JPH09208738A - Method of recollecting plastic powder from waste plastic material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recollecting method of waste plastic able to recollect polyethylene, polypropylene and polystyrene in powdery state, striving these plastic raw material to be used in versatile use, and enhancing the operability of the operation. SOLUTION: A hydrocarbon oil is added to the waste plastic material in raw material mixing tank 11 and heated and dissolved at a high temperature, the insoluble content is separated in separating tank 12, to extract a plastic solution dissolving polyethylene, polypropylene and polystyrene. A poor solvent inferior in compatibility with polyethylene, polypropylene and polystyrene is added to the plastic solution and deposited polyethylene, polypropylene and polystyrene is crashed and the plastic powder comprising polyethylene, polypropylene and polystyrene is recollected after filtration of the plastic solution.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering plastic powder from waste plastic material, and more particularly to polyethylene, polypropylene and polystyrene powdered from a plastic solution containing polyethylene, polypropylene and polystyrene extracted from the waste plastic material. Regarding how to recover.

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. Hei 7-24801.
In No. 6, a method for recovering polyethylene, polypropylene and polystyrene by mixing a waste plastic material and an extraction solvent composed of hydrocarbon oil was presented. The whole structure of the waste plastic material oilification processing equipment C which can be conveniently used for the method concerning FIG. 3 is shown. As shown in the figure, in this method, first, a waste plastic material in the form of a crushed product, a fluff, and a crushed product is supplied to a raw material mixing tank 51 containing a hydrocarbon oil heated to a temperature of 100 ° C to 200 ° C. And stir to mix. By this operation, only polyethylene, polypropylene and polystyrene in the waste plastic material have a relatively low melting point as compared with other plastics and have a melting point of 100.
Since it liquefies at temperatures above ℃, it is easy to dissolve in hydrocarbon oil. On the other hand, since other plastics do not reach the melting point, they remain solid without liquefaction and are hardly dissolved.

After that, the plastic melt produced by mixing and stirring is sent to a separation tank 52, and by the separation tank 52,
The insoluble matter is removed from the plastic melt and the plastic solution consisting of the produced oil and the dissolved matter is extracted. The plastic solution extracted in this way is sent to the cracking distillation column 53 of the oil treatment section, which comprises a thermal decomposition section and a distillation section,
The plastic solution is pyrolyzed. Note that a pyrolysis oil heating furnace 54 and a residue processor 55 are connected to the cracking distillation column 53. The pyrolysis gas generated by the pyrolysis in the pyrolysis section of the cracking distillation column 53 is separated by distillation into an aromatic fraction, a kerosene / light oil fraction, and a wax fraction by the distillation section of the cracking distillation column 53. Used as a product such as light oil. Further, the obtained oil is used as a fuel or a hydrocarbon oil used in the extraction step by blending by putting it in the receiving tank 56.

[0004]

However, the above-mentioned methods for recovering polyethylene, polypropylene and polystyrene still have the following problems to be solved. That is,
Since polyethylene, polypropylene and polystyrene recovered by the above method are recovered in a state of being dissolved in a plastic solution, the entire plastic solution is then oiled and used only for commercialization into kerosene, light oil, etc. Has been. It is also conceivable that the recovered plastic solution in which polyethylene, polypropylene, and polystyrene are dissolved may be used as a raw material for producing other types of recycled products without performing the above-described oil treatment.
However, in order to do so, the plastic solution must be transported to a recycling facility. Considering that the plastic solution has the property of solidifying at room temperature, it is necessary to constantly heat the solution, which is extremely complicated and dangerous. Work is required, and transportation costs are high.

The present invention has been made in view of the above circumstances. By recovering polyethylene, polypropylene and polystyrene in powder form from waste plastic materials, the versatility of these plastic raw materials is achieved and An object of the present invention is to provide a method for recovering plastic powder from a waste plastic material, which can improve handleability.

