JP5106433B2 - Sorting device - Google Patents

Description

  The present invention relates to a sorting apparatus for recycling an object, a sorting method, and a method for producing a recycled resin material, and in particular, an apparatus for sorting according to the presence or absence of bromine contained in a resin when recycling the resin, The present invention relates to a method and a method for producing a recycled resin material using the sorting method.

  The EU RoHS Directive came into force in July 2006, and six substances, mercury, cadmium, lead, hexavalent chromium, polybrominated biphenyl (PBB), and polybrominated diphenyl ether (PBDE), are subject to use restrictions. Accordingly, when recycling electrical and electronic products, it is important to develop technology that can easily determine the presence or absence of PBB or PBDE used as a flame retardant containing bromine, especially in resin pieces that have been broken. It has become.

  The above bromine is one of halogen elements and has a specific physical property and excellent reactivity. For example, the above-mentioned PBB, PBDE, polystyrene resin, polypropylene resin, and ABS resin may be used as excellent flame retardants by containing bromine in a high concentration. In addition, it is a substance used as a raw material for organic intermediates, inorganic chemicals, photographic light-sensitive materials, dyes, pharmaceuticals, agricultural chemicals, flame retardants and the like. In addition, it is a useful substance that may be used as an interior material for aircraft and Shinkansen vehicles, and bromine is contained in many members of electric and electronic products.

  However, bromine is extremely toxic by nature and has a great impact on the environment. For this reason, when recycling a resin piece from which a product is broken, it is necessary to sort into a resin piece containing bromine and a resin piece containing no bromine, and to recycle or dispose of it.

  As a method for identifying and separating objects of different chemical compositions, for example, Japanese Patent Laid-Open No. 5-131176 (Patent Document 1) discloses the following method. Specifically, irradiate resin products such as resin containers to be recycled with electromagnetic radiation, detect the amount of electromagnetic radiation transmitted through the resin products, and determine whether the resin products are chlorinated plastics. A method is disclosed. In general, for substances having the same thickness, substances formed with elements having a higher atomic number have a higher absorption rate of electromagnetic radiation than substances formed with elements having a lower atomic number, There exists a tendency for the transmittance | permeability to become small. In the above-mentioned Patent Document 1, this property is used. Further, in Patent Document 1, since there are variations in absorption characteristics and transmission characteristics of electromagnetic radiation in the thick part and the crease part of the resin container, a method of detecting a signal by irradiating the thinnest part of the resin product with radiation. Is used.

JP-A-5-131176

Even when a specific element such as bromine is detected and a resin piece is selected, it is conceivable to apply a method of detecting based on the amount of transmission of electromagnetic radiation as in Patent Document 1. However, in general, resin pieces obtained by breaking various products are a mixture of many resin pieces having various thicknesses. Moreover, it does not necessarily have a thin part like a resin container. For this reason, it is impossible to select with high accuracy by the method of detecting the transmission amount of the thin part in the resin piece as in Patent Document 1.

  If the accuracy of performing the sorting is poor, after the sorting, the resin containing bromine is mixed into the resin not containing bromine. This increases the average bromine concentration in the recycled resin material that should not contain bromine. If sorting with poor accuracy is repeated, the bromine concentration in the recycled resin material increases. Eventually, if the concentration of bromine contained in the recycled resin material exceeds the RoHS standard value, the recycled resin material cannot be used for a RoHS-compliant product.

  Therefore, the present invention has been made in view of the above problems. The purpose is to determine the presence or absence of bromine, which is a specific element in the resin piece, a sorting apparatus, a sorting method, and a recycled resin that uses the sorting method to suppress the judgment result from being influenced by the thickness of the resin piece. It is to supply a manufacturing method of the material.

The sorting apparatus according to the present invention contains an X-ray source that irradiates continuous X-rays, a first filter containing bromine, and an element having an X-ray absorption edge on the higher energy side than the X-ray absorption edge of bromine. A first filter that detects the first X-ray intensity by detecting the first X-ray transmitted through the first filter and the resin piece from the continuous X-rays irradiated from the X-ray source; An X-ray detector, and a second X-ray that detects a second X-ray intensity by detecting the second X-ray transmitted through the second filter and the resin piece from the continuous X-rays irradiated from the X-ray source. A line detector, and a control unit that sorts resin pieces by using the first X-ray intensity and the second X-ray intensity . The control unit includes a storage unit and a calculation unit, and the storage unit Using a plurality of first standard resin pieces having different thicknesses when no bromine is contained, the first X-ray The first data obtained for the relationship between the degree and the second X-ray intensity, and a plurality of second standard resin pieces having different thicknesses when containing bromine, the first X-ray intensity and The second data obtained with respect to the relationship of the second X-ray intensity is stored, the calculation unit, the first X-ray intensity and the second X-ray intensity obtained for the resin piece to be measured, An operation for determining the presence or absence of bromine based on the relationship between the first data and the second data is performed.

  According to each sorting apparatus and each sorting method described above in the present invention, the following matters are possible. In other words, in determining whether or not there is bromine as a specific element in a resin piece that is an object to be selected, the determination result is suppressed from being influenced by the thickness of the resin piece, and the possibility of erroneous determination of the result is reduced. be able to. Therefore, the resin piece sorted using the above sorting apparatus and sorting method has a sufficiently low bromine concentration. For this reason, by the manufacturing method of the recycled resin material using the above-described sorting method, it is possible to provide a recycled resin material that has a sufficiently small bromine content and can be used repeatedly.

It is the schematic which shows the apparatus which sorts | segments a resin piece according to the presence or absence of bromine in Embodiment 1 of this invention. It is the schematic which shows the detail of the measurement part for determining the presence or absence of bromine in Embodiment 1 of this invention. It is a graph which shows the example of the X-ray energy dependence of the X-ray transmittance of the 1st filter containing bromine. It is a graph which shows the X-ray energy dependence of the X-ray transmittance of the filter formed with molybdenum. (A) It is the schematic which shows the filter formed with molybdenum used as a 2nd filter. (B) It is the schematic which shows the filter of the structure where the surface of the support body which has carbon as a main component was coat | covered with the thin film of molybdenum used as a 2nd filter. (C) It is the schematic which shows the filter of the structure where the thin film of molybdenum used as a 2nd filter was formed only in one main surface of a support body. It is a calibration curve which shows the relationship between the thickness of a test piece, and the transmission intensity of the continuous X-rays which let the 1st filter and the test piece pass. It is a calibration curve which shows the relationship between the thickness of a test piece, and the transmission intensity of the continuous X-rays which let the 2nd filter and the test piece pass. It is a graph which shows the transmittance | permeability with respect to the X-ray energy of the polypropylene of 1 mm thickness, and the transmittance | permeability with respect to the X-ray energy of the polypropylene of 1 mm thickness containing 1 mass% of bromine. It is a flowchart which shows the selection method in Embodiment 1 of this invention. It is a flowchart which shows a detailed process about the process (S100) or process (S200) in the flowchart of FIG. In the second embodiment of the present invention, in the sorting apparatus that sorts resin pieces according to the presence or absence of bromine, an outline showing only a measurement unit formed by an X-ray source, a filter, a resin piece, and an X-ray detector. FIG. Of the sorting apparatus that sorts resin pieces according to the presence or absence of bromine in Embodiment 3 of the present invention, a measurement unit formed by an X-ray source, a filter, a resin piece, an X-ray image intensifier, and a motor It is the schematic which shows only. Outline of only the measurement unit formed by the X-ray source, the filter, the resin piece, and the X-ray detector in the sorting apparatus that sorts the resin piece according to the presence or absence of bromine in Embodiment 4 of the present invention. FIG. 4 is a graph showing a change with time in X-ray transmission intensity detected in each cell of the line sensor 36; 4 is a graph showing a change with time in X-ray transmission intensity detected in each cell of the line sensor 46; In the sorting apparatus which sorts a resin piece according to the presence or absence of bromine in Embodiment 5 of the present invention, an outline showing only a measurement unit formed by an X-ray source, a filter, a resin piece, and an X-ray detector. FIG. It is a flowchart which shows the selection method in Embodiment 5 of this invention. Outline of only the measurement unit formed by the X-ray source, the filter, the resin piece, and the X-ray detector in the sorting apparatus that sorts the resin piece according to the presence or absence of bromine in Embodiment 6 of the present invention. FIG. It is the schematic which shows the apparatus which classify | selects the resin piece according to the presence or absence of bromine in Embodiment 7 of this invention. Using a test piece not containing bromine, the transmission intensity when continuous X-rays passed through the first filter were passed through the test piece, and when continuous X-rays passed through the second filter were passed through the test piece It is the graph which plotted transmission intensity for every thickness of the test piece. When a test piece containing a certain amount of bromine is used, the transmission intensity when continuous X-rays passed through the first filter are passed through the test piece, and the continuous X-ray passed through the second filter is passed through the test piece. Is a graph in which the transmission intensity is plotted for each thickness of the test piece. It is a graph in which 105 and 106 are overlapped. It is a flowchart which shows the selection method in Embodiment 8 of this invention. It is a flowchart which shows a detailed process about the process (S71) or process (S72) in the flowchart of FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each embodiment, portions having the same function are denoted by the same reference numerals, and the description thereof will not be repeated unless particularly necessary.

