The present invention relates to a plastic identifying apparatus and a plastic identifying method for identifying the kinds of plastics to be discarded (in the following, referred to as discarded plastics).
Conventionally, discarded plastics discarded from households or the like are disposed of by incineration or in landfills. However, incineration and landfills have come to cause social problems such as impact on the global environment and shortages of landfill sites. Accordingly, in recent years, there has been an effort to sort/collect or recycle discarded plastics. In order to recycle the discarded plastics, it is necessary to identify the kinds of discarded plastics.
Conventional methods for identifying the kinds of discarded plastics include, for example, a method utilizing specific gravities. However, the method utilizing specific gravities has had a problem in that plastics are difficult to identify when there is little difference in their specific gravities.
Also, another method for identifying the kinds of discarded plastics is a method utilizing infrared light, for example. As an example of this method utilizing infrared light, the method capable of identifying, for example, plastics whose surface is coated, plastics to which dirt or the like adheres and plastics containing flame retardants in a highly precise manner has been suggested (see JP 2003-202291 A, for example). In this method, a test piece is cut out by punching out a discarded plastic partially, and infrared light is made to enter one face of this test piece (a face corresponding to a surface of the discarded plastic) and the other face, which is different from the above-noted one face (a section taken at the time of forming the test piece (a face exposed for the first time when cut out as the test piece)), while varying a wave number for each face, thereby detecting the intensity (or absorbance) of totally-reflected infrared light corresponding to each wave number. More specifically, as shown in
However, in the methods and apparatuses of identifying discarded plastics in a highly precise manner by detecting two different faces of a test piece as described above, it has been necessary to hold the test piece with the chuck and rotate the chuck so as to change the test piece face to be analyzed. Thus, in these methods, it has taken time to hold the test piece with the chuck or release it and to rotate the test piece by 90°. Moreover, a large number of processes have been required for identification.
Further, in order to hold the test piece with the chuck, the shape of the test piece is restricted in many ways: for example, the test piece has to be thick enough to be held and has to have a shape adapted for the chuck shape. Moreover, at the time of holding the test piece with the chuck, there has been a risk of dropping the test piece due to chucking error, posing a problem in workability.
A plastic identifying apparatus according to the present invention is a plastic identifying apparatus for identifying the kind of a plastic in an object to be identified, including an identifying and detecting portion for identifying the kind of the plastic included in the object to be identified, and a toppling system for toppling the object to be identified by applying an external force to the object to be identified in order to change an identification face of the object to be identified facing the identifying and detecting portion.
A plastic identifying method according to the present invention is a plastic identifying method for identifying the kind of a plastic in an object to be identified, including (a) identifying the kind of the plastic included in the object to be identified placed such that a first face of the object to be identified serves as an identification face, using the first face, (b) toppling the object to be identified so as to change the identification face of the object to be identified facing the identifying and detecting portion from the first face to a second face by applying an external force to the object to be identified, (c) identifying the kind of the plastic included in the object to be identified using the second face of the object to be identified, and (d) determining the kind of the plastic included in the object to be identified using an identification result obtained by using the first face and an identification result obtained by using the second face.
In a plastic identifying apparatus according to the present invention, a toppling system for toppling an object to be identified applies an external force to the object to be identified, so that a smaller number of processes are needed at the time of changing an identification face of the object to be identified to another face thereof. Thus, identification can be carried out in a short time. Also, since a simple method of applying an external force is adopted, it is possible to achieve a stable workability.
