KR101366959B1 - Apparatus and method for distinguishing resins - Google Patents

Abstract

(Problem) Regardless of the presence or absence of additives such as carbon black and filler in the resin, a resin identification device and method with little misjudgment and high identification accuracy are obtained.
(Solution means) Infrared light analysis apparatus 30 and infrared light analysis which irradiate infrared light L1 to resin flake 1 on conveyor 20, detect intensity of infrared reflected light L2, and perform spectral analysis of infrared reflected light L2, and infrared light analysis The controller 40 which identifies the kind of resin flake 1 based on the spectrum analysis result of the apparatus 30 is provided. The infrared reflectance of the conveyor surface 20a is higher than the infrared reflectance of the resin flake 1, and the identification order of the controller 40 differs from the first resin which transmits a specific wavelength of the infrared light L1 and the second resin which does not transmit. .

Description

Resin identification device and method {APPARATUS AND METHOD FOR DISTINGUISHING RESINS}

TECHNICAL FIELD This invention relates to the recycling technique of resin. Specifically, It is related with the resin identification apparatus and method which analyze and identify recycled resin for every composition by an optical method.

In general, in the recycling of the resin in the waste home appliances, the part where the resin can be dismantled by hand is limited. For this reason, it is necessary to set it as a recycling material, after mechanically grinding | pulverizing and selecting a metal or resin etc. about a small component and a component of a complicated structure.

In this case, since it is required to separate each material from the state which grind | pulverized and mixed, high sorting technique is needed. Among them, metals can be selected by specific gravity or electric or magnetic force, but resins cannot be selected by electric or magnetic force. Therefore, a classification method based on specific gravity or electrostatic charge amount is proposed.

However, for similar types of resins, it is difficult to identify them by the above-described classification method. Therefore, an identification method that pays attention to differences in the wavelength (wavelength) dependence of the resin absorption or reflectance in the near-infrared or mid-infrared light is difficult. Proposed.

However, in the case of identifying black resin containing carbon black or the like, the absorption in the near-infrared is large, so that the required signal strength cannot be obtained, so that identification is difficult. Therefore, it is preferable to use the medium-infrared band which has little influence by carbon black absorption for identification of black resin.

As a method of identifying each crushed resin piece using a mid-infrared band, a sample is sequentially flowed by a conveyor, and is measured by a diffuse reflection method using a Fourier transform type infrared spectrophotometer from the top of the sample (infrared Spectroscopy) are known (see, for example, Patent Document 1 and Patent Document 2).

However, the said conventional resin identification apparatus method (apparatus) has the following subjects.

In other words, in order to confirm the resin identification using the mid-infrared, if the actual measurement results by the reflection method using the mid-infrared are analyzed for a plurality of resins, even if the same type of resin, the material that does not transmit infrared light (filler or carbon It was confirmed that the shape of the reflection spectrum was different between the resin (hereinafter referred to as "opaque resin") to which the black and the like was added and the resin (hereinafter referred to as "transparent resin") to which the material was not added. .

Specifically, in transparent resin, the peak of the spectrum derived from the spectrum inherent in the patent documents 1, 2, etc., or an additive, etc. (Hereafter, "a peak" includes the meaning of "a valley" other than "an acid". In addition to this, a new peak (hereinafter referred to as a "ghost peak") was recognized.

As a result of irradiation, the ghost peak is peculiar to a transparent resin (resin which does not contain additives such as carbon black or filler), and the peak shape is inherent for each type of resin (hereinafter, abbreviated as "resin species"). One proved to be.

In addition, as a result of further investigation, the ghost peak reflects the wave number by the infrared ray having a wave number having almost no absorption in the resin passing through the resin, being reflected at the sample stage, and again passing through the resin and entering the detector. It was found that the cause was that the strength became apparently strong. At this time, in the wave number slightly absorbed, since the reflection intensity decreases, the ghost peak becomes a complicated shape.

Moreover, when the resin used as a measurement sample contains the additive (carbon black etc.) which absorbs infrared light, since a infrared ray does not permeate the resin of a measurement sample, a ghost peak does not appear.

Such ghost peaks are not found in general measurements.

In the transmission type infrared absorption measurement which is generally performed, infrared light is transmitted through a sample having a thickness of about 10 μm and the absorption degree is measured. However, since the sample resin is thin, most infrared light is transmitted and inherent to the resin. Since only the strongly absorbed wavenumber of is absorbed, the ghost peak does not appear.

In the infrared reflection measurement of the thin film, infrared light is transmitted from a sample having a thickness of about 10 μm, and the degree of absorption of infrared light reflected from the reflective layer below the sample and transmitted again is measured. For the same reason as the infrared absorption measurement of the transmission type, the ghost peak does not appear.

In the infrared reflection measurement of a solid, the sample is irradiated with infrared light, and the wave dependence of the infrared light reflected from the sample outermost surface is measured. If no external light is detected and the sample is large, the infrared light transmitted through the sample is not detected in a direction different from that of the detector, so that no ghost peak appears.

However, if the thickness of the sample is about several millimeters or less, in addition to the infrared light reflected from the sample surface, the infrared light transmitted through the sample, reflected from the sample stage, and then transmitted through the sample again is detected by the detector. As a situation, a ghost peak appears.

