JP2002139434A - Device and method for discriminating waste resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device and method for discriminating waste resin by which a waste resin can be discriminate with accuracy. SOLUTION: A reflection type spectroscope 8 using a medium infrared ray and a contact detecting means which detects the contact pressure of the waste resin 7 with a crystal 9 which is the measuring member of the spectroscope 8 are arranged in the waste resin discriminating device and the waste resin 7 is brought into contact with the crystal 9. The device starts measurement when the contact pressure is coincident with a prescribed value. Consequently, it becomes possible to obtain a measuring spectrum with high reproducibility without crushing the resin 7 having the shape of parts, etc., and the type of the resin 7 can be discriminated accurately without relying upon the skillfulness of workers.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for identifying waste resin.

[0002]

2. Description of the Related Art Resins are frequently used in electric appliances such as air conditioners, televisions, refrigerators, and washing machines because of their flexibility in shape and design. When these products are discarded, the resin has been disposed of by landfilling or incineration, but since it becomes a source of environmental pollution, in recent years, efforts have been made to identify the types thereof, separate them, and recycle them. Various techniques, such as a fluorescent X-ray method, a near-infrared absorption method, and a thermal decomposition analysis method, are conventionally known as this type of waste resin identification technology. Further, Japanese Patent Application Laid-Open No. 11-23500 discloses a method for separating a resin using a nuclear magnetic resonance absorption method.
000-108126A) discloses a classification method using a near-infrared identification device.

[0003]

However, in the above-mentioned prior art, a system could not be constructed due to reasons such as insufficient identification and an expensive device. For example, in the fluorescent X-ray method, the sensitivity of X-rays to light elements frequently used in resins is poor, and the apparatus is expensive. In the near-infrared absorption method, near-infrared rays are absorbed by a resin colored in black, and measurement is impossible.

An object of the present invention is to solve the above-mentioned problem and to provide an identification device and a method capable of accurately identifying a waste resin.

[0005]

According to the present invention, in order to solve the above-mentioned problems, the present invention relates to a method of guiding mid-infrared light to waste resin, which is provided in contact with a measuring member, through the measuring member. A total reflection type spectroscope for detecting reflected light totally reflected on the contact surface; a contact pressure measuring means arranged in the same plane as the measuring member for measuring a contact pressure of the waste resin with respect to the measuring member; An identification unit for comparing the spectrum pattern obtained from the reflected light detected by the type spectrometer with the spectrum patterns of various resins stored in advance and detecting a matching spectrum pattern to specify the waste resin, and measuring the contact pressure. A waste resin identification apparatus characterized in that detection of reflected light is started by the total reflection spectrometer when the contact pressure measured by the means matches a predetermined value.

According to this configuration, since a total reflection type spectrometer using mid-infrared light is used, it is not necessary to crush waste resin in the form of parts and the like, and the measurement can be performed with a constant contact pressure. As a result, the measured spectrum can be obtained with good reproducibility, and the type of waste resin can be accurately identified without depending on the skill of the operator.

Here, the mid-infrared light has a wavelength of 2.5 to 25 μm.
(Wave number 4000 to 400 cm ^-1 ). Since the light in this region has an absorption spectrum in the vibrational state of the molecular bond of the resin, the light has a more specific spectrum shape depending on the resin. Therefore, by using the mid-infrared light, a spectrum unique to the resin can be obtained, and the resin can be easily identified.

According to a second aspect of the present invention, in the waste resin identifying apparatus according to the first aspect, the contact pressure measuring means is a pressure-sensitive switch arranged near the measuring member.

According to this configuration, the total reflection type spectroscope can be automatically and easily operated when the contact pressure matches the predetermined value. According to a third aspect of the present invention, in the waste resin identification device according to the second aspect, the pressure-sensitive switch is formed of conductive rubber.

According to a fourth aspect of the present invention, there is provided an apparatus for identifying a waste resin according to any one of the first to third aspects,
A cleaning means for cleaning the contact surfaces of the waste resin and the measuring member is provided.

