KR102592137B1 - Device for regenerating waste pet film - Google Patents

Abstract

The present invention relates to a waste PET classification and recycling device, the purpose of which is to separate and recover PET film, PP, PE, etc. from PET waste contained in waste, and to separate the coating layer, thin film layer, and adhesive layer coated on the surface of the PET film. Alternatively, the purpose is to provide a waste PET classification and recycling device that simultaneously separates, washes, dries, and regenerates the waste in order to obtain high-purity PET film by removing it and then pelletize and recycle it.

Description

Waste PET film sorting and recycling device {DEVICE FOR REGENERATING WASTE PET FILM}

The present invention relates to a waste PET film sorting and recycling device. Specifically, the waste PET film is classified from compressed and stored PET waste, and the waste PET film is recycled by peeling, washing and drying the film printed on the surface of the waste PET film. and playback devices.

PET (polyethylene terephthalate) is a material widely used in all industrial fields for industrial purposes, packaging materials, solar cell materials, optical displays, etc., and is a representative recycled material. PET material is usually processed into the same form as a beverage bottle or manufactured into a film form, but when manufactured in the form of a beverage bottle, it is easy to separate and collect, so the recycling rate is high. However, in the case of film form, in most cases, printed matter such as nickel forms a thin film layer or contains impurities, so it is difficult to separate and collect high-purity PET, so it cannot be recycled as PET and is simply used as fuel for incineration to operate boilers such as power plants. It is common to only recycle.

The reason for this low recycling rate of waste PET film is that when producing PET film, silicone, urethane, PC (polycarbonate), and acrylic are usually used on one side of the PET film to reinforce strength, UV protection, prevent static electricity, or other necessary functions. This is because it is produced by coating functional materials such as , PP, and PE in a thin film or bonding them in the form of a film. However, if waste PET film can be separated and recycled, it is a material whose added value can be more than 10 times higher than when processed for incineration fuel, so it is desirable to separate it from both an economic and resource recycling perspective.

To this end, in order to separate and recycle high-purity PET material from waste, a technology is needed to separate waste PET film from waste and functional materials from waste PET film. Technologies that can be proposed include combining PET and functional materials. There is a method of melting them together and separating and refining each component, and a method of physically removing the thin film layer directly.

However, the method of separating PET and functional materials in a molten state consumes a lot of energy in the melting process, and separating each component in a molten state also requires a complicated process, and similar technology to physically remove the coating layer is not a thin film layer. It is a difficult technology to apply to thin film layers because it involves removing a separable film layer. In relation to this, the method of using a polishing roller with polishing cloth wound as shown in Figure 1 is not easy to precisely polish waste PET film, which has a thin film of about 100㎛ thick, so it is easy to polish even PET material, and if polished strongly, the rotational force is reduced. Since the PET film may be damaged by this, if polishing at low speed is taken into account, the polishing time will take a long time, and an operator must be stationed in front of the device to continuously observe polishing, which has the disadvantage of being impractical in terms of time and cost. there is.

In addition, currently, waste containing PET is classified as general waste, and plastic bottles, waste film, etc., along with PP, PE, etc. are mixed and collected, and these are compressed and stored at once and incinerated. Waste PET film is classified from waste, and waste PET film is separated from waste PET film. Each process for sorting, washing, and recycling the coating layer, thin film layer, and adhesive layer is carried out separately, which reduces process efficiency and makes it impossible to obtain high-purity PET film.

Therefore, there is a need for a technology that can classify waste PET film from waste and remove PE, PP, etc., coating layers, thin film layers, and adhesive layers coated on waste PET reliably and economically.

The purpose of the present invention to solve the above problems is to remove PP and PE from collected PET waste, and ultrasonic clean the coating layer, thin film layer, and adhesive layer made of viscous and non-viscous functional materials coated on the surface of the waste PET film. , the purpose is to provide a waste PET film sorting and recycling device that removes waste through microbubble washing and allows the waste generated in the removal process to be sorted, selected, and collected from the waste PET film based on specific gravity.

Furthermore, the aim is to provide a waste PET sorting and recycling device that can recycle waste PET film from which the coating layer, thin film layer, and adhesive layer such as PP or PE has been removed, into pellets.

