Side, 14 ... Groove.

Claims (1)

[Claims] 1. A volume reducing device for waste synthetic resin having the following structure. (A) The volume reducing device is equipped with a cylinder (1). (B) The cylinder includes a pushing cylinder (1B) and a volume reducing cylinder (1A). (C) The pushing cylinder (1B) has a screw shaft (5) for transferring the supplied waste synthetic resin to the volume reducing cylinder (1A).
Is built in. (D) The volume reduction cylinder (1
A) is connected. (E) The volume reduction cylinder (1A) is provided with a tapered heat generation volume reduction opening (7) whose cross-sectional area increases toward the opening end. (F) A taper shaft (6) is arranged inside the heat-generation volume reducing opening (7). (G) The tapered shaft (6) gradually becomes thicker in the extruding direction of the waste synthetic resin so that a heat-reduction clearance is formed between the tapered shaft (6) and the inner surface of the heat-reduction volume opening (7). It has a tapered shape. (H) A plurality of ridges (13) extending in the axial direction are provided on the outer circumference of the tapered shaft (6). (I) The ridge (13) is inclined with respect to the axial direction of the taper shaft (6). (J) The ridge (13) is inclined in the direction in which the taper shaft (6) rotates and pushes out the synthetic resin. (K) The taper shaft (6) is connected to the base so as to be movable in the axial direction via the tailstock (3).