JP5874032B2 - Sorting method and sorting apparatus - Google Patents

Description

  The present invention relates to a selection technique for selecting an object made of a desired type of material from an object group including a plurality of plastic objects obtained by pulverizing used home appliances for the purpose of recycling. .

  Recent mass production, mass consumption, and mass disposal economic activities have caused global environmental problems such as global warming and resource depletion. Under these circumstances, the Home Appliance Recycling Law has been enforced in Japan for the establishment of a recycling-oriented society, and recycling of used air conditioners, TVs, refrigerators, freezers and washing machines is obligatory.

  When such household electrical appliances are crushed, a group of objects consisting of one plastic material and another plastic material is generated. It is desirable to select and recycle.

  For example, Patent Document 1 describes a technique for selecting a plastic member of a desired material type.

  FIG. 9 is a diagram showing a conventional plastic object sorting apparatus.

  The sorting apparatus 100 shown in the figure automatically sorts plastic objects for each material type as follows. That is, the material type of the plastic object 102 flowing on the belt conveyor 101 of the sorting device 100 is individually identified by the material type detection device 103, and the identified plastic object 102 of the specific material type is identified by the belt conveyor 101. It blows off with the pulsed air from the air nozzle 104 arranged at the rear, and the object 105 made of plastic of a specific material type is separated from the plastic object 102.

  The material type detection device 103 provided in the sorting device 100 identifies the material type of the plastic object 102 using light including near-infrared light, and applies light to the plastic object 102 on the belt conveyor 101. The material type is identified by the reflected light received. In the near-infrared light region, since there are different absorption characteristics for each plastic material type, it is possible to identify the plastic material type by comparing the waveform data registered in advance with the waveform data of the reflected light. it can.

  In this way, according to the conventional object group sorting apparatus in which the plastic material types are mixed, the plastic object of the specific material type can be selected from the object group by the material type detection device and the pulse air. It is possible to select from a group of objects including objects made of plastics having similar compositions such as polypropylene (hereinafter referred to as PP), polystyrene (hereinafter referred to as PS) and acrylonitrile butadiene styrene (hereinafter referred to as ABS) which are generated in large quantities.

  The conventional sorting apparatus 100 sorts plastic objects of two or more specific material types from the object group in order to select one type of specific material plastic object in a single sorting process. In this case, the object group is selected by performing a plurality of selection processes.

Japanese Patent No. 3806163

  However, in home appliances or the like, a filler may be blended as an additive to plastics in order to improve strength. In a conventional sorting apparatus, it is difficult to sort a plastic object containing filler and a plastic object not containing filler from a group of objects obtained by pulverizing such home appliances. For this reason, it has the subject that the material recycling of the plastic object generated in a recycling factory cannot be performed.

  In view of such a problem, the present invention can select a filler-containing plastic object from an object group including a filler-containing plastic object and a filler-free (including a trace amount, the same applies hereinafter) plastic object. An object is to provide a sorting method and a sorting apparatus.

  In order to achieve the above object, a sorting method according to the present invention is a sorting method for sorting a plastic object containing a filler from a group of objects including a plurality of plastic objects, and the object is conveyed by a conveying means. A heating step for heating the surface portion of the object to be conveyed to a temperature equal to or higher than the melting point of the plastic constituting the object, and detecting the absorbance at a specific wavelength in the infrared region on the surface of the object. A detection step of detecting the filler, a determination step of determining that the absorbance is greater than or equal to a predetermined threshold, and a filler-containing plastic object determined by the determination step; or And an extraction step of extracting other objects from the object group.

  In the heating step, the surface portion of the object may not exceed the temperature of the melting point of the plastic constituting the object + 30 ° C.

  In the heating step, the heating time of the object may be selected from a range of 5 seconds to 60 seconds.

Moreover, a specific wavelength the detection device detects, when expressed in wave number 900 cm ^-1 or more, in the range of 1100 cm ^-1 or less.