As a result, since the peak used for resin identification (due to resin) is skewed by the said ghost peak, it turned out that resin identification may become difficult. More specifically, when the ghost peak shape of the resin is similar to the peak shape used for identification of other resins by chance (due to the resin species), the possibility of misidentification increases.

Particularly difficult to identify is when the PS (Polystyrene) resin and the ABS (Acrylonitrile-Butadiene-Styrene) resin are identified.

Although each infrared spectrum of PS resin and ABS resin is very similar, the point which differs significantly is the presence or absence of the peak (henceforth "CN peak") resulting from CN bond of 2200 cm <^-1> vicinity. That is, it can be identified that one having a CN peak is an ABS resin and one having a CN peak is a PS resin.

However, in the case of the transparent PS resin, the experiment showed that the ghost peak of the shape similar to a CN peak exists in the position of the CN peak shown by ABS resin, and it is easy to misidentify by the ghost peak.

(Prior art technical literature)

(Patent Literature)

(Patent Document 1) Japanese Unexamined Patent Publication No. 60-89732

(Patent Document 2) Japanese Unexamined Patent Application Publication No. 8-300354

The conventional resin identification apparatus and method had the subject that the peak for resin identification may be distorted by the ghost peak, and resin identification may become difficult.

In particular, since a ghost peak exists near the CN peak of the transparent PS resin, it is difficult to determine the presence or absence of a CN peak for distinguishing each infrared spectrum of the PS resin and the ABS resin, and there is a problem that the identification accuracy is lowered.

This invention is made | formed in order to solve the above subjects, and it aims at obtaining the resin identification apparatus and method with little misjudgment and high identification precision, regardless of the presence or absence of additives, such as carbon black and a filler in resin. do.

The resin identification device according to the present invention is an infrared light analysis device that sequentially irradiates a plurality of to-be-recognized resins on a sample stage and acquires a spectrum of each infrared reflected light, and infrared reflection from an infrared light analysis device. A resin identifying device having a controller for identifying a plurality of types of identified resins based on a spectrum, wherein the infrared light analyzing device identifies among the infrared rays irradiated to the identified resin based on the acquired spectrum of infrared reflected light. The presence or absence of infrared light in a specific wavelength region transmitted through the resin, reflected from the sample stage, and again transmitted through the identified resin is determined. The controller determines whether the infrared light is detected in the specific wavelength region by the infrared light analyzer. Therefore, at least a part of the wavelength region of the infrared reflection spectrum for identification uses a different identification algorithm to identify the type of the identified resin. It is.

According to the present invention, by changing the spectral analysis order for the to-be-identified resin to which the ghost peak is generated and to the to-be-identified resin which does not generate the ghost peak, the additives such as carbon black and filler in the to-be-recognized resin are changed. Regardless of the presence or absence of ghost peaks, it is possible to provide a resin identification device and method with less misjudgment and high identification accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the infrared reflection spectrum of the to-be-identified resin (transparence and opacity of PP resin board, PS resin board, and ABS resin board) in Embodiment 1 of this invention.
FIG. 2 is an explanatory diagram showing an enlarged vicinity of a peak due to CH coupling of the infrared reflection spectrum of FIG. 1.
It is explanatory drawing which shows the infrared reflection spectrum of to-be-identified resin (opaque PS resin board and opaque ABS resin board) in Embodiment 1 of this invention.
It is explanatory drawing which shows the infrared reflection spectrum of to-be-recognized resin (transparent PS resin board and transparent ABS resin board) in Embodiment 1 of this invention.
It is explanatory drawing which shows the infrared reflection spectrum of to-be-recognized resin (transparent PS resin flakes (three types) and transparent PS resin plate) in Embodiment 1 of this invention.
It is explanatory drawing which shows the infrared reflection spectrum of to-be-identified resin (transparent ABS resin flakes (3 types) and transparent PS resin plate) in Embodiment 1 of this invention.
7 is a configuration diagram showing a resin identification device according to Embodiment 1 of the present invention.
8 is a flowchart showing a resin identification method according to Embodiment 1 of the present invention.
9 is a flowchart showing another example of the resin identification method according to the first embodiment of the present invention.
It is explanatory drawing which shows the ghost peak of to-be-recognized resin (PE resin) in Embodiment 1 of this invention.

Embodiment Mode 1.

First, before demonstrating the resin identification apparatus and method which concern on Embodiment 1 of this invention, explanatory drawing of FIGS. 1-4 based on the analysis result of Experiment 1, FIG. 5 and based on the analysis result of Experiment 2 With reference to the explanatory drawing of FIG. 6, the basic technical idea and the ghost peak in Embodiment 1 of this invention are demonstrated in detail.

[Experiment 1]

BRIEF DESCRIPTION OF THE DRAWINGS It is explanatory drawing which shows the infrared reflection spectrum of the to-be-identified resin (transparence and opacity of PP resin board, PS resin board, and ABS resin board) in Embodiment 1 of this invention, and a horizontal axis shows wave number [cm <^-1>. ], The vertical axis represents the reflection intensity of the infrared light.