The waste PET classification and recycling device of the present invention, which achieves the above-mentioned purpose and eliminates the conventional drawbacks, includes a separation unit 10 for inputting and separating compressed and stored general waste, and a separation unit 10. A first moving unit 11 through which the separated general waste moves, a pulverizing unit 20 through which the general waste moved through the first moving unit 11 is pulverized, and the pulverized general waste moves through the pulverizing unit 20. a second moving unit 21, an ultrasonic cleaning unit 100 for ultrasonically cleaning the general waste moved through the second moving unit 21, a microbubble cleaning unit 200 for cleaning ultrasonic cleaned waste microbubbles, cleaning A dehydration unit 300 for dehydrating the waste, a PP and PE dehydration and discharge unit 30, a stirring unit 400 for pelletizing waste PET from which PP and PE has been removed by heat stirring, and removing adhesive substances from the surface of the pellets. From the hot water washing unit 500, the drying unit 600 for drying the hot water washed pellets, the storage silo 40 for storing the dried pellets, the ultrasonic washing unit 100, and the microbubble washing unit 200. It is characterized by including a wastewater storage tank 50 for storing discharged wastewater.

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The present invention, which has the above features, classifies PP and PE from compressed and stored PET waste, and removes, washes, and dries the coating layer, thin film layer, and adhesive layer from the waste PET film in one process line, and can be recycled into pellets, which are recycled raw materials. . Therefore, high-purity PET pellets, which are recycled raw materials, can be collected just by inputting compressed and stored PET waste, improving the process efficiency of classification, recycling, and collection.

Figure 1 is a photograph of a device that physically separates a coating layer, a thin film layer, etc. from a conventional waste PET film.
Figure 2 is a schematic front view of a sorting and recycling device for waste PET film according to an embodiment of the present invention.
Figure 3 is a plan view of a waste PET film sorting and recycling device according to an embodiment of the present invention.
Figure 4 is a process diagram of a classification and recycling method according to a waste PET film classification and recycling device according to an embodiment of the present invention.
The attached drawings are intended as reference for understanding the technical idea of the present invention, and are not intended to limit the scope of the present invention.

In describing the present invention, detailed descriptions of related known functions will be omitted if they are obvious to those skilled in the art and are judged to unnecessarily obscure the gist of the present invention.

Figure 2 is a schematic front view of a waste PET film sorting and recycling device according to an embodiment of the present invention, and Figure 3 is a waste PET film sorting and recycling device according to an embodiment of the present invention. It is a top view, and Figure 4 is a process diagram of a classification and recycling method according to a waste PET film classification and recycling device according to an embodiment of the present invention.

As shown, the configuration of the present invention includes a separation unit 10, a grinding unit 20, a washing unit, a dewatering unit 300, a stirring unit 400, a storage silo 40, etc.

Discarded waste is generally collected mixed with PE, PP, etc., and the collected waste is separated into general waste and compressed for storage and treatment. In order to separate general waste that is compressed and processed, the separation unit 10 inputs general waste and pressurizes it to separate and/or crush it. The general waste separated from the separation unit 10 moves to the grinding unit 20 along the first moving unit 11 to be pulverized to facilitate washing and classification. The first moving unit 11 is a means for moving compressed general waste after it is separated from the separating unit 10, and may have a structure such as a belt conveyor, for example. In addition, it may be structured to move from the belt conveyor along the busket conveyor and then fall into the crushing unit 20 so that it can fall into the crushing unit 20, which will be described later. The general waste moved through the above-described first moving unit 11 is pulverized in the grinding unit 20 to facilitate classification of PET, PP, PE, etc., coating layer, thin film layer, and adhesive layer, and the general waste in the pulverized state is divided into three parts. 2 Moves to the washing section through the moving section (21).

The cleaning unit may be comprised of an ultrasonic cleaning unit 100 and a microbubble cleaning unit 200. First, general waste moved through the second moving unit 21 can be ultrasonic cleaned in the ultrasonic cleaning unit 100. Ultrasonic cleaning is used to clean foreign substances on the object to be cleaned without damaging the object through microbubbles generated when the energy of the ultrasonic wave propagates through the solution due to the cavitation phenomenon of ultrasonic waves. Therefore, foreign substances attached to the surface of general waste, especially coated coating layers, thin film layers, and adhesive layers, can be removed by ultrasonic cleaning without using physical methods (manual work, polishing, etc.) or chemical methods (acidic or basic chemicals). Damage to waste is minimized and only foreign substances coated, thin film, or adhered to PET film can be removed.