[0006]

According to the present invention, there is provided a semiconductor device comprising:
The method of recovering the plastic powder from the waste plastic material described is a method in which hydrocarbon oil is added to the waste plastic material in the raw material mixing tank and then melted by heating at a high temperature, and then insoluble matter is removed in a separation tank to remove polyethylene, A plastic solution in which polypropylene and polystyrene are dissolved is extracted, and a poor solvent having poor compatibility with the polyethylene, polypropylene and polystyrene is mixed into the plastic solution to precipitate and grind polyethylene, polypropylene and polystyrene, and the plastic solution Is filtered to collect a plastic powder consisting of polyethylene, polypropylene and polystyrene. The method for recovering plastic powder from waste plastic material according to claim 2 is the method for recovering plastic powder from waste plastic material according to claim 1, wherein the filtrate produced by the filtration is separated by distillation to obtain a fractionated product. While being reused as the poor solvent, the residual liquid after the distillation separation is reused as the hydrocarbon oil.

According to a third aspect of the present invention, a method for recovering plastic powder from a waste plastic material comprises adding hydrocarbon oil to the waste plastic material in a raw material mixing tank and then heating and melting at a high temperature.
Then, remove the insoluble matter in the separation tank, polyethylene,
A plastic solution in which polypropylene and polystyrene are dissolved is extracted, and a poor solvent having poor compatibility with the polyethylene and polypropylene is mixed into the plastic solution to precipitate and grind polyethylene and polypropylene,
While performing a first-stage filtration on the plastic solution to recover a plastic powder consisting of polyethylene and polypropylene, the plastic solution produced by the filtration and capable of dissolving polystyrene is mixed with a poor solvent having poor compatibility with the polystyrene. Polystyrene is precipitated and pulverized, and the plastic solution is subjected to second-stage filtration to recover polystyrene-containing plastic powder, thereby recovering plastic powder from a waste plastic material.

The method for recovering plastic powder from waste plastic material according to claim 4 is the method for recovering plastic powder from waste plastic material according to claim 3, wherein the filtrate produced by the latter-stage filtration is separated by distillation. Two different fractionated products are reused as the two poor solvents, respectively, and the residual liquid after the distillation separation is reused as the hydrocarbon oil.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Next, referring to the attached drawings, an embodiment in which the present invention is embodied will be described to provide an understanding of the present invention. Here, FIG. 1 is a block diagram showing the entire configuration of a waste plastic material processing facility that can be suitably used in the method for recovering plastic powder from waste plastic material according to the first embodiment of the present invention. Two
FIG. 6 is a block diagram showing an overall configuration of a waste plastic material processing facility that can be suitably used in a method for recovering plastic powder from waste plastic material according to a second embodiment of the present invention. First, the configuration of a waste plastic material processing facility A that can be suitably used in the method for recovering plastic powder from waste plastic material according to the first embodiment will be described with reference to FIG. As shown in FIG. 1, the waste plastic material treatment facility A is a powder from a plastic solution to a waste plastic material oilification treatment facility A1 having the same configuration as the waste plastic material oilification treatment facility C described with reference to FIG. The structural characteristic is that a plastic powdering treatment facility A2 for producing the converted polyethylene, polypropylene and polystyrene is added. That is, in FIG. 1, the waste plastic material oilification treatment facility A1 includes a raw material mixing tank 11, a separation tank 12, a cracking distillation column 13, and a pyrolysis oil which are arranged in the same manner as the waste plastic material oilification treatment facility C. It comprises a heating furnace 14, a residue treatment machine 15, and a receiving tank 16.