In addition, in FIG. 1, the reflection spectrum of an opaque resin is shown by the thin line, respectively, and the reflection spectrum of the transparent resin is shown by the thick line.

In addition, 1% of carbon black is added with "opaque resin" in FIG. 1, and carbon black, a filler, etc. are not added with "transparent resin."

In FIG. 1, the resin plate which controlled the presence or absence of each additive is used in order to acquire the reflection spectrum originating only in each resin type.

In addition, in resin flakes (flakes) that are actually to be identified, the peak shape of the reflection spectrum may be skewed or other peaks may appear due to the surface irregularities, the size, and the influence of additives.

Therefore, in Experiment 1, the basic function is confirmed first using the ideal resin plate which controlled the additive and the shape. After that, in Experiment 2 (to be described later), it is confirmed whether or not the same holds true for the actual resin flakes.

In the identification of the actual resin flakes, the infrared reflection spectrum of the resin flakes is compared with the ideal infrared reflection spectrum (resin plate spectrum) of each resin.

As a specific measuring device in Experiment 1, FT-IR5500 made by Nippon Electronics was used, for example, and an MCT (HgCdTe) detector was used as an infrared light detector. In addition, as measurement conditions, it integrated 10 times with the resolution of 4 cm <^-1> , As the optical system, the baseball for reflection measurement was used, and both the incident angle and the reflection angle were 10 degrees. In addition, stainless steel was used as a sample stand.

As shown in FIG. 1, the infrared reflection spectra of the transparent and opaque PP resin plates, PS resin plates, and ABS resin plates were all attributable to CH bonding at a wavenumber of 3000 cm ⁻¹ and 1500 cm ⁻¹ . A plurality of CH peaks CHp1, CHp2 are recognized.

Also, 2400㎝ ^-1 vicinity of the absorption peak attributable to the CO ₂ in the atmosphere to P3, 1300 ~ 1800㎝ ^-1, a small peak due to water in the atmosphere at 3500 ~ 4000㎝ ^-1 P4, P5 is recognized both.

FIG. 2 is an explanatory view showing an enlarged vicinity of CH peak CHp1 (3000 cm ⁻¹ ) in FIG. 1.

As is apparent from FIG. 2, in all of the PP resin plate, the PS resin plate and the ABS resin plate, the peaks around 3000 cm ⁻¹ are the same in transparency and opacity. Also, the reflection spectra near the CH peak CHp1 (3000 cm ⁻¹ ) of the PS resin plate and the ABS resin plate are very similar.

Therefore, it can be seen from the peak shape around 3000 cm ^-1 that it can be identified whether it is PP resin, PS resin or ABS resin.

1, the remarkable difference between the infrared reflection spectra of the PS resin plate and the ABS resin plate is the presence or absence of the CN peak CNp due to the CN bond appearing at around 2200 cm ^-1 .

FIG. 3 is an explanatory view showing an enlarged vicinity of the CN peak CNp of 2200 cm ^-1 in FIG. 1, and shows infrared reflection spectra of the opaque PS resin plate and the opaque ABS resin plate.

In FIG. 3, the CN peak is not recognized in the infrared reflection spectrum of the opaque PS resin plate, whereas the CN peak CNp is recognized in the infrared reflection spectrum of the opaque ABS resin plate.

FIG. 4 is an explanatory view showing an enlarged vicinity of the CN peak CNp as shown in FIG. 3, and shows infrared reflection spectra of the transparent PS resin plate and the transparent ABS resin plate.

Also in FIG. 4, CN peak CNp is recognized by the infrared reflection spectrum of a transparent ABS resin board.

In this case, however, also in the infrared reflection spectrum of the transparent PS resin plate, a shoulder (refer to the dashed-dotted line range) that is not originally generated is recognized in the vicinity of the wave number (2200 cm ⁻¹ ) where the CN bonds appear. In particular, when the to-be-recognized resin is resin flakes, since the variation of the baseline is often large, there is a possibility that the shoulder is misjudged as a CN peak.

Therefore, as a result of Experiment 1, it became clear that the problem that the identification precision of a transparent PS resin and a transparent ABS resin falls due to the shoulder in FIG.

The shoulder means a shape (rounded shoulder line) that does not have the tip shape as clearly as the CN peak CNp, but has the inflection point clearly.

[Experiment 2]

FIG. 5 is an explanatory diagram showing an infrared reflection spectrum of the to-be-identified resin in Embodiment 1 of the present invention, examples of the infrared reflection spectrum of the transparent PS resin flakes (3 types), and the infrared reflection spectrum of the transparent PS resin plate Indicates.

5, a transparent infrared reflection spectrum of the PS resin flakes (see the thin line), the degree to which the three kinds, 3500㎝ ^-1 at 2000㎝ ^-1 and near infrared reflection spectrum of the transparent resin plate PS (bold And ghost peaks Gp1 and Gp2 having the same shape as each other.

In addition, it turns out that the peak intensity of each ghost peak Gp1 and Gp2 is larger than the intensity of CH peak CHp1 of 3000 cm <^-1> vicinity.