(Embodiment 1)
Regarding the “presence / absence” of bromine in the following description, when bromine is contained in a certain proportion or more, for example, bromine is said to be contained, and when bromine is not contained in a certain proportion, for example, bromine is absent or not contained I will say. Hereinafter, the details of the first embodiment of the present invention will be described mainly with reference to FIGS.

  As shown in FIG. 2, the sorting apparatus 110 according to Embodiment 1 of the present invention shown in FIG. 1 irradiates continuous X-rays 6 as a measurement unit 100 for determining the presence or absence of bromine as a specific element. An X-ray source 1, a first filter 3, and a second filter 4 are provided. Further, X is a first X-ray detector that detects the intensity of continuous X-rays 6 irradiated from the X-ray source 1 and successively transmitted through the first filter 3 and the resin piece 2 that is the object to be selected. A line image intensifier 15 is provided. Further, X is a second X-ray detector that detects the intensity of continuous X-rays 6 irradiated from the X-ray source 1 and successively transmitted through the second filter 4 and the resin piece 2 that is the object to be selected. A line image intensifier 16 is provided. Moreover, the conveyor 7 which can move the resin piece 2 which is the target object to sort is provided. For example, a piece of polypropylene resin, polystyrene resin, or ABS resin can be applied to the resin piece 2. In the sorting apparatus 110 showing the first embodiment of the present invention, two X-ray image intensifiers 15 and 16 are provided. However, this is for convenience of explanation, and if the structure can detect both continuous X-rays 6 transmitted through the first filter 3 and the second filter 4, the X-ray image intensifier is There can be only one. Further, the X-ray image intensifiers 15 and 16 are connected to a data processing device 21 which is a control unit for selecting a resin to be determined based on the X-ray detection data of the X-ray image intensifiers 15 and 16. ing. The data processing device 21 includes a storage unit 26 and a calculation unit 27, which respectively serve as a computer memory and a CPU. In addition, a display device for displaying X-ray image images 28 and 29 that can easily confirm the data transferred to the data processing device 21 is provided.

  Furthermore, the sorting device 110 according to Embodiment 1 of the present invention includes a resin piece supply device 24 for supplying the resin piece 2 to the measuring unit 100 for determining the presence or absence of bromine. 2 is supplied. In addition, after measurement is performed by the measuring unit 100 for determining the presence or absence of bromine, the air blow gun 20 with a solenoid valve for separating the resin piece 2 into two places, the resin piece 2 is selected according to the presence or absence of bromine And containers 22 and 23 for storage.

  Continuous X-rays 6 are used as X-rays emitted from the X-ray source 1. The continuous X-ray 6 is generated by irradiating a tungsten target with an electron beam, for example, and irradiating an X-ray having a wavelength corresponding to the energy lost when the electron orbit is bent and braked by the Coulomb field of the nucleus. . Since there are various ways of collision, this X-ray has a continuous wavelength distribution and is called continuous X-ray. An apparatus for irradiating a target with an electron beam to obtain a minute X-ray light source as described above is commercially available and can be used. When the X-ray image transmitted through the resin piece 2 is projected onto the X-ray image intensifier 15 as in the first embodiment of the present invention, the projected image is smaller when the size of the X-ray source is smaller. The possibility of blurring can be reduced. For this reason, it is preferable to use a point light source as the X-ray source 1.

  The first filter 3 contains bromine which is a specific element. Further, the first filter 3 may be a resin made of the same material as the resin piece 2 and containing bromine. On the other hand, the second filter 4 contains an element having an X-ray absorption edge on the higher energy side than the X-ray absorption edge of bromine, which is a specific element. Here, the X-ray absorption edge is an energy value of the continuous X-ray 6 when the ratio of the absorbed continuous X-ray 6 rapidly increases. Thus, the first filter 3 and the second filter 4 have different transmission characteristics inside and outside the energy region where the bromine absorption is large. Compared with the second filter 4, the first filter 3 has a large absorption of X-rays in the energy region absorbed by bromine and a low transmittance. Absorption of X-rays in other regions is small, and X-rays in an energy region that is lower than the X-ray absorption edge of bromine and that has a large absorption due to resin components and the like are relatively transmitted. On the other hand, the second filter 4 is less absorbed in the region where the energy is slightly higher than the absorption edge of bromine, that is, the region where the absorbed energy of bromine is large, compared with the first filter 3, and the X-ray transmittance. Is expensive. More specifically, in the wavelength region between the absorption edge of bromine and the X-ray absorption edge of another element contained in the second filter 4, the absorption is small and the transmittance is large. Therefore, the second filter 4 has a relatively large transmission of X-rays in the energy region absorbed by bromine compared to the transmission in other regions.

Here, FIG. 3 is a calculation example when the composition of the first filter is 100% bromine, the density is 1 g / cm ³ , and the thickness is 300 μm. In the graph of FIG. 3, the horizontal axis indicates the magnitude of the incident X-ray energy, and the vertical axis indicates the transmittance of the X-ray incident on the filter. There is an X-ray absorption edge of bromine near the energy value of 13000 eV, and the transmittance is rapidly reduced. In the energy region where the X-ray absorption edge of bromine is near 13000 eV and below 20000 eV, absorption by bromine is large. In the example shown in the figure, the transmittance is 20% or less within this range, that is, the absorptance is 80% or more. The first filter 3 transmits X-rays in an energy region lower than 13000 eV that is the absorption edge of bromine, that is, energy regions in which bromine transmits at a large rate. The energy region lower than 13000 eV is a wavelength region where absorption by the resin component is large. In this region, the lower the energy, the greater the absorption of the resin component. However, since the resin component absorbs less than bromine, even if the first filter 3 containing bromine in the resin is used as described above, X-rays are transmitted in a wavelength region where the absorption by the resin component is large. .

  Accordingly, in order to realize such a filter, for example, the main component of the filter may be bromine as the first filter 3. Moreover, you may form using the solid made from carbon or an element lighter than carbon as a mixture. For example, it is preferable to use a resin containing beryllium bromide or bromine at a high concentration because the filter can be easily formed and handled. For example, as a technique for adding bromine to polystyrene resin, polypropylene resin, ABS resin or the like, there is a known technique for adding to a resin as a brominated flame retardant. There are also commercially available resin materials containing about 20% bromine by mass ratio, and these may be used as they are, or bromine may be used at a high concentration.

In addition, as the proportion of bromine contained in the filter increases, specifically, as the density of bromine or the thickness of the filter formed with bromine and a mixture increases, the energy at the absorption edge below the bromine edge and above the absorption edge respectively. The ratio of continuous X-ray transmission intensity in the region is increased. In other words, the greater the proportion of bromine contained in the first filter 3, the better the removability of the energy region that bromine contained in the resin piece 2 absorbs better. However, since the absolute amount of X-ray transmitted decreases, the signal intensity for measuring the X-ray intensity and determining the presence or absence of bromine cannot be obtained. In particular, the signal intensity cannot be obtained because the absolute amount that transmits X-rays in the energy region above the absorption edge of bromine decreases. In order to suppress this situation, there is an appropriate range for the amount of bromine contained in the filter. Specifically, the ratio of the X-ray transmission intensity below the bromine absorption edge and above the bromine absorption edge is preferably greater than 5: 1. In order to effectively use the output signal intensity for the determination of the presence or absence of bromine, the X-ray transmittance in the energy region below the bromine absorption edge is preferably 0.1 or more. In order to satisfy the above conditions, if the density of the filter is d (g / cm ³ ) and the thickness of the filter is t ₁ (μm),
130 ≦ dt ₁ ≦ 1000
It is preferable that the following relational expression is satisfied. For example, when the density of the filter is 1, the thickness is preferably 130 μm or more and 1000 μm or less. Incidentally, if the bromine density of the filter doubles, it is preferable to provide a thickness of 1/2.

  As described above, for example, when a filter formed of a mixture containing bromine is used as the first filter 3 and the presence or absence of bromine contained in the resin piece 2 is determined, continuous X-rays 6 are transmitted through the first filter 3. The following phenomenon occurs. The first filter absorbs a large proportion of X-rays in the energy region where X-rays are absorbed by bromine at a large proportion. Therefore, in the transmitted X-ray, the ratio of the energy region where the absorption by bromine is large from around 13000 eV to around 20000 eV decreases. Therefore, the transmitted continuous X-ray 6 is less influenced by bromine and depends mainly on the resin component of the resin piece 2. Since the absorption of continuous X-rays 6 by the resin component depends on the thickness of the resin component of the resin piece 2 as described above, the thickness of the resin piece 2 can be estimated by detecting this transmission intensity. .