The ultrasonic cleaning process is carried out through the action of ultrasonic waves and a mixed solution of water and cleaning liquid stored in the ultrasonic cleaning unit 100. General cleaning and precision cleaning can be performed depending on the intensity and density of the ultrasonic waves. That is, the separation process of PP, PE, etc., functional coating layer, thin film layer, and adhesive layer from PET (film) is carried out by the ultrasonic cleaning unit 100 depending on the adhesive strength, range, and amount of the coating layer, thin film layer, and adhesive layer coated on the surface of the waste PET. By controlling the solution temperature, frequency of ultrasonic waves, intensity and density of ultrasonic waves, pulverized PET waste can be washed step by step. For example, the separation of label paper glued to the surface of waste PET can be done through general cleaning, and the coating layer coated on the surface of waste PET, the thin film layer with text printed on it, and the adhesive material can be separated through repeated precision cleaning.

In particular, in the case of waste PET film, as mentioned above, it is difficult to precisely polish only the coating layer, thin film layer, and adhesive on the film, and not only is it easy to polish even the PET material, but strong polishing can damage the PET film, making it difficult to improve the purity of PET recycling. not. Therefore, damage to the surface of the PET film can be prevented through ultrasonic cleaning. At this time, the intensity of ultrasonic cleaning can be adjusted by adjusting the ultrasonic frequency and temperature to cleanly separate the thin film layer without damaging the waste PET film.

For example, the solution temperature of the ultrasonic cleaning unit 100 is set to 60 to 80, and the frequency of the ultrasonic waves is adjusted (25 to 30 Khz) to make the size of the bubbles caused by the ultrasonic waves visible to the naked eye, so that they adhere relatively weakly to the PET surface. Separate the widely distributed coating layer through general cleaning. In other words, some of the foreign substances that can be seen with the naked eye on the surface of the PET film can be removed through general cleaning. Afterwards, by adjusting the frequency of the ultrasonic waves (35~45Khz), the relative size of the bubbles caused by the ultrasonic waves is reduced and the density and strength of the bubbles are increased, allowing it to penetrate between the PET film surface and the thin film layer to precisely separate the thin film layer. there is. Additionally, when the temperature of the solution is adjusted to 80~100→, the density of cavitation caused by ultrasonic waves increases, enabling precise cleaning. However, when the mixed solution is heated, a chemical reaction may be induced, which may cause stains or damage to the surface of the waste. Therefore, the concentration of the cleaning solution can be adjusted according to the temperature of ultrasonic cleaning and the intensity and density of ultrasonic waves. At this time, the frequency of ultrasonic waves is adjusted to prevent dissolved gases in the solution from being included in the bubbles and deteriorating the cleaning effect. Ultrasonic waves are output intermittently to improve the cleaning effect and do not damage the surface of the waste due to continuous high pressure and temperature. It is desirable. For this purpose, it is desirable to preheat the temperature of the cleaning solution to the above temperature range before using ultrasonic waves and then provide ultrasonic waves intermittently. At this time, in the ultrasonic cleaning unit 100, ultrasonic waves are provided from the left and right sides of the cleaning unit to enable specific gravity selection.

In addition, when the coating layer, thin film layer, adhesive layer, adhesive material, etc. are separated from the PET film through ultrasonic cleaning, primary selective separation from PET based on specific gravity is possible. In detail, the coating layer, thin film layer, adhesive layer, and adhesive material have a relatively large specific gravity compared to the PET film, so they settle to the bottom of the solution and can be collected separately and recycled after the PET is moved to the next process for washing. On the other hand, PP and PE are materials with a smaller specific gravity than PET film, so they can be removed by ultrasonic cleaning and collected separately for recycling.

Afterwards, the waste from which PP and PE has been partially removed by ultrasonic cleaning is moved to the microbubble washing unit 200, and microbubble washing can be performed for precise cleaning and separation.
At this time, it will be apparent that the microbubble washing unit generates microbubbles through a typical pressure dissolution type microbubble generating device.
Through ultrasonic cleaning, bubbles of 1 to 10 μm particles are provided to the first separated waste to adsorb and levitate foreign substances such as coating layer, thin film layer, and adhesive layer remaining on the film surface, and the floating foreign substances are removed through ultrasonic cleaning. Foreign substances that were not removed can be removed. Therefore, by controlling the density, intensity, and solution temperature of the ultrasonic waves of the above-described ultrasonic cleaning unit 100, foreign substances on the surface of the film that can be seen with the naked eye, such as label paper, thin film layer, adhesive material, and adhesive material, are first removed, and then secondarily. Remaining foreign substances on the film surface can be removed by the high pressure effect of bubbles in the solution. At this time, microbubbles are supplied from the bottom of the microbubble washing unit 200 toward the surface of the solution stored in the washing unit, and the bottom may be provided with a dispersing means so that the microbubbles can be uniformly supplied to the entire washing unit. The dispersion means is not particularly limited as long as it is a means that can disperse the supply path of microbubbles, such as a propeller.

