JP4021528B2 - Discrimination method for different plastic materials, discrimination method and discrimination device for PVC bottle and PET bottle, and PET bottle recovery device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for discriminating between one plastic material and the other plastic material in a situation where two types of plastic materials are mixed, and in particular, PET bottles and PVC bottles that are difficult to visually distinguish with waste plastic materials. For distinguishing PVC bottles from PET bottles that are separated from PVC (polyethylene terephthalate) bottles, which are harmful to recycling, and to collect the desired PET bottles The present invention also relates to a discrimination device and a PET bottle collection device.
[0002]
[Prior art]
Recently, there is a social demand for the recovery and recycling of waste plastic materials. In particular, plastic bottles used as containers for drinking water and food are imported plastics such as drinking water and food, even though most of the plastic bottles produced in Japan are recyclable PET bottles. The bottle contains some harmful PVC bottles, and it is necessary to separate these when collecting them.
[0003]
These plastic bottles are widely spread and penetrated as household items in general households, and it is difficult to distinguish between PET bottles and PVC bottles at a glance. In order to realize a separate collection system that can be adopted by ordinary consumers on a daily basis, it is necessary to have separation facilities that can be easily operated by ordinary consumers, and such facilities can be used in supermarkets and retail stores. The condition that it can be safely installed in a daily and public place such as a store is required. It is not easy to separate and collect PET bottles in a simple manner by removing only harmful PVC bottles while satisfying such conditions.
[0004]
Known methods for separating waste plastic include specific gravity separation using the difference in specific gravity, X-ray using the difference in X-ray absorption, or near-infrared using the near-infrared absorption spectrum type determination. It has been.
[0005]
[Problems to be solved by the invention]
In the specific gravity fractionation method, wet analysis is the mainstream, but the wet method greatly impedes the adoption because of the large equipment size and the need for wastewater treatment. In particular, PET and PVC are unsuitable because they cannot be clearly separated due to their close specific gravity. Both the X-ray method and the near-infrared method are optical measurement separations. The presence or absence of liquid deposits or paste deposits on the surface of waste plastic materials, or the presence or absence of fillers in plastic materials, and the filling of fillers These matters, such as the difference in rate, make the optical measurement conditions constant, and it is difficult to obtain high reliability of the measurement results. Therefore, reliable separation is difficult, or a device on the apparatus for making the optical measurement conditions constant is necessary. In particular, the X-ray method has to solve the problem of human exposure, and as a safety problem, it is practically impossible to implement in public places as described above.
[0006]
The present invention has been conceived in order to effectively solve the above-described conventional technical problems. Accordingly, an object of the present invention is to provide a method for easily, safely and reliably separating two types of waste plastic materials.
[0007]
A further object of the present invention is to provide a method and apparatus for discriminating between PET bottles and PVC bottles safely and reliably with a simple apparatus, and further an apparatus for collecting the sorted PET bottles. .
[0008]
[Means for Solving the Problems]
The method for discriminating different plastic materials according to the present invention has the following characteristics in order to solve the problems of the prior art as described above and achieve the object.
[0009]
Another method for discriminating different plastic materials according to the present invention is to use an indenter heated to a temperature higher than the lower melting point and lower than the higher melting point for two types of plastic materials having different melting points. By pressing, the plastic material is discriminated from the one in which the indenter enters the plastic material within a predetermined time and the one in which the predetermined time elapses without entering.
[0010]
Another method for discriminating different plastic materials according to the present invention is an indenter in which two types of plastic materials having different melting points are heated to a temperature not lower than the lower melting point and lower than the higher melting point. The indenter penetrates the plastic material before the pressing force reaches the predetermined value, and the indenter reaches the predetermined value without penetrating the plastic material. It is characterized by discriminating.
[0011]
In addition, as a different kind of plastic material to be discriminated as described above, when one is made of polyethylene terephthalate (PET), the other plastic material is made of polypropylene (PP) or polyvinyl chloride (PVC). A plastic material having a melting point lower than that of polyethylene terephthalate, such as polyethylene (PE), or a composite material thereof (for example, a bottle made of a laminate of PP and PE) can be selected. As in the case of PET and PVC, these are difficult to distinguish from each other, but can be distinguished safely and reliably and extremely easily. Polystyrene (PS) has a melting point that is not much different from that of PET, but since this plastic material is mixed with a plasticizer at the time of molding, the melting point in that case is almost 200 ° C. or less. Can be determined.
[0012]
Further, the method for distinguishing PVC bottles and PET bottles according to the present invention is a temperature that is higher than the melting point of polyvinyl chloride and lower than the melting point of polyethylene terephthalate with respect to plastic bottles including unidentified PVC bottles and PET bottles. The indenter that is heated is pressed against the plastic material within a predetermined time to determine that it is a PVC bottle, and the one that has passed the predetermined time without intrusion is determined to be a PET bottle. To do.
[0013]
Further, another PVC bottle and PET bottle discriminating method according to the present invention is more than the melting point of polyvinyl chloride and less than the melting point of polyethylene terephthalate with respect to plastic bottles including unidentified PVC bottles and PET bottles. An indenter heated to a temperature of 10 mm is pressed, and the indenter penetrates the wall of the plastic bottle before the pressing force reaches a predetermined value, and is determined as a PVC bottle, and the indenter is the wall of the plastic bottle. What has reached a predetermined value without penetrating is characterized as being a PET bottle.
[0014]
Further, the PVC bottle / PET bottle discriminating apparatus of the present invention includes an indenter heated to a temperature not lower than the melting point of polyvinyl chloride and lower than the melting point of polyethylene terephthalate.
[0015]
Furthermore, the PVC bottle / PET bottle discriminating device of the present invention discriminates the object to be inspected as a PET bottle when the pressing force pressing the indenter against the object to be inspected reaches a predetermined value. It is preferable to further include a pressing release means for releasing the action on the inspection plastic bottle. In addition, the pressing release means does not operate as a PET bottle when the pressing force reaches a predetermined value, but the predetermined time elapses without the indenter entering the object to be inspected after starting pressing. In this case, the object to be inspected may be determined as a PET bottle and the pressing force may be released.