  On the other hand, the second filter 4 has a high ratio of transmitting X-rays in the energy region higher than the X-ray absorption edge of bromine, that is, in the energy region absorbed by bromine. That is, as the material constituting the second filter 4, it is preferable to use a material having an X-ray absorption edge in an energy region higher than the X-ray absorption edge of bromine.

  As the second filter 4, for example, a filter formed of molybdenum is used. The horizontal axis and vertical axis in the graph of FIG. 4 are the same as those of the graph of FIG. In the data extraction of FIG. 4, a filter formed to have a molybdenum density of 10.22 and a molybdenum thickness of 50 μm is used. From FIG. 4, it can be seen that the energy transmittance increases from about 13000 eV to about 20000 eV, which is an energy region in which bromine absorbs at a large rate, contrary to the first filter 3 containing bromine. From this, by using a molybdenum filter, X-rays having an energy region from about 13000 eV to about 20000 eV, which is the absorption edge of bromine, can be selectively transmitted.

  Therefore, for example, when a filter made of molybdenum is used as the second filter 4 and the presence or absence of bromine contained in the resin piece 2 is determined, if the continuous X-ray 6 is transmitted through the second filter 4, the resin The presence or absence of bromine contained in the piece 2 can be detected with high accuracy. The reason is as follows. Bromine has an energy region with high absorption in an energy region higher than the X-ray absorption edge of bromine, as described above, from about 13000 eV to about 20000 eV. Therefore, by irradiating the second filter 4 formed of molybdenum with continuous X-rays 6, the transmittance of X-rays with energy of 20000 eV or more, which is the absorption edge of molybdenum, decreases. This is because the absorption by molybdenum increases for the energy of X-rays near 20000 eV. Therefore, in the transmitted X-rays, the ratio of the energy region where the absorption by bromine is large increases from the X-ray absorption edge of bromine to the X-ray absorption edge of molybdenum from around 13000 eV to around 20000 eV. For this reason, for example, even if the X-ray image intensifier 15 which is an X-ray detector does not have energy resolution, the presence or absence of bromine can be detected with high accuracy.

Further, for the same reason as the filter formed with bromine and the mixture described above, if the thickness of the filter formed with molybdenum having a density of 10.22 is t ₂ (μm), 25 ≦ t ₂ ≦ 180. Is preferred.

  In addition, in the first filter 3, the element for absorbing X-rays is selenium in addition to bromine, but the X-ray absorption range is relatively close to bromine, so that the filter effect according to bromine is obtained. Can be obtained. Further, in the second filter 4, even if niobium, technetium, or ruthenium is used in addition to molybdenum, the X-ray absorption range is relatively close to molybdenum, so that a filter effect equivalent to molybdenum can be obtained. .

  As described above, the second filter 4 may be formed of, for example, molybdenum, but the surface of the support mainly composed of carbon or boron is covered with the above-described thin film formed of, for example, molybdenum. A structured body may be used. As the second filter 4, a filter having any structure shown in FIGS. 5A, 5 </ b> B, and 5 </ b> C may be used. In the second filter 4 shown in FIG. 5B or FIG. 5C, the support 12 is a structure containing carbon as a main component. However, this may be a simple substance containing 100% carbon or a resinous compound containing carbon as a main component and other components combined with, for example, hydrogen or oxygen. Further, it may be formed in the same manner as described above using boron instead of carbon. The thin film 13 may be a thin film of niobium, technetium, or ruthenium instead of molybdenum.

The reason why the structure as described above can be used as the second filter 4 is that carbon and boron have a small atomic number and thus transmit the irradiated continuous X-rays 6 at a high rate. For this reason, the filter configured using carbon or boron does not hinder the operation as the second filter 4. Further, since the support 12 uses a material that transmits the continuous X-rays 6 at a high rate, the influence of absorption of the continuous X-rays 6 is reduced. For this reason, the mathematical formula 25 ≦ t ₂ ≦ 180 that holds for the thickness of the filter formed of molybdenum described above is also established for the second filter 4 shown in FIGS. 5B and 5C. In the structure having molybdenum thin films 13 on both main surfaces of the support 12 as shown in FIG. 5 (B), the optimum molybdenum required to obtain the sum of the thicknesses of the thin films 13 on both main surfaces from X-ray absorption. The thickness of the thin film 13. For example, when the optimum thickness of the thin film 13 is 100 μm, the thin film 13 may be formed by 50 μm on one main surface and the other main surface.

  Next, the principle of determining the presence or absence of bromine using the first filter 3 formed of bromine and a mixture and the second filter 4 formed of molybdenum will be described with reference to FIGS. 1 and 2 as appropriate. .

  It is desired to actually determine the presence or absence of bromine. For example, before performing measurement on the resin piece 2, the continuous X-ray 6 transmitted through the first filter 3 in advance is the same as the resin piece 2 that does not contain bromine. First data indicating the relationship between the transmission intensity when passing through a test piece formed of the resin and the thickness of the test piece is obtained as a calibration curve 101. The second filter 4 is also processed in the same manner as described above, and the second data is obtained as the calibration curve 102 in the same manner as described above. In the calibration curve 101 of FIG. 6, the horizontal axis indicates the thickness of the test piece not containing bromine, and the vertical axis indicates the intensity of X-ray transmission through a filter formed of bromine and a mixture. In the calibration curve 102 of FIG. 7, the horizontal axis and the vertical axis are the same as those of the calibration curve 101 of FIG. The calibration curve 101 in FIG. 6 is obtained by the following method. First, a plurality of test pieces having a uniform thickness not containing bromine and made of a resin of the same material as the resin piece 2 and having different thicknesses are prepared. Then, the continuous X-ray 6 from the X-ray source 1 is irradiated to, for example, the first filter 3 formed of bromine and a mixture and the test pieces having the above-described thicknesses. Is obtained, a calibration curve 101 shown in FIG. 6 is obtained. Similarly, the continuous X-rays 6 from the X-ray source 1 are irradiated to the second filter 4 formed of, for example, molybdenum and the test pieces having the thicknesses described above, and the obtained X-ray transmission intensity and the thickness of the test pieces are obtained. Is obtained, the calibration curve 102 shown in FIG. 7 is obtained.

  When the calibration curve is obtained, the data of the calibration curve 101 and the calibration curve 102 are stored in the storage unit 26 of the data processing device 21. Here, the resin piece 2 for which it is actually desired to determine the presence or absence of the specific element bromine is measured. First, continuous X-rays 6 from the X-ray source 1 are passed through the first filter 3 formed of bromine and a mixture, and then passed through the resin piece 2. Then, as shown in FIG. 3, the first filter 3 absorbs X-rays in the energy region from around 13000 eV to around 20000 eV at a large rate, so that the transmittance of the X-rays in this region is in other energy regions. It is lower than This is apparent from FIG. In FIG. 8, the horizontal axis indicates the magnitude of the incident X-ray energy, and the vertical axis indicates the transmittance of the X-ray incident on the filter. That is, the resin containing 1.0% by mass of bromine in polypropylene absorbs X-rays in the energy region from around 13000 eV to around 20000 eV, compared to pure polypropylene resin. Conversely, from FIG. 8, the transmittance of X-rays in the energy region below 13000 eV shows a close value both for pure polypropylene and for polypropylene containing 1.0 mass% bromine. . That is, it can be considered that X-rays in the energy region below about 13000 eV are absorbed by bromine. The ratio of the continuous X-rays 6 after passing through the first filter 3 includes an energy region from around 13000 eV to around 20000 eV. Therefore, the resin piece 2 is irradiated with only X-rays in the energy region below 13000 eV. Then, it can be approximated that absorption by only the resin component in the resin piece 2 occurs regardless of the presence or absence of bromine in the resin piece 2. Therefore, it is considered that the difference in transmittance does not depend on the presence or absence of bromine contained in the resin piece 2 but only due to the difference in thickness of the resin piece 2. Therefore, first, the transmission intensity of the X-ray transmitted through the first filter 3 and the resin piece 2 is obtained, and this is prepared in advance and compared with the calibration curve 101 stored in the storage unit 26 of the data processing device 21. From the above, the expected thickness of the resin piece 2 can be determined.

  Then, the continuous X-ray 6 is passed through the second filter 4 made of molybdenum and then passed through the resin piece 2. Since the second filter 4 transmits X-rays in the energy region near 13000 eV, which is the absorption edge of bromine, at a large rate, when the resin piece 2 is irradiated with this, the X-ray absorption by the resin component of the resin piece 2 And X-ray absorption by bromine contained in the resin piece 2 can occur. Therefore, the transmission intensity of the X-ray transmitted through the second filter 4 and the resin piece 2 is determined, and the storage unit 26 and the calculation unit 27 of the data processing device 21 are calculated from the predicted thickness value of the resin piece 2 obtained previously. And compared with the expected transmission intensity that can be calculated from the calibration curve 102. As a result of this comparison, if there is a significant difference, it is determined that X-ray absorption occurs due to the inclusion of bromine. As the determination criterion, an allowable displacement amount from the expected transmission intensity is set in advance. Then, if the difference between the X-ray transmission intensity measured through the resin piece 2 and the expected transmission intensity is equal to or greater than the allowable displacement, it is determined that X-ray absorption has occurred. As described above, it is determined whether or not the resin piece 2 contains bromine. Based on the above principle, the presence or absence of bromine in the resin piece 2 can be determined using the first filter 3 and the second filter 4.

