JP2001341131A - Method for pre-treating waste plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To pre-treat waste plastics including plastic films into granular plastic moldings having strength necessary for a raw material, etc., to be charged into a furnace properly and efficiently. SOLUTION: In a method, the waste plastics including solid plastics (A) obtained from plastic moldings and thin pieces of plastics (and/or foamed plastics) (B) obtained from plastic non-moldings, with the plastics (A) and (B) mixed, are processed into the granular plastic moldings through a granulation process for compression or compression/crushing and the following extrusion molding. In the granulation process, at least a part of the plastics (B) are semi- melted or melted, and at least a part of the plastics (A) are left without being semi-melted or melted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the pretreatment of waste plastic (plastic waste) as general waste or industrial waste into a granular material suitable for a raw material to be blown into a furnace such as a blast furnace or a cement kiln. About the method.

[0002]

2. Description of the Related Art When waste plastic is used as a raw material to be blown into a blast furnace or the like, it must be supplied to a blast furnace tuyere by air transport and blown into the furnace. It is necessary to process in advance into granules having a certain particle size and bulk density suitable for blowing. In particular, film plastics have a lower bulk density than solid (bulk) plastics, and there is a problem that clogging in pipes is likely to occur during pneumatic transportation simply by crushing. Processing (granulation) into granules having a large particle size is practically essential.

For this reason, conventionally, waste plastics are separated into solid (bulk) plastics and film-like plastics in advance, solid plastics are processed into granules by crushing and pulverization, and film plastics are heated and granulated. Pre-processing, such as processing into particles by processing or the like, is performed.

Conventionally, as a method of heating and granulating a film-like plastic, a plastic is semi-molten or melted by frictional heat or external heating while crushing and stirring the film-like plastic with a rotating crushing blade or the like. A method of granulating a granular plastic by cooling by spraying water is known. However, since this granulation method is a batch process, the processing efficiency (productivity) is low, a post-drying step is necessary because water is used for cooling, and the particle size of the granular plastic obtained by the processing conditions and the amount of plastic input Disadvantages, such as the tendency to produce variations.

In view of such a problem, Japanese Patent Laid-Open No. 11-15 / 1999
Japanese Patent No. 6855 proposes a method of pretreating a film plastic using a specific plastic compression molding apparatus. In this method, a film-shaped plastic separated from waste plastic is rotatable so that a large number of die holes penetrate the entire circumference and the inside of this die ring is in contact with the inner peripheral surface of the die ring. Pre-processing using a plastic compression molding device equipped with rolling rollers arranged in the, the film-like plastic put into the inside of the die ring, the rolling roller with the inner peripheral surface of the die ring By pressing into the die hole of the die while compressing and crushing it, the plastic molded product that has passed through the die hole and extruded to the outer surface of the die is cut or scraped off from the outer surface of the die to become a furnace blowing raw material To obtain a granular plastic molding,
In the usual form of this pretreatment, a plastic molded product is obtained by semi-melting or melting the film-like plastic mainly due to frictional heat in the die hole and then solidifying.

According to this method, it is not necessary to spray water on the processed plastic for cooling, so that dried granular plastic can be obtained. Since continuous processing is possible, high processing efficiency (productivity) is obtained. In addition, there is an advantage that the plastic is extruded from a die hole, so that a granular plastic having a uniform particle size can be obtained.

[0007]

However, as a result of an experiment conducted by the present inventors, a granular plastic molded product obtained by pre-treating a film plastic by the above-described method has insufficient strength. It was found that the material easily collapsed during handling and pneumatic transportation after the treatment, and that the fluff-like foreign matter generated by the collapse was liable to cause troubles such as clogging in piping during pneumatic transportation and blowing from tuyeres. On the other hand, as a method of increasing the strength of the granular plastic molded product, a method of increasing the melting property of the film-shaped plastic in the die ring by external heating or the like can be considered, but in such a case, the molten plastic flows from the die hole. Since it flows out, a granular plastic molded product cannot be obtained properly.

Further, it has been found that a granular plastic molded product having a small strength and being easily disintegrated has a poor combustion efficiency as a raw material to be blown into a furnace. In other words, if the strength of the granular plastic molding is low, the particles will collapse during pneumatic transportation or during blowing into the furnace, and will be sent into the raceway at the tuyere at a small shape after collapse. Such small-sized plastics are scattered immediately after being sent into the raceway, so that the time of staying in the raceway is extremely short, and the combustion efficiency is deteriorated.

Accordingly, an object of the present invention is to solve such problems of the prior art, and to apply waste plastics including film plastics to granular plastic moldings having the necessary strength as raw materials for furnaces and the like. An object of the present invention is to provide a method capable of performing pre-processing efficiently.

[0010]

Means for Solving the Problems The inventors of the present invention have found that when a plastic film is granulated by using the above-mentioned plastic compression molding apparatus, it is impossible to obtain a granular plastic molded product having sufficient strength. The improvement measures were examined, and as a result, the following knowledge was obtained. Although a granular plastic molded product formed only from a film-like plastic is made of plastic that has been solidified after being melted or melted, sufficient strength cannot be obtained as described above. This is considered to be because it does not contain a solid material serving as a "core" effective for maintaining the strength of the grains.

On the other hand, by mixing a solid plastic and a film plastic in an appropriate ratio and granulating the mixture into a specific form, specifically, compressing or compressing and crushing waste plastic. In the granulation step of performing extrusion molding, performing granulation such that at least a part of the film-like plastic is semi-molten or melted and at least a part of the solid plastic is left without being semi-molten or melted. Thereby, the strength of the granular plastic molded article is remarkably increased, and collapse at the time of pneumatic transportation or blowing can be effectively prevented.

The reason why the granulated plastic molded product thus granulated has a high strength is that at least a part thereof is partially melted or melted and then solidified after film plastic is used as a “matrix” in the granular plastic molded product. There are solid plastic particles (solid plastic remaining without being semi-molten or melted in the granulation step) that can be the "core", and the "matrix" serves as a binder for bonding the "cores" together. It is thought that this is to fulfill its role.