On the other hand, as shown in FIG. 1, the plastic powdering treatment facility A2 includes a branch pipe 18 branched from a plastic solution feed pipe 17 connecting the separation tank 12 and the decomposition distillation column 13, and a branch pipe 18. Mixing tank 1 connected downstream
9, and a filtration pretreatment device 20 connected to the downstream side of the mixing tank 19.
And a filter 21 connected to the downstream side of the filtration pretreatment device 20.
And an inlet connected to a filtrate outlet of the filter 21, a fractionated product outlet thereof connected to a poor solvent inlet of the mixing tank 19, and a residual liquid outlet further carbonized in the raw material mixing tank 11. And a distiller 22 connected to the hydrogen oil inlet. In the above configuration, the mixing tank 19 is provided to mix ethanol, which is an example of a poor solvent, with the plastic solution in which polyethylene, polypropylene, and polystyrene are fed, which is fed through the branch pipe 18. In such mixing, the solvent in the plastic solution is soluble in ethanol, which is a poor solvent, but the plastic consisting of polyethylene, polypropylene, and polystyrene is poor in compatibility with ethanol, and thus is insoluble in ethanol, and only polyethylene, polypropylene, and polystyrene are separated. Will be deposited.

By the way, the polyethylene, polypropylene, and polystyrene thus separated / precipitated are in the form of porous brittle lumps because the plastics that are uniformly dispersed in the solvent are deposited. The pre-filtration treatment machine 20 is provided to give ultrasonic vibrations or the like to these for fine pulverization. The pulverization of the plastic can also be performed by applying mechanical force such as stirring to polyethylene, polypropylene and polystyrene. The filter 21 is for filtering the finely pulverized plastic powder made of polyethylene, polypropylene and polystyrene from the above plastic solution, and the plastic powder is 30 to 2000.
It is a fine powder with a fine particle size of μm. Distiller 2
2 is for distilling the filtrate which is the residual liquid after filtering the plastic powder consisting of polyethylene, polypropylene and polystyrene by the filter 21. Ethanol is separated by this distillation, and this ethanol is used as a poor solvent in a mixing tank. It can be refluxed to 19 and recycled. Further, the hydrocarbon oil, which is the residual liquid after ethanol is separated by the distiller 22, is refluxed into the raw material mixing tank 11, is mixed again with the waste plastic material, and is similarly recycled.

Next, a method for recovering plastic powder using the waste plastic material processing facility A having the above-mentioned structure will be described with reference to FIG. First, in the raw material mixing tank 11, hydrocarbon oil is added to the waste plastic material and then heated and melted at a high temperature to generate a melted product. Then, in the separation tank 12, the insoluble matter is removed from the dissolved material to produce a plastic solution in which polyethylene, polypropylene and polystyrene are dissolved. This plastic solution flows into the mixing tank 19 through the branch pipe 18. Then, in the initial operation, ethanol as a poor solvent, which has been preliminarily filled in the mixing tank 19, and the plastic solution are mixed to form polyethylene in the plastic solution.
Precipitate polypropylene and polystyrene. further,
This plastic solution is sent to the filtration pretreatment device 20, and in the filtration pretreatment device 20, ultrasonic vibration or mechanical vibration is applied to the plastic solution. By this operation, the precipitated polyethylene, polypropylene and polystyrene in the plastic solution are made into fine powder.

Thereafter, the plastic solution is filtered by the filter 21 to recover the plastic powder consisting of polyethylene, polypropylene and polystyrene having a particle size of 30 to 2000 μm. The filtrate produced by the above-mentioned filtration is sent to the distiller 22 to separate ethanol. Then, this ethanol is refluxed to the mixing tank 19, and mixed as a poor solvent into the plastic solution in which polyethylene, polypropylene and polystyrene are fed into the mixing tank 19 and is reused. The hydrocarbon oil, which is the residual liquid after the filtrate is distilled, is returned to the raw material mixing tank 11, mixed with the waste plastic material fed into the raw material mixing tank 11, and reused. . On the other hand, when you want to commercialize the plastic solution extracted from the waste plastic material as kerosene or light oil, the plastic solution extracted from the waste plastic material is decomposed and distilled in the oil treatment section consisting of a thermal decomposition section and a distillation section. Thirteen
To pyrolyze. Then, the pyrolysis gas generated by the pyrolysis in the pyrolysis section of the cracking distillation column 13 is separated into an aromatic fraction, a kerosene / light oil (also called kerosene / light oil) fraction, and a wax fraction in the distillation section. After that, it will be commercialized as kerosene or light oil.