In the plastic identifying apparatus according to the present invention, it is preferable that the object to be identified includes a first face and a second face that are used as the identification face and located adjacent to each other, and in a state where the object to be identified is placed such that the first face faces the identifying and detecting portion as the identification face, the toppling system topples the object to be identified by applying a pushing force to at least a part of an end region of the second face on a side of the first face and at least a part of an end region of a third face, which is opposed to the second face, on a side opposite to the first face, thereby allowing the second face to face the identifying and detecting portion as the identification face. At this time, for example, a pair of pushing members can be used as the toppling system. In the state where the object to be identified is placed so as to face the identifying and detecting portion such that the first face serves as the identification face, it is appropriate that the pair of pushing members be provided so as to be movable in a direction crossing (preferably, perpendicular to) the second face and the third face of the object to be identified and apply the pushing force to the object to be identified by pushing the second face and the third face directly. Also, the toppling system may be a pair of air nozzles, and in the state where the object to be identified is placed so as to face the identifying and detecting portion such that the first face serves as the identification face, it is appropriate that the pair of air nozzles be provided so that their jet tips face the second face and the third face and apply the pushing force to the object to be identified by expelling air from the jet tips toward the second face and the third face of the object to be identified. With the above-described toppling system, the external force can be applied with a simple configuration, thus improving productivity. Incidentally, in the present invention, the magnitude of the pushing force to be applied for toppling the object to be identified is not particularly limited but can be set suitably in the range capable of toppling the object to be identified considering the size of the object to be identified, etc.
The identifying and detecting portion may carry out the identification by allowing an infrared light with a predetermined wave number to enter the object to be identified and detecting an intensity of the infrared light that is totally-reflected by the object to be identified.
The plastic identifying apparatus according to the present invention further may include a pressing portion for pressing the object to be identified so as to bring the object to be identified into close contact with the identifying and detecting portion. The object to be identified is brought into close contact with the identifying and detecting portion using the pressing portion, thereby achieving an identification with even higher precision.
The plastic identifying apparatus according to the present invention further may include a holding portion for holding the object to be identified placed in the identifying and detecting portion. With this holding portion, the object to be identified can be arranged stably at a predetermined position at the time of identification, so that it becomes possible to achieve the identification with even higher precision.
The plastic identifying apparatus according to the present invention may include a first cleaning portion for cleaning a face serving as the identification face of the object to be identified after being toppled. In the case where a holding portion is provided for holding the object to be identified placed in the identifying and detecting portion, this first cleaning portion may be provided in a region in the holding portion facing the face serving as the identification face of the object to be identified after being toppled. Further, the plastic identifying apparatus according to the present invention further may include a second cleaning portion for cleaning the identifying and detecting portion, and this second cleaning portion may be provided in the toppling system. By providing the first cleaning portion and the second cleaning portion as described above, it becomes possible to remove impurities adhering to the identification face of the object to be identified and the identifying and detecting portion, so that the identification can be carried out with even higher precision.
The plastic identifying apparatus according to the present invention further may include an object-to-be-identified positioning portion used for positioning at a time of placing the object to be identified in the identifying and detecting portion. This makes it possible to place the object to be identified in the apparatus in a suitable orientation, so that a face to be identified can be made to face the identifying and detecting portion more reliably.
The plastic identifying apparatus according to the present invention further may include a displacement preventing portion for preventing a displacement of the object to be identified from the identifying and detecting portion by restricting a position of one end portion of the object to be identified when the object to be identified is toppled. This makes it possible to place the object to be identified at a suitable position on the identifying and detecting portion after toppling the object to be identified, so that an identification operation after toppling can be carried out smoothly.
With a plastic identifying method according to the present invention, a smaller number of processes are needed at the time of changing an identification face to another face, so that identification can be carried out in a short time. Also, since a simple method of applying an external force is adopted, it is possible to achieve a stable workability.
In the toppling of the object to be identified in the plastic identifying method according to the present invention, in the case where the second face is adjacent to the first face in the object to be identified, the object to be identified may be toppled by applying a pushing force to at least a part of an end region in the second face on a side of the first face and at least a part of an end region in a third face, which is opposed to the second face, on a side opposite to the first face, thus placing the object to be identified such that the second face serves as the identification face. When applying the pushing force, the second face and the third face may be pushed directly using a pushing member, or air may be blown against the second face and the third face of the object to be identified. By applying these methods, it becomes possible to topple the object to be identified easily.
In identifying in the plastic identifying method according to the present invention, it is preferable that a plastic identifying apparatus including the identifying and detecting portion for identifying the kind of the plastic included in the object to be identified is used, the first face is identified in a state where the first face of the object to be identified is in close contact with the identifying and detecting portion, and the second face is identified in a state where the second face is in close contact with the identifying and detecting portion. With this method, identification with still higher precision becomes possible.