That is, the basic concept of the prior art in using waste plastic as a raw material to be blown into a furnace is as follows: (a) Solid (mass) plastic has good air transportability only by crushing and crushing. Since granular plastics are obtained and this processing method is the lowest cost, solid plastics are pre-processed by crushing and crushing. (B) Film plastics are simply crushed and crushed as described above. In such a case, clogging in the piping is likely to occur during pneumatic transportation, etc., and therefore, after separating from solid plastic, granulate it into granular plastic using the above-mentioned heating granulator or compression molding device. It was that. On the other hand, the present inventors mix solid plastic and film plastic at an appropriate ratio when granulating waste plastic using the above-described plastic compression molding apparatus or the like, and then form the mixture into a specific form. By granulating, the strength of the obtained granular plastic molded article is dramatically increased. Therefore, according to this method, the solid plastic and the film plastic are separated and pretreated by a separate processing method. It has been found that the pretreatment of waste plastic can be performed more appropriately and efficiently than technology.

The present invention has been made based on such findings, and the features thereof are as follows. [1] Including solid plastic (A) (excluding foamable plastic) originating from a plastic molded product, and thin-walled plastic and / or foamable plastic (B) originating from a non-plastic molded product A method of processing a waste plastic into a granular plastic molded product by a granulation step of compressing or compressing and crushing the two plastics (A) and (B) in a mixed state, followed by extrusion molding, In the granulating step, at least a part of the thin plastic and / or the expandable plastic (B) is semi-molten or melted, and at least a part of the solid plastic (A) is semi-molten or melted. A method for pretreating waste plastic, characterized in that the waste plastic is left unremoved.

[2] The solid plastic (A) in the waste plastic to be pretreated in the pretreatment method of the above [1].
And the ratio of the thin plastic and / or the foamable plastic (B) is (A) / (A) + (B) =
A pretreatment method for waste plastics, which is 0.1 to 0.7. [3] The pretreatment method for waste plastic according to the pretreatment method according to the above [1] or [2], wherein the plastics (A) and (B) are preliminarily mixed and granulated.

[4] The pretreatment method for waste plastic according to any one of the above-mentioned [1] to [3], wherein the plastics (A) and (B) are mixed in the granulation step. . [5] In the pretreatment method according to any one of the above [1] to [4], one or two or more porous die rings are disposed inside the porous die ring so as to be in contact with the inner peripheral surface of the die ring. Using a plastic compression molding device with rolling rollers,
The waste plastic put into the inside of the porous die ring is compressed or compressed / crushed between the inner peripheral surface of the die ring by the rolling rollers, and is pushed into the die hole of the porous die ring, through the die hole. A method for pretreating waste plastics, comprising extruding plastics.

[6] In the pretreatment method of the above [5], the plastic molded product that has passed through the die hole and is extruded to the outer surface of the porous die is cut or scraped off from the outer surface of the porous die. A pretreatment method for waste plastics, which comprises obtaining a molded product. [7] The pretreatment method according to any one of the above [1] to [6], wherein the granular plastic molded product obtained by processing the waste plastic is used as a furnace blowing raw material or a solid raw fuel. Pretreatment method for waste plastics.

In the present invention, the plastic molded body which is the origin of the solid plastic (A) includes, in addition to the plastic molded body as a plastic product, plastic molded waste generated during plastic molding, plastic molded body And plastic parts scraps generated when processing or assembling into plastic parts or products.

[0019]

1 and 2 schematically show an example of a plastic compression molding apparatus used for carrying out the present invention. FIG. 1 is a perspective view and FIG. 2 is a front view. In this plastic compression molding apparatus, a perforated die ring 1 (hereinafter, simply referred to as “die ring”) having a plurality of die holes 4 penetrating all around, and an inner peripheral surface of the die ring inside the die ring 1. Rollers 2a and 2b rotatably arranged as described above, and a cutter 3 arranged outside the die ring 1 are provided. In the perspective view of FIG. 1, a part of a die hole 4 provided over the entire periphery of the die ring 1 is omitted.

The die ring 1 is formed of a ring body having an appropriate width, is rotatably supported by a device main body (not shown), and is driven to rotate by a drive device (not shown). A plurality of die holes 4 are provided in the circumferential direction and the width direction of the die ring 1. These die holes 4 are provided so as to penetrate between the inside (inner peripheral surface) and the outer side (outer peripheral surface) of the die ring 1 along the radial direction of the die ring 1. The diameter (diameter) of the die hole 4 is determined according to the size (diameter) of the granular plastic molded product to be granulated, but is usually about 3 to 20 mm. Die hole 4
The length (thickness of the ring tie 1) is determined from the viewpoint of the strength of the plastic molded product, but is usually 30 to 150 m.
m.

The rolling rollers 2a and 2b are rotatably supported by the main assembly of the apparatus, and are provided inside the die ring 1.
They are arranged so as to face each other by 80 °. These rolling rollers 2a and 2b are non-driven free rollers and are in contact with the inner peripheral surface of the die ring 1 and rotate with the rotation of the die ring 1 due to friction with the inner peripheral surface. The number of the rolling rollers 2 is arbitrary, and one or three or more rolling rollers may be provided. Further, the rolling elements 2a and 2b may be driven to rotate by a driving device. The cutter 3
Is provided so that the cutting edge thereof is in contact with the outer peripheral surface of the die ring 1 or is located in the vicinity of the outer peripheral surface.
A plastic molded product extruded out of the die ring 1 into a bar shape is cut into an appropriate length (or scraped off from the outer peripheral surface of the die ring).