  The X-ray image intensifiers 15 and 16 are, for example, photoelectric plates that receive a fluorescent material that emits fluorescence when X-rays are incident thereon, and receive the fluorescence emitted from the plate and convert it into an electrical signal. It consists of an element. The continuous X-ray 6 irradiated from the X-ray source 1 is partially absorbed by bromine contained in the first filter 3, but the rest is transmitted, and the resin piece 2 partially contains resin component or bromine. Is absorbed by but the rest is transmitted. Moreover, a part is absorbed with the conveyor 7, but the remainder permeate | transmits. Then, the X-rays that have been transmitted to the end reach the X-ray image intensifier 15. Similarly, the continuous X-ray 6 that has passed through the second filter 4 reaches the X-ray image intensifier 16 if it continues to pass through to the end. Since the photoelectric element has a light receiving surface on which light receiving elements are arranged in a matrix, the X-ray image intensifier 15 detects continuous X-rays 6 as a two-dimensional image. As the thickness of the resin piece 2 increases, the amount of X-ray absorption by the resin component increases. Therefore, the X-ray transmission intensity detected at the portion where the X-ray does not pass through the resin piece 2 is strong, The transmitted intensity of the detected X-ray is weak in the part that has passed through 2. In particular, it is detected weaker in a portion that has passed through a thick portion of resin. Signals from each cell of the X-ray image intensifier 15 are transferred to the data processing device 21. The data is used to determine the presence or absence of bromine in the resin, but can also be confirmed as an X-ray image 28 of the resin piece 2.

  The conveyor 7 is for moving the resin piece 2 to a desired position. In principle, the conveyor 7 is preferably made of a material and a thickness that pass the irradiated continuous X-rays 6. For example, a thin synthetic fiber such as nylon stockings is preferable. Moreover, in order to apply compressed air to the resin piece 2 in the process of finally selecting the resin piece 2 to be described later, it is preferable that the structure has a hole such as a mesh shape.

  After the X-ray finally transmitted by the resin piece 2 is received on the X-ray image intensifier 15, the resin piece 2 moves onto the X-ray image intensifier 16 by the conveyor 7. Here again, the continuous X-rays 6 irradiated from the X-ray source 1 are partially absorbed by molybdenum contained in the second filter 4, but the remainder are transmitted, and the resin piece 2 partially contains resin or is contained. It is absorbed by bromine, but the rest passes. Moreover, a part is absorbed with the conveyor 7, but the remainder permeate | transmits. Then, X-rays that have been transmitted to the end reach the X-ray image intensifier 16. Further, when two X-ray sources 1 are installed as shown in FIGS. 1 and 2, it is not always necessary that the targets of the two X-ray sources 1 and the acceleration voltage, current, etc. of the electron beams are the same. Since the photoelectric element has a light receiving surface on which light receiving elements are arranged in a matrix, the X-ray image intensifier 16 detects continuous X-rays 6 as a two-dimensional image. Signals from each cell of the X-ray image intensifier 16 are transferred to the data processing device 21. The data is used to determine the presence or absence of bromine in the resin, but can also be confirmed as an X-ray image 29 of the resin piece 2.

  Since many resin pieces 2 can be determined at a time, X-ray image intensifiers 15 and 16 having a large detection area are preferably used. Further, in order to detect as an image, the cell size of each of the X-ray image intensifiers 15 and 16 (more precisely, the distance between the cells) is sufficiently smaller than the size of the resin piece 2, for example, 1/5. It is preferable to make it about. If the cell size is not sufficiently small, for example, if the distance between the X-ray source 1 and the resin piece 2 is X1, and the distance between the resin piece 2 and the X-ray image intensifier 15 or 16 is X2, for example, X1 < It is preferable to shorten X1 and lengthen X2 so as to be X2. If the distance between the X-ray source 1 and the resin piece 2 is X1, and the distance between the resin piece 2 and the X-ray image intensifier 15 is X2, the enlargement ratio is (X1 + X2) / X1. Thereby, since the projection image of the resin piece 2 projected on the X-ray image intensifiers 15 and 16 can be enlarged to an arbitrary enlargement ratio, the projection image can be enlarged with respect to the cell size. As a result, the intensity distribution of X-rays transmitted through the resin piece 2 can be detected more clearly as an image.

  Finally, signals from the X-ray image intensifiers 15 and 16 are calculated by the data processing device 21 while making full use of the built-in storage unit 26 and calculation unit 27, and the bromine-containing resin piece 2 contains Determine presence or absence.

  While determining whether or not the resin piece 2 contains bromine, the resin piece 2 is moved by the conveyor 7 to a location where the tip of the air blow gun 20 with a solenoid valve is facing. Here, when it is determined by the data processing device 21 that the resin piece 2 contains bromine, the electromagnetic valve of the air blow gun 20 with a solenoid valve is opened by a signal output from the data processing device 21. Apply compressed air. In this way, the resin piece 2 is skipped and placed in the installed container 22. If it is determined in the previous determination that the resin piece 2 does not contain bromine, no signal is output from the data processing device 21, so the solenoid valve of the air blow gun 20 with solenoid valve is not operated, and the conveyor 7 The resin piece 2 is put into another container 23 by the movement.

  Hereinafter, the selection method for determining the presence or absence of bromine in the resin piece 2 will be described more specifically. FIG. 10 is a flowchart common to the step (S100) and the step (S200). The sorting method according to the first embodiment will be described with reference to FIGS. 9 and 10 and FIGS. 1 to 8 as appropriate.

  Prior to measurement of the resin piece 2 to be determined, a step of deriving first data (S100) is performed. Here, the first data is data indicating the relationship between the intensity of the X-ray transmitted through both the first filter 3 and the test piece arranged in series and the thickness of the test piece. In order to derive the first data, first, as shown in the flowchart of FIG. 10, a step of preparing a test piece (S1000) is performed. As described above, a plurality of test pieces having a uniform thickness not containing bromine and made of the same resin as the resin piece 2 and having different thicknesses are prepared.

  Then, the process (S1001) of detecting the transmission intensity | strength of the continuous X-ray which permeate | transmits a 1st (2nd) filter and a test piece is implemented. In the step (S1001), the continuous X-ray 6 from the X-ray source 1 is irradiated with the first filter 3 and the above-described test piece arranged in series, for example, so that both are successively transmitted. Is a step of detecting the transmission intensity of the X-rays transmitted through each of the thicknesses of the test pieces. And it progresses to the process (S1002) which calculates | requires the relationship between thickness and the detected permeation | transmission intensity | strength. This is a step of obtaining the calibration curve 101 by obtaining the relationship between the X-ray transmission intensity detected in the previous step (S1001) and the thickness of the test piece. As described above, the calibration curve 101 is mainly obtained by measuring the transmission intensity of X-rays having an energy value of about 13000 eV or less, which is the absorption edge of bromine.

  Similarly, a step of deriving second data (S200) is performed. Here, the second data is data indicating the relationship between the intensity of the X-ray transmitted through both the second filter 4 and the test piece arranged in series and the thickness of the test piece. In this case, similarly to the step of deriving the first data (S100), the step of preparing a test piece (S1000) is first performed. Then, the process (S1001) of detecting the transmission intensity of the continuous X-ray which permeate | transmits a 1st (2nd) filter and a test piece is implemented. In the step (S1001), the continuous X-ray 6 from the X-ray source 1 is irradiated to the one in which the second filter 4 and the above-described test piece are arranged in series, for example, so that both are successively transmitted. Is a step of detecting the transmission intensity of the X-rays transmitted through each of the thicknesses of the test pieces. In Embodiment 1 of the present invention, a filter formed of molybdenum is used as the second filter. And it progresses to the process (S1002) which calculates | requires the relationship between thickness and the detected permeation | transmission intensity | strength. This is a step of obtaining the calibration curve 102 by determining the relationship between the X-ray transmission intensity detected in the previous step (S1001) and the thickness of the test piece.

  When the calibration curve 101 and the calibration curve 102 are obtained, the resin piece 2 to be actually determined is measured. First, a step (S11) of detecting the transmission intensity of continuous X-rays that pass through the first filter and the resin piece is performed. That is, as shown in FIG. 1, while irradiating continuous X-rays 6 from an X-ray source 1 to, for example, a first filter 3 and a resin piece 2 arranged in series so as to pass through each other one after another. This is a step of detecting the transmission intensity of X-rays transmitted through both. In carrying out the step (S11), in the first embodiment of the present invention, as shown in FIGS. 1 and 2, for example, the continuous X-rays 6 irradiated from the X-ray source 1 are the first filter 3 first. Is then installed so as to pass through the resin piece 2. Further, the resin piece 2 is supplied from the resin piece supply device 24 and installed so as to be mounted on the conveyor 7.