As described above, in the method of recovering the plastic powder from the waste plastic material according to the first embodiment, the plastic solution extracted from the waste plastic material is treated with a poor solvent for polyethylene, polypropylene and polystyrene. A certain ethanol is mixed and the plastics are precipitated and pulverized from a plastic solution in which polyethylene, polypropylene and polystyrene are dissolved, and this is filtered to recover a plastic powder composed of polyethylene, polypropylene and polystyrene. Therefore, not only can polyethylene, polypropylene, and polystyrene be oil-treated to produce kerosene or light oil, but also the versatility of these plastic raw materials can be achieved, and the handleability thereof can be improved, Safety can also be improved. Further, in the method for recovering plastic powder from waste plastic material according to the present embodiment, the poor solvent and the hydrocarbon oil produced by distilling and separating the filtrate are respectively used to precipitate the plastic from the plastic solution and to mix the raw materials. Tank 1
Since it can be reused in the mixing with the waste plastic material in No. 1, the economical efficiency in the production of the plastic powder can be increased.

Next, a waste plastic material treatment facility B which can be suitably used in the method for recovering plastic powder from waste plastic material according to the second embodiment of the present invention.
The configuration will be described with reference to FIG. As shown in FIG. 2, the waste plastic material processing facility B is shown in FIG.
Waste plastic material oil treatment equipment A described with reference to
Waste plastic material oil treatment equipment B with the same structure as C
1, polyethylene powdered from plastic solution,
A structural feature is that a plastic powdering treatment facility B2 for separately producing polypropylene and polystyrene is added. That is, in FIG. 2, the waste plastic material oilification treatment equipment B1 as the former stage is a raw material mixing tank 3 arranged in the same manner as the waste plastic material oilification treatment equipments A1 and C.
1, a separation tank 32, a cracking distillation column 33, a pyrolysis oil heating furnace 34, a residue treatment machine 35, and a receiving tank 36.

On the other hand, as shown in FIG. 2, the plastic pulverization processing facility B2 in the latter stage comprises a separation tank 32 and a decomposition distillation column 3
3, a branch pipe 38 branched from a plastic solution supply pipe 37, a first mixing tank 39 connected to the downstream side of the branch pipe 38, and a first mixing tank 39 connected to the downstream side of the first mixing tank 39. Filtration pre-treatment device 40 and first filtration pre-treatment device 40
A first filter 41 connected to a downstream side of the second filter, a second mixing tank 42 connected to a filtrate outlet of the first filter 41, and a second
Second pretreatment device 4 connected to the downstream side of the mixing tank 42
3 and the second connected to the downstream side of the second filtration pretreatment device 43
Filter 44 and the inflow port of the second filter 44 are connected to the filtrate outflow port, and the fractionated product outflow port is connected to the first and second distillates.
Connected to the poor solvent inlets of the mixing tanks 39 and 42 of
Further, the residual liquid outlet comprises a distiller 45 connected to the hydrocarbon oil inlet of the raw material mixing tank 31.

In the above structure, the first mixing tank 39 is
It is provided for mixing xylene, which is an example of a poor solvent, with a plastic solution in which polyethylene, polypropylene and polystyrene are fed through the branch pipe 38. In such mixing, the solvent and polystyrene in the plastic solution are soluble in xylene, but polyethylene and polypropylene have poor compatibility with xylene and therefore are insoluble in xylene, and only polyethylene and polypropylene are separated and deposited. The first filtration pretreatment device 40 is composed of the polyethylene thus separated / precipitated,
It is provided in order to finely pulverize the precipitated polyethylene and polypropylene by applying ultrasonic vibration or the like to a plastic solution in which polypropylene and polystyrene are dissolved. The pulverization can also be performed by applying mechanical force such as stirring to polyethylene and polypropylene.