In the above-described plastic compression molding apparatus, the die ring 1 is driven to rotate in the direction of the arrow in the figure, and the rolling rollers 2a and 2b are rotated accordingly.
Waste plastic x is introduced into the inside of the die ring 1 from an input port (not shown).
Is pressed into the die hole 4 of the die ring 1 while being compressed or compressed / crushed (also mixed) with the inner peripheral surface of the die ring 1 by the rolling rollers 2a and 2b. The waste plastic x pushed into the die hole 4 passes through the die hole and is sequentially extruded in a state of being molded into a rod shape on the outer surface side of the die ring 1 (plastic molded product y). By cutting into an appropriate length by the cutter 3, the granular plastic molded product a is granulated.

As will be described later, the waste plastic x partially becomes semi-molten or molten due to frictional heat in the above-mentioned granulation step, and then solidifies. In the most typical form in which a part of the waste plastic x is semi-molten or melt-solidified in the above-mentioned granulation step, frictional heat generated when a part of the waste plastic x passes through the die hole 4 with the inner peripheral surface of the die hole The plastic in the semi-molten or molten state is solidified in the region near the exit side in the die hole 4 or near the exit of the die hole 4 or when it is extruded from the die hole 4. I do. Needless to say, the form in which a part of the waste plastic x is semi-molten or melt-solidified is not limited to the specific one described above. For example, a part of the waste plastic x is compressed by the rolling rollers 2a and 2b or It may be semi-melted or melted during compression / crushing. Further, a cooling means may be provided outside the die ring 1 so that the plastic molding y extruded from the die hole 4 in a partially or molten state is cooled and solidified by the cooling means.

In the method of the present invention, when a waste plastic is molded and granulated by using such a plastic compression molding apparatus, a solid plastic (A) originating from a plastic molded body and a plastic non-plastic A waste plastic containing a thin-walled plastic (such as a film-like plastic) and / or an expandable plastic (B) derived from a molded body is charged, and both forms of the plastics (A) and (B) are mixed. In the granulation step of compression or compression / crushing-extrusion molding, at least a part of the plastic (B) is semi-molten or melted, and at least a part of the plastic (A) remains without being semi-molten or melted. This allows the plastic to solidify after being semi-molten or melted, without semi-molten or molten Obtain a granular plastic molded product a consisting of presence plastic. The granular plastic molded product a thus obtained has a remarkably improved strength as compared with a granular plastic molded product obtained by granulating only a thin plastic such as a film plastic.

Thus, both types of plastic (A),
The reason why the granular plastic molded product a obtained by granulating (B) in a specific form has high strength is considered to be as follows. That is, the basic structure of the granular plastic molded product a is the solid plastic (A) remaining without being semi-molten or melted in the granulation step.
Crushed material becomes a "core", and a thin-walled plastic and / or foamable plastic (B) solidified at least partially after being semi-molten or melted serve as a binder for the "core". It is considered to be a structure that constitutes, and by such a grain structure consisting of a core and a matrix, the strength is remarkably higher than that of a granular plastic molded product obtained by granulating only a thin plastic such as a film plastic. Is considered to be obtained.

FIG. 3 schematically shows an example of a cross section of the granular plastic molded product a. In FIG. 3, c is a solid plastic (A) grain (solid plastic remaining without being melted or melted in the granulation step), which is a “core” of a granular plastic molded product, and m is a “core” between the granules. A "matrix" plastic that serves as a bonding binder, at least a portion of which comprises a thin-walled plastic and / or foamable plastic (B) that has solidified after being semi-molten or melted.

In the above-mentioned granulation step, it is used to semi-melt or melt at least a part of the plastic (B) and to leave at least a part of the plastic (A) without semi-melting or melting. The structure and granulation conditions of the granulator are appropriately selected. For example, in the case of the plastic compression molding apparatus shown in FIGS. 1 and 2, the plastic is mainly melted or melted by frictional heat with the inner peripheral surface of the die hole when passing through the die hole 4. The semi-molten or molten form of the plastic is selected by selecting the diameter and length of the plastic, or by adjusting the rotation speed of the die ring 1 to adjust the amount of plastic pushed into the die hole 4 (production amount). It can be arbitrarily controlled. In general, solid plastics have a lower heat transfer characteristic than film plastics and thus are less likely to be melted. Therefore, by appropriately selecting the structure of the granulator and the granulation conditions as described above, the plastic (B ) Is semi-molten or melted, and at least a part of the plastic (A) is left without being semi-molten or melted, and the “core” is formed in the granulated plastic molded article a. Can exist as

The plastics (A) and (B) need to be compressed or compressed / crushed-extruded in a mixed state, but the mixing of the plastics (A) and (B) is put into a granulating apparatus. It may be carried out before carrying out, or a granulating apparatus of a type in which both plastics (A) and (B) are mixed in the apparatus may be used. The apparatus shown in FIGS. 1 and 2 corresponds to this. Further, both plastics (A), which are mixed in advance, are added to a granulating apparatus having such a mixing function.
(B) may be charged and mixing may be performed in this granulation apparatus. The crushing of plastic means, for example, crushing and crushing the solid plastic (A). However, the crushing of the plastic may be such that the solid plastic (A) supplied to the granulation step can become the above-mentioned "core". In the case of the particle size, it is not always necessary to be crushed in the granulation step.

Among solid plastics (A) originating from plastic molded articles, in addition to plastic molded articles as plastic products, plastic molding waste generated during plastic molding, plastic molded articles may be used as plastic parts or products. Includes plastic parts waste generated when processing or assembling. Examples of the plastic molded body include plastic containers (eg, PET bottles, plastic tanks, detergent containers), automobile parts (interior parts, bumpers, etc.), bodies and frames for office equipment or home electric appliances, decorative plywood, pipes, hoses, and magnets. Examples include, but are not limited to, cards, daily necessities and miscellaneous goods (hangers, stationery, plastic trays, plastic cups, and the like), printed circuit boards, and the like. In addition, the waste of expandable plastics such as styrene foam also originates from a plastic molded body. However, since the expandable plastic has a low bulk density and does not function as a “core” of a granular plastic molded article, the present invention does not use the same. It is not included in the category of solid plastic (A).