[0016]
In addition, a limit switch is provided in the vicinity of the tip of the indenter so as to be movable in parallel with the indenter and at a predetermined distance behind the tip of the indenter. When the indenter pressed against the bottle penetrates the container wall of the plastic bottle, the limit switch comes into contact with the container wall of the plastic bottle and determines that the plastic bottle is a PVC bottle, and generates a PVC bottle determination signal. It is preferable to configure to output.
[0017]
In addition to the above-described indenter, it is preferable to further include a notifying means for notifying the user that the pressing force for pressing the indenter against the object to be inspected has reached a predetermined value in order to provide a portable simple discrimination device. . Or you may make it notify a user that the indenter pressed on the to-be-inspected plastic bottle penetrated the container wall of the plastic bottle as an alerting | reporting means.
[0018]
The PET bottle recovery apparatus according to the present invention includes a determination section that determines whether a waste plastic bottle is a PET bottle or a PVC bottle, and a sorting section that separates the determined plastic bottle into a PET bottle and a PVC bottle. A PET bottle recovery apparatus having a first recovery section for recovering the sorted PET bottle and a second recovery section for recovering the sorted PVC bottle, wherein the discrimination section has a melting point of polyvinyl chloride. An indenter heated to a temperature below the melting point of polyethylene terephthalate, a pressing means for pressing the indenter against the plastic bottle, and when the pressing force of the pressing means reaches a predetermined value, the plastic bottle is a PET bottle. PET that discriminates and outputs a PET bottle discrimination signal When the indenter has passed through the container wall of the plastic bottle before the pressing force of the pressing means reaches a predetermined value, it determines that the plastic bottle is a PVC bottle and outputs a PVC bottle determination signal. And a PVC discriminating unit, wherein the sorting section sorts the plastic bottle into a PET bottle and a PVC bottle in accordance with respective output signals of the PET discriminating unit and the PVC discriminating unit.
[0019]
Another PET bottle recovery apparatus according to the present invention separates the determined plastic bottle into a PET bottle and a PVC bottle, and a determination section for determining whether the waste plastic bottle is a PET bottle or a PVC bottle. A PET bottle collection device having a sorting section, a first collection section for collecting sorted PET bottles, and a second collection section for collecting sorted PVC bottles, wherein the discrimination section is made of polyvinyl chloride. An indenter heated to a temperature above the melting point and below the melting point of polyethylene terephthalate, a pressing means for pressing the indenter against the plastic bottle, and after the pressing by the pressing means starts, the indenter penetrates the container wall of the plastic bottle. When the predetermined time has passed, the plastic bottle PET discriminating means for discriminating that it is a bottle and outputting a PET bottle discriminating signal, and when the indenter penetrates the container wall of the plastic bottle within a predetermined time after pressing by the pressing means, the plastic bottle is PVC PVC discriminating means for discriminating that it is a bottle and outputting a PVC bottle discriminating signal, and according to the respective output signals of the PET discriminating means and the PVC discriminating means, the sorting section converts the plastic bottle into a PET bottle and a PVC bottle. It is characterized by sorting.
[0020]
Further, each of the first recovery sections preferably has a PET bottle pulverization / volume reduction means.
[0021]
DETAILED DESCRIPTION OF THE INVENTION
The method for discriminating different plastics according to the present invention is particularly effective for two types of plastic materials having a large difference in melting point. For example, the melting point of polyethylene terephthalate is 265 ° C. The melting point of vinyl is as low as 200 to 210 ° C, and the melting point difference is approximately 50 to 60 ° C. Therefore, when these plastic materials are placed in a temperature environment of 200 to 210 ° C., the decrease in mechanical strength of polyethylene terephthalate is not so great, but polyvinyl chloride is almost melted and almost loses mechanical strength. End up. For example, if the surface properties of the plastic material are optically observed in that state, the change will be visible, and if a mechanical force such as tension, compression, or bending is applied, polyvinyl chloride exhibits almost resistance. It transforms without. However, under the same conditions, polyethylene terephthalate does not reach the melting point, so it maintains the mechanical strength and exhibits a large resistance to the same mechanical force. By comparing the mechanical strength of both plastic materials in such a temperature environment, it is possible to distinguish the strong one as a plastic material with a high melting point and the weakened one as a plastic material with a low melting point. it can.
[0022]
In general, the method of discriminating two types of plastic materials based on the temperature difference is basically safe by merely preparing a heat source and not using harmful X-rays or chemicals. Moreover, the melting point of the plastic material is lower than that of metal or the like, and is within a temperature range that can be handled relatively safely and easily. When comparing plastic materials having a large difference in melting points, it is possible to reliably determine both.
[0023]
The principle of the PVC bottle and PET bottle discriminating method and the PET bottle recovery apparatus according to the present invention also uses the difference in softening point or melting point of polyethylene terephthalate and polyvinyl chloride. As described above, the melting point of polyethylene terephthalate is 265 ° C., whereas the melting point of polyvinyl chloride is as low as 200 to 210 ° C., and the difference between the two melting points is approximately 50 to 60 ° C. Therefore, for example, when a bar-shaped heating element at 200 ° C. is directly pressed against a plastic bottle, the heating element easily penetrates the bottle if it is a PVC bottle, but until it penetrates to the extent that it is slightly distorted if it is a PET bottle. It does n’t come. Thus, a PVC bottle and a PET bottle can be discriminated by comparing the difference in strength between plastic bottles near the melting point temperature of polyvinyl chloride.
[0024]
As the heat source, a heating rod, a hot needle, a hot air heater, irradiation with visible light or infrared light, or laser irradiation can be used. When using a heating rod or a hot needle, press it directly against the bottle. Moreover, as a detection means, a load sensor, a pressure sensor, a position detection sensor, a displacement sensor, and an image sensor can be used. As the position detection sensor, a micro switch, a limit switch, a proximity switch, a photoelectric switch, or the like is effective. Further, as conditions, in the case of using a heater, the pressing force and pressing time of the indenter pressed against the plastic bottle, and the set temperature of the heater can be changed.