The first filter 41 is for filtering plastic powder made of polyethylene and polypropylene pulverized from the above-mentioned plastic solution, and the plastic powder has a fine particle diameter of 30 to 2000 μm. It is a fine powder. Second mixing tank 42
Is the filtrate sent from the first filter machine 41, that is,
It is provided for mixing ethanol with a plastic solution containing polystyrene in a molten state. In such mixing, the solvent in the plastic solution is soluble in ethanol, but polystyrene is poor in compatibility with ethanol and therefore is insoluble in ethanol, and only polystyrene is separated and deposited. The second filtration pretreatment device 43 is provided in order to finely pulverize the precipitated polystyrene by applying ultrasonic vibration or the like to the plastic solution in which the polystyrene thus separated / precipitated is dissolved. The pulverization can also be performed by applying mechanical force such as stirring to polystyrene.

The second filter 44 is for filtering the plastic powder made of finely pulverized polystyrene from the above-mentioned plastic solution, and the plastic powder has a fine particle size of 30 to 2000 μm. Has become. The distiller 45 distills the filtrate which is the residual liquid after filtering the plastic powder made of polystyrene by the second filter 44, separates xylene and ethanol by this distillation, and separates this xylene and ethanol. It can be circulated and used as a poor solvent by refluxing to the first and second mixing tanks 39 and 42, respectively.
Further, the hydrocarbon oil, which is the residual liquid after distilling and separating xylene and ethanol by the distiller 45, is refluxed into the raw material mixing tank 31, is mixed again with the waste plastic material, and is similarly circulated and used. .

Next, a method for recovering plastic powder using the waste plastic material processing facility B having the above-mentioned structure will be described with reference to FIG. First, in the raw material mixing tank 31, hydrocarbon oil is added to the waste plastic material and then heated and melted at a high temperature to generate a melted product. Then, in the separation tank 32, the insoluble matter is removed from the dissolved matter to produce a plastic solution in which polyethylene, polypropylene and polystyrene are dissolved. This plastic solution flows into the first mixing tank 39 through the branch pipe 38.
Then, in the initial operation, xylene as a poor solvent, which has been filled in the first mixing tank 39 in advance, and the plastic solution are mixed to precipitate polyethylene and polypropylene in the plastic solution. Further, this plastic solution is sent to the filtration pretreatment device 40, and in the filtration pretreatment device 40, ultrasonic vibration or mechanical vibration is applied to the plastic solution. By this operation, the precipitated polyethylene and polypropylene in the plastic solution are made into fine powder.

After that, the plastic solution is filtered by the first filter 41 to recover the plastic powder consisting of polyethylene and polypropylene having a particle size of 30 to 2000 μm. A plastic solution in which polystyrene, which is a filtrate generated by the filtration, is dissolved is flown into the second mixing tank 42. Then, in the initial operation, ethanol as a poor solvent, which has been filled in the second mixing tank 42 in advance, and the plastic solution are mixed to precipitate polystyrene in the plastic solution. Further, this plastic solution is added to the second filtration pretreatment device 43.
Then, in the second filtration pretreatment device 43, ultrasonic vibration or mechanical vibration is applied to the plastic solution. By this operation, the precipitated polystyrene in the plastic solution is made into fine powder. After that, the plastic solution is filtered by the second filter 44 so that the particle size is 30 to 2000 μm.
The plastic powder consisting of polystyrene is recovered.

The filtrate produced by the above-mentioned second filter 44 is fed to the distiller 45, and xylene and ethanol are separated by distillation. Then, these xylene and ethanol are respectively refluxed to the first and second mixing tanks 39 and 42, and the polyethylene, polypropylene and polystyrene fed into the first mixing tank 39 are used as poor solvents. Dissolved plastic solution and second mixing tank 42
It will be reused by being mixed with the plastic solution in which the polystyrene sent to is dissolved. The hydrocarbon oil, which is the residual liquid after the filtrate is distilled and separated by the distiller 45, is returned to the raw material mixing tank 31, mixed with the waste plastic material fed into the raw material mixing tank 31, and reused. Will be done.