On the other hand, as the thin-walled plastic (B) originating from a non-molded plastic, for example, a plastic film (PET material, aluminum or paper laminate material), a plastic sheet (agricultural policy, a construction sheet, Packing sheets, PET sheets, etc.), plastic bags,
Examples include, but are not limited to, magnetic tapes, PP bands, packing material, and the like. In addition, since the expandable plastic such as styrene foam becomes a “matrix” instead of a “core” of the granular plastic molded product a,
In the present invention, it is treated as equivalent to a thin plastic. The waste plastics treated by the method of the present invention may contain materials other than plastics which are inevitably mixed, for example, inorganic materials such as paper, metal, wood, earth and sand, and stone.

In the present invention, the ratio of the solid plastic (A) to the thin plastic and / or the expandable plastic (B) in the waste plastic to be pretreated is determined from the viewpoint of the strength of the obtained granular plastic molded product a. The weight ratio is preferably in the range of (A) / (A) + (B) = 0.1 to 0.7, more preferably 0.2 to 0.6. (A)
If the weight ratio of / (A) + (B) is less than 0.1, the proportion of solids that become "cores" is insufficient, while (A) / (A)
When the weight ratio of + (B) exceeds 0.7, the amount of the “matrix” functioning as a binder between “nuclei” is too small,
In any case, sufficient strength cannot be obtained.

FIG. 4 is a graph showing the relationship between the weight ratio (A) / (A) + (B) and the compressive strength of the granulated plastic molded article based on the results of granulating various kinds of waste plastic. It is a summary of the relationship, according to which (A) /
When the weight ratio of (A) + (B) is in the range of 0.1 to 0.7, and preferably in the range of 0.2 to 0.6, high compressive strength that can withstand pneumatic transportation and the like is obtained. Also, (A) /
If the weight ratio of (A) + (B) is less than 0.1, the melting of the plastic (B) in the die hole becomes remarkable, and
When the weight ratio of (A) / (A) + (B) exceeds 0.7, the ratio of the plastic (A) becomes excessive and a bridge is easily formed in the die hole, so that the processing efficiency (productivity) is increased. Tends to decrease.

Since the granular plastic molded product a obtained by the method of the present invention has a sufficient strength, it collapses during handling and pneumatic transportation after granulation as compared with a conventional granulated plastic film alone. ), Which can appropriately prevent clogging in pneumatic transportation piping and the like. Specifically, while the powdering rate of a conventional granular plastic molded product made only from film-like plastic is at least about 10%, according to the present invention, the powdering rate is reduced to at least about 3%. Can be done. In addition, the rate of collapse during the process before or inside the furnace is extremely small, and the tuyere can reach the raceway at the tuyere while maintaining its size. Therefore, the residence time in the raceway can be sufficiently secured, and high combustion efficiency can be obtained.

Further, the granular plastic molded product a obtained by the method of the present invention has a higher bulk density than that of a granular plastic molded product granulated only from a film plastic, and accordingly, the amount of blowing into the furnace increases accordingly. Can be done. For example, depending on the weight ratio of the above (A) / (A) + (B), the bulk density is 1.1 to 1.1 in comparison with a conventional granulated film-like plastic alone.
It can be about 1.8 times the bulk density.

The present invention is not limited to the plastic compression molding apparatus (granulating apparatus) shown in FIGS. 1 and 2, but various types capable of performing at least compression or compression / crushing of plastic and subsequent extrusion molding. For example, an apparatus of a type in which plastic is compressed or compressed / crushed by a rotating screw body and pushed into a die hole may be used. In these granulating apparatuses including the apparatuses shown in FIGS. 1 and 2, the waste plastic charged may be semi-molten or melted by external heating.

However, the plastic compression molding apparatus shown in FIGS. 1 and 2 has a higher processing efficiency (productivity) than other granulating apparatuses, and has a function of compressing and crushing waste plastic (and a mixing function). High quality, hard solid plastic and flexible film plastic can be compressed and crushed together and extruded in a relatively uniform mixed state. Foreign materials other than plastic (paper, metal, etc.) in waste plastic Can be used to granulate plastic without any problem, a part of plastic can be semi-molten or melted only by frictional heat, and the plastic temperature during processing does not become excessively high. Even if a small amount of chlorine-containing resin such as vinyl is contained, there are advantages such as no generation of hydrogen chloride gas.
Therefore, it can be said that the apparatus is particularly suitable for implementing the present invention.

Next, specific treatment facilities and process examples of waste plastic to which the method of the present invention is applied will be described. FIG. 5 shows an example of a waste plastic processing facility and a process to which the method of the present invention is applied, in which solid plastic (A) and thin plastic (B) are supplied in a mixed state. In addition, these waste plastics contain a considerable amount of foreign matter such as metal or paper (for example, foreign matter mixing ratio of 5 to 3).
0 wt%) and a small amount of chlorine-containing plastic such as vinyl chloride (for example, a mixing rate of 1 wt% or less).

This processing equipment includes a sorter 5, a crusher 6, a dryer 7, a compression molding device 8, and a storage tank 9 from the upstream side of the processing step. The sorting machine 5 separates the waste plastic into a solid plastic (A), a thin plastic and a foamable plastic (B) (hereinafter, (B) will be described using “thin plastic” as an example) and It is for selecting a part of foreign matter such as metal contained in waste plastic, and for example, a rocking type or a wind type can be used. In the processing equipment and process shown in FIG. 5, for example, waste plastic in which solid plastic (A) and thin plastic (B) are mixed is supplied to the sorter 5, where the solid plastic (A) and thin plastic are mixed. In addition to being separated from the plastic (B), a part of foreign matter such as metal and earth and sand contained in the waste plastic is selectively removed.