The waste washed through the microbubble washing unit 200 is dehydrated in the dehydration unit 300.

At this time, the waste washed through the ultrasonic cleaning unit 100 and the microbubble cleaning unit 200 can be rotated at high speed to select the remaining PP and PE, etc., which have not been separated from the waste, from PET based on specific gravity, and the selected PP and PE can be discharged and recovered through a separate discharge unit 30. In particular, in the case of PET bottles among PET waste, the bottle caps made of PE and PP are not separated and are compressed and stored as waste. Conventionally, bottle caps were separated manually, but through ultrasonic cleaning and dehydration using high-speed rotation, PET is removed without manual labor. It has the advantage of being able to select the specific gravity from . However, the selection through ultrasonic washing and dehydration is a specific gravity selection, so foreign substances including PE and PP, such as adhesive components or coating layers contained in PET or adhesive components that have a small specific gravity difference or are strongly adhered to the surface, are stirred as described later. It can be separated through the part 400 and the hot water washing part 500.

After the waste from which PP and PE has been partially removed is moved to the heat stirring unit 400, it can be pelletized by heat stirring under high temperature and high speed conditions. In this process, the PP and PE remaining in the waste coagulate into a soft state due to high temperature, increase in specific gravity, and fall to the bottom of the heat stirring unit 400. On the other hand, PET is also plastic processed at high temperatures, but its specific gravity is relatively small compared to PP and PE, so it congeals at the top of the heat stirring unit 400. Therefore, the PP and PE that have been separated and solidified from the PET that has solidified at the top can be separated and discharged through the discharge portion (30) at the bottom of the heat stirring portion (400) to separate the PP and PE from PET.

Afterwards, it moves to the hot water washing unit 500 and hot water washing is performed on the surface of the pelletized PET to remove any adhesive substances that have not been removed. Afterwards, the hot water washed pellets are dried in the drying unit 600, and then the dried pellets can be stored in the storage silo 40 and recycled as raw materials such as fiber.

The wastewater discharged from the ultrasonic cleaning unit 100 and the microbubble cleaning unit 200 is stored in the wastewater storage tank 50, and the wastewater stored in the tank is recovered and the coating layer, thin film layer, and adhesive layer remaining in the wastewater are further separated. and can be collected and reused as raw materials for recycling.

The method of sorting and recycling waste PET film using the above-described waste PET film sorting and recycling device may include the steps of separating, pulverizing, washing, and drying the waste. In detail, a separation step in which the compressed and stored waste is inputted into the separation unit 10 and separated, a first movement step in which the separated waste moves through the first movement unit 11, and the waste moved in the first movement step is moved to the pulverization unit. It includes a grinding step in (20). Afterwards, in the pulverizing step, the pulverized waste goes through a second moving step through the second moving part 21, and is ultrasonic cleaned through an ultrasonic cleaning step in the ultrasonic cleaning part 100, and is classified into PET, PE, PP, etc. , Separate and remove the coating layer, thin film layer, adhesive layer, and adhesive material coated on the surface of the waste PET film. In detail, the coating layer, thin film layer, adhesive layer, and adhesive material coated on the surface of the waste PET film are materials with a relatively large specific gravity compared to PET, and sink to the bottom of the ultrasonic cleaning unit 100 and have a relatively small specific gravity compared to PET. PE, PP, etc. can be floated on the top of the ultrasonic cleaning unit 100 to select and separate the separated waste based on specific gravity. At this time, as described above, foreign substances can be separated and removed by adjusting the density and intensity of ultrasonic waves and the temperature of the solution, taking into account the strength of the bond to the PET surface.

Waste that is ultrasonically cleaned to first separate PE, PP, etc. from coating layers, thin film layers, adhesive layers, adhesive materials, etc. is washed with microbubbles in the microbubble washing unit 200 to secondarily float and remove foreign substances on the surface, filter them, and then dehydrate them. A dehydration step may be performed in unit 300.

Afterwards, the dehydrated waste is rotated at high speed so that PP and PE, which have a small specific gravity, sink to the top of the dehydration unit 300, and PET, which has a relatively large specific gravity, sinks to the bottom, and PET, PP, and PE are separated and discharged again according to their specific gravity. can do. The separation of waste through ultrasonic cleaning and dehydration described above corresponds to physical selection by specific gravity selection, and the purity of PET can be improved by further separating PP and PE mixed in the waste and not separated by plastic processing through heat stirring. There is a need.