According to this configuration, by removing dirt by washing, noise at the time of detecting reflected light can be prevented, and identification accuracy can be improved. According to a fifth aspect of the present invention, in the waste resin identifying apparatus according to any one of the first to fourth aspects, a display unit for displaying a result of identifying the waste resin is provided.

According to this configuration, the operator can confirm that the identification is performed smoothly. It is desirable that the display method be such that it can be easily recognized, for example, by changing the color, shading, blinking time and number of times depending on the type of waste resin and whether recycling is possible or not.

According to a sixth aspect of the present invention, there is provided a method for identifying a waste resin, the method comprising the step of contacting and installing the waste resin with a measuring member of a total reflection type spectroscope using mid-infrared light. The contact surface of the waste resin in a state where the contact pressure of the waste resin placed in contact with the measurement member is measured through contact pressure measurement means disposed in the same plane as the measurement member and a predetermined contact pressure is measured. In the measuring step of detecting the reflected light totally reflected in the, the spectral pattern obtained from the reflected light detected in the measuring step is compared with the spectral pattern of various resins stored in advance to detect a matching spectral pattern and detect the waste resin And an identification step of specifying

According to a seventh aspect of the present invention, in the method for identifying a waste resin according to the sixth aspect, a separation step of separating the waste resin specified in the identification step into storage containers according to the type is performed. And This sorting step may be automatically performed by the control unit based on the specified result, or may be manually performed by an operator.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram illustrating a schematic configuration of a waste resin identification device according to an embodiment of the present invention. This waste resin identification device includes a cleaning unit 1, a measurement unit 2, an identification unit 3, and a classification unit 4.

The cleaning section 1 has a cleaning tool 6 which can enter the opening 5a of the stage 5 from below.
Thereby, the measurement surface of the waste resin 7 moved along the upper surface of the stage 5 is cleaned.

The measuring section 2 has a total reflection type spectroscope 8 and a contact detecting means 10 for detecting contact of the sample with a crystal 9 provided therein. The total reflection spectroscope 8 includes a light source unit 11 for irradiating mid-infrared light, and a total reflection for guiding the mid-infrared light from the light source unit 11 to the sample and guiding the mid-infrared light reflected on the sample surface to the detector 12. And a measurement attachment 13.

The total reflection measurement attachment 13 is of a single reflection horizontal ATR (Attenuated Total Reflection) type, and the upper part of the crystal 9 faces the opening 14 a of the casing 14. The sample is brought into contact with the crystal 9 horizontally from above, and the sample is totally reflected once.

The crystal 9 is an internal reflection element having a shape suitable for one-time reflection, and can be used without particular limitation as long as it is made of a material that transmits mid-infrared light and has a higher refractive index than the sample. The surface of the crystal 9 is mirror-finished so that light is not dispersed by total reflection, and the mid-infrared light is condensed by a total reflection measurement attachment 13 as a lens, and once at the interface between the crystal 9 and the sample. Internal reflection detector 12
Reach Since the refractive index of the waste resin 7 is about 1.5, the crystal 9 is made of Si (refractive index 3.4 at a thickness of 10 μm), G
e (refractive index: 4.0), thallium bromide + thallium iodide (refractive index: 2.37), diamond (2.38), or the like.

The contact detecting means 10 is arranged around the opening 14a of the casing 14 so as to be flush with the upper surface of the crystal 9, and detects contact with itself.
Specifically, the contact pressure is detected as a contact pressure. For detecting the contact pressure, a known method such as a method using a strain gauge or a method using a change in the conductivity of an anisotropic conductive rubber can be used, and the use of a conductive rubber is the simplest and preferable. Here, a switch using conductive rubber is used as the contact detection means 10.

The identification unit 3 is an analyzer 1 for analyzing mid-infrared light.
5, a memory unit 16 and an identification unit 17. The analyzer 15 Fourier-transforms the power spectrum of the mid-infrared light detected by the detector 12 and outputs the result as a frequency spectrum.