On the other hand, when it is desired to commercialize the plastic solution extracted from the waste plastic material as kerosene or light oil, the extracted plastic solution is decomposed and distilled in the oil distillation treatment section 33 including a thermal decomposition section and a distillation section. To pyrolyze. Then, the pyrolysis gas generated by the pyrolysis in the pyrolysis section of the cracking distillation tower 33 is separated into an aromatic fraction, a kerosene / light oil fraction, and a wax fraction in the distillation section, and thereafter, kerosene, light oil, etc. Will be commercialized as.

As described above, in the method for recovering the plastic powder from the waste plastic material according to the second embodiment, xylene, which is a poor solvent for polyethylene and polypropylene, is added to the plastic solution extracted from the waste plastic material. And, by sequentially mixing ethanol, which is a poor solvent with respect to polystyrene, separately precipitating and crushing the plastic in the plastic solution in which polyethylene, polypropylene and polystyrene are dissolved,
This is filtered to collect the plastic powder made of polyethylene and polypropylene and the plastic powder made of polystyrene separately. Therefore, not only can polyethylene, polypropylene, and polystyrene be oil-treated to produce kerosene, light oil, etc., but also the versatility of these plastic raw materials can be further improved, and the handleability thereof can be improved. , Safety can also be improved.

Also, in the method for recovering plastic powder from waste plastic material according to the present embodiment, the poor solvent and hydrocarbon oil produced by distilling and separating the filtrate are respectively precipitated from the plastic solution to remove the plastic. Also, since it can be reused for mixing with the waste plastic material in the raw material mixing tank, the economical efficiency in the production of plastic powder can be improved.

Although the present invention has been described above with reference to a plurality of embodiments, the present invention is not limited to the configurations described in the above embodiments, and is described in the scope of claims. It also includes other embodiments and modifications possible within the scope of the matters described. For example, in the above-mentioned embodiment, ethanol and xylene are used as the poor solvent, but other poor solvents can also be used.

[0027]

In the method for recovering plastic powder from waste plastic materials according to claims 1 and 2, a poor solvent is mixed with the plastic solution extracted from the waste plastic material, and polyethylene, polypropylene and polystyrene in the plastic solution are mixed. A plastic consisting of is deposited and crushed, and this is filtered to remove polyethylene,
A plastic powder composed of polypropylene and polystyrene is collected. Therefore, not only can polyethylene, polypropylene and polystyrene be oil-treated to produce kerosene, light oil, etc., but also the versatility of these plastic raw materials can be achieved, and the handleability thereof can be improved, Safety can also be improved. Particularly, in the method for recovering the plastic powder from the waste plastic material according to claim 2, the poor solvent and the hydrocarbon oil produced by separating the filtrate by distillation are respectively
Since it can be reused for the coagulation of the plastic solution and the mixing with the waste plastic material in the raw material mixing tank, the economical efficiency in the production of the plastic powder can be improved. In the method for recovering plastic powder from a waste plastic material according to claims 3 and 4, hydrocarbon oil is added to the waste plastic material in a raw material mixing tank and then heated and melted at a high temperature, and then insoluble matter is removed in a separation tank. After removal, a plastic solution in which polyethylene, polypropylene and polystyrene are dissolved is extracted, and a poor solvent having poor compatibility with polyethylene and polypropylene is mixed into this plastic solution to precipitate polyethylene and polypropylene and then pulverize the plastic solution. The solution is subjected to pre-stage filtration to recover a plastic powder consisting of polyethylene and polypropylene, and a polystyrene solution produced by the filtration and in which polystyrene is dissolved is mixed with a poor solvent having poor compatibility with polystyrene to form polystyrene. After crushing and crushing So that the recovery of plastic powder of polystyrene by performing the subsequent filtration for plastic solution. Therefore, the plastic powder made of polyethylene and polypropylene and the plastic powder made of polystyrene can be separately recovered, and the versatility of these plastic raw materials can be further improved. In particular, in the method for recovering plastic powder from waste plastic material according to claim 4, two different fractionated products are reused as two poor solvents by distilling and separating the filtrate produced by the latter-stage filtration, Since the residual liquid after separation is reused as hydrocarbon oil, the economical efficiency in the production of plastic powder can be improved.