  Then, the process (S13) of determining the expected thickness of the resin piece is performed. That is, the relationship between the intensity of the transmitted X-ray and the thickness of the resin obtained in the step of deriving the first data (S100), and the continuous X-ray transmitted through the first filter and the resin piece. The transmission intensity data of the continuous X-ray 6 detected in the transmission intensity detection step (S11) is compared. And the process which calculates | requires the estimated thickness of the resin piece 2 is performed. This processing can be easily performed by calculating in the storage unit 26 and the calculation unit 27 of the data processing device 21. In the first embodiment of the present invention, as another method for measuring the thickness of the resin piece 2, for example, a displacement meter using ultrasonic waves or light is used from the upper side of the resin piece 2 to increase the height of the resin piece 2. A method of measuring the thickness may be used. In this case, since the step (S11) to the step (S13) are changed to a method of measuring the height of the resin piece 2 using, for example, a displacement meter using ultrasonic waves or light, X passing through the first filter is used. The source 1 and the X-ray image intensifier 15 may be omitted.

  Similarly to the above, the step (S21) of detecting the transmission intensity of continuous X-rays that pass through the second filter and the resin piece is performed. Specifically, the resin piece 2 is moved by the conveyor 7 so as to come below the second filter 4. And in this state, while irradiating the continuous X-ray 6 from the X-ray source 1 to, for example, the second filter 4 and the resin piece 2 arranged in series so as to pass through each other one after another. This is a step of detecting the transmission intensity of transmitted X-rays.

  Then, a step (S120) of determining the expected transmission intensity is performed. That is, it is built in the data processing device 21 from the expected thickness of the resin piece 2 determined in the step (S13) and the calibration curve 102 derived in the step of deriving the second data (S200). In this step, the storage unit 26 and the calculation unit 27 are used to determine the expected intensity of X-rays that pass through the second filter 4 and the resin piece 2.

  Subsequently, a step of comparing the strengths and determining the presence or absence of bromine (S121) is performed. Specifically, in the step of determining the presence or absence of bromine in the resin piece 2 by comparing the predicted transmission intensity obtained in the previous step (S120) with the transmission intensity detected in the step (S21). is there. Since the data of the calibration curve 102 is transmission intensity data for a resin not containing bromine, if there is a difference of, for example, a preset allowable displacement amount or more as a result of the above comparison, X-ray absorption due to the inclusion of bromine Determine that is happening. In addition, the allowable displacement amount from the expected transmission intensity as the determination criterion is set in advance. For example, the allowable displacement amount is set to be within 5% of the expected transmission intensity value. If the difference between the measured transmission intensity of the X-rays transmitted through the resin piece 2 and the expected transmission intensity is equal to or greater than the allowable displacement, it is determined that X-ray absorption due to the presence of bromine has occurred. To do.

  Finally, a step of selecting resin pieces (S122) is performed. The solenoid valve of the air blow gun with solenoid valve 20 is opened by a signal output from the data processing device 21 according to the determination result in the previous step (S121), and the compressed air is applied to the resin piece 2 determined to contain bromine. Hit. In this way, the resin piece 2 is skipped and placed in the installed container 22. If it is determined in the previous determination that the resin piece 2 does not contain bromine, no signal is output from the data processing device 21, so the solenoid valve of the air blow gun 20 with solenoid valve is not operated, and the conveyor 7 The resin piece 2 is put into another container 23 by the movement. By performing the above steps, the presence or absence of bromine in the resin piece 2 can be determined and selected.

  The resin piece 2 accommodated in the container 23 is a resin piece 2 that has been determined not to contain bromine by a highly accurate sorting method, and is unlikely to contain the resin piece 2 containing bromine. Therefore, the resin piece 2 accommodated in the container 23 is a recycled resin material that can be repeatedly used even for products in which the bromine concentration is limited. In this manner, a recycled resin material can be manufactured. Further, the resin piece 2 containing bromine contained in the container 22 can also be reused for products having no standard bromine concentration, or used as a thermal recycle fuel. Therefore, the recycling efficiency of the resin piece 2 can be greatly improved by the method for manufacturing the recycled resin material described above.

  For example, the recycled resin material stored in the container 23 can be provided as a recycled resin material to be used for a member of a newly produced electrical appliance through a subsequent process such as re-grinding or washing.

  In the first embodiment of the present invention, the actually selected resin piece 2 is obtained by finely breaking a resin case or the like constituting an electric product to be recycled. It includes flat shapes with a constant thickness, but there are corners of the case and bent ones. That is, the thickness of the resin piece 2 that is actually selected is not uniform. Therefore, the transmission intensity varies depending on the location where X-rays are actually transmitted in the resin. Therefore, the transmission intensity of the resin piece 2 through the first filter 3 and the second filter 4 corresponds to the X-ray intensity sent from each cell of the X-ray image intensifiers 15 and 16 shown in FIG. The smallest value is used among the received signals. This means that the thickest part of the resin piece 2 is determined. Since the measurement of the resin piece 2 is performed at the thickest portion, the measurement can be performed regardless of the shape of the resin piece 2.

  X-rays that are transmitted through the first filter 3 made of bromine and a mixture and that are in the energy region below the absorption edge of bromine are also slightly absorbed by the bromine contained in the resin piece 2. For this reason, when the concentration of bromine contained in the resin piece 2 is high, the thickness of the resin obtained by the above-described calculation method is slightly larger than the actual thickness. However, when the bromine concentration is high, X-rays that have passed through the second filter 4 formed of molybdenum are absorbed at a very high rate. For this reason, there is little possibility of erroneous determination of the presence or absence of bromine. Also from this, it is preferable to measure the resin piece 2 in the thickest part. On the other hand, even when measurement of the resin piece 2 that is considered to be severe and has a low bromine concentration is performed, the thickness of the resin piece 2 is increased because the amount of X-ray absorbed by the bromine in the resin piece 2 is small. It can be determined with accuracy. Therefore, there is little possibility that the determination will be hindered.

(Embodiment 2)
In the second embodiment of the present invention, as shown in the measurement unit 120 in the second embodiment of FIG. 11, the first filter 3 and the second filter 4 are detected from the conveyor 7 and X-rays are detected. For example, the continuous X-rays 6 that are installed on the lower side and irradiated from the X-ray source 1 first pass through the resin piece 2 and then pass through the first filter 3 and the second filter 4. . In this way, the same effect can be obtained even if the transmission order of the filter and the resin piece 2 is changed. Further, by using one X-ray image intensifier 5 divided into two parts (for example, the right side and the left side of the screen) and using only one X-ray reduction 1, the capital investment can be reduced. It differs from Embodiment 1 of this invention only in the above point.

(Embodiment 3)
In Embodiment 3 of the present invention, a motor 8 is attached to the first filter 3 and the second filter 4 as shown in the measurement unit 130 in Embodiment 3 of FIG. That is, the first filter 3 and the second filter 4 rotate. As a result, the first filter 3 and the second filter 4 are alternately inserted between the X-ray source 1 and the resin piece 2. Therefore, it is possible to transmit the continuous X-ray 6 transmitted through the first filter 3 or the continuous X-ray 6 transmitted through the second filter 4 to the resin piece 2 and detected by the X-ray image intensifier 5. It becomes. It differs from Embodiment 1 of this invention only in the above point. In addition, the part which inserts the 1st filter 3 and the 2nd filter 4 by turns is the resin piece 2 like Embodiment 2 of this invention instead of between the X-ray source 1 and the resin piece 2. FIG. And the X-ray image intensifier 5 may be installed. Further, the conveyor 7 may be stopped or may be moved at a speed equal to or lower than a speed at which an image can be confirmed by the X-ray image intensifier 5. In the third embodiment of the present invention, as shown in the measurement unit 130 in the third embodiment, the X-ray source 1 and the X-ray image intensifier 5 are provided one by one, so that the capital investment can be made inexpensively. can do.

(Embodiment 4)
In the fourth embodiment of the present invention, as shown in the measurement unit 140 in the fourth embodiment of FIG. 13, X-ray line sensors 36 and 46 are used as X-ray detectors instead of the X-ray image intensifier. Used. It differs from Embodiment 2 of this invention only in the above point.

  Continuous X-rays 6 irradiated from the X-ray source 1 and transmitted through the resin piece 2, the conveyor 7, and the first filter 3 are detected by the cells 31 to 35 of the line sensor 36. However, in FIG. 13, the cell 35 is not shown because it is hidden. X-rays irradiated from the X-ray source 1 and transmitted through the second filter 4 are detected by the cells 41 to 45 of the line sensor 46. At this time, the conveyor 7 moves from left to right in FIG. 13 at a constant speed.