[0025]
As an experimental example, the bottom of the PET bottle and the PVC bottle are set upward with an experimental apparatus as shown in FIG. 1, and the heating rod 11 is attached to the load cell (load detection device) 12 as an indenter. The load and distortion of the plastic bottle were measured while pressing the tip of the indenter. In the figure, 14 is a heat insulating material. When the temperature of the heating rod 11 was set to 200 ° C. and pressed at a speed of 5 mm per minute for several seconds, the PVC bottle was softened immediately and no significant load was applied. However, a large load was applied to the PET bottle. Was detected. As a numerical value, the maximum load of 0.32 kgf was detected when the strain distance reached 0.8 mm in the PVC bottle, but after that, the load decreased sharply only by increasing the strain distance, and the indenter pushed the bottom of the bottle. It penetrated and became a load of 0 kgf. On the other hand, the PET bottle detected a load of 2 kgf when the strain distance reached 3.2 mm, but did not reach the maximum value. The graph of FIG. 2 represents the result of this experiment. As can be seen from the experimental results, the PET bottle and the PVC bottle can be discriminated by checking whether or not the load exceeds 0.32 kgf.
[0026]
3 and 4 show a schematic configuration of the first embodiment of the PET bottle recovery apparatus according to the present invention. 3 is a view of the apparatus as seen from the back, and FIG. 4 is a view of the side as seen. In the center of the upper part in the apparatus 21, a support base 24 for receiving a plastic bottle 23 is disposed, the front of the apparatus being inserted from a slot 22 and sliding down (see FIG. 4). The support 24 is composed of two door members 25 and 26 that are perpendicular to each other so that the back can be opened to the left and right when seen from the back, and the slope on which the plastic bottle 23 slides down. The lower end part of the Further, stopper walls 27 and 28 are formed so as to extend in a direction orthogonal to the lower end edge of the inclined surface so as to receive the bottom of the plastic bottle 23 sliding down the inclined surface. Each door member 25, 26 is driven by the first and second air cylinders 29, 30 and independently rotates around each fulcrum 31 or 32. When the first door 25 on the right side in FIG. 3 is opened while the plastic bottle 23 is placed on the support base 24, the plastic bottle 23 falls to the right side, and when the second door 26 on the left side in FIG. Fall to. A sorting wall 33 is provided below the pedestal 24 so that the bottle falling to the right side and the bottle falling to the left side are reliably sorted. The stopper wall 28 of the second door 26 is provided with a sensor 34 that detects the presence or absence of a plastic bottle. The bottom of the plastic bottle 23 abuts against the sensor 34 to detect that the plastic bottle 23 has been inserted. And an operation for sorting is started based on the detection signal.
[0027]
A needle-like heating rod 35 is disposed above the support 24. The heating rod 35 is attached to the tip of the drive rod of the third air cylinder 36 so as to be able to advance and retract in a direction perpendicular to the plastic bottle 23 on the support 24 and toward the center thereof. Although the setting of the temperature of the heating rod 35 and the pressing force of the third air cylinder 36 will be described later, when it is determined that the plastic bottle 23 put into the apparatus 21 is a PET bottle based on the principle of the present invention. The first air cylinder 29 opens the first door 25 and drops the PET bottle to the right side of the sorting wall 33. When it is determined that the bottle is a PVC bottle, the second air cylinder 30 opens the second door 26 and drops the PVC bottle to the left side of the sorting wall 33. The gap between the upper end of the sorting wall 33 and the lower end edge of each door member 25, 26 of the support base 24 is sufficiently small, and the plastic bottle that falls when one of the doors opens is sorted from the gap. It does not fall to the opposite side of the wall 33, and the determined plastic bottle is reliably sorted.
[0028]
In order to accommodate the plastic bottles sorted to the left and right, a first collection container 37 for collecting PET bottles is disposed on the right side of the sorting wall 33 at the bottom of the apparatus 21 and a second collection for collecting PVC bottles is disposed on the left side. A container 38 is placed. The PVC bottle dropped to the left side when the second door 26 is opened is directly dropped into the second collection container 38 and stored.
[0029]
A shredder 39 is provided between the first door 25 and the first collection container 37, and the PET bottle that has dropped when the first door 25 opens is stored in the shredder 39 before being accommodated in the first collection container 37. And then cut into fine pieces to reduce the volume. The PET bottle becomes a flake-shaped plastic piece finely cut by the shredder 39 and further falls and is accommodated in the first collection container 37.
[0030]
Next, details of the heating rod 35 and the third air cylinder 36 will be described with reference to FIGS. 5 and 6. The heat generating rod 35 is attached to the tip of the drive rod 40 of the third air cylinder 36 via a heat radiating plate 42, and advances when the drive rod 40 extends from the cylinder 41 so as to pierce the side wall surface of the plastic bottle 23. A limit switch 43 is extended from the drive rod 40 in parallel with the heating rod 35, and the tip position of the limit switch 43 is set back about 2 cm from the tip of the heating rod 35. In order to extend or contract the drive rod 40, the cylinder 41 is connected with two inlet pipes 44 for pressurized air at the front end portion and the rear end portion. The drive rod 40 contracts when pressurized air is introduced from the front end (first connection port) of the cylinder 41, and extends when introduced from the rear end (second connection port). A solenoid valve 45 is interposed in the middle of the introduction pipe 44 in order to switch the introduction direction of the pressurized air. A pressure switch 47 is provided between the solenoid valve 45 and the second connection port to switch the solenoid valve 45 upon detecting that the pipe pressure has reached a predetermined pressure value. In the figure, 46 is a regulator for stabilizing the pressurized air supplied into the cylinder 41 via the solenoid valve 45 at a constant pressure.
[0031]
As described above, since the limit switch 43 is in the vicinity of the heating rod 35 and is retracted about 2 cm from the tip thereof, the heating rod 35 is pressed against the PET bottle or the PVC bottle with a relatively strong momentum, and the heating rod 35 is pressed. Even if the periphery of is depressed to some extent, the limit switch 43 does not abut against the container wall and does not malfunction. Further, the heating rod 35 does not operate unless it penetrates the container wall, and a reliable discrimination is possible. If the present invention is applied to a thick plastic material here, even if the heating rod penetrates without passing through, it is determined that the limit switch is operated as PVC.