[Brief description of drawings]

FIG. 1 is a block diagram showing an overall configuration of a waste plastic material processing facility that can be suitably used for a method of recovering plastic powder from a waste plastic material according to a first embodiment of the present invention.

FIG. 2 is a block diagram showing an overall configuration of a waste plastic material processing facility that can be suitably used in a method for recovering plastic powder from waste plastic material according to a second embodiment of the present invention.

FIG. 3 is a block diagram showing an overall configuration of waste plastic material oil treatment equipment that can be suitably used in a conventional method for recovering plastic from waste plastic material.

[Explanation of symbols]

A Waste plastic material treatment equipment A1 Waste plastic material oil treatment equipment A2 Plastic powder treatment equipment B Waste plastic material treatment equipment B1 Plastic waste oil treatment equipment B2 Plastic powder treatment equipment 11 Raw material mixing tank 12 Separation tank 13 Decomposition distillation Tower 14 Pyrolysis oil heating furnace 15 Residue treatment machine 16 Receiving tank 17 Plastic solution feed pipe 18 Branch pipe 19 Mixing tank 20 Filtration pretreatment machine 21 Filtration machine 22 Distiller 31 Raw material mixing tank 32 Separation tank 33 Decomposition distillation tower 34 Thermal decomposition Oil heating furnace 35 Residue treatment machine 36 Receiving tank 37 Plastic solution feeding pipe 38 Branch pipe 39 First mixing tank 40 First filtration pretreatment machine 41 First filtration machine 42 Second mixing vessel 43 Second filtration before Processor 44 Second filter 45 Distiller

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area // B29K 23:00 25:00

Claims (4)

[Claims] 1. A hydrocarbon solution is added to a waste plastic material in a raw material mixing tank and then heated and melted at a high temperature, and then an insoluble matter is removed in a separation tank to obtain a plastic solution in which polyethylene, polypropylene and polystyrene are dissolved. Extract and
A poor solvent having poor compatibility with the polyethylene, polypropylene and polystyrene is mixed in the plastic solution to precipitate and pulverize polyethylene, polypropylene and polystyrene, and the plastic solution is filtered to obtain a plastic comprising polyethylene, polypropylene and polystyrene. A method for recovering plastic powder from a waste plastic material, characterized in that the powder is recovered. 2. The filtrate produced by the filtration is separated by distillation to reuse the fractionated product as the poor solvent,
The method for recovering plastic powder from a waste plastic material according to claim 1, wherein the residual liquid after separation by distillation is reused as the hydrocarbon oil. 3. A plastic solution in which polyethylene, polypropylene and polystyrene are dissolved by adding hydrocarbon oil to the waste plastic material in a raw material mixing tank and then heating and dissolving it at a high temperature, and then removing insolubles in a separation tank. Extract and
In the plastic solution, a poor solvent having poor compatibility with the polyethylene and polypropylene is mixed to precipitate polyethylene and polypropylene, followed by pulverization, and the plastic solution is pre-filtered to obtain a plastic powder composed of polyethylene and polypropylene. Along with the recovery, in a plastic solution that is produced by the filtration and dissolves polystyrene, a poor solvent having poor compatibility with the polystyrene is mixed to precipitate and pulverize polystyrene, and the polystyrene solution is subjected to post-stage filtration for the plastic solution. A method for recovering plastic powder from waste plastic material, which comprises recovering plastic powder consisting of 4. The filtrate produced by the latter-stage filtration is separated by distillation to reuse two different fractional fractions as the two poor solvents, respectively, and the residual liquid after the distillation separation is reused as the hydrocarbon oil. The method for recovering plastic powder from a waste plastic material according to claim 3, wherein the method is used.