  In FIG. 14, the horizontal axis indicates the passage of time, and the vertical axis indicates the X-ray transmission intensity confirmed in each cell at each time. In FIG. 14, a curve 51 indicates a time change of the X-ray transmission intensity detected in the cell 31. Similarly, a curve 52 is a cell 32, a curve 53 is a cell 33, a curve 54 is a cell 34, and a curve 55 is a cell 35. The time change of the detected X-ray transmission intensity is shown. Also in FIG. 15, the horizontal and vertical axes are the same as those in FIG. 14. Curve 61 is cell 41, curve 62 is cell 42, curve 63 is cell 43, curve 64 is cell 44, and curve 65 is cell 45. The time change of the detected X-ray transmission intensity is shown. In the graph 103 shown in FIG. 14 and the graph 104 shown in FIG. 15, the X-ray transmission intensity detected in each cell of each line sensor indicates that the resin piece 2 passes immediately above each line sensor, that is, the continuous irradiation. It decreases when the X-ray 6 passes through the resin piece 2. Further, for example, a curve 63 representing the X-ray transmission intensity from the cell 43 represents the distance between the line sensor 36 and the line sensor 46 with respect to the curve 53 representing the X-ray transmission intensity from the cell 33, and the speed of the conveyor 7. The timing at which the X-ray transmission intensity is reduced is detected with a delay corresponding to the time divided by. In the system as described above, when the lowest value of the X-ray transmission intensity or the average value in the time range in which the X-ray transmission intensity decreases is passed through the first filter 3 and the second filter 4 The X-ray transmission intensity of the resin piece 2 is defined. Then, a step of determining the presence or absence of bromine in the resin piece 2 is performed by the same method as in the first to third embodiments.

  When detecting an object that moves continuously like the resin piece 2 in Embodiment 4 of the present invention, if a line sensor is used, video is output for each scan, so that images are continuous. Processing can be performed easily. When the line sensor is used, the position where the screen is scanned does not move, so that the possibility that the image is deformed when the moving image is observed is small. For this reason, image processing can be easily performed.

  In the above description, it is assumed that the resin pieces 2 move on the conveyor 7 on the line sensors 36 and 46 one by one. However, even when a plurality of resin pieces 2 are lined up side by side and pass over the line sensors 36 and 46 without overlapping, a plurality of resin pieces 2 can be simultaneously recognized by recognizing the individual resin pieces 2 from the X-ray transmission intensity signal. It is possible to determine the presence or absence of bromine in the resin piece 2. In this case, a plurality of air blow guns 20 with electromagnetic valves are installed between the cells 31 and 35 of the line sensor 36 shown in FIG. The air blow gun 20 with a solenoid valve corresponding to the position of the resin piece 2 determined to contain bromine is selected, and the solenoid valve is operated to select the resin piece 2. Further, one air blow gun 20 with a solenoid valve may be moved between the cell 31 and the cell 35 of the line sensor 36 shown in the measurement unit 140 in the fourth embodiment. Alternatively, one air blow gun 20 with a solenoid valve may be rotated to face a desired direction. In the measurement unit 140 according to the fourth embodiment, as in the second embodiment, the continuous X-rays 6 irradiated from the X-ray source 1 first pass through the resin piece 2 and then the first filter. Although it is the arrangement | positioning which permeate | transmits 3 and the 2nd filter 4, it is good also as the arrangement | positioning which permeate | transmits a filter previously and permeate | transmits the resin piece 2 similarly to Embodiment 1 of this invention.

(Embodiment 5)
In the fifth embodiment of the present invention, as shown in the measurement unit 150 in the fifth embodiment of FIG. 16, what corresponds to the first filter 3 shown in the first to fourth embodiments of the present invention is as follows. Do not install.

  In the fifth embodiment of the present invention, a filter 14 made of molybdenum is used as shown in FIG. However, the filter is made of molybdenum, and it is prepared so as to satisfy the condition that the X-ray in the energy region from 13000 eV to 20000 eV, which is well absorbed by bromine, is transmitted at a large rate. . Specifically, the filter 14 made of molybdenum is prepared to have a thickness of 50 nm to 100 nm. Thus, the filter 14 formed of molybdenum in the fifth embodiment of the present invention can be used as the second filter 4 in the first to fourth embodiments of the present invention. Will be added. For this reason, in Embodiment 5 of this invention, it distinguishes by making the reference number 14 of the filter formed with molybdenum. In order to generate continuous X-rays 6 by setting the acceleration voltage of the electron beam in the X-ray source 1 to be 40 kV or more and 60 kV or less so as to have an intensity peak in the energy region from about 13000 eV to about 20000 eV. Tungsten is prepared as a target for electron beam irradiation. Furthermore, preparations are made so that the thickness of the resin piece 2 at the thickest portion is 1 mm or more and 3 mm or less. If the step of determining the presence or absence of bromine is performed in the sorting apparatus using the measurement unit 150 in Embodiment 5 after satisfying the above conditions, the possibility of erroneous determination can be further reduced. . In FIG. 16, the filter 14 previously formed of molybdenum is transmitted and then the resin piece 2 is transmitted. However, the resin piece 2 is transmitted first and then formed of molybdenum. Alternatively, the filter 14 may be arranged so as to pass through. It differs from Embodiment 1 of this invention only in the above point.

  Hereinafter, the process will be described according to the flowchart. As described above, in the fifth embodiment, the first filter 3 does not exist. Further, there is no process for examining the thickness of the resin piece 2. However, the presence or absence of bromine can be accurately determined. In order to achieve such a configuration, it is necessary to carefully prepare the components of the sorting device while paying attention to dimensions and materials. First, a step (S31) of preparing a resin piece is performed. Specifically, as described above, this refers to a step of preparing the resin piece 2 so that the thickness of the thickest portion is 1 mm or more and 3 mm or less.

  Next, a step (S32) of detecting the transmission intensity of continuous X-rays is performed. Specifically, as described above, first, the acceleration voltage of the electron beam in the X-ray source 1 constituting the measurement unit 150 in the fifth embodiment is set to be 40 kV or more and 60 kV or less. Further, tungsten is prepared as a target to be irradiated with an electron beam in order to generate continuous X-rays 6. Furthermore, the filter 14 formed of molybdenum is prepared so that the thickness is 50 nm or more and 100 nm or less. Then, as shown in FIG. 16, continuous X-rays 6 are irradiated on a filter 14 made of molybdenum and a resin piece 2 arranged in series so as to pass through both in succession. And it is the process of detecting the transmission intensity of the X-ray which permeate | transmitted both the filter 14 and the resin piece 2 which were formed with molybdenum, performing irradiation of the continuous X-ray 6. FIG.

  Here, as described above, the filter 14 formed of molybdenum transmits sharply X-rays in the energy region from 13000 eV to 20000 eV, which are well absorbed by bromine. For this reason, if bromine is contained in the resin piece 2, when X-rays pass through the resin piece 2, X-ray absorption by bromine is performed at a high rate. As described above, X-rays in the energy region from around 13000 eV to around 20000 eV are less likely to be absorbed by the resin component (see FIG. 8), and the thickness of the resin piece 2 is set to 1 mm or more and 3 mm or less. In particular, the absorption of X-rays by the resin component can be made smaller and the absorption of X-rays by bromine can be made larger. If bromine is contained in the resin piece 2, X-rays in the energy region near 13000 eV to 20000 eV are absorbed at a certain rate, and if bromine is not contained, absorption occurs only at a very small rate.

  And the process (S33) of determining the presence or absence of a bromine is performed. Here, first, the continuous X-ray 6 transmitted through the filter 14 formed of molybdenum, which is recorded in advance in the storage unit 26 of the data processing device 21, the transmission intensity detected in the above-described step (S32), Comparison is made with X-ray transmission intensity data detected when passing through a resin not containing bromine. For example, if there is a difference equal to or greater than a preset allowable displacement amount between the two, it is determined that bromine is contained in the resin piece 2 in a large proportion. In this way, the presence or absence of bromine in the resin piece 2 is determined. Finally, in the step of sorting resin pieces (S34), the solenoid valve of the air blow gun 20 with solenoid valve is operated as described above based on the result of the presence or absence of bromine in the resin piece 2 determined. To make a selection.

  If Embodiment 5 of this invention is used, the installation of a filter will be one unit. Further, from the flowchart showing the selection method according to the fifth embodiment of the present invention, the process of performing the selection can be simplified, and the selection operation can be performed at a low cost. In the fifth embodiment of the present invention, as shown in the measurement unit 150 in the fifth embodiment of FIG. 16, the filter 14 in which continuous X-rays 6 irradiated from the X-ray source 1 are first formed of molybdenum is used. It is good also as a structure which permeate | transmits the resin piece 2 after permeate | transmitting. Or it is good also as a structure which permeate | transmits the resin piece 2 previously, and permeate | transmits the filter 14 formed with molybdenum after that.