FIG. 6 is an explanatory diagram showing an infrared reflection spectrum of the to-be-identified resin in Embodiment 1 of the present invention, examples of the infrared reflection spectrum of the transparent ABS resin flakes (three types), and the infrared reflection spectrum of the transparent ABS resin plate Indicates.

In FIG. 6, the infrared reflection spectrum (see thin line) of the transparent ABS resin flake is also the same as the infrared reflection spectrum (see bold line) of the transparent ABS resin plate in the vicinity of 2000 cm ⁻¹ as shown in FIG. 5. The ghost peak Gp2 of shape is recognized.

Also, in Figure 6, is, 3000㎝ ^-1 vicinity of the CH peak CHp1 or, 2200㎝ ^-1 vicinity of the peak CNp CN (because too small, make the scale of the vertical axis of Fig difficult) the peak intensity of the ghost peak Gp2 It can be seen that greater than the strength of.

As apparent from FIG. 5 and FIG. 6, the results of Experiment 2 showed that the shapes of the ghost peaks of the transparent PS resin flakes and the transparent ABS resin flakes were the same as those of the peaks of the transparent PS resin plate and the transparent ABS resin plate. .

From the above, the PS and ABS can be distinguished from the transparent PS resin flakes and the transparent ABS resin flakes based on the peak shape of the ghost peak.

As the measuring device in Experiment 2 (FIGS. 5 and 6), as in Experiment 1 described above (FIGS. 1 to 4), for example, FT-IR5500 manufactured by Japan Electronics was used, and as an infrared light detector, MCT (HgCdTe) The detector was used.

In addition, the baseball for reflection measurement was used as an optical system, and both the incidence angle and the reflection angle were 10 degrees. In addition, stainless steel (semi-gloss) was used as a sample stand.

In this case, even if a semi-gloss rolled aluminum plate (material A5052) is used instead of the stainless steel sample stage, it has been confirmed that almost the same infrared reflection spectrum can be obtained including the ghost peak.

It is also confirmed that a stronger ghost peak can be obtained by changing the sample stage to an aluminum mirror. On the contrary, when a material with a low infrared reflectance (for example, alumina) is used as the sample stage, it is confirmed that the ghost peak is reduced.

From the above, the infrared light having a specific wave rate that can pass through the transparent resin plate (or transparent resin flake) is transmitted through the transparent resin plate (or transparent resin flake), is reflected from the surface of the sample stage, and is again transparent resin plate (or And transparent resin flakes) and captured by a detector, it can be seen that they are detected as ghost peaks Gp1 and Gp2.

Therefore, the shapes of the ghost peaks Gp1 and Gp2 are considered to be unique to the resin species, and it is clear that the resin species can be identified using the ghost peaks Gp1 and Gp2.

Hereinafter, the resin identification apparatus which concerns on Embodiment 1 of this invention is demonstrated, referring FIG. 7, after considering the result of the experiment 1, 2 mentioned above.

7 is a configuration diagram schematically showing an entire resin identification device according to Embodiment 1 of the present invention.

In FIG. 7, the resin identification apparatus is the supply apparatus 10 which supplies the resin flake 1 (identified resin) like a broken arrow, and the conveyor 20 which conveys the resin flake 1 like a dashed-dotted arrow. ) And the type of the resin flakes 1 based on the analysis results of the infrared light analyzer 30 for irradiating infrared light L1 to the resin flakes 1 on the conveyor 20 and the infrared light analyzer 30. The controller 40 is identified.

Here, a Fourier transform type infrared spectrometer (FT-IR) is used as an infrared light analyzer. In addition, although illustration is abbreviate | omitted in FIG. 7, the infrared light analysis apparatus 30 is equipped with the emission part which emits infrared light L1, and the light receiving part (detector) which receives infrared reflection light L2 from the resin flake 1. . Moreover, the surface 20a of the conveyor 20 which mounts the resin flake 1 functions as a sample stand.

First, the supply apparatus 10 supplies the some resin flake 1 (identified resin) on the conveyor 20 sequentially.

At this time, the supply of the resin flakes 1 onto the conveyor 20 is performed so that the individual resin flakes 1 line up in a straight line with a predetermined gap without overlapping each other. The adjacent resin flakes 1 may be spaced apart from each other, and the intervals may not be constant.

The conveyor 20 conveys the resin flakes 1 to just under the infrared light analyzing apparatus 30, and the infrared light analyzing apparatus 30 irradiates the infrared rays L1 to the resin flakes 1, and the infrared reflected light The spectrum is acquired by analyzing the intensity of L2.

Finally, the controller 40 compares the spectrum of the infrared reflection light acquired by the infrared light analysis device 30 with the standard spectrum of the infrared reflection light L2 of each resin type previously obtained, thereby obtaining the resin flakes 1. The resin species of are determined.

In addition, although not specifically shown here, based on the identification result by the controller 40, air is blown out and resin flakes 1 other than a target species are excluded from the track | orbit of the conveyor 20, and resin It is also possible to screen.

In addition, when confirming the mixing ratio of resin based on the determination result of the controller 40, only the basic structure shown in FIG. 7 is enough. For example, 1000 resin flakes 1 can be extracted from a population, and the mixing ratio can be investigated.

That is, when the resin flakes 1 (resin flake group) which classified resin species are made into a population, the purity (number of resin flakes 1 which becomes an impurity) can be known.