The memory section 16 stores data relating to the resin predicted as the waste resin 7. This accumulated data is obtained by measuring the total reflection of a standard sample piece of a resin used in the past, and includes polystyrene (PS), acrylonitrile-butadiene-styrene copolymer (AB
S), polypropylene (PP), polyethylene (P
E), acrylonitrile-styrene copolymer (AS),
It is a database such as polyphenyl oxide (PPO). The total reflection spectrum uses an evanescent wave transmitted from the crystal 9 to the resin side. Here, since the spectrum intensity changes depending on the wavelength, the refractive index of the crystal 9 and the resin, and the like, it is desirable to create a database based on the total reflection spectrum rather than using a database of a normal infrared absorption spectrum.

The identification means 17 performs pattern recognition of the frequency spectrum output from the analyzer 15 and compares the frequency spectrum with the infrared total reflection spectrum data of the resin stored in the memory unit 16 to identify the resin.

The separation unit 4 has a control unit 18 linked to the identification unit 17. The control unit 18 displays the identification result on the display unit 19 and identifies the resin that is being recycled. With regard to (2), the storage container 20 determined for each resin type is opened and collected. When it is found that resin that has not been stored is mixed, the display unit 19 displays “recyclable” in red, and the “separable” storage container 20.
Put in.

Hereinafter, an identification flow in the waste resin identification device will be described. In the cleaning unit 1, the waste resin 7 is moved along the stage 5, so that the lower surface is wiped off with a cleaning tool 6 impregnated with an aqueous ethanol solution into the nonwoven fabric, thereby removing stains on the surface layer. This is because dust, oil, mold, and the like often accumulate on the surface of the waste resin 7 due to long-term use, and when the total reflection spectrum is measured as it is, the information of the dirt is strongly detected, and there is a possibility that the identification may be erroneously made. Because there is. Here, since the evanescent wave is used for the total reflection spectrum, the spectrum intensity is close to the crystal 9 but tends to be strong. Since the crystal 9 also becomes contaminated during repeated measurement, it is appropriately cleaned to prevent noise.
However, if a cleaning liquid such as an aqueous ethanol solution remains, the spectrum of the cleaning liquid is detected and it becomes difficult to identify the resin. Therefore, it is necessary to start measurement after the surfaces of the waste resin 7 and the crystal 9 are dried.

Next, in the measuring section 2, the washed waste resin 7 is supplied to the opening 1 of the casing 14 of the total reflection spectroscope 8.
Set to 4a and press against Crystal 9. Then, a switch using conductive rubber as the contact detecting means 10 detects that the conductive particles have come into contact and the resistance has dropped to a predetermined value, whereby the waste resin 7 comes into contact with the surface of the crystal 9 at a constant pressure. After confirming that the measurement is complete, start measuring the mid-infrared light.

When the waste resin 7 having a lower refractive index than the crystal 9 is in contact with the crystal 9, the mid-infrared light from the light source 11 is totally reflected inside the crystal 9 as shown in FIG. Since there is an evanescent wave that partially penetrates the waste resin 7 side, the detector 12 detects mid-infrared light equivalent to the infrared absorption spectrum of the resin. However, since the infrared spectrum obtained at this time is slightly different depending on the contact state between the waste resin 7 and the crystal 9, in order to ensure reproducibility of the spectrum, the waste resin 7 and the crystal 9 are kept in a fixed contact as described above. It is important to state.

After that, in the measuring section 2, the power spectrum of the infrared light detected by the detector 6 is Fourier-transformed by the analyzer 15 and is output as a frequency spectrum. The waste resin 7 is identified by comparing with the resin standard spectrum stored in the memory unit 16. The measurement time at this time depends on the resolution of the infrared absorption device and the setting of the number of integrations.
-1, 32 scans is sufficient.

The identified waste resin 7 is displayed on the display unit 19 as a result, and is automatically stored in the storage unit 20 according to the resin type by the control unit 18 in the sorting unit 4. This sorting may be performed by an operator. For this purpose, it is preferable that the display is performed by color display on the display unit 19, or in the case of black-and-white display, by a difference in density or blinking for easy understanding by the operator.