As described above, the separation of the waste plastic into the solid plastic (A) and the thin plastic (B) by the sorter 5 is performed by the following manual sorting step 11a,
This is for facilitating the removal of foreign matter in 11b. That is, the foreign substances contained in the waste plastic cannot be completely removed only by the sorter 5 and must be removed by manual selection. However, the solid plastic (A) and the thin plastic (B) are mixed. In this state, the foreign matter cannot be efficiently removed by manual selection. For this reason, the waste plastic is once separated into a solid plastic (A) and a thin plastic (B), and foreign substances contained in each (particularly, many foreign substances are contained in the solid plastic (A)) are manually selected. It is removed at 11a and 11b.

Manual selection process 11a, 11 for foreign matter removal
b, the solid plastic (A) and the thin plastic (B) are both supplied to the same crusher 6 and crushed to a predetermined particle size. In order to adjust the ratio of the thin plastic (B) and the thickness, for example, as shown in FIG.
storage tanks 12a and 12b for temporarily storing the solid plastic (A) and the thin plastic (B) that have passed through a and 11b, respectively, and the solid plastic (A) to be supplied to the compression molding device 8 The solid plastic (A) and the thin plastic (B) are temporarily stored in the storage tanks 12a and 12b as appropriate in accordance with the ratio of the solid plastic (B) and the thin plastics (B).
May be supplied to the crusher 6 as appropriate.

The waste plastic (mixture of the solid plastic (A) and the thin plastic (B)) crushed by the crusher 6 is charged into the dryer 7 to a predetermined moisture content (for example, 20 wt% or less). After being subjected to the drying treatment, it is supplied to the compression molding device 8 and granulated to obtain the granular plastic molded product a as described above. Then, the granular plastic molded product a is stored in the storage tank 9 as a furnace blowing raw material or the like. In the above processing equipment, two or more crushers 6 may be provided in series according to the required particle size of the plastic. In addition, for the purpose of protecting the crusher 6, equipment for removing foreign substances such as a magnetic separator or a wind separator may be provided upstream of the manual separation process 11a, 11b, or upstream of the crusher 6, or a plurality of units. When the crushers are provided in series, they may be arranged between the crushers.

FIG. 6 shows another example of a waste plastic processing facility and process to which the method of the present invention is applied. The solid plastic (A) and the thin plastic (B) are supplied in a mixed state. In addition, such waste plastics contain a considerable amount of foreign matter such as metal and paper (for example, foreign matter mixing ratio of 5 to 30 wt%), and a considerable amount of chlorine-containing plastics such as vinyl chloride (for example, The processing equipment and steps suitable for the case where the mixture is contained are shown. The processing equipment includes a sorter 5, a crusher 6, a PVC separator 1
0, a dryer 7, a compression molding device 8, and a storage tank 9. The separator 5 is the same as that shown in FIG. 5, and the PVC separator 10 separates and removes chlorine-containing plastics such as vinyl chloride contained in waste plastics by specific gravity separation or the like.

In the processing equipment and process shown in FIG. 6, for example, waste plastic in which solid plastic (A) and thin plastic (B) are mixed is supplied to the sorting machine 5, where the solid plastic (A) And the thin plastic (B) (part of the foreign matter contained in the waste plastic is selectively removed), and the metal contained in each waste plastic in the manual sorting steps 11a and 11b as in FIG. Foreign matter such as is removed.

The solid plastic (A) and the thin plastic (B) that have passed through the manual sorting steps 11a and 11b are both supplied to the same crusher 6 and crushed to a predetermined particle size. Are provided with storage tanks 12a and 12b for temporarily storing the solid plastic (A) and the thin plastic (B), respectively. The solid plastic (A) and the thin plastic ( According to the ratio of B), the solid plastic (A) and the thin plastic (B) are temporarily stored in the storage tanks 12a and 12b as appropriate, or these storage tanks 12a and 12b are stored.
May be supplied to the crusher 6 as appropriate.

The waste plastic (mixture of the solid plastic (A) and the thin plastic (B)) crushed by the crusher 6 is used to separate and remove chlorine-containing plastics such as vinyl chloride in the PVC separator 10 and then dry. Machine 7 and a predetermined moisture content (for example, 20 wt.
% Or less), is supplied to the compression molding device 8 and granulated to obtain the granular plastic molded product a as described above. Then, the granular plastic molded product a is stored in the storage tank 9 as a furnace blowing raw material or the like. In the above processing equipment, two or more crushers 6 may be provided in series according to the required particle size of the plastic. In order to protect the crusher 6, equipment for removing foreign substances such as a magnetic separator or a wind separator may be provided upstream of the manual separation processes 11a and 11b, upstream of the crusher 6, or a plurality of units. When the crushers are provided in series, they may be arranged between the crushers.

FIG. 7 shows another example of a waste plastic processing facility and process to which the method of the present invention is applied, in which the solid plastic (A) and the thin plastic (B) are supplied separately. In addition, these waste plastics hardly contain foreign matter such as metal and paper (for example, foreign matter mixing rate of 5 wt% or less), and a small amount of chlorine-containing plastic such as vinyl chloride is mixed (for example, mixing rate is 1%).
(% by weight or less). The processing equipment includes crushers 6a and 6b for crushing the solid plastic (A) and the thin plastic (B) from the upstream side of the process, a dryer 7 for a crushed product of the thin plastic (B), It is provided with a mixing tank 13, a compression molding device 8, and a storage tank 9 for crushed plastic (A) and thin-walled plastic (B).

In the processing equipment and process shown in FIG. 7, the solid plastic (A) and the thin plastic (B) are crushed to a predetermined particle size by separate crushers 6a and 6b, respectively. The crushed product of the plastic (B) is put into the dryer 7 and has a predetermined moisture content (for example, 20 wt.
%) Is supplied to the mixing tank 13. On the other hand, the ratio (weight ratio) of the crushed solid plastic (A) to the crushed thin plastic (B) after crushing by the crusher 6a is (A) / (A) + (B). =
The whole or a part thereof is supplied to the mixing tank 13 so as to be 0.1 to 0.7, preferably 0.2 to 0.6.
If there is an excess of the crushed solid plastic (A), the crushed material is directly supplied to the storage tank 9 and stored as a furnace blowing raw material.