[0032]
When the plastic bottle 23 is put into the recovery device, the sensor 34 of the support 24 detects the presence of the plastic bottle 23, the heating rod 35 is heated to the melting point (200-210 ° C.) of the PVC, and the solenoid valve Pressurized air is introduced from the second connection port into the cylinder 41 through 45, and the heated heating rod 35 is pressed against the side wall of the plastic bottle 23.
[0033]
In the case where the plastic bottle 23 is a PET bottle, even if the heating rod 35 is pressed against the bottle side wall, the bottle side wall hardly deteriorates in strength. Therefore, as shown in FIG. The pressure in the introduction pipe 44 is 2 kg / cm until the limit switch 43 contacts the side wall of the bottle. ² And the pressure switch 47 is activated. When the pressure switch 47 is activated, the solenoid valve 45 is switched to retract the heating rod 35 and the first air cylinder 29 is activated to open the first door 25.
[0034]
On the other hand, when the plastic bottle 23 is a PVC bottle, as shown in FIG. 6, the heating rod 35 melts and penetrates the side wall of the bottle. Therefore, the pressure switch 47 is 2 kg / cm. ² Without exceeding the limit switch 43, the limit switch 43 comes into contact with the bottle side wall and operates. When the limit switch 43 is actuated, the solenoid valve 45 is switched to retract the heating rod 35 and the second air cylinder 38 is actuated to open the second door 26.
[0035]
The heating rod 35 may be a rod in which a heater is directly embedded in a metal rod such as brass, or a rod that can be replaced by screwing a metal rod into a unit incorporating the heater. The temperature of the heater can be adjusted by a temperature controller. If molten PVC adheres to the surface of the heating rod 35, it may be transferred to a PET bottle. Therefore, it is preferable that the rod surface is subjected to fluororesin processing so that it does not easily adhere. Moreover, it is good also to arrange | position the rotating brush and wiper which wipe off this, even if PVC adheres so that the front-end | tip and peripheral surface of the heat generating bar 35 may be touched.
[0036]
In the above-described embodiment, since the posture of the bottle is unstable when the tip of the heating rod 35 is pressed against the plastic bottle 23 on the support base 24, a holding means for stably holding the bottle on the support base 24 is provided. It is good. As the holding means, for example, a holding plate that moves forward together with the drive rod 40 and clamps the bottle between the support base 24 can be elastically supported on the drive rod 40 via a spring.
[0037]
In the above-described embodiment, the shredder 39 that performs pulverization and volume reduction is provided as a PET bottle volume reduction means. However, a press device that performs compression volume reduction may be used instead. However, pulverized volume reduction is preferable in that the volume reduction rate is higher than compression volume reduction and a large amount of PET bottles can be accommodated in the collection container. In particular, the crushing step in the recycling process of the PET bottle can be omitted, and it is advantageous for transportation from the recovery device to the recycling facility or the recycling facility. Also, plastic pieces that have been finely cut with a shredder and formed into flakes are very difficult to be surely separated when PVC and PET are mixed. It is demanded that this separation is made surely. According to the present invention, it is reliably avoided that PVC is mixed in PET by utilizing the melting point difference.
[0038]
Further, instead of providing the pressure switch 47, the following timer switch may be provided. That is, this timer switch measures the time from when the solenoid valve 45 is switched to the side to press the heating rod and starts pressing, and switches the solenoid valve 45 when the limit switch 43 does not operate even after a predetermined time has elapsed. . The predetermined time mentioned here is a time in seconds in which it can be confirmed that the heating rod does not penetrate due to the pressing force. Normally, it is about 0.5 to 3 seconds, but if this is lengthened, the number of treatments will decrease, and if it is too short, it will be determined that it is PET before the heat is sufficiently transferred to the plastic material (PVC bottle). This will cause a malfunction. The predetermined time may be determined in consideration of the thickness of the plastic material and the required accuracy and speed.
[0039]
In addition, when the heating rod 35 presses the plastic bottle and the movement speed is relatively fast and vigorous, the pressing force is 2 kg / cm even if the plastic bottle is a PVC bottle. ² May have been reached and then penetrated. In such a case, it is not determined whether the pressing force reaches a predetermined value, but whether or not the heating rod enters the plastic bottle within the predetermined time after the pressing of the heating rod is continued for a predetermined time. Thus, it is possible to distinguish between PET and PVC. When making such a determination, the above-described timer switch is particularly effective.
[0040]
FIG. 7 is a diagram showing a schematic configuration of a second embodiment of the PET bottle recovery apparatus. The point that the heating rod heated to the melting point of PVC is pressed against the plastic bottle to discriminate the PVC bottle from the PET bottle is the same as the first embodiment, but the structure for sorting the discriminated bottle is the first embodiment. Different from the example.
[0041]
In the figure, the recovery device is viewed from the left side, but a bottle input port 52 is provided on the upper end surface of the device 51 that is inclined forward (forward), and a bottle passage 53 extends directly below. A first shutter 54 is disposed at the lower end of the bottle passage 53 so as to receive the plastic bottle 57 that is inserted and descended. An opening 55 is formed at the lower end of the rear wall of the bottle passage 53, and a heating rod 56 is disposed further rearward of the opening 55. The heating rod 56 advances and retreats through the opening 55 with respect to the plastic bottle 57 received on the first shutter 54. The heating rod 56 is cylinder driven as in the first embodiment. In the figure, reference numeral 58 denotes a holding plate that presses the bottle 57 against the front wall of the passage 53 to stabilize the posture, and is attached to the cylinder device 60 via a spring 59. A sensor 61 for detecting the presence or absence of the plastic bottle 57 is provided in the first shutter 54, detects that the bottom of the plastic bottle 57 is in contact with the sensor 61 and the plastic bottle 57 is inserted, and based on the detection signal. The operation for sorting is started.