In addition, if the resin flakes 1 (resin flake group) mixed after crushing are used as a population, the mixing ratio for each resin species can be known, and the optimization of subsequent classification process conditions and the amount of each resin species of the final product can be determined. You can know in advance.

In Embodiment 1 of this invention, the conveyor surface 20a corresponded to a sample stand is a material (specifically, metals, such as stainless steel and aluminum) with a high reflectance of the infrared light of wave number with a ghost peak. . Here, "high reflectance" means higher than the reflectance of the resin flake 1 which is an identification object.

This makes it possible to amplify and detect the intensity of the ghost peak.

Next, the spectral analysis procedure (resin identification method) of the resin identification device which concerns on Embodiment 1 of this invention shown in FIG. 7 is demonstrated, referring FIG.

8 is a flowchart showing a resin identification method according to Embodiment 1 of the present invention, wherein the spectrum analysis by the controller 40 for identifying the resin species from the infrared reflection spectrum of the resin flake 1 (identified resin) The order is shown.

In FIG. 8, when three types of resin flakes of PP resin, PS resin, and ABS resin are mixed as a specific example, the case where resin species is determined based on the infrared reflection spectrum of each resin flake 1 is shown. It is shown.

In this case, as described above, in the transparent or opaque PP resin, the transparent or opaque PS resin, and the transparent or opaque ABS resin, the CH peak CHp1 due to CH appears in the vicinity of the wave number 2700 to 3000 cm ⁻¹ , and is transparent or opaque. In the ABS resin, the CN peak CNp attributable to CN appears near the wave number 2200 cm ^-1 .

Further, the wave number 3200 ~ 3700㎝ in the vicinity of ^-1, the ghost peak Gp1 by the transparent resin PS appears, wave number 1700 ~ 2200㎝ in the vicinity of ^-1, the ghost caused by the transparent resin PP, PS transparent resin and a transparent ABS resin peak Gp2 appears.

In FIG. 8, the controller 40 first determines the presence or absence of a ghost peak Gp2 (near 2000 cm ⁻¹ ) in the infrared reflection spectrum from the resin flake 1 (identified resin) (step S1). If it is determined that there is no peak Gp2 (that is, the resin flakes 1 are opaque), then the CH peak CHp1 (near 2700 to 3000 cm ⁻¹ ) is compared (step S6).

On the other hand, when it is determined in step S1 that there is a ghost peak Gp2 (the resin flake 1 is transparent), first, the shape of the ghost peak Gp2 is determined by the standard spectrum of the transparent PP resin (for example, the transparent PP resin in FIG. 1). Compared with the spectrum of the plate), and compared with the standard PS or standard ABS (standard spectrum of the transparent PS resin or the transparent PPABS resin), the similarity of both is determined (step S2).

In step S2, if the ghost peak Gp2 matches the standard PP (standard spectrum of the transparent PP resin), the resin flake 1 is determined to be a transparent PP resin (step S11).

In addition, if it is determined that the ghost peak Gp2 matches the standard PS or standard ABS (standard spectrum of the transparent PS resin or the transparent ABS resin), then the ghost peak Gp1 (near 3500 cm ^-1 ) is compared (step S3).

In step S3, the shape of the ghost peak Gp1 is defined by the standard spectrum of the transparent PS resin (eg, the spectrum of the transparent PS resin plate in FIG. 1) and the standard spectrum of the transparent ABS resin (eg, the spectrum of the transparent ABS resin plate in FIG. 1). ), And if the ghost peak Gp1 matches the standard PS, it is determined as PS (step S4).

If the ghost peak Gp1 matches the standard ABS, it is determined as ABS (step S5).

That is, as described above, since the standard spectral shapes of the ghost peak Gp2 of the transparent PS resin and the transparent ABS resin are similar to each other, the controller 40, in step S2, the infrared reflectance spectrum from the resin flake 1, It is divided into the case where it matches with a transparent PP resin, and when it matches with a transparent PS resin or a transparent ABS resin, In addition, in step 3, the infrared reflection spectrum from the resin flake 1 matches with a transparent PS resin, or is transparent It is determined whether it matches with ABS resin.

In the comparison of similarity, the values of covariance within the range of the ghost peak Gp2 are determined for the infrared reflection spectrum of the resin flake 1 and the respective standard infrared reflection spectra, and the similarity of the peaks is obtained from the magnitude of each value. The method of quantification and comparison is applied.

At this time, an appropriate threshold value may be provided, and the case where the most similar one among the threshold values is exceeded may be considered to be a match, and all cases below the threshold value may be regarded as "no ghost peak Gp2". In addition, the method of quantifying the similarity is not limited to covariance, and a standard deviation may be used.

As a specific classification method, it can be determined in step S1 that the covariance with the standard spectrum of the transparent PP coincides with the transparent PP when a certain threshold is exceeded.

In addition, when the covariance with the standard spectrum of transparent PS or transparent PS exceeds a certain threshold, it can be determined that it matches with PS resin or ABS resin.

When the ghost peak Gp2 of the infrared reflection spectrum from the resin flake 1 matches with a standard PP resin, it is determined as a PP resin (step S11).