(Embodiment 6)
In the sixth embodiment of the present invention, the absorption of X-rays by the resin component of the resin piece 2 is suppressed, contrary to the fifth embodiment of the present invention in which the absorption of X-rays by the bromine component of the resin piece 2 is promoted. . For this reason, continuous X-rays are transmitted through a resin filter 70 made of the same resin component as that of the resin piece 2 and having a thickness five times that of the resin piece 2. Then, when the continuous X-rays 6 are transmitted through the resin filter 70 having a large thickness, the energy region that is absorbed by the resin component in a large proportion of the continuous X-rays 6 is absorbed in a large proportion. As a result, the X-ray energy region where the rate of absorption of continuous X-rays 6 by the resin component is large is removed, and the rate at which X-rays are absorbed by the resin component in the resin piece 2 is reduced. From the above, the influence of the thickness of the resin piece 2 on the determination of the presence or absence of bromine can be reduced. As the above-described configuration, for example, instead of the filter 14 formed of molybdenum shown in the measurement unit 150 in Embodiment 5 in FIG. 16, the resin piece 2 is formed of the same resin component as the resin piece 2. A resin filter 70 having a thickness of 5 times or more is installed. Only the above points are different from the fifth embodiment of the present invention. That is, as in the first to fourth embodiments of the present invention, the process of examining the expected thickness and the expected transmission strength of the resin piece 2 using two filters is also included in the sixth embodiment of the present invention. Absent. In the sixth embodiment of the present invention, continuous X-rays 6 irradiated from the X-ray source 1 first pass through the resin piece 2 as shown in the measurement unit 160 in the sixth embodiment in FIG. Thereafter, the resin filter 70 may be transmitted. Or it is good also as arrangement | positioning which permeate | transmits the resin filter 70 previously and permeate | transmits the resin piece 2 after that.

  The sorting method according to the sixth embodiment of the present invention can be described with reference to the flowchart of FIG. 17 showing the sorting method according to the fifth embodiment of the present invention. First, a step (S31) of preparing a resin piece is performed. Specifically, it refers to the step of preparing the resin piece 2 as in the first to fourth embodiments of the present invention.

  Next, a step (S32) of detecting the transmission intensity of continuous X-rays is performed. Specifically, first, the acceleration voltage of the electron beam in the X-ray source 1 constituting the measurement unit 160 in the sixth embodiment is set to be 40 kV or more and 60 kV or less. Further, tungsten is prepared as a target to be irradiated with an electron beam in order to generate continuous X-rays 6. Moreover, as a filter, the resin filter 70 which has the thickness 5 times or more of the resin piece 2 and was formed with the same resin component as the resin piece 2 is prepared. Then, the continuous X-ray 6 is irradiated on the resin filter 70 and the resin piece 2 arranged in series so as to pass through them one after another. Then, as described above, since the thickness of the resin filter 70 formed of the same resin component as the resin piece 2 is sufficiently large, X-ray absorption by the resin component occurs at a large rate in the resin filter 70. Therefore, the ratio of the absorption by the resin component contained in the resin piece 2 out of the X-ray absorption in the resin piece 2 can be reduced. As described above, in the resin piece 2, the absorption of X-rays by the resin component can be relatively reduced, and the absorption of X-rays by bromine can be increased. Then, the X-ray transmission intensity transmitted through both the resin filter 70 and the resin piece 2 is detected while irradiating the continuous X-ray 6. Theoretically, if the resin piece 2 contains bromine, X-rays in the energy region from about 13000 eV to 20000 eV are absorbed at a certain rate, and if it does not contain bromine, the absorption is only at a very small rate. Does not happen.

  And the process (S33) of determining the presence or absence of a bromine is performed. Here, the continuous X-ray 6 transmitted through the resin filter 70 in which the transmission intensity detected in the above-described step (S32) is previously recorded in the storage unit 26 of the data processing device 21 does not contain bromine. Comparison with X-ray transmission intensity data detected when passing through the resin. For example, if there is a difference equal to or greater than a preset allowable displacement amount between the two, it is determined that bromine is contained in the resin piece 2 in a large proportion. In this way, the presence or absence of bromine in the resin piece 2 is determined. Finally, in the step (S34) of selecting the resin piece, the electromagnetic valve of the air blow gun 20 with the electromagnetic valve as described above is based on the result of the presence or absence of bromine in the resin piece 2 determined. Sorting is performed by operating.

(Embodiment 7)
Further, the following configuration is also conceivable. In the sorting apparatus 170 in Embodiment 7 shown in FIG. 19, the resin filter 70 used in Embodiment 6 of the present invention is moved to the conveyor 7 for moving the resin piece 2 in Embodiments 1 to 6 of the present invention. The resin piece 2 is installed as a member. That is, the resin filter 70 is configured to have both a function as the conveyor 7 (see FIG. 1) and a function as a filter. In addition, about the sorting device which has this structure, a conveyor cannot let compressed air pass. That is, the resin piece 2 containing a large proportion of bromine cannot be selected by using air from below the resin piece 2 using the air blow gun 20 with a solenoid valve. However, for example, it is possible to perform mechanical selection by rotating the rotary blade 71 from above the resin piece 2 and colliding with the resin piece 2 containing bromine in a large proportion. In this case, the data processor 21 is connected to the rotary blade 71 so that a signal from the data processor 21 can be received. The operation of the resin filter 70 also serving as a conveyor is controlled by driving a roller 72 and a roller 73 with a spring. In the seventh embodiment of the present invention, it is preferable to set the acceleration voltage of the electron beam in the X-ray source 1 to be 40 kV or more and 60 kV or less as in the fifth and sixth embodiments. Further, tungsten is prepared as a target to be irradiated with an electron beam in order to generate continuous X-rays 6. This makes it possible to increase the ratio of the X-ray output in the energy range from about 13000 eV to about 20000 eV, which is absorbed by bromine. The sorting method according to the seventh embodiment of the present invention can be described with reference to the flowchart of FIG. 17 showing the sorting method according to the fifth embodiment of the present invention.

(Embodiment 8)
Furthermore, as an embodiment of the present invention, the following sorting method is also conceivable. In the eighth embodiment of the present invention, sorting is performed using the same sorting device as the sorting device 110 in the first embodiment of the present invention. However, it differs from the first embodiment in that the presence or absence of bromine is determined without obtaining the expected thickness of the resin piece 2.

  In Embodiment 8 of the present invention, it is desired to actually determine the presence or absence of bromine. For example, before performing measurement on the resin piece 2 (see FIG. 1), the first filter 3 (see FIG. 1) is preliminarily measured. ) For the continuous X-rays 6 (see FIG. 1) that have been transmitted through the test piece of the same thickness as the resin piece 2 that does not contain bromine. . Also, the continuous X-ray 6 transmitted through the second filter 4 (see FIG. 1) is the same as the resin piece 2 that does not contain bromine, like the continuous X-ray 6 transmitted through the first filter 3 described above. The transmission strength of a test piece formed of the resin is determined. These measurement results are obtained as a graph 105 plotted. In order to obtain these data, first, a plurality of test pieces having a uniform thickness not containing bromine and made of the same resin as the resin piece 2 and having different thicknesses are prepared. Similarly, for a test piece formed of the same resin as the resin piece 2 containing a certain amount of bromine, the transmission intensity of the continuous X-rays 6 that have passed through each filter is similarly determined in advance for each thickness of the test piece. And obtained as a graph 106 in which the measurement results are plotted. In order to obtain these data, first, a test piece having a uniform thickness containing a certain amount (for example, 1.0% by mass) of bromine and made of the same resin as the resin piece 2 is different in thickness. Prepare several things.

  In FIG. 20, the horizontal axis (A) represents the X-ray transmission intensity through the first filter and the test piece, and the vertical axis (B) represents the X-ray transmission intensity through the second filter and the test piece ( The same applies to FIGS. 21 and 22 below).

  In the graph 107 in which 105 and 106 in FIG. 22 are overlapped, the white circle is the plotted graph 105, that is, the transmission intensity detected by the test piece not containing bromine is plotted for each thickness of the test piece. A curve indicated by a dotted line is a curve formed by roughly connecting white circle data, and is a determination criterion determined in consideration of a measurement error (variation), a margin, and the like. Similarly, in the graph 107 in which 105 and 106 in FIG. 22 are overlapped, the black circle is the plotted graph 106, that is, the transmission intensity detected by the test piece containing a certain amount of bromine is plotted for each thickness of the test piece. It is. A curve indicated by a solid line is a curve formed by roughly connecting black circle data, and is a determination criterion determined in consideration of measurement error (variation), margin, and the like.