  In order to achieve the above object, a sorting apparatus according to the present invention is a sorting apparatus that sorts a plastic object containing a filler from an object group including a plurality of plastic objects. A conveying means for conveying; a heating means for heating the surface portion of the object to be conveyed to a temperature equal to or higher than the melting point of the plastic constituting the object; When the absorbance is equal to or greater than a predetermined threshold value, a determination unit that determines that the object is a plastic material containing filler, a filler-containing plastic object that is determined by the determination unit, or another object And extraction means for extracting from the object group.

  By using the present invention, it becomes possible to sort plastic objects containing fillers and plastic objects not containing fillers, which has been difficult in the past, and it is possible to recycle plastic objects that have been processed without material recycling. It becomes possible to plan resource recycling.

FIG. 1 is a side view showing a schematic configuration of a sorting apparatus according to the present invention. FIG. 2 is a graph showing the relationship between wave number and absorbance. FIG. 3 is a graph showing the relationship between wave number and absorbance due to a plurality of heating temperatures. FIG. 4 is a graph showing the relationship between the content concentration of the glass filler and the discrimination peak ratio D. FIG. 5 is a graph showing the difference in the discrimination peak ratio D depending on the heating temperature. FIG. 6 is a graph showing the result of measuring the identification peak when the heating time is changed for each heating temperature. FIG. 7 is a side view showing a schematic configuration of a sorting apparatus according to another embodiment. FIG. 8 is a graph showing the relationship between the wave number and absorbance of a plastic object containing talc. FIG. 9 is a perspective view showing a configuration of a conventional sorting apparatus.

  Next, embodiments of the sorting method and the sorting apparatus according to the present invention will be described with reference to the drawings. The following embodiment is merely an example of a sorting method and a sorting device according to the present invention. Accordingly, the scope of the present invention is defined by the wording of the claims with reference to the following embodiments, and is not limited to the following embodiments.

  FIG. 1 is a side view showing a schematic configuration of a sorting apparatus according to the present invention.

  The sorting device 20 includes a filler-containing plastic object (indicated by a white oval in the figure) from the object group 2 including a plurality of plastic objects (indicated by an ellipse in the figure; the same applies hereinafter). The same), and includes a conveying means 21, a heating means 10, a detecting device 22, a judging means (included in the control device 13), and an extracting means 6.

  The transport unit 21 is a device that transports an object in a predetermined direction, that is, a device that transports the object group 2 in a predetermined direction. In the case of the present embodiment, the conveying means 21 includes a belt conveyor 1 and a heat-resistant belt conveyor 11. A heat resistant belt conveyor 11 is disposed on the upstream side of the belt conveyor 1. Further, the sorting device 20 includes a vibration feeder 8 that generates vibration between the heat-resistant belt conveyor 11 and the belt conveyor 1 so as to disperse the object group 2 evenly.

  The heating means 10 is a device that heats the surface portion of the object to be conveyed to a temperature equal to or higher than the melting point of the plastic constituting the object. In the case of the present embodiment, the heating means 10 includes a heater 9 and heats the object group 2 conveyed by the heat-resistant belt conveyor 11 from above and heats the upper surface of the object.

  The detection device 22 is a device that detects the absorbance of a specific wavelength in the infrared region on the surface of the object. In the case of the present embodiment, the detection device 22 detects the light source 3 that irradiates the object group 2 with infrared light 16 including a specific wavelength in the infrared region, and the infrared light 16 reflected from the object group 2. A light receiving element 5 and an arithmetic device 4 that calculates the absorbance for each wavelength by calculation are provided.

  The determination unit is a processing unit that acquires the absorbance at a specific wavelength from the detection device 22 and determines that the object is a plastic object containing filler when the absorbance is equal to or greater than a preset threshold value. In the case of the present embodiment, the determination means is realized by software by the control device 13 composed of a computer or the like.