In identifying in the plastic identifying method according to the present invention, the kind of the plastic in the object to be identified may be identified by allowing an infrared light with a predetermined wave number to enter the object to be identified and detecting an intensity of the infrared light that is totally-reflected by the object to be identified.
The toppling of the object to be identified in the plastic identifying method according to the present invention may be started in a state where a third face of the object to be identified is supported. By applying this method, the object to be identified can be prevented from being toppled in a direction opposite to a desired direction.
The plastic identifying method according to the present invention further may include cleaning the second face of the object to be identified before identifying the second face. Also, during the topping of the object to be identified in the plastic identifying method according to the present invention, the identifying and detecting portion may be cleaned. By applying these methods, it becomes possible to remove impurities adhering to the identification face of the object to be identified and the identifying and detecting portion before the identification, so that the identification can be carried out with even higher precision.
In the plastic identifying method according to the present invention, in the case where in the identifying the object to be identified is judged not to be placed at an accurate position with respect to the identifying and detecting portion, an identification operation may be stopped, the object to be identified may be discharged and then the identification operation may be ended.
The following is a description of embodiments of the plastic identifying apparatus and the plastic identifying method according to the present invention, with reference to the accompanying drawings.
In the plastic identifying apparatus and identifying method in the present embodiment, for example, a test piece cut out from a discarded plastic is used as an object to be identified, and at least two faces of this test piece are identified as identification faces. This is because, by identifying each of a first face (for example, a face corresponding to the surface of the object to be identified) and a second face, which is different from the first face (for example, a section taken at the time of forming the test piece (a face exposed for the first time when cut out as the test piece)), the identification can be carried out in a highly precise manner even if the surface of the object to be identified is coated or degraded.
Further, the plastic identifying apparatus according to the present embodiment identifies plastics utilizing infrared light, more particularly, identifies the kinds of plastics included in a test piece by allowing infrared light to enter the test piece and detecting the intensity of the infrared light that is totally-reflected by the test piece (hereinafter, this method is referred to as an infrared light total reflection measurement method in the instant specification).
As shown in
In the case of using the above-noted infrared light total reflection measurement method, it is possible to identify the kinds of plastics included in the test piece more precisely even when the test piece includes dark-colored plastics or flame retardants. It should be noted that the infrared light with a predetermined wave number described above is light whose wave number ranges from 400 cm−1 to 4000 cm−1, for example. When identifying the kinds of plastics included in the test piece, it is appropriate to allow infrared light to enter the test piece while varying the wave number and detect the intensity (or absorbance) of the totally-reflected infrared light according to each wave number. Alternatively, utilizing Fourier transform infrared (FT-IR) spectroscopy, the intensity (or absorbance) of the totally-reflected infrared light for the above-noted predetermined wave number also may be detected. For example, the wavelength-intensity distributions for predetermined plastics may be stored in advance in, for instance, a control portion (not shown) provided in the peripheral portion 100 and then compared with the wavelength-intensity distribution obtained by the above-mentioned detection, thereby identifying the kinds of plastics included in the test piece easily.
Further, as described above, the plastic identifying apparatus according to the present embodiment includes the holding portion having the holding members 6a and 6b for holding a test piece from both lateral surfaces when the test piece is placed in the identifying and detecting portion, namely, placed over the detection hole 3 of the identifying stage 2, the pushing members 7a and 7b as the toppling system for applying an external force to the test piece and the pressing portion 9 having the presser 8 for bringing the test piece into close contact with the identifying and detecting portion. The holding portion includes a movable system (not shown) for allowing a pair of the holding members 6a and 6b to move in a substantially horizontal direction. By moving the holding members 6a and 6b in the horizontal direction with this movable system, it is possible to hold the placed test piece from both lateral surfaces. The pressing portion 9 includes a movable system (not shown) for allowing the presser 8 to be raised and lowered. By raising and lowering the presser 8 with this movable system, it is possible to bring the test piece into close contact with the identifying and detecting portion at the time of identification. The detailed operation of the pushing members 7a and 7b will be described later.