[0042]
The first shutter 54 is configured by a flat plate and is slid rearward by the shutter driving unit 62. Further below the first shutter 54, a second shutter 63 having a slope inclined forward is disposed, and the second shutter 63 is also slid rearward by the shutter driving unit 62. When it is determined that the plastic bottle 57 put into the collection device 51 is a PET bottle based on the principle of the present invention, both the first shutter 54 and the second shutter 63 slide rearward and directly below the bottle 57. Let fall. A shredder 64 is disposed immediately below the first shutter 54 and the second shutter 63, and a first collection container 65 for collecting the PET bottle is disposed below the shredder 64, and crushed and reduced to form a flaky plastic piece. The PET is stored in the first collection container 65. In the figure, reference numeral 66 denotes a guide passage for guiding the falling bottle to the shredder 64. When it is determined that the plastic bottle 57 is a PVC bottle, only the first shutter 54 slides backward while the second shutter 63 is positioned on the guide passage 66 to drop the bottle 57. The bottle 57 slides down along the slope of the second shutter 63 and is accommodated in a second collection container 67 for collecting PVC bottles arranged in front of the shredder 64 and the first collection container 65.
[0043]
In the figure, reference numeral 68 denotes a switching circuit for switching the sliding operation of the first shutter 54 and the second shutter 63 between the case of the PET bottle and the case of the PVC bottle, and a discrimination signal output from the cylinder driving unit 69 of the heating rod 56. The operation of the shutter driving unit 62 is switched based on the above.
[0044]
FIG. 8 is a diagram showing a schematic configuration of a third embodiment of the PET bottle recovery apparatus. The point of discriminating the PVC bottle and the PET bottle by pressing the heating rod heated to the melting point of the PVC against the plastic bottle is the same as in the first and second embodiments, but for sorting the discriminated bottles. The structure is different from the above-described embodiments.
[0045]
FIG. 8 also shows the left side surface of the recovery device as seen from FIG. A bottle inlet 82 is provided on the upper end surface of the recovery device 81 whose front surface is inclined toward the front (front), and the bottle passage 83 extends obliquely rearward. A shutter 87 that is slidable in the front-rear direction is provided at the lower end of the bottle passage 83 so as to receive the plastic bottle 84 that slides down the bottle passage 83 from the inlet at almost the center position of the slide range. The innermost part of the upper wall of the bottle passage 83 is opened upward, and a heating rod 86 is disposed obliquely above the open part 85. The heating rod 86 is driven by a cylinder in the same manner as in the first embodiment so as to be able to advance and retract in a direction orthogonal to the plastic bottle 84 received on the shutter 87 and toward the center thereof. In the figure, 88 is a holding plate that stabilizes the posture by pressing the bottle 84 against the lower wall of the passage 83, and is attached to the cylinder device 89. In this embodiment, the cylinder device 89 and the holding plate 88 move integrally, and the heating rod 86 is driven by the cylinder from the state in which the holding plate 88 is in contact with the side surface of the plastic bottle 84 and securely held. A sensor 90 for detecting the presence / absence of the plastic bottle 84 is provided at the lower end of the lower wall of the bottle passage 83. The side of the lower side of the plastic bottle 84 abuts the sensor 90 and the plastic bottle 84 is inserted. Detection is performed, and an operation for classification is started based on the detection signal.
[0046]
The shutter 87 is formed in a flat plate shape that is long in the front-rear direction (the right-left direction in the figure in FIG. 8), and a central portion substantially divided into three equal parts in the longitudinal direction is closed. The first opening 92 and the second opening 93 are formed in such a size that can pass through. The shutter 87 is slid back and forth by the shutter drive unit 91. When it is determined that the plastic bottle 84 put into the collection device 81 is a PET bottle based on the principle of the present invention, the shutter 87 is pulled backward, and the first opening 92 is directly below the PET bottle. The PET bottle falls from the first opening 92 downward. When it is determined that the plastic bottle 84 is a PVC bottle, the shutter 87 is pushed forward, and the second opening 93 comes directly under the PVC bottle, so that the PVC bottle falls downward from the second opening 93. As in the first and second embodiments described above, the PET bottle is crushed and reduced by the shredder 94 and collected in the first collection container 95, and the PVC bottle is collected in the second collection container 96 as it is. In the figure, reference numeral 97 denotes a sorting wall for guiding the PET bottle to the shredder 94 and the PVC bottle to the second collection container 96. On the lower end surface of the shutter 87, a first movable guide plate 98 and a second movable guide plate 99 are hung down by being hinged to respective boundary portions between the central closed portion and the first opening 92 or the second opening 93. Is attached. When the shutter 87 slides back and forth, the guide plates 98 and 99 are inclined such that the lower ends thereof abut against the top portion 100 of the sorting wall 97, and the PET bottles falling from the first opening 92 are transferred to the shredder 94. The PVC bottle falling from 93 is reliably guided to the second collection container 96.
[0047]
In the figure, reference numeral 101 denotes a switching circuit that switches the sliding direction of the shutter 87 between the case of a PET bottle and the case of a PVC bottle, and the shutter driving unit 91 is based on a determination signal output from the cylinder driving unit 102 of the heating rod 86. Switching the operation.
[0048]
Furthermore, another embodiment of a mechanism for sorting bottles is shown in FIGS. The plastic bottle is discriminated by a cylinder-driven heating rod as in the first embodiment, but the discriminated bottle is sorted by a very simple mechanism. FIG. 9 shows the case where the inserted plastic bottle is a PET bottle as seen from the side, and FIG. 10 shows the case where the inserted plastic bottle is a PVC bottle as seen from the side. FIG. 11 shows only the bottle sorting mechanism portion in FIG. 10 as viewed from above. FIG. 12 shows a state in which the PVC bottle is pulled out from the state of FIG. A flat support 112 for receiving the charged plastic bottle 111 is provided under the bottle passage 113. Discrimination between PET and PVC by pressing the heating rod 114 is performed on the support 112. The flat support 112 is rotatably supported around the support shaft 115, and two arm-shaped counter weights 116 extend to the opposite side of the support shaft 115. The counterweight 116 is configured such that when the plastic container (approximately 30 g) having a capacity of 500 ml is placed on the support base 112 (or when a plastic container having a larger capacity is placed), the support base 112 in FIG. The weight and the position of its center of gravity are given so that a clockwise moment is generated around the support shaft 112 and a counterclockwise moment is generated around the support shaft 115 when nothing is placed on the support base 112. . The tip of the support 112 comes into contact with the lower end of the wall of the bottle passage 113 so that it is horizontal when nothing is placed thereon.