  The extraction means 6 is an apparatus that extracts the filler-containing plastic object determined by the determination means or other objects from the object group 2. In the case of the present embodiment, the extracting means 6 is a device that changes the dropping path of an object falling from the belt conveyor 1 of the conveying means 21 with air, and includes a nozzle that can discharge pulsed air at an arbitrary timing. ing.

  In the case of the present embodiment, the sorting device 20 includes a collection zone 17 that collects articles and a partition plate 7 that divides the collection zone 17. The extraction means 6 can change the falling path of the object so that only the filler-containing plastic object is accommodated in one of the recovery zones 17 partitioned by the partition plate 7.

  In addition, the sorting device 20 includes a material supply device 12 that supplies the object group 2 to the heat-resistant belt conveyor 11 that is the conveying means 21. The object group 2 supplied from the material supply device 12 to the heat-resistant belt conveyor 11 includes a plastic object containing a filler and a plastic object not containing a filler.

  Next, a sorting method using the sorting device will be described.

  The object group 2 supplied from the material supply device 12 to the heat-resistant belt conveyor 11 is conveyed by the heat-resistant belt conveyor 11 while being heated by the heating means 10. Thereafter, the object is dispersed by the vibration feeder 8 so as not to overlap in plan view. And it is conveyed with the belt conveyor 1 comprised with a belt different from the heat-resistant belt conveyor 11. FIG. The detection device 22 detects the absorbance at a specific wavelength of the plastic material type for each article. The determination means of the control device 13 that has acquired the detection result of the detection device 22 as detection information controls the extraction means 6 having a pulse air-nozzle installed on the side of the downstream end of the belt conveyor 1, and The fall path of the object made of plastic containing filler is changed from the object group 2 dropped from the conveyance end, and the object made of plastic containing filler is accommodated in one of the recovery zones 17 partitioned by the partition plate 7.

  Here, generally two types of fillers added to plastics are glass and talc. As the object group 2 obtained by crushing home appliances or the like in a recycling factory, plastic objects having a particle diameter of 10 mm to 150 mm are mixed.

  For the object group 2 as described above, the sorting device 20 passes the object group 2 supplied from the material supply device 12 and placed on the heat-resistant belt conveyor 11 under the heating means 10 at a constant speed. (Heating process). The surface portion of the object heated by the heating means 10 above the melting point is melted and the filler is deposited. The melting state of the surface of the object is determined by the temperature of the heater section 9 of the heating means 10 and the time during which the object is heated by the heating means 10. In the case of this embodiment, the time for conveying an object on the belt conveyor 1 and passing under the heating means 10 is the heating time. Therefore, in order to heat the surface state of the object group 2 to a temperature higher than the melting point of the plastic, it is necessary to adjust the heating temperature and the heating time. In the case of the present embodiment, the surface of the object group 2 is melted due to the passage time of the heat-resistant belt conveyor 11, and a large amount of filler is deposited inside the filler-containing plastic object included in the object group 2. .

  In the present embodiment, the conveyor speed of the belt conveyor 1 is higher than that of the heat-resistant belt conveyor 11. This is because the interval between the articles dispersed by the vibration feeder 8 is widened and conveyed to the belt conveyor 1.

  The conveyance speed of the belt conveyor 1 is, for example, 1 m / s to 3 m / s, but the heat-resistant belt conveyor 11 puts the article under the heating means 10 for 5 seconds in order to make the surface temperature of the object group 2 equal to or higher than the melting point. In the case of staying, the conveyance speed of the heat-resistant belt conveyor 11 is 0.1 m / s.

  In order to heat the object group 2 uniformly, it is preferable that the objects do not overlap each other even on the heat-resistant belt conveyor 11. Moreover, heat insulation may be improved by enclosing the periphery of the heat-resistant belt conveyor 11, and a heat space with high heating efficiency may be formed. If the temperature of the heater 9 of the heating means 10 is set to 350 ° C., the object group 2 can be raised in a short time.