In the mixing tank 13, each crushed product of the solid plastic (A) and the thin plastic (B) is mixed, and the mixed crushed plastic is granulated by the compression molding device 8 and is described above. Such a granular plastic molded product a is obtained. Then, the granular plastic molded product a is stored in the storage tank 9 as a furnace blowing raw material or the like.
In the case where the compression molding device 8 has a supply hopper or the like, each crushed product of the solid plastic (A) and the thin plastic (B) can be directly mixed in the supply hopper. In this case, The mixing tank 13 can be omitted. In general, the crushed material of the solid plastic (A) has a small amount of adhering moisture, but when the moisture content is high (for example, 20 wt% or more), the mixing tank 13 is disposed on the upstream side of the dryer 7 and the solid plastic (A) is disposed. The crushed material of (A) can be dried together with the crushed material of thin-walled plastic (B).

In the above processing equipment, the crushers 6a, 6b
May be provided two or more in series according to the required particle size of the plastic. In addition, in order to protect the crushers 6a and 6b, equipment for removing foreign substances such as a magnetic separation device and a wind separation device is provided upstream of the crushers 6a and 6b or a plurality of crushers are provided in series. May be arranged between crushers. When the foreign matter mixing ratio is high (for example, 5 wt% or more), foreign materials such as a magnetic force sorting device, a wind force sorting device, a hand sorting conveyor, or the like are used to protect the crushers 6a and 6b and the compression molding device 8. When the equipment for removal is provided on the upstream side of the crusher or when a plurality of crushers are provided in series, it is preferable to arrange them between the crushers.

FIG. 8 shows another example of a waste plastic processing facility and process to which the method of the present invention is applied. The solid plastic (A) and the thin plastic (B) are (A).
/ (A) + (B) in a mixed state that satisfies the weight ratio of 0.1 to 0.7, and the waste plastic contains almost no foreign matter such as metal or paper. (For example, foreign matter mixing rate of 5 wt% or less) and a small amount of chlorine-containing plastic such as vinyl chloride (for example,
It shows processing equipment and steps suitable for the case where the mixing ratio is 1 wt% or less). This processing equipment includes, from the upstream side of the process, a manual sorting process 11, a crusher 6, a dryer 7, a compression molding device 8, and a storage tank 9.

In the processing equipment and process shown in FIG. 8, large amounts of foreign substances are removed from the input waste plastic by a manual sorting process 11 and then crushed by a crusher 6 to a predetermined particle size. A predetermined moisture content (for example,
(20 wt% or less) and granulated by the compression molding machine 9. Then, the granular plastic molded product a is stored in the storage tank 9 as a furnace blowing raw material or the like.

In the above processing equipment, two or more crushers 6 may be provided in series according to the required particle size of the plastic. In addition, in order to protect the crusher 6, if a device for removing foreign substances such as a magnetic separation device or a wind separation device is provided upstream of the crusher 6 or a plurality of crushers are provided in series, the crusher is used. It may be arranged between them. When the foreign matter mixing ratio is high (for example, 5 wt% or more), foreign matters such as a magnetic force sorting device, a wind sorting device, a hand sorting conveyor, and the like are removed in order to protect the crusher 6 and the compression molding device 8. When a plurality of crushers are provided upstream of the crusher or a plurality of crushers are provided in series, it is preferable that the equipment be disposed between the crushers.

FIG. 9 shows another example of a waste plastic processing facility and process to which the method of the present invention is applied, wherein solid plastic (A) and thin plastic (B) are supplied in a mixed state. In addition, these waste plastics contain a considerable amount of foreign matter such as metal or paper (for example, a foreign matter mixing rate of 5 to 30 wt%), and a small amount of chlorine-containing plastic such as vinyl chloride (for example, It shows processing equipment and steps suitable for the case where the mixing ratio is 1 wt% or less).

This processing equipment includes a sorting machine 5 and a manual sorting process 11a, 11 for manually sorting the solid plastic (A) and the thin plastic (B) from the upstream side of the process.
b, crushers 6a and 6b for crushing both plastics (A) and (B) respectively, dryer 7 for crushed thin plastic (B), solid plastic (A)
And a mixing tank 13 for each crushed material of thin plastic (B),
A compression molding device 8 and a storage tank 9 are provided.

Here, the sorting machine 5 is the same as that shown in FIGS. After the waste plastic supplied to the sorting machine 5 is separated into a solid plastic (A) and a thin-walled plastic (B), and after a part of foreign substances such as metal and earth and sand contained in the waste plastic is sorted and removed. ,
As in FIGS. 5 and 6, foreign substances such as metals contained in each waste plastic are removed in the manual sorting steps 11a and 11b.

The solid plastic (A) and the thin plastic (B) which have passed through the manual sorting steps 11a and 11b are crushed to a predetermined particle size by separate crushers 6a and 6b, respectively. The crushed product B) is put into the dryer 7 and has a predetermined moisture content (for example, 20 wt%).
After the drying treatment described below, the mixture is supplied to the mixing tank 13. On the other hand, the ratio (weight ratio) of the solid plastic (A) crushed by the crusher 6a to the thin plastic (B) is (A) / (A) + (B) = 0.1 to 0.7. The whole or a part of the solid plastic (A) is supplied to the mixing tank 13 so as to be preferably 0.2 to 0.6. Is supplied directly to the storage tank 9 and stored as a furnace blowing raw material or the like.

In the mixing tank 13, each crushed product of the solid plastic (A) and the thin plastic (B) is mixed, and the mixed crushed plastic is supplied to the compression molding device 8 and granulated. As described above, a granular plastic molded product a is obtained. Then, the granular plastic molded product a is stored in the storage tank 9 as a furnace blowing raw material or the like. In the case where the compression molding device 8 has a supply hopper or the like, each crushed product of the solid plastic (A) and the thin plastic (B) can be directly mixed in the supply hopper. In this case, The mixing tank 13 can be omitted. In general, the crushed material of the solid plastic (A) has a small amount of attached water, but when the moisture content is high (for example, 20 wt% or more), the mixing tank 13 is arranged on the upstream side of the dryer 7 and the solid plastic (A) is disposed. The crushed product of (A) can be dried together with the crushed product of the thin plastic (B).