If the ghost peak Gp2 matches the standard PS resin or the standard ABS resin, the process proceeds to step S3 and, with respect to the ghost peak Gp1, the covariance with the standard spectrum of the transparent PS resin and the standard spectrum of the transparent ABS resin Covariance is calculated | required, and the comparison of the value of these covariances determines that the more similar one is the resin species.

That is, in step S3, when the controller 40 matches the standard PS with respect to the ghost peak Gp1 (near 3500 cm ^-1 ) in the infrared reflection spectrum of the resin flake 1, the resin flake 1 is PS resin. (Step S4), and when it matches with standard ABS, it determines with the resin flake 1 being ABS resin (step S5).

In step S1, when the determination result about the ghost peak Gp2 (near 2000 cm <^-1> ) does not correspond with any of PP resin, PS resin, or ABS resin (resin flake 1 is opaque), step S6 Next, the similarity with the PP resin, PS resin, or ABS resin is compared with respect to CH peak CHp1 (near 2700-3000 cm <^-1> ) in the infrared reflection spectrum of the resin flake (1).

In step S6, when it is determined that the CH peak CHp1 of the resin flake 1 matches the standard PP resin, it is determined that the resin flake 1 is a PP resin (step S7).

In addition, when it is determined in step S6 that the CH peak CHp1 of the resin flakes 1 matches the standard PS resin or the standard ABS resin, the CN peak CNp (near 2200 cm ^-1 ) is then compared ( Step S8).

In step S8, the controller 40 compares the CN peak CNp of the resin flake 1 with the similarity between the standard PS resin and the standard ABS resin, and the more similar resin is the resin species of the resin flake 1. Determine.

That is, in step S8, when it is determined that the CN peak CNp of the resin flake 1 matches the standard PS, it is determined that the resin flake 1 is PS resin (step S9), and when it matches the standard ABS, the resin flakes ( It is determined that 1) is an ABS resin (step S10).

As a result, even when the resin flake 1 is transparent or opaque, the determination of the presence or absence of ghost peak Gp2 (near 2000 cm ^-1 ) (step S1) and the ghost peak Gp1 (near 3500 cm ^-1 ) (step The resin species of the resin flakes 1 were obtained by comparing S3) with the CH peak CHp1 (near 3000 cm ^-1 ) (step S6) and the CN peak CNp (near 2200 cm ^-1 ) (step S8). Precise identification

In addition, the processing routine shown in FIG. 8 is only an example of the spectrum analysis procedure (resin identification method) of the resin identification apparatus which concerns on Embodiment 1 of this invention, even if it applies PP, for example, the processing routine shown in FIG. Resin, PS resin and ABS resin can be identified.

In FIG. 9, the same code | symbol as the above-mentioned is attached about the process similar to the above-mentioned (refer FIG. 8).

In FIG. 9, first, the infrared reflection spectrum of the resin flake 1 is compared with the infrared reflection standard spectrum of PP resin, PS resin, and ABS resin with respect to CH peak CHp1 (near 3000 cm <^-1> ) (step S6). In the case of matching with the standard PP resin, it is determined that the resin flake 1 is the PP resin (step S7).

On the other hand, in step S6, when the infrared reflection spectrum of the resin flake 1 at the CH peak CHp1 matches the standard PS resin or the standard ABS resin, next, the presence or absence of ghost peak Gp2 (near 2000 cm ^-1 ) Is determined based on the similarity with the ghost peak Gp2 (step S1).

In step S1, when it is determined that there is a ghost peak Gp2 (the resin flake 1 is transparent), a comparison judgment is then made based on the similarity of the ghost peak Gp1 (near 3500 cm ^-1 ) (step S3).

In step S3, if the ghost peak Gp1 in the infrared reflection spectrum of the resin flake 1 matches the standard PS resin, it is determined that the resin flake 1 is PS resin (step S4), and if it matches the standard ABS, the resin flakes It is determined that (1) is ABS resin (step S5).

On the other hand, in step S1, when it is determined that the infrared reflection spectrum of the resin flake 1 does not have a ghost peak Gp2 (the resin flake 1 is opaque), then the CN peak CNp (near 2200 cm ^-1 ) A comparison judgment is made based on the similarity (step S8).

That is, if the CN peak CNp in the infrared reflection spectrum of the resin flake 1 matches the standard PS resin, it is determined that the resin flake 1 is the PS resin (step S9), and if it matches the standard ABS, the resin flake 1 It is determined that is ABS resin (step S10).

Thereby, as above-mentioned, based on the similarity with a standard resin spectrum, it can pinpoint whether the resin flake 1 is PS resin or ABS resin.

In addition, the identification procedure by Embodiment 1 of this invention is not limited to the processing routine of FIG. 8 or FIG. 9, In addition to the comparison determination by the said wave number, in order to improve the identification precision of resin species, another wave number is added. It may be included to determine the similarity between the infrared reflection spectrum and the standard resin.

In addition, although the case where resin flake 1 (identification resin) is three types of PP resin, PS resin, or ABS resin was demonstrated, it is not limited to these and needless to say that it is applicable also to identification of other resin types.