[0049]
The plastic bottle 111 is placed on the horizontal support base 112 and the support base 112 is kept below the support base 112 so that the support base 112 is kept horizontal while being discriminated by the heating rod 114. A support stand stopper 117 is provided to support from the outside. This support stopper 117 is operated by an electromagnet, and when it is determined that the plastic bottle 111 is a PET bottle, it is operated so as to remove the support from below. When the support of the support stand stopper 117 is lost, the support stand 112 to which the weight of the bottle 111 is added rotates in the clockwise direction, so that the bottle falls down and is collected in a PET bottle collection container (not shown). The When it is determined that the plastic bottle 111 is a PVC bottle, the electromagnet of the support base stopper 117 does not operate, and the support base 112 is supported in a horizontally maintained state.
[0050]
After the bottle has fallen, the counterclockwise moment by the counterweight 116 overcomes the clockwise moment by the support stand 112 alone and the support stand 112 is rotated until it becomes horizontal as described above. Thereafter, the support base stopper 117 is operated by the electromagnet and returns to the position where it is supported from below the support base 112.
[0051]
A bottle pulling arm 121 is attached to the drive rod 119 of the cylinder device 118 in addition to the heating rod 114 and the limit switch 120. The bottle retracting arm 121 extends downward from the drive rod 119 and is bent further forward. The tip of the bottle retracting arm 121 forms an opening 122 larger than the bottle diameter so as to allow the inserted bottle 111 to pass therethrough. . This is a configuration for drawing the bottle toward the cylinder device 118 when the plastic bottle 111 is a PVC bottle. That is, when the heating rod 114 passes through the side wall of the bottle 111 and the limit switch 120 is operated, the solenoid valve 123 is switched, and the bottle pulling arm 121 is pulled into the cylinder device 118 together with the drive rod 119 and the heating rod 114 (FIG. 12). At this time, the bottle 111 in the opening 122 of the pull-in arm 121 is also pulled from the top of the support stand 112 by pulling the cylinder device 118 to the side, and falls downward between the two counterweights 116. The dropped bottle is collected in a PVC bottle collection container (not shown). When the bottle 111 is pulled by the cylinder device 118 toward the hook, if the heating rod 114 remains stuck in the bottle 111, the bottle 111 hits the stopper 124 provided above the drive rod 119, Further, when the drive rod 119 is drawn, the heating rod 114 is removed from the bottle 111.
[0052]
In each of the above-described embodiments, it is assumed that only the plastic bottle is put into the collection device, but considering the conditions for installing the device in a public place such as a street or a retail store, There is a risk that foreign objects such as empty cans and empty bottles may be thrown into the apparatus. In order to deal with such a case, for example, for a metallic foreign object such as an empty can, it is possible to determine whether or not it is a foreign object by detecting the conductivity of the inserted object, or an empty bottle, etc. As described above, it is possible to detect foreign matter having a weight larger than that of the plastic bottle by detecting that the weight of the input product exceeds a predetermined value. These detection means may be used in combination, and when a foreign object is detected, the input may be excluded and collected in another container without performing measurement with a heating rod.
[0053]
In addition, each of the above embodiments is a PET bottle recovery device that discriminates between PET bottles and PVC bottles, sorts them, and further stores them in a collection container. If the plastic bottles collected in the state where both types of bottles are mixed are brought to a facility specializing in recycling processing and discriminated, the sorting work may be performed manually by the worker. For use in such a situation, a portable simple discrimination device is convenient, for example, 2 kg / cm similarly to the above-mentioned heating rod. ² When a pressing force exceeding 1 is applied, an apparatus having a notification means for notifying the operator by sound or display can be made. Alternatively, when the heating rod penetrates the container wall of the plastic bottle, it is possible to make a device provided with an informing means for notifying the operator by sound or display. Examples thereof are shown in FIGS. In the example of FIG. 13, a handle 131 that an operator can hold by hand is formed at one end of the device 130, and a heating rod 132 protrudes and is attached to the other end. The base of the heat generating bar 132 is held in the apparatus via a coil spring 133 and can be pushed in the axial direction of the heat generating bar 132 against the spring force. The spring force of the coil spring 133 is 2 kg / cm. ² When the plastic bottle is a PET bottle, it does not penetrate even if the heating rod 132 is pressed, so that the heating rod 132 is pushed into the apparatus against the spring force. In the apparatus, there is provided a limit switch 134 that is turned on when the proximal end portion of the heated heating rod is brought into contact therewith. When the limit switch 134 is turned on, a sounding device (not shown) such as a buzzer emits a sound to notify that it is a PET bottle. If the plastic bottle is a PVC bottle, press the heating bar 132 to 2kg / cm ² Since it penetrates with the following pressing force, the limit switch 134 is not turned on. Therefore, the operator presses the heating rod 132 against the plastic bottle and determines whether the heating rod penetrates without sound or whether the heating rod penetrates without making noise. Can be determined.
[0054]
FIG. 14 shows an example of another portable discrimination device. The device 140 is of a pistol type, and a heater switch 141 is provided at a trigger portion. The heating rod 142 is fixed, and a flange-like member 143 that can be pushed in is provided around the heating rod 142. The flange-like member 143 is held by a coil spring (not shown) to such an extent that the flange-like member 143 is pushed when the heating rod 142 passes through the PVC bottle. Although not shown, a limit switch similar to that in the example of FIG. 13 is provided, and when the flange-like member 143 is pushed in, it is turned on and the indicator lamp 144 is lit. In other words, when the plastic bottle is a PVC bottle, it is penetrated when the heating rod 142 is pressed, so that the flange-like member 143 is pressed by the PVC bottle wall, the limit switch is turned on, and the indicator lamp 144 is lit. When the plastic bottle is a PET bottle, it does not penetrate even if the heating rod 142 is pressed, so the flange-like member 143 is not pushed in, and the limit switch is not turned on, so the indicator lamp 144 is not lit.