In the above processing equipment, the crushers 6a, 6b
May be provided two or more in series according to the required particle size of the plastic. In order to protect the crushers 6a and 6b, equipment for removing foreign substances such as a magnetic separator or a wind separator is installed upstream of the manual separation processes 11a and 11b or upstream of the crushers 6a and 6b. Alternatively, when a plurality of crushers are provided in series, they may be arranged between the crushers.

FIG. 10 shows another example of a waste plastic processing facility and process to which the method of the present invention is applied. Solid plastic (A) and thin plastic (B) are supplied in a mixed state. In addition, these waste plastics contain a considerable amount of foreign matter such as metal and paper (for example, a foreign matter mixing rate of 5 to 30 wt%), and also contain a considerable amount of chlorine-containing plastics such as vinyl chloride (for example, mixed in). (The rate is 1 wt% or more).

This processing equipment includes a sorting machine 5 for manually sorting solid plastic (A) and thin plastic (B) from the upstream side of the process.
b, crushers 6a and 6b for crushing both plastics (A) and (B) respectively, a PVC separator 10 for removing chlorine-containing plastic from crushed thin plastic (B), thin plastic ( A crushed material dryer 7 for B), a mixing tank 13 for each crushed material of solid plastic (A) and thin-walled plastic (B), a compression molding device 8 and a storage tank 9 are provided.

Here, the separator 5 is the same as that shown in FIGS. 5 and 6, and the PVC separator 10 is
Is the same as that shown in FIG. After the waste plastic supplied to the sorting machine 5 is separated into a solid plastic (A) and a thin-walled plastic (B), and after a part of foreign substances such as metal and earth and sand contained in the waste plastic is sorted and removed. 5 and 6, foreign matter such as metal contained in each waste plastic is removed in the manual sorting steps 11a and 11b.

The solid plastic (A) and the thin plastic (B) that have passed through the manual sorting steps 11a and 11b are crushed to predetermined particle sizes by separate crushers 6a and 6b, respectively. The crushed material of B) is PVC
Chlorine-containing plastics such as vinyl chloride are separated and removed in the separation device 10 and then put into the dryer 7.
After being dried to a predetermined moisture content (for example, 20 wt% or less), the water is supplied to the mixing tank 13. On the other hand, the ratio (weight ratio) of the solid plastic (A) crushed by the crusher 6a to the thin plastic (B) is (A) /
(A) + (B) = 0.1-0.7, preferably 0.2-
The whole or a part of the solid plastic (A) is supplied to the mixing tank 13 so as to be 0.6, and if there is an excess of the crushed solid plastic (A), the crushed substance is directly supplied to the storage tank 9. And stored as furnace blowing raw material.

In the mixing tank 13, the crushed materials of the solid plastic (A) and the thin plastic (B) are mixed, and the mixed crushed plastic is supplied to the compression molding device 8 to be granulated, and then granulated. As described above, a granular plastic molded product a is obtained. Then, the granular plastic molded product a is stored in the storage tank 9 as a furnace blowing raw material or the like.

When the compression molding device 8 has a supply hopper or the like, the crushed materials of the solid plastic (A) and the thin plastic (B) can be directly mixed in the supply hopper. In this case, the mixing tank 13 can be omitted. In general, the crushed material of the solid plastic (A) has a small amount of attached water, but when the moisture content is high (for example, 20 wt% or more), the mixing tank 13 is arranged on the upstream side of the dryer 7 and the solid plastic (A) is disposed. The crushed material of (A) can be dried together with the crushed material of thin-walled plastic (B).

In the above processing equipment, the crushers 6a, 6b
May be provided two or more in series according to the required particle size of the plastic. In addition, for the purpose of protecting the crushers 6a and 6b, equipment for removing foreign substances such as a magnetic separation device or a wind separation device is provided by a manual selection process 11a or 11b.
Upstream, or upstream of the crushers 6a, 6b, or when a plurality of crushers are provided in series, they may be arranged between the crushers. In addition, general solid plastic (A) has a very low content of chlorine-containing plastic (usually,
(1 wt% or less), it is not necessary to treat in the PVC separator 10, but when the content of chlorine-containing plastic is high, the mixing tank 13 is arranged on the upstream side of the PVC separator 10, and the solid plastic (A) After supplying each crushed product of the thin-walled plastic (B) and the thin-walled plastic (B) to the mixing tank 13, the mixture may be treated by the PVC separator 10 to remove the chlorine-containing plastic.

In each of the processing facilities shown in FIGS. 5 to 10, the transfer of the waste plastic or the granular plastic molded product a between the apparatuses is performed by a conveyor or a pneumatic transport pipe. The granular plastic molded product a obtained by pretreating waste plastic by the method of the present invention can be used as a raw material for blowing into various furnaces including a blast furnace, a solid raw fuel, and the like. As the solid raw fuel, for example, a raw fuel for a coke oven can be used. However, it can be used as a raw fuel for any other use. ) Can be appropriately prevented.

[0067]

EXAMPLES Example 1 Pretreatment of waste plastics according to the present invention and comparative examples (conventional method) was performed using the granulator shown in FIGS. In this embodiment, the inner diameter of the die:
840 mm, die width: 240 mm, die thickness (die hole length): 60 mm, rolling roller diameter: 405
mm, die hole diameter: 6 mm, number of die holes: 10,000 Using a granulator with a solid plastic (A) and a thin plastic (B) (film plastic), a total of 1.0
It was fed at a rate of ~ 1.5 t / h. Thin plastic (B) is polyethylene 32wt%, polypropylene 31
wt%, polystyrene 22wt%, other (paper etc.) 1
5 wt%. The solid plastic (A) is composed of 37 wt% of polyethylene, 34 wt% of polypropylene, 22 wt% of polystyrene, and 7 wt% of other materials (such as paper).