Now, referring to FIGS. 3 to 7, an identification operation will be described. FIGS. 3 to 7 are schematic diagrams showing how a test piece 1 is identified using the apparatus shown in
First, as shown in
Next, as shown in
Next, as shown in
Thereafter, as shown in
As described above, in accordance with the plastic identifying apparatus in the present embodiment, two faces of the test piece can be identified with a small number of processes and a simple operation in a highly precise manner within a short time. Also, since there is less restriction in the shape of the test piece, it is possible to achieve versatility and stable workability. It should be noted that the shapes of the pushing members 7a and 7b are not limited to those shown in
Further, it also is possible to provide the plastic identifying apparatus according to the present embodiment with a function of dealing with the case in which the test piece cannot be placed properly on the identifying and detecting portion. By providing such a function, a continuous identification operation can be carried out more smoothly. For example, it is appropriate to provide a function of moving to the next step if the test piece is judged to be identifiable and discharging the test piece if it is judged not to be identifiable. The judgment of whether or not the test piece is identifiable is made by, for example, detecting whether or not the test piece is in contact with the identifying and detecting portion with a pressure-sensitive sensor provided in the identifying and detecting portion. Alternatively, the judgment also can be made by detecting whether or not there is any clearance between the identifying and detecting portion and the test piece with an infrared ray sensor provided around the identifying and detecting portion.
The following is a description of another embodiment of the plastic identifying apparatus and the plastic identifying method according to the present invention. The plastic identifying apparatus of the present embodiment has a configuration similar to the plastic identifying apparatus shown in
The following is a description of yet another embodiment of the plastic identifying apparatus and the plastic identifying method according to the present invention. The plastic identifying apparatus of the present embodiment has a configuration similar to the plastic identifying apparatus shown in
The second cleaning portion includes a brush 11 provided on the side of the identifying stage 2 of the pushing member 7b on the side of the second face 1b. By providing the second cleaning portion in this manner, the pushing member 7b is moved in the X directions in the figure during the toppling operation, thereby cleaning the identifying and detecting portion simultaneously (see
As described above, providing the first and second cleaning portions makes it possible to identify the test piece 1 precisely even in the case where impurities such as dirt adhere to the surface of the test piece 1 and the identifying and detecting portion. It should be noted that the first and second cleaning portions may be in any form as long as they can clean the surface of the test piece and the identifying and detecting portion. Thus, these cleaning portions may be provided as members different from the holding member 6b and the pushing member 7b or can be a cloth or a sponge instead of a brush.
The following is a description of yet another embodiment of the plastic identifying apparatus and the plastic identifying method according to the present invention. The plastic identifying apparatus of the present embodiment has a configuration similar to the plastic identifying apparatus shown in
In the case of using the plastic identifying apparatus according to the present embodiment, the test piece 1 is provided with a cut-out portion id as shown in
With the above-described configuration, an error in the orientation of supplying the test piece 1 can be prevented, so that a face to be identified (the second face of the test piece in this case) can be brought into contact with the identifying and detecting portion more reliably when toppling the test piece 1. Incidentally, the shape of the cut-out portion id of the test piece 1 shown in
The following is a description of another embodiment of the plastic identifying apparatus and the plastic identifying method according to the present invention. The plastic identifying apparatus of the present embodiment has a configuration similar to the plastic identifying apparatus shown in
In the plastic identifying apparatus according to the present embodiment, the holding member 6b on the side of the second face 1b of the test piece 1 also has a function as a displacement preventing portion for preventing the displacement of the test piece 1 when toppling the test piece 1.
The following is a description of yet another embodiment of the plastic identifying apparatus and the plastic identifying method according to the present invention. The plastic identifying apparatus of the present embodiment has a configuration similar to the plastic identifying apparatus shown in
In Embodiments 1 to 6 described above, the description has been directed to the case of identifying plastics included in an object to be identified by the infrared light total reflection measurement method. However, it also is possible to use other measurement methods.
In accordance with a plastic identifying apparatus and a plastic identifying method of the present invention, it is possible to identify the kinds of plastics in a highly precise manner within a short time and achieve high versatility and excellent workability owing to less restriction on a test piece shape.
Number | Date | Country | Kind |
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2003-276845 | Jul 2003 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP04/10433 | 7/15/2004 | WO | 1/4/2006 |