[0055]
FIG. 15 shows another example of the portable type discrimination device. This device 150 has a heating rod 151 and a spring force of 2 kg / cm. ² The coil spring 152 and the limit switch 153 are configured in substantially the same manner as in the example of FIG. 13, and a protective cylinder 154 is further provided around the heating rod 151. The protective cylinder 154 is attached to the apparatus main body with a second coil spring 155 that is weaker than the coil spring 152. Even if the operator presses the heating rod 151 against the plastic bottle with a force much stronger than the spring force of the first coil spring 152. It is buffered by the spring force of the second coil spring 155, and it is possible to prevent a strong force from acting on the heating rod 151 abruptly. Since only the spring force of the first coil spring 152 acts on the heat generating rod 151 pressed against the plastic bottle, it is possible to vary the discrimination accuracy based on individual differences such as the strength of the operator and the pressing method. I can prevent it.
[0056]
In these apparatuses shown in FIGS. 13 to 15, if the worker presses the heating rod against the plastic bottle and the heating rod penetrates the container wall of the bottle, it is a PVC bottle, and if the heating rod escapes before penetrating. It can be determined that it is a PET bottle, and each can be put into a dedicated sorting space. In addition, a skilled worker can determine whether or not the heating rod penetrates the bottle while appropriately adjusting the pressing force as per the operator's sense, such as the limit switch, sounding device, indicator lamp, etc. The notification means may not be provided. It can also be used as an on-line device that automatically discriminates and sorts plastic bottles carried on a belt conveyor in a facility specialized in regeneration processing. In addition, by installing the device for discriminating and sorting of the present invention in a resource recovery vehicle that collects PET bottles, it is possible to sort and discriminate while collecting, shortening the time and reducing the equipment. It is also possible to build a better system.
[0057]
【The invention's effect】
As described above, in the method for discriminating different plastic materials according to the present invention, the difference between the melting points of the plastic materials is used, so that the plastic material can be discriminated easily and safely, and in particular, a method for discriminating between a PVC bottle and a PET bottle. In addition, it is useful for a discrimination device. The PET bottle recovery apparatus of the present invention provides an apparatus that can be installed in a public place such as a street because of its safety and simplicity. In particular, since the discrimination between the PVC bottle and the PET bottle is reliable, even if the PET bottle is crushed and reduced with a shredder, there is no fear of mixing PVC. According to pulverization and volume reduction, a larger amount of plastic bottles can be handled than when compression volume reduction is performed, and the bottles can be collected efficiently.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an apparatus for experimenting with a method for discriminating between different plastic materials and a method for discriminating between a PVC bottle and a PET bottle according to the present invention.
FIG. 2 is a graph showing the results of an experiment performed using the apparatus of FIG.
FIG. 3 is a view showing the first embodiment of the PET bottle recovery apparatus according to the present invention as seen from the rear side.
FIG. 4 is a diagram showing a first embodiment of a PET bottle recovery apparatus according to the present invention as seen from the side.
FIG. 5 is a diagram showing details of a PVC bottle and PET bottle discriminating apparatus according to the present invention, and shows a case where the plastic bottle to be discriminated is a PET bottle.
FIG. 6 is a diagram showing details of a PVC bottle and PET bottle discriminating apparatus according to the present invention, and shows a case where the plastic bottle to be discriminated is a PVC bottle.
FIG. 7 is a view showing a second embodiment of the PET bottle recovery apparatus according to the present invention as seen from the side.
FIG. 8 is a view showing a third embodiment of the PET bottle recovery apparatus according to the present invention as seen from the side.
FIG. 9 is a diagram showing another embodiment of a mechanism for sorting bottles as seen from the side, and shows a case where the plastic bottle that has been put in is a PET bottle.
FIG. 10 is a diagram illustrating a case where the plastic bottle introduced is a PVC bottle in the mechanism of FIG. 9;
FIG. 11 is a view showing a bottle sorting mechanism portion in the state of FIG. 10 as viewed from above.
12 is a view showing a state in which the PVC bottle is pulled out from the state of FIG.
FIG. 13 is a diagram showing an example of a portable PVC bottle and PET bottle discrimination device according to the present invention.
FIG. 14 is a diagram showing another example of a portable PVC bottle and PET bottle discrimination device according to the present invention.
FIG. 15 is a diagram showing still another example of a portable PVC bottle / PET bottle discrimination device according to the present invention.