  In the heating step, it is preferable that the surface portion of the object does not exceed the temperature of the melting point of the plastic constituting the object + 30 ° C. Therefore, the heating means 10 is preferably adjusted so as to maintain a temperature selected from the range of 170 ° C. or more and 300 ° C. or less, and the time for the object to pass under the heating means 10 is 5 seconds or more, It is preferable to select from a range of 60 seconds or less.

  Next, an operation for identifying the type of plastic constituting the object will be described. That is, the detection device 22 may detect not only the absorbance at a specific wavelength for detecting the presence or absence of the filler, but also the absorbance at a wavelength capable of identifying the plastic material type.

  Different plastic grades will have different molecular structures and therefore different behavior in the infrared absorption characteristics of plastic. The plastic material type is identified using the above behavior. Specifically, the light source 3 irradiates the object group 2 with light including the infrared region, and the light receiving element 5 detects the light reflected from each object, and obtains the obtained signal output and the signal output registered in advance. The calculation value is calculated by the calculation device 4 and checked by the control device 13, whereby the plastic material type can be determined.

Two points are detected: the peak of the normal plastic material type and the peak of the component peculiar to the filler-containing plastic, and whether or not the filler is contained is checked by checking whether the absorbance is equal to or higher than a predetermined threshold. Species determination is possible. The specific wavelength for detecting the absorbance needs to be selected from the range of 900 cm ⁻¹ to 1100 cm ⁻¹ . In the case of identifying many types of plastic materials, the absorbance is detected covering the above range.

  Next, an operation for selecting only an object made of a desired plastic material type will be described.

  In the object group 2 determined by the detection device 22, a filler-containing plastic object determined by the determination unit or another object is extracted by the extraction unit 6 at a preset point. In the case of the present embodiment, the extraction is performed by changing the falling path of the filler-containing plastic object. Specifically, at the timing when the filler-containing plastic object passes from the end of the belt conveyor 1 while dropping, pulse air is generated by the extraction means 6 provided on the downstream side of the belt conveyor. As described above, the filler-containing plastic object can be blown off at a predetermined location, and only the filler-containing plastic object can be selected from the object group 2. This operation can be controlled by synchronizing the speed of the belt conveyor 1 and the detecting device 22 and the extracting means 6 by the control device 13.

  In order to process continuously, it is preferable to install the nozzle of the extraction means 6 at a position where the dropping path can be changed at a timing when the object group 2 discharged from the discharge end of the belt conveyor 1 is separated by 100 mm. The normal fall trajectory of the object group 2 falls in an arc and is recovered to the other side partitioned by the partition plate 7 in the recovery zone 17. By installing the partition plate 7 at a position where it cannot be recovered by a normal trajectory, and by installing the partition plate 7 at a position where the partition plate 7 can be recovered only when it is ejected by pulsed air by the extraction means 6, the desired plastic is obtained from the object group 2. Sorted and collected. For example, it is possible to extract from the object group 2 by injecting only the plastic-free object containing no filler with pulsed air.

  Next, a specific method for determining whether the filler is contained or not will be described.

  As described above, two types of glass and talc are generally widely used as fillers. Here, a glass filler detection method will be described.

  FIG. 2 is a diagram showing the results of measuring the absorbance peak in the infrared region by FT-IR for judging whether or not glass filler is contained in typical PP used in plastics. is there.

  In the figure, the horizontal axis represents the wave number of infrared rays, and the vertical axis represents the absorbance. The absorbance is represented by A = −log (reflectance R / 100), and the reflectance R of the plastic is a value that can be measured by the ATR method (attenuated total reflection).

  As an analyzer, AVATAR360 / OMNI-Sampler (crystal Ge) manufactured by Nicolet can be used. As the object, glass fiber reinforced polypropylene (hereinafter referred to as GFPP) manufactured by Prime Polymer, to which 50% of the glass filler additive is added, and PP (J2000GP) manufactured by Prime Polymer without glass filler are used.