  In the eighth embodiment of the present invention, the data of the plotted graphs 105 and 106 described above are stored in advance in the storage unit 26 of the data processing device 21 as first data and second data, respectively. Here, the resin piece 2 for which it is actually desired to determine the presence or absence of bromine is measured. The method is the same as that of the test piece mentioned above. That is, the relationship between the transmission intensity of X-rays detected through the first filter and the resin piece 2 and the transmission intensity of X-rays detected through the second filter and the resin piece 2 is represented by the third data. Asking. Then, the third data is compared with the first data and the second data using the storage unit 26 and the calculation unit 27 of the data processing device. For example, referring to 107 shown in FIG. 22, it is examined where the third data is present in comparison with the first data and the second data. Thus, the presence or absence of bromine in the resin piece 2 is determined.

  Hereinafter, the selection method for determining the presence or absence of bromine in the resin piece 2 will be described more specifically. FIG. 24 is a flowchart common to the step (S71) and the step (S72). A sorting method according to the eighth embodiment will be described with reference to FIGS. 20 to 24 and FIGS.

  Prior to the measurement of the resin piece 2 to be determined, a step of deriving first data (S71) is performed. Here, the first data is data indicated by the plotted graph 105 described above. That is, the transmission intensity detected when the continuous X-ray 6 transmitted through each of the first filter 3 and the second filter 4 passes through a test piece not containing bromine is shown. To derive the first data, as shown in the flowchart of FIG. 24, first, a step of preparing a test piece (S81) is performed. As described above, a plurality of test pieces having a uniform thickness not containing bromine and made of the same resin as the resin piece 2 and having different thicknesses are prepared.

  Then, the process (S82) which detects the transmission intensity | strength of the continuous X-ray which permeate | transmits a 1st filter and a test piece is implemented. That is, the continuous X-ray 6 from the X-ray source 1 is irradiated on the first filter 3 and the test piece arranged in series, for example, so that they pass through each other one after another. This is a step of detecting the transmission intensity. In addition, about the order, you may pass through a test piece (refer resin piece 2), after passing a filter previously like the measurement part 100 for determining the presence or absence of bromine shown, for example in FIG. Or conversely, like the measurement part 120 in Embodiment 2 shown in FIG. 11, you may pass a filter after passing a test piece previously. For the detection of the transmission intensity, for example, the configuration of measuring unit 100 for determining the presence or absence of bromine shown in FIG. 2 may be used, or the configuration of measuring unit 120 in the second embodiment shown in FIG. 11 is used. Also good. Alternatively, the configuration of measurement unit 130 in Embodiment 3 shown in FIG. 12 may be used, or the configuration of measurement unit 140 in Embodiment 4 shown in FIG. 13 may be used.

  Subsequently, similarly to the above-described step (S82), a step (S83) of detecting the transmission intensity of continuous X-rays transmitted through the second filter and the test piece is performed. That is, the continuous X-rays 6 from the X-ray source 1 are irradiated to the one in which the second filter 4 and the test piece are arranged in series, for example, so as to pass through them one after another. This is a step of detecting the transmission intensity. Finally, a step of obtaining the relationship between the two types of transmission intensities (S84) is performed. That is, the relationship between the first transmission intensity detected in step (S82) and the second transmission intensity detected in step (S83) is obtained for each thickness of the test piece. This is shown in the graph 105 plotted above.

  Similarly, the step of deriving the second data (S72) is performed according to the procedure shown in the flowchart of FIG. Here, the second data is data indicated by the plotted graph 106 described above. That is, the transmission intensity detected when the continuous X-ray 6 transmitted through each of the first filter 3 and the second filter 4 passes through a test piece containing a certain amount of bromine is shown. In order to derive the second data, as shown in the flowchart of FIG. 24, first, a step of preparing a test piece (S81) is performed. As described above, a plurality of test pieces having a uniform thickness containing a certain amount of bromine and made of the same resin as the resin piece 2 and having different thicknesses are prepared. Hereinafter, similarly to the case of obtaining the first data described above, the second data is obtained by performing the steps (S82) to (S84). This is shown in the graph 106 plotted above.

  When the plotted graphs 105 and 106 are obtained, the resin piece 2 to be actually determined is measured. First, a step (S41) of detecting the transmission intensity of continuous X-rays that pass through the first filter and the resin piece is performed. Similarly, a step (S51) of detecting the transmission intensity of continuous X-rays that pass through the second filter and the resin piece is performed. And the process (S61) of deriving the data which shows the relationship between both transmitted intensity is performed. This is the third data.

  Next, a step (S62) of determining the presence or absence of bromine based on the data is performed. That is, the first data and the second data stored in advance in the storage unit 26 of the data processing device 21 and the third data obtained this time are used by making full use of the calculation unit 27 of the data processing device 21. Compare. Referring to the graph 107 in which 105 and 106 shown in FIG. 22 are overlapped, for example, it is assumed that the test piece used when detecting the second data contains 1.0% by mass of bromine. Here, for example, if the third data is plotted, if it exists below the black circle (solid line) indicating the second data, the resin piece 2 contains bromine at a high ratio of 1.0 mass% or more. It can be determined that it contains. For example, when the third data is plotted, if it exists between a white circle (dotted line) indicating the first data and a black circle (solid line) indicating the second data, the resin piece 2 has no bromine. It can be determined that it is contained at a low ratio of 1.0% by mass or less. For example, when the third data substantially overlaps the white circle (dotted line) indicating the first data, it can be determined that the resin piece 2 contains almost no bromine. In this way, the presence or absence of bromine in the resin piece 2 is determined. Finally, a step (S63) of sorting resin pieces is performed.

  As described above, in carrying out the eighth embodiment of the present invention, instead of the measurement section 100 for determining the presence or absence of bromine used in the first embodiment of the present invention as the measurement section of the sorting device. Alternatively, the measurement unit 120 in the second embodiment may be used. Similarly, the measurement unit 130 in the third embodiment or the measurement unit 140 in the fourth embodiment may be used. The eighth embodiment of the present invention is different from the first embodiment of the present invention only in the above points. That is, regarding the eighth embodiment of the present invention, all configurations and conditions not described above are in accordance with the first embodiment of the present invention.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is shown not by the above-described embodiment but by the scope of claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

  The present invention is suitable for use as a technology for sorting based on the presence or absence of bromine contained in a resin when the resin that is the object to be sorted is recycled.

  DESCRIPTION OF SYMBOLS 1 X-ray source, 2 Resin piece, 3 1st filter, 4 2nd filter, 5, 15, 16 X-ray image intensifier, 6 Continuous X-ray, 7 Conveyor, 8 Motor, 12 Support body, 13 Thin film , 14 Filter made of molybdenum, 20 Air blow gun with solenoid valve, 21 Data processing device, 22, 23 Container, 24 Resin piece supply device, 26 Storage unit, 27 Calculation unit, 28, 29 X-ray image image, 31 -35, 41-45 cells, 36, 46 line sensors, 51-55, 61-65 curves, 70 resin filters, 71 rotating blades, 72 rollers, 73 rollers with springs, 100 Measuring unit for determining the presence or absence of bromine , 101, 102 Calibration curve, 103, 104 graph, 105, 106 Plotted graph, 107 105 and 106 110, sorting apparatus in the first embodiment, 120 measuring unit in the second embodiment, 130 measuring unit in the third embodiment, 140 measuring unit in the fourth embodiment, 150 measuring unit in the fifth embodiment, 160 A measurement unit according to the sixth embodiment, and a sorting apparatus according to the seventeenth embodiment.

Claims (2)

A sorting device that sorts resin pieces according to the presence or absence of bromine,
An X-ray source that emits continuous X-rays;
A first filter containing bromine;
A second filter containing an element having an X-ray absorption edge on the higher energy side than the X-ray absorption edge of bromine;
First X-ray detection for detecting a first X-ray intensity by detecting a first X-ray transmitted through the first filter and the resin piece from the continuous X-rays irradiated from the X-ray source. And
Second X-ray detection for detecting a second X-ray intensity by detecting a second X-ray transmitted through the second filter and the resin piece from the continuous X-rays irradiated from the X-ray source. And
A controller for selecting the resin pieces by using the first X-ray intensity and the second X-ray intensity ;
The control unit includes a storage unit and a calculation unit,
The storage unit obtains in advance a relationship between the first X-ray intensity and the second X-ray intensity by using a plurality of first standard resin pieces having different thicknesses when no bromine is contained. The relationship between the first X-ray intensity and the second X-ray intensity is obtained using the first data and a plurality of second standard resin pieces having different thicknesses in the case of containing bromine. Second data is stored,
The arithmetic unit calculates bromine based on the relationship between the first X-ray intensity and the second X-ray intensity, the first data, and the second data obtained for the resin piece to be measured. A sorting apparatus that performs an operation for determining the presence or absence of the inclusion of . Before SL arithmetic unit, wherein the first X-ray strength level and on the basis of the first data to determine the expected thickness of the resin piece, it is expected based on the expected thickness and said second data 2. The sorting apparatus according to claim 1, wherein the X-ray intensity of 2 is determined, and the resin pieces are sorted by comparing the second X-ray intensity and the expected second X-ray intensity .

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