Table 1 shows the results of the present invention and comparative examples.
The strength, productivity, and bulk density of the examples of the present invention shown in the same table are 100 compared to the comparative example using only the conventional thin plastic (B).
Is the value when As shown in the table, in the examples of the present invention, remarkable results were observed in strength, productivity, and bulk density.

[0069]

[Table 1]

[Embodiment 2] Using the granulating apparatus shown in FIGS. 1 and 2 and having different die ring configurations (die hole diameter and length), the processing flow shown in FIGS. Pretreatment of waste plastics of various materials. In addition,
Except for the configuration shown in Table 2, the configuration of the granulating apparatus is substantially the same as the apparatus used in Example 1. Bulk density of granulated plastic,
Table 2 shows the powdering rate and the processing speed together with the content of the waste plastic to be processed. According to the table, it is found that by performing the pretreatment under the conditions of the present invention, a granular plastic molded product having high strength can be efficiently obtained.

[0071]

[Table 2]

[0072]

As described above, according to the method of the present invention, waste plastics including film plastics can be efficiently converted into granular plastic moldings having the necessary strength as raw materials for furnace blowing and other solid raw fuels. Processing can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an example of a plastic compression molding apparatus used for carrying out the present invention.

FIG. 2 is a front view schematically showing the plastic compression molding apparatus shown in FIG.

FIG. 3 is an explanatory view schematically showing a cross section of a granular plastic molded product obtained by the present invention.

FIG. 4 shows the weight ratio of solid plastic (A) to thin plastic and / or foamable waste plastic (B) in waste plastic supplied to a plastic compression molding apparatus, and the strength and strength of the obtained granular plastic molded product. Graph showing the relationship with productivity

FIG. 5 is an explanatory view showing an example of waste plastic processing equipment and steps to which the method of the present invention is applied.

FIG. 6 is an explanatory view showing another example of waste plastic processing equipment and steps to which the method of the present invention is applied.

FIG. 7 is an explanatory view showing another example of waste plastic processing equipment and steps to which the method of the present invention is applied.

FIG. 8 is an explanatory view showing another example of waste plastic processing equipment and steps to which the method of the present invention is applied.

FIG. 9 is an explanatory view showing another example of a waste plastic processing facility and process to which the method of the present invention is applied.

FIG. 10 is an explanatory view showing another example of waste plastic processing equipment and steps to which the method of the present invention is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Die ring, 2a, 2b ... Rolling roller, 3 ... Cutter, 4 ... Die hole, 5 ... Sorter, 6, 6a, 6b ... Crusher, 7 ... Dryer, 8 ... Plastic compression molding device, 9 ...
Storage tank, 10 ... PVC separator, 11, 11a, 11b
... hand sorting process, 12a, 12b ... storage tank, 13 ... mixing tank, a ... granular plastic molded product, x ... waste plastic, y ... plastic molded product

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroki Ishiguro 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Nihon Kokan Co., Ltd. (72) Inventor Yoji Ogaki 1-2-1, Marunouchi, Chiyoda-ku, Tokyo Sun (72) Inventor Shuo Terada 1-1-2 Marunouchi, Chiyoda-ku, Tokyo, Japan Nihon Kokan Co., Ltd. (72) Minoru Asanuma 1-2-1, Marunouchi, Chiyoda-ku, Tokyo, Japan (72) Inventor Hideo Nakamura 1-2-1, Marunouchi, Chiyoda-ku, Tokyo F-term (reference) 4F301 AA12 AA15 AA25 BA12 BA17 BA23 BB05 BB07 BC12 BD09 BD34 BD38 BE29 BF12 BF16 BF31 BG04 BG05 BG11 BG12 4H015 AA02 AA17 AB01 BA13 BB03 BB05 BB06 CA03 CB01

Claims (7)

[Claims] 1. A solid plastic (A) (excluding foamable plastic) originating from a plastic molded body, and a thin plastic and / or foamable plastic (B) originating from a non-plastic molded body. Waste plastics containing the two plastics (A), (B)
Is a method of processing into a granular plastic molded product by a granulation step of performing compression or compression / crushing and subsequent extrusion molding in a state in which the mixture is mixed, wherein the granulation step includes thin plastic and / or foaming. At least a part of the conductive plastic (B) is semi-molten or melted, and the solid plastic (A)
A pre-treatment method for waste plastics, wherein at least a part of the waste plastic is left without being semi-molten or melted. 2. The weight ratio of the solid plastic (A) and the thin plastic and / or foamable plastic (B) in the waste plastic to be pretreated is (A) /
2. The method for pretreating waste plastic according to claim 1, wherein (A) + (B) = 0.1 to 0.7. 3. The plastics (A) and (B) are mixed in advance and granulated.
A method for pretreating waste plastic according to item 1. 4. The method for pretreating waste plastic according to claim 1, wherein the plastics (A) and (B) are mixed in the granulation step. 5. A plastic compression molding apparatus comprising: a perforated die ring; and one or more rolling rollers disposed inside the perforated die ring so as to be in contact with the inner peripheral surface of the die ring; The waste plastic put into the inside of the perforated die ring is pressed or compressed / crushed between the inner peripheral surface of the perforated die ring and the rolling plastic, and is pushed into the die hole of the perforated die ring, and the plastic is passed through the die hole. 5. The method for pretreating waste plastic according to claim 1, wherein said resin is extruded. 6. A granular plastic molded product obtained by cutting or scraping off a plastic molded product that has passed through the inside of a die hole and extruded to the outer surface of a porous die ring. 6. The method for pretreating waste plastic according to 5. 7. A granular plastic molded product obtained by processing waste plastic, which is used as a furnace blowing raw material or a solid raw fuel. A method for pretreating waste plastic according to the above.