  For comparison, the surface and internal absorbance peaks of PP containing glass filler were measured. Regarding the inside, it is the result of measuring the inside of which the surface state was cut by 0.5 mm or more with a sharp blade.

The figure shows that a characteristic spectrum cannot be confirmed on the surface of PP containing glass filler, but an absorbance spectrum peculiar to the filler is generated inside PP containing glass filler. The remarkable range is 900 cm ⁻¹ to 1100 cm ⁻¹ , and the waveform range indicated by the hatched portion not overlapping with the PP peak in FIG. This is because the infrared absorption spectrum of Si—O, which is the main component of glass as a filler, is 985 cm −1, and its derivative is detected as a characteristic peak. Confirmed as a peak.

  As described above, the inventor has found that the surface of a plastic member constituting an electric appliance generally has a coating material and the like, and thus the surface of the object has a low filler content, and the filler tends to exist in the interior. Yes. And it has been found that it is difficult to determine whether or not it is a plastic containing filler by simply detecting the absorbance of the surface of the object.

  Next, an experiment was conducted in which the heating condition of the surface of the PP object was changed in order to improve the detection accuracy of whether or not it contains a filler. The result of the experiment will be described with reference to FIG.

  FIG. 3 is a diagram showing the absorbance for each heating condition of the surface of the object.

  The horizontal axis in the figure is the wave number of infrared rays, and the vertical axis is the absorbance. The plastic used was Prime Polymer GFPP with 50% glass filler additive added. The object made of GFPP was heated with a heating means (for example, an experimental hot plate) for 5 seconds, and then the object was separated from the heating means and naturally cooled. In this experiment, the heating temperature of the heating means was performed under two conditions of 160 ° C. and 170 ° C. FIG. 3 shows the result. In the lower graph of the figure, the peak of the glass filler can be confirmed. This is presumably because the melting point of PP is 170 ° C., so that when the surface temperature becomes 170 ° C. or higher, the surface of the object is dissolved and the surface state is changed, and the filler is precipitated. On the other hand, since the melting of the surface of the object was not reached at a heating temperature of 160 ° C., the glass filler peak could not be confirmed from the absorbance. That is, it seems that the filler is not deposited on the surface of the object.

In particular, in the graph shown in the figure, the slope of absorbance may change due to measurement variations even when an object of the same plastic material type is measured in a portion after the wave number of 1500 cm ⁻¹ . Therefore, in this experiment, baseline correction was performed to make the slope of absorbance the same by using analysis software (omnic: Ver6.0A manufactured by Thermo). By using the analysis software, it is possible to accurately determine the presence or absence of the filler by making the information other than the glass filler peak equal.

A value taking the ratio of peak height of the 985cm ^-1 with a peak of 1377 cm ^-1 and glass filler is a representative peak of the PP is defined as identifying peak ratio D, and compared as a value indicating a difference between the glass filler presence went. Was the heating temperature of 160 ℃ D = 0.051 (0.00138 / 0.02695 = absorbance at the absorbance / 1377 cm ^-1 in the 985cm ^-1). Was the heating temperature of 170 ℃ D = 0.77 (0.00567 / 0.00740 = absorbance at the absorbance / 1377 cm ^-1 in the 985cm ^-1). From the above, when the surface temperature is 170 ° C., superiority in judging the presence or absence of glass filler was found. It was found that the glass filler detection peak increases because the glass filler present inside the plastic precipitates when the surface state of the object is changed by heating above the melting point of the plastic constituting the object.

  FIG. 4 is a graph showing a result of comparison between the content concentration of the glass filler and the discrimination peak ratio D.