The purpose of the present invention is to determine the transparency or opacity of the to-be-recognized resin using the ghost peak Gp2 (near 2000 cm ^-1 ) in the resin identification step, and in each case, an optimal identification method (similarity determination processing). It is to include the process of applying).

In addition, it is not limited to Gp2, It uses the ghost peak to determine the transparency or opacity of to-be-recognized resin, and includes the process which applied the optimal identification method (similarity determination process) in each case.

For example, the generation of ghost peaks in the transparent resin is not limited to PP resins, PS resins, and ABS resins, but may include transparent PE (polyethylene: polyethylene) resins, transparent PC (polycarbonate: Polycarbonate) resins, and many other types of ghost peaks. It is confirmed by resin.

It is explanatory drawing which shows the reflection intensity characteristic in the case of PE resin, The thick line characteristic shows the reflection spectrum of opaque PE resin, and the thin line characteristic shows the reflection spectrum of transparent PS resin.

In FIG. 10, a remarkable ghost peak is generated in the reflection spectrum of the transparent PS resin in the vicinity of 2000 cm ⁻¹ .

Thus, even when the to-be-recognized resin contains transparent resin or opaque resin as PE resin, and the ghost peak shown in FIG. 10 generate | occur | produces, as mentioned above, the identification procedure in an appropriate wave number is set, and a standard resin By applying the similarity comparison process with, the resin species can be identified.

Regarding the resin identification using the ghost peak, as in the above-described experiments, the effect was confirmed using a stainless steel sample stand, and even if a rolled aluminum alloy (A5052) was used for the sample stand, almost equivalent effects could be obtained. I am checking.

In addition, when using what deposits aluminum on mirror glass as a sample stand, the ghost peak which appears in the reflection spectrum of the transparent resin flake 1 is emphasized more.

As another specific example, a method of attaching a narrow metal plate to the surface 20a of the conveyor 20 in FIG. 7 in the advancing direction (a dashed-dotted arrow), a method of using a metal mesh as a material of the conveyor 20, or the like may be used. have.

In addition, although the conveyor 20 which flows in one direction (a dashed-dotted arrow) is shown as an example in FIG. 7, you may use the metal disc (not shown) which rotates around the central axis instead of the conveyor 20. As shown in FIG. .

In this case, the difference from FIG. 7 is that the metal disc has only a transverse rotation structure as compared with the longitudinal rotation structure in which the conveyor 20 rotates the axes of both ends. However, in the case of the metal original plate, since the rounded resin flakes 1 are repeatedly returned, it is necessary to remove all the resin flakes by air blow or the like when the identification of the resin flakes 1 is completed.

As mentioned above, the resin identification apparatus which concerns on Embodiment 1 (FIG. 7) of this invention irradiates infrared light L1 to the some resin flakes 1 (identification resin) on the conveyor surface 20a (sample stage). On the basis of the spectral analysis results from the infrared light analysis device 30 and the infrared light analysis device 30 which detect the intensity of the infrared reflected light L2 from the plurality of resin flakes 1 and perform spectral analysis of the infrared reflected light. The controller 40 which identifies the kind of the some resin flakes 1 is provided.

Resin identification procedure (FIG. 8, 9) in the controller 40 is a 1st resin which permeate | transmits infrared light of a specific wavelength, although the some resin flakes 1 are the same kind mutually, In the case of including both of the second resins that do not transmit infrared light having a specific wavelength, the identification order of the first resin and the identification order of the second resin are different from each other.

The conveyor surface 20a (sample stage) is made of stainless steel or aluminum alloy so that the infrared reflectance of the surface becomes higher than the infrared reflectance of the resin flake 1.

The controller 40 identifies the type of the to-be-identified resin based on the spectrum analysis result from the infrared light analyzing apparatus 30.

In the resin identification method according to Embodiment 1 (FIGS. 7 to 9) of the present invention, the plurality of resin flakes 1 on the conveyor surface 20a are irradiated with infrared light L1, and the plurality of resin flakes 1 are separated from the plurality of resin flakes 1. As a resin identification method for identifying the types of the plurality of resin flakes 1 by detecting the intensity of the infrared reflected light L2 and performing the spectral analysis of the reflected light, the plurality of resin flakes 1 are of the same kind. Nevertheless, in the case of including both the first resin that transmits infrared light of a specific wavelength and the second resin that does not transmit infrared light of a specific wavelength, the identification sequence of the first resin and the identification sequence of the second resin Are different.

The identification procedure (FIGS. 8 and 9) of the 1st and 2nd resin is a ghost peak determination step of determining the presence or absence of the ghost peak Gp2 based on the infrared reflection spectrum of the resin flake 1 contained in the spectrum analysis result ( Step S1) is provided.

The identification sequence of the first resin identifies the type of the resin flake 1 based on the inherent peak (CN peak CNp) of the first resin when it is determined in step S1 that there is no ghost peak Gp2 in the infrared reflection spectrum. And a first identification step (step S8).

In addition, "a peak inherent in resin" means the peak inherent to the resin species recognized in the spectrum of infrared reflection light L2, with or without additives, such as carbon black and filler, and also includes the ghost peak here I never do that.