Next, an example in which the above-mentioned waste resin identification device of the present invention is used to identify a cross-flow fan material for an indoor unit of a waste air conditioner will be described. The cross flow fan material is black, and is generally made of AS resin, PS resin, AB
What added glass fiber (GF) to S resin is used. Here, identification was performed on a black crossflow fan material containing an AS resin, whose material is known from the manufacturer and the model. As a comparative example, identification was similarly performed using an identification device using near-infrared light.

According to the waste resin identification device of the present invention, it was possible to measure an infrared absorption spectrum even with a black crossflow fan material. The obtained infrared absorption spectrum is as shown in FIG. 2, and it was determined that the resin type was AS (+ GF) by comparing with the standard spectrum obtained in advance. Even if this infrared absorption spectrum is examined in detail,
Since the absorption of the nitrile group is present at 200 cm @ -1 and the absorption of -C = C- of 1460 cm-1 and 720 cm-1 existing in ABS is not observed, it can be determined that the resin type is AS. This cross-flow fan material was automatically transported to the AS resin container.

On the other hand, with a resin identification device using near-infrared light, it was impossible to measure a black crossflow fan material, and a spectrum could not be obtained. In addition,
The present invention is not limited to the above-described embodiment, and various modifications and changes can be made within the scope of the present invention.

[0033]

As described above, according to the present invention, the reflection type spectroscope using the mid-infrared light and the contact detecting means for detecting the contact pressure in the measuring member are arranged to measure the waste resin. By contacting the member and starting the measurement when the contact pressure matches a predetermined value, it is possible to obtain a measurement spectrum with good reproducibility without crushing the waste resin, and to improve the skill of the operator. This makes it possible to accurately identify the type of waste resin without relying on it, which facilitates resin material recycling.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a schematic configuration of a waste resin identification device according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a result of identification of a spectrum of a waste resin using the identification device of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cleaning part 2 ... Measuring part 3 ... Identification part 4 ... Separation part 7 ... Waste resin 8 ... Total reflection type spectroscope 9 ... Crystal (measurement member) 10 ... Contact detection means 15 ... Analyzer 16 ... Memory part 17 ... Identification Means 19… Display unit 20… Storage container

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G059 AA05 BB08 EE02 EE12 GG00 HH01 HH06 KK01 MM05 MM10 PP04 4F301 AA07 AA12 AA15 AA20 AD09 BF08 BF26 BG53

Claims (7)

[Claims] 1. A total reflection type spectroscope for guiding mid-infrared light to waste resin placed in contact with a measurement member via the measurement member and detecting reflected light totally reflected on a contact surface of the waste resin, A contact pressure measuring means arranged in the same plane as the measuring member for measuring a contact pressure of the waste resin with respect to the measuring member; and various resins in which spectrum patterns obtained from reflected light detected by the total reflection type spectroscope are stored in advance. And a discriminating part for identifying the waste resin by detecting a matching spectral pattern by comparing with the spectral pattern of the total reflection spectroscope when the contact pressure measured by the contact pressure measuring means matches a predetermined value. A waste resin identification device, characterized in that the detection of reflected light is started by the method. 2. The waste resin identification device according to claim 1, wherein the contact pressure measuring means is a pressure-sensitive switch arranged near the measuring member. 3. The apparatus for identifying waste resin according to claim 2, wherein the pressure-sensitive switch is formed of conductive rubber. 4. The waste resin identification device according to claim 1, further comprising a washing unit for washing each contact surface of the waste resin and the measuring member. 5. The waste resin identification device according to claim 1, further comprising a display unit for displaying a result of specifying the waste resin. 6. A method for identifying a waste resin, the method comprising: placing a waste resin in contact with a measuring member of a total reflection spectrometer using mid-infrared light; The reflected light totally reflected at the contact surface of the waste resin in a state where the contact pressure of the waste resin is measured through a contact pressure measuring means arranged in the same plane as the measuring member and a predetermined contact pressure is measured. And a discriminating step of identifying the waste resin by detecting a matching spectral pattern by comparing the spectral pattern obtained from the reflected light detected in the measuring step with the spectral patterns of various resins stored in advance. A method for identifying a waste resin, which is performed. 7. The method according to claim 6, further comprising the step of separating the waste resin specified in the identification step into storage containers according to the type of the waste resin.