  The discrimination peak ratio D in the figure is a value calculated from data measured by FT-IR for PP produced for each glass filler content concentration as in the previous case. It can be seen that there is a correlation in which the discrimination peak ratio D increases as the glass filler content increases. On the other hand, the discrimination peak ratio D is not detected in the plastic containing no filler. Generally, the concentration of glass filler contained in a plastic member constituting a home appliance is 15% to 50%. In the range of the concentration, a significant discrimination peak ratio D is obtained by heating the surface of an object to the melting point of the plastic in advance. And the presence / absence of filler can be identified using the identification peak ratio D.

  FIG. 5 is a graph showing the difference in the discrimination peak ratio D depending on the heating temperature.

  The horizontal axis in the figure is the heating temperature, and the vertical axis is the discrimination peak ratio D calculated from the infrared chart measured by FT-IR in the same manner as described above for PP prepared for each glass filler content concentration. is there. This is a result of carrying out heating for 5 seconds using GFPP having a glass filler content of 50%. If the identification peak ratio D is 0.3 or more, the SN level can be continuously determined on the belt conveyor, and thus the possibility of identification was determined using the above index as a guide. As shown in the figure, it was found that if the heating time of the object surface is 5 seconds, the discrimination peak ratio D is 0.3 or more at 170 ° C. or more, which is a preferable range. When the temperature is 200 ° C. or higher (melting point + 30 ° C. or higher), the melting of the surface state of the plastic increases, and the case where the object adheres to the conveying means or the case where the objects adhere to each other occurs. Therefore, when the heating time is 5 seconds, the heating temperature is preferably selected from the range of 170 ° C. or higher and 200 ° C. or lower. Thus, the degree of change in the surface state of the object is related to the heating temperature and the heating time.

  FIG. 6 is a graph showing the result of measuring the identification peak when the heating time is changed for each heating temperature.

  The results shown in the figure are the results of heating using GFPP having a glass filler content concentration of 50% and setting the heating temperature in six stages in the range of 150 ° C to 200 ° C. If the heating time is shorter than 5 seconds, heat may not be sufficiently transmitted to the object surface, and it may be difficult to melt the object surface and deposit the filler. Therefore, the heating time was set to 5 seconds as the shortest time. As shown in the figure, it became clear that the discrimination peak ratio D decreases as the heating time becomes longer. This is because although the glass filler is deposited on the surface by heating, the surface of the object is again coated with a composition other than the glass filler by heating for 60 seconds or more, so that it is considered that the glass filler is hardly deposited apparently. . The same tendency is obtained when GFPP having a glass filler content of 15% is used. In order for the discrimination peak ratio D to exceed 0.3, the heating temperature is 200 ° C. or less and the heating time is 60 seconds or less. It has been found preferable to employ. From the above results, it has been found that it is desirable to set the heating temperature in the range of 170 ° C. or more and 200 ° C. or less in PP and the heating time in the range of 5 to 60 seconds.

  Although the melting point varies depending on the type of plastic, the above method is not limited to PP but can be applied to other types of plastic. That is, it is possible to determine whether or not the filler is precipitated by heating the surface state of the plastic object of another material to the melting point of the plastic material or higher. In addition, by setting the surface heating temperature to be equal to or lower than the melting point of the plastic + 30 ° C., it is possible to improve the detection accuracy as to whether or not the filler is contained without causing an undesirable state in the production process.

  In addition, this invention is not limited to the said embodiment. For example, another embodiment realized by arbitrarily combining the components described in this specification and excluding some of the components may be used as an embodiment of the present invention. In addition, the present invention includes modifications obtained by making various modifications conceivable by those skilled in the art without departing from the gist of the present invention, that is, the meaning described in the claims. It is.