In addition, the identification order of 2nd resin is a 2nd identification step of identifying the kind of resin flake 1 using another ghost peak Gp1, when it is determined by step S1 that ghost peak Gp2 exists in an infrared reflection spectrum. (Step S3) is provided.

The ghost peak Gp2 corresponds to a region near the wave number 2000 cm ^-1 of the infrared reflection spectrum, and the other ghost peak Gp1 corresponds to a region near the wave number 3500 cm ^-1 of the infrared reflection spectrum.

In this way, the transparency or opacity of the resin flakes 1 is determined based on the presence or absence of ghost peaks in the infrared reflection spectrum of the resin flakes 1, and the optimal identification sequence is determined for each of the transparent or opaque determination results. Use (Algorithm).

That is, when there is no ghost peak Gp2, resin species are identified by peaks inherent to the resin, and when there is ghost peak Gp2, at least ghost peak Gp1 is used to identify resin species to avoid misjudgment. The identification accuracy can be improved.

Therefore, according to Embodiment 1 of this invention, in the to-be-identified resin by changing spectral analysis procedures, respectively, with respect to the to-be-identified resin which ghost peak Gp2 generate | occur | produces, and the to-be-identified resin which does not generate ghost peak Gp2, respectively. Regardless of the presence or absence of additives such as carbon black and filler (with or without ghost peaks), a resin identification device and method with less misjudgment and high identification accuracy can be provided.

1: Resin Flake (Identified Resin)
10: feeder
20: Conveyor
20a: Conveyor surface (sample stage)
30: infrared light analysis device
40: controller
CHp1: CH peak
CNp: CN peak
Gp1: Another Ghost Peak
Gp2: Ghost Peak
L1: infrared light
L2: infrared reflected light
S1: ghost peak determination step
S3: second identification step
S8: first identification step

Claims (7)

An infrared light analyzing apparatus for irradiating infrared light sequentially on a plurality of to-be-identified resins on a sample stage and acquiring a spectrum of each infrared reflected light;
A controller for identifying the types of the plurality of identified resins based on the infrared reflection spectrum from the infrared light analyzing apparatus.
A resin identification device having a
The infrared light analyzing apparatus transmits the specific resin out of the infrared light irradiated to the identified resin on the basis of the acquired infrared reflected light spectrum, reflects at the sample stage, and passes through the identified resin again. Determine the presence or absence of infrared light in the area,
The controller identifies the identified resin by using an identification algorithm in which at least a part of the wavelength region of the infrared reflection spectrum for identification differs according to a determination result of the presence or absence of infrared light in the specific wavelength region by the infrared light analyzing apparatus. To identify the type of
Resin identification device, characterized in that.
The method of claim 1,
When the infrared light analyzing apparatus determines that there is infrared light in the specific wavelength region and infrared light in the specific wavelength region that has passed through the identified resin, reflected from the sample stage, and has passed through the identified resin again. The wavelength for identification used when it is determined that there is no infrared light in the wavelength region for identification to be used, and the infrared light for the specific wavelength region that has passed through the identified resin and has been reflected by the sample bed and has passed through the identified resin again. The infrared light of an area | region is irradiated to the said some to-be-recognized resin, The resin identification apparatus characterized by the above-mentioned.
3. The method according to claim 1 or 2,
The infrared reflectance of the said sample stand is higher than the infrared reflectance of the said to-be-identified resin, The resin identification apparatus characterized by the above-mentioned.
The method of claim 3, wherein
The surface of the said sample stand consists of stainless steel or an aluminum alloy, Resin identification apparatus characterized by the above-mentioned.
As a resin identification method of irradiating infrared light to the plurality of identified resins on the sample stage sequentially and identifying the types of the plurality of identified resins based on the spectrum of each infrared reflected light,
And a determination step of determining the presence or absence of a peak of an infrared light spectrum in a specific wavelength region that has passed through the identified resin, reflected from the sample stage, and has passed through the identified resin again.
According to the determination result of the presence or absence of the peak by the determination step, all or part of the wavelength region of the infrared light spectrum for identification is used to identify the type of the identified resin by using different identification algorithms.
Resin identification method, characterized in that.
The method of claim 5, wherein
The infrared light for identification irradiated to the plurality of identified resins is a product of the specific wavelength region and the specific wavelength region that has passed through the identified resin, is reflected at the sample stage, and is again transmitted through the identified resin. Identification used when it is determined that there is no infrared light in the wavelength region for identification to be used when it is determined to be outside light and the specific wavelength region which has passed through the identified resin, reflected from the sample stage, and then passed through the identified resin again. It has a wavelength range of the dragon, The resin identification method characterized by the above-mentioned.
The method of claim 5, wherein
The identification resin includes at least ABS resin or PS resin,
The specific wavelength region includes at least a part of the region having a frequency of 2000-2300 cm ^-1 to identify ABS and PS,
At least a part of a wave number of 3200 to 3600 cm ^-1 when it is determined that there is infrared light that has passed through the identified resin in the specific wavelength region, is reflected from the sample stage, and has passed through the identified resin again. To identify the infrared reflection spectrum shape of the said to-be-recognized resin by comparing with the standard spectrum shape of PS or ABS prepared previously
Resin identification method, characterized in that.

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