Therefore, the PET film from which PP and PE has been removed is pelletized by heat stirring in the stirring unit 400, but the fine coating layer, thin film layer, adhesive layer, adhesive material, etc. that are not separated along with PP and PE are further separated and removed by specific gravity. The stirring step can be performed. Waste is pelletized by thermal agitation, and specific gravity selection can be facilitated through separation and condensation. Therefore, the PP and PE contained in the waste are lowered to the bottom of the heat stirring unit 400, and the PET film with a relatively small specific gravity is condensed at the top of the heat stirring unit 400 to separate the congealed PP from the PET congealed at the top. and PE can be separated and discharged through the discharge part 30 at the bottom of the heat stirring part 400. In addition, the fine coating layer, thin film layer, and adhesive layer have a relatively large specific gravity compared to the PET film, so they can be separated and discharged together with the separated and congealed PP and PE through the discharge portion 30 at the bottom.

Afterwards, hot water is supplied to the surface of the pellets made from the separated and screened PET film, and the adhesive substances that were finely mixed in PET due to the high temperature during the pelletization process are discharged to the surface of the pellets or the adhesive components that were not removed are removed to PET. The purity can be improved. Afterwards, recycled raw materials such as fiber can be manufactured through a drying step of drying the hot water washed pellets in the drying unit 600 and a storage step of storing the dried pellets in the storage silo 40. At this time, the wastewater discharged from the ultrasonic cleaning step and the microbubble cleaning step is stored, and the thin film layer and adhesive layer are further classified from the wastewater, so that the coating layer, thin film layer, and adhesive layer can be reused as recycled raw materials.

As mentioned above, by inputting compressed and stored waste, foreign substances such as PP, PE, thin film layer, and adhesive layer can be separated from waste PET film without any additional process, and high purity PET pellets can be obtained, thereby improving process efficiency. .

Meanwhile, the scope of protection of the present invention is not limited to the description and expression of the embodiments explicitly described above. In addition, it is once again added that the scope of protection of the present invention may not be limited due to changes or substitutions that are obvious in the technical field to which the present invention pertains.

10 Separation part
11 1st moving unit
20 Grinding section
21 2nd moving unit
100 Ultrasonic cleaning unit
200 Microbubble washing unit
300 dehydration unit
30 discharge part
400 stirring unit
500 hot water washing unit
600 drying section
40 storage silo
50 Wastewater storage tank

Claims (2)

A separation unit that inputs and separates compressed and stored PET waste;
a first moving part through which the PET waste separated from the separating part moves;
a pulverizing unit in which the PET waste moved through the first moving unit is pulverized;
a second moving unit through which the pulverized PET waste moves through the pulverizing unit;
a washing unit that multiple washes the PET waste moved through the second moving unit;
A dehydration unit for dehydrating the PET waste washed through the washing unit;
A discharge unit that dehydrates and discharges PP and PE separated from the PET waste;
A stirring unit that thermally agitates the PET waste from which the PP and PE have been removed to pelletize it;
A hot water washing unit that removes sticky substances from the surface of the pellets;
A drying unit for drying the pellets washed through the hot water washing unit;
A storage silo for storing pellets dried through the drying unit; and
It includes a wastewater storage tank that stores wastewater discharged from the washing unit,
The washing unit,
An ultrasonic cleaning unit that cleans the PET waste using an ultrasonic cleaner in a mixed solution environment consisting of at least one of water and a cleaning liquid in an acceptable form; and
After passing through the ultrasonic cleaning unit, a microbubble washing unit is continuously formed to expose the PET waste to microbubbles generated from a microbubble generator,
In the ultrasonic cleaning unit,
A general cleaning unit provided for cleaning in an environment where the frequency is maintained at 25 to 60 (kHz) and the mixed solution temperature is maintained at 60 to 80°C; and
After passing through the general cleaning section, the frequency is continuously maintained at 35 to 45 (kHz) and the mixed solution temperature is maintained at 80 to 100°C to form a cavitation density slightly higher than that of the general cleaning section, thereby forming a precise It includes a precision cleaning unit provided to perform cleaning,
In the precision cleaning department,
When outputting the ultrasonic waves, the dissolution rate of gas in the solution can be minimized through intermittent ultrasonic output.
The microbubble washing unit,
A waste PET sorting and recycling device further comprising a dispersing means formed to disperse bubbles generated from the bottom.
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