  For example, like the sorting device 20 shown in FIG. 7, the heating means 10 may be a hot air heater. With the configuration in which the heating means 10 generates the hot air 15, the surface portion of the object can be melted. By setting the temperature of the hot air 15 to 170 ° C. or higher and setting the heating time for heating the object with the hot air to 5 seconds or longer, the filler can be deposited on the object surface. Specifically, by setting the heating temperature by the hot air 15 to 350 ° C. and setting the distance between the hot air outlet and the heat-resistant belt conveyor 11 to 30 mm, it is possible to melt the surface portion of the object and deposit the filler. It is. With the apparatus configuration of FIG. 7, the heating means can be reduced in size.

  According to the present invention, it becomes possible to sort an object made of plastic according to the presence or absence of filler content, which has been difficult in the past, and as a sorting method for recycling specific material species contained in waste home appliances and general waste It can be used widely.

  FIG. 8 is a diagram showing the absorption peak of talc filler.

In the figure, the horizontal axis represents the wave number of infrared rays, and the vertical axis represents the absorbance. The plastic used was Prime Polymer GFPP with 50% talc filler additive added. FIG. 8 shows the result of heating for 5 seconds by the heating means and the result of not heating. The peak of talc filler is detected at 1000 cm ⁻¹ and the absorbance is more remarkable than that of glass filler. Moreover, since the absorption peak of the talc filler is larger than that in the case where the surface of the plastic is not heated by heating, there is a similar tendency for a plastic-containing member containing a filler other than the glass filler. Therefore, it has been found that the method of depositing the filler by heating and melting the surface portion of the object is also effective for other fillers.

  According to the present invention, it has become possible to sort filler-containing plastic materials, which has been difficult in the past, and can be widely used as a sorting method for recycling specific material types contained in waste home appliances and general waste. is there.

  It can be used in recycling factories that recycle home appliances and cars for recycling.

DESCRIPTION OF SYMBOLS 1 Belt conveyor 2 Object group 3 Light source 4 Arithmetic device 5 Light receiving element 6 Extraction means 7 Partition plate 8 Vibration feeder 9 Heating heater part 10 Heating means 11 Heat-resistant belt conveyor 12 Material supply apparatus 13 Control apparatus 15 Hot air 16 Infrared light 17 Recovery Zone 20 Sorting device 21 Conveying means 22 Detection device

Claims (6)

A sorting method for sorting filler-containing plastic objects from a group of objects including a plurality of plastic objects,
A transport step of transporting an object by a transport means;
A heating step of heating the surface portion of the object to be conveyed by a heating means to a temperature equal to or higher than the melting point of the plastic constituting the object;
A detection step of detecting the absorbance of a specific wavelength in the infrared region on the surface of the object with a detection device;
When the absorbance is equal to or greater than a predetermined threshold, a determination step of determining that the object is a plastic object containing filler,
The extraction method includes a filler-containing plastic object determined in the determination step or an extraction step of extracting other objects from the object group. The sorting method according to claim 1, wherein, in the heating step, the surface portion of the object is prevented from exceeding a temperature of a melting point of the plastic constituting the object + 30 ° C. The sorting method according to claim 2, wherein in the heating step, the heating time of the object is selected from a range of 5 seconds to 60 seconds. The sorting method according to claim 2, wherein the plastic constituting the object is polypropylene having a melting point of 170 ° C. 2. The sorting method according to claim 1, wherein the specific wavelength detected by the detection device is in a range of 900 cm ⁻¹ or more and 1100 cm ⁻¹ or less in terms of wave number. A sorting device for sorting filler-containing plastic objects from a group of objects including a plurality of plastic objects,
Conveying means for conveying an object in a predetermined direction;
Heating means for heating the surface portion of the object to be conveyed to a temperature equal to or higher than the melting point of the plastic constituting the object;
A detection device for detecting the absorbance of a specific wavelength in the infrared region on the surface of the object;
When the absorbance is equal to or greater than a predetermined threshold, a determination unit that determines that the object is a plastic object containing filler,
A sorting apparatus comprising: a filler-containing plastic object determined by the determining means, or an extracting means for extracting other objects from the object group.