[Explanation of symbols]
11 Heating rod
12 Load cell
13 Plastic bottle
14 Insulation
21 PET bottle collection device
22 Bottle slot
23 Plastic bottle
24 Support stand
25 First door member
26 Second door member
27 Stopper wall
28 Stopper wall
29 First air cylinder
30 Second air cylinder
31 fulcrum
32 fulcrum
33 Sorting wall
34 sensors
35 Heating rod
36 Third Air Cylinder
37 First collection container
38 Second collection container
39 Shredder
40 Third air cylinder drive rod
41 Cylinder of third air cylinder
42 Heat sink
43 Limit switch
44 Introduction pipe
45 Solenoid valve
46 Regulator
47 Pressure switch
51 PET bottle collection device
52 Bottle slot
53 Bottle passage
54 First shutter
55 opening
56 Fever Bar
57 plastic bottle
58 Retaining plate
59 Spring
60 Cylinder device
61 sensors
62 Shutter drive
63 Second shutter
64 Shredder
65 First collection container
66 Guide passage
67 Second collection container
68 Switching circuit
69 Cylinder drive
81 PET bottle collection device
82 Bottle slot
83 Bottle passage
84 Plastic bottle
85 Open part
86 Fever stick
87 Shutter
88 Retaining plate
89 Cylinder device
90 sensors
91 Shutter drive
92 1st opening
93 Second opening
94 Shredder
95 First collection container
96 Second collection container
97 Sorting wall
98 First movable guide plate
99 Second movable guide plate
100 Top of the sorting wall
101 switching circuit
102 Cylinder drive
111 plastic bottles
112 pedestal
113 Bottle passage
114 heating rod
115 Support shaft
116 counter weight
117 Stopper stopper
118 Cylinder device
119 Drive rod
120 Limit switch
121 Bottle retraction arm
122 opening
123 Solenoid valve
124 Stopping
130 Portable discrimination device
131 Handle
132 Heating rod
133 Coil spring
134 Limit switch
140 Portable discrimination device
141 switch
142 Fever Bar
143 Flange-shaped member
144 Indicator light
150 Portable discrimination device
151 Fever stick
152 Coil spring
153 Limit switch
154 protective cylinder
155 Second coil spring

Claims (11)

  Two types of plastic materials having different melting points are pressed against an indenter heated to a temperature not lower than the lower melting point and lower than the higher melting point, and the plastic materials are allowed to move within a predetermined time. A method for discriminating between different plastic materials, wherein the indenter discriminates between a plastic material and a plastic material that does not penetrate and a predetermined time passes.   Two types of plastic materials having different melting points are pressed against an indenter heated to a temperature not lower than the lower melting point and lower than the higher melting point, and the plastic material has a predetermined pressing force. A method for discriminating different plastic materials, characterized in that the indenter penetrates the plastic material before reaching the value and the indenter reaches a predetermined value without penetrating the plastic material.   An indenter heated to a temperature above the melting point of polyvinyl chloride and below the melting point of polyethylene terephthalate is pressed against a plastic bottle including unidentified PVC bottles and PET bottles, and the indenter is within a predetermined time. A method for discriminating PVC bottles from PET bottles, wherein a bottle that intrudes into a plastic material is discriminated as a PVC bottle, and a bottle that does not invade and passes a predetermined time is discriminated as a PET bottle.   An indenter heated to a temperature higher than the melting point of polyvinyl chloride and lower than the melting point of polyethylene terephthalate is pressed against a plastic bottle including unidentified PVC bottles and PET bottles. If the indenter has penetrated through the wall of the plastic bottle before reaching the level, it is determined as a PVC bottle, and if the indenter reaches a predetermined value without penetrating through the wall of the plastic bottle, it is determined as a PET bottle. A method for discriminating between PVC bottles and PET bottles.   An apparatus for discriminating between a PVC bottle and a PET bottle, comprising an indenter (35) heated to a temperature not lower than the melting point of polyvinyl chloride and lower than the melting point of polyethylene terephthalate.   When the pressing force pressing the indenter (35) against the object to be inspected reaches a predetermined value, it is determined that the object to be inspected is a PET bottle and the pressing force is released to release the pressing force from acting on the plastic bottle to be inspected further. The apparatus for discriminating PVC bottles and PET bottles according to claim 5, further comprising means (45).   When the indenter (35) is pressed against the object to be inspected and a predetermined time elapses without the indenter intruding into the object to be inspected, the object to be inspected is determined to be a PET bottle, and the pressing to release further pressing is continued. The apparatus for discriminating between a PVC bottle and a PET bottle according to claim 5, further comprising a release means (45).   A limit switch (43) is provided in the vicinity of the tip of the indenter (35) so as to be movable in parallel with the indenter, and arranged behind the tip of the indenter by a predetermined distance. When the indenter pressed against the plastic bottle passes through the container wall of the plastic bottle, the limit switch comes into contact with the container wall of the plastic bottle and determines that the plastic bottle is a PVC bottle. 6. The apparatus for discriminating between a PVC bottle and a PET bottle according to claim 5, wherein a signal is output.   A discrimination section for discriminating whether the waste plastic bottle is a PET bottle or a PVC bottle, a sorting section for sorting the discriminated plastic bottle into a PET bottle and a PVC bottle, and a first for collecting the sorted PET bottle A PET bottle recovery device having a recovery section and a second recovery section for recovering the sorted PVC bottle, wherein the discrimination section is at a temperature above the melting point of polyvinyl chloride and below the melting point of polyethylene terephthalate. A heated indenter (35), a pressing means (36) for pressing the indenter against the plastic bottle, and when the pressing force of the pressing means reaches a predetermined value, it is determined that the plastic bottle is a PET bottle. PET discrimination means (47) for outputting a PET bottle discrimination signal; PVC discriminating means (43) for discriminating that the plastic bottle is a PVC bottle and outputting a PVC bottle discriminating signal when the indenter penetrates the container wall of the plastic bottle before the pressing force of the means reaches a predetermined value. A PET bottle collecting apparatus, wherein the sorting section sorts plastic bottles into PET bottles and PVC bottles according to respective output signals of the PET discriminating means and the PVC discriminating means.   A discrimination section for discriminating whether the waste plastic bottle is a PET bottle or a PVC bottle, a sorting section for sorting the discriminated plastic bottle into a PET bottle and a PVC bottle, and a first for collecting the sorted PET bottle A PET bottle recovery device having a recovery section and a second recovery section for recovering the sorted PVC bottle, wherein the discrimination section is at a temperature above the melting point of polyvinyl chloride and below the melting point of polyethylene terephthalate. When a predetermined time elapses without the indenter penetrating the container wall of the plastic bottle after the indenter (35) to be heated, the pressing means (36) for pressing the indenter against the plastic bottle, and the pressing by the pressing means are started. It is determined that the plastic bottle is a PET bottle. A PET discriminating means (47) for outputting a T bottle discriminating signal, and when the indenter penetrates the container wall of the plastic bottle within a predetermined time after the pressing by the pressing means, the plastic bottle is a PVC bottle. A PVC discriminating means (43) for discriminating and outputting a PVC bottle discriminating signal, and the sorting section sorts the plastic bottle into a PET bottle and a PVC bottle according to the respective output signals of the PET discriminating means and the PVC discriminating means. A PET bottle recovery apparatus characterized by the above.   11. The PET bottle recovery apparatus according to claim 9, wherein the first recovery section includes a PET bottle pulverization and volume reduction means (39).

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