JPH11226955A - Method for treating used foamed polystyrene and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the molding efficiency of polystyrene pellets based on used foamed polystyrene. SOLUTION: This device for treating used foamed polystyrene comprises a crushing means 2 which grinds used foamed polystyrene after removal of impurities to the specified size, a volume reduction means 8 which removes air and gas contained in the polystyrene crushed by the crushing means 2 by compression and granulates it to the specified bulk density and the specified size, a fixed quantity feed means 10 which feeds the foamed polystyrene compressed and granulated by the volume reduction means 8 by the fixed quantity, and pellet molding means 12, 18 which fuse and knead the polystyrene fed by the fixed quantity by the fixed quantity feed means 10, in a short time, with the help of an extrusion machine 11, then extrude the polystyrene after removing air and gas contained therein further using a deaeration means, and pelletize the polystyrene following the cooling and setting process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a so-called expanded polystyrene (hereinafter referred to as expanded polystyrene) widely used as a packaging material for home electric appliances and electronic devices, or a food tray used for packaging in a supermarket or the like. Regarding a method and an apparatus for treating used expanded polystyrene for recycling used ones as polystyrene pellets (hereinafter simply referred to as pellets),
The present invention relates to a method and an apparatus for treating used polystyrene foam, which is pre-compressed and further degassed by an extruder into pellets.

[0002]

2. Description of the Related Art In recent years, packaging materials for home appliances and electronic devices, as well as containers for keeping freshness such as fish boxes, fruits and vegetable boxes, as well as civil engineering and construction materials, and food trays for packaging in supermarkets and the like have been widely used. So-called expanded polystyrene (hereinafter referred to as expanded polystyrene) is used in large quantities. However, there are problems in terms of disposal, such as shortening the life of the incinerator by generating high temperatures during incineration, and not biodegrading when discarded.Recycling is extremely difficult in recent years from the viewpoint of environmental protection and resource saving. Is desired.

For this reason, the following method has been devised in which used expanded polystyrene is treated and recycled into polystyrene pellets (hereinafter simply referred to as pellets). As a first method, there is a method of heating and melting by an electric heater, a kerosene burner, hot air by a gas or the like, frictional heat, and the like, compressing it into an ingot shape, crushing and recycling as pellets.

[0004] As a second method, there is a method in which used foamed polystyrene is crushed and mixed with pre-foamed new foamed polystyrene beads, and the foamed polystyrene is recycled again as foamed polystyrene. As a third method, citrus such as d-limonene and styrosolve; terpenes such as dipentene; ketones such as methyl ethyl ketone, diethyl ketone, methyl-n-propyl ketone and hexanone; and aromatics such as benzene, toluene, xylene and ethyl benzene. There is a method of dissolving in a solvent such as hydrocarbons, halogenated hydrocarbons such as ethylene chloride, trichloroethylene and carbon tetrachloride, and esters such as methyl acetate, ethyl acetate and isoamyl acetate, and separating and recycling polystyrene from the solvent. As a separation method, the solution is heated, the solution is evaporated, and the polystyrene resin is melted for separation. Practical methods include d-limonene, styrosolve, and a dissolution method using an organic solvent.

[0005] As a fourth method, used polystyrene foam is crushed and directly supplied to a single-screw extruder.
There is a method of melting and recycling as pellets.
(For example, see Gyosei Co., Ltd., September 1, 1995, "Styrofoam Recycling Manual-Wholesale Market Environmental Measures Business Report", pp. 52-55)

[0006]

However, the above-mentioned conventional method has the following problems. In the case of the first method, when the used expanded polystyrene is heated and melted by hot air from a heater, a kerosene burner, a gas or the like, frictional heat, etc., the molecular weight of the polystyrene is greatly reduced due to a long exposure time to a high temperature, and the physical properties of the pellet are increased. The drop is large. This is because the melting temperature of polystyrene is as low as about 80 ° C., and the molecular weight decreases as the polystyrene is easily melted and exposed to a high temperature for a longer time. At the same time, the heat causes the ingot to change color to black, making it an application as low-quality expanded polystyrene. Further, an odor is generated during the melting process. Furthermore, the expanded polystyrene before heating is
Since it is foamed 30 to 50 times, there is a problem that the amount of processing per time is small.

In the case of the second method, when the used expanded polystyrene is crushed and mixed with a pre-expanded new expanded polystyrene bead, and the resulting foam is recycled again into expanded polystyrene, the adhesion between the expanded particles is poor. For this reason, there is a problem that the appearance of the molded article of expanded polystyrene is poor and the physical strength is inferior to that of expanded polystyrene produced only with virgin pellets. Further, only the expanded polystyrene can be molded by this method, and cannot be used as a polystyrene resin.

In the case of dissolving in the third method, when the solvent and the polystyrene resin are separated, a treatment such as a reduced pressure treatment, a gas filling treatment with nitrogen or the like, and a high-temperature heating treatment must be performed. Because equipment becomes large and expensive,
There is a problem that the profitability of the pellets is not appropriate and it is difficult to spread them. Further, the solvent may decrease the physical properties of the polystyrene resin. For example, when melted by solvent treatment, the molecular weight of polystyrene is reduced by about 10%, and the quality as pellets is reduced.

The fourth method of supplying directly pulverized expanded polystyrene to an extruder mainly has the following problems. The expanded polystyrene foamed 30 to 50 times is pulverized and supplied to an extruder. Since the bulk density of the expanded polystyrene is very small (about 0.02 g / cc), the extruder per unit time is extruded. Is very small, and the efficiency of pellet processing is very poor. In order to increase the processing efficiency, the extruder must be increased in size, occupying a larger area, and resulting in higher processing costs. In addition, since the bulk density of the expanded polystyrene is very small and very light, when the pulverized expanded polystyrene is supplied to the extruder, a pressing device such as a screw feeder for forcibly pressing the extruder has to be used. .
It is difficult for the pushing device to supply a fixed amount to the extruder with constant accuracy, and the supply amount and the bulk density of the raw materials become uneven, so that when the strand is discharged from the extruder, unevenness occurs, that is, surging occurs. In addition, there is a problem that the strand is easily broken. When the strand breaks, the strand cannot be produced stably, and the productivity of the pellets decreases. For example, even if the pulverized expanded polystyrene to be supplied to the indenting device is previously supplied in a fixed amount by a constant-amount supply device, it is difficult to precisely supply a fixed amount because the expanded polystyrene is extremely lightweight.

Further, in order to reduce the residual ratio of air or gas in the extruder and to form pellets without bubbles, it is necessary to sufficiently knead and deaerate the extruder. It has to be lengthened, and as a result, there is a problem that the extruder device becomes large. On the other hand, if the screw of the extruder is long, the residence time until it is melted and discharged is long, so that the raw material polystyrene is exposed to high temperatures for a long time. There is a problem that it becomes a pellet. On the other hand, if the extruder is discharged in a short time with a small extruder so that the molecular weight of polystyrene does not decrease, air bubbles enter the pellets and the quality is reduced because the air or gas residual ratio of the pellets is large. There is a problem that the strand is liable to be broken due to bubbles inside the strand when it is discharged from the air. Furthermore, before supplying to the extruder, a warehouse for storing the crushed expanded polystyrene is required, but even if the expanded polystyrene is crushed, since the volume is expanded about 30 to 50 times, There is a problem that the warehouse is very large and the occupied area is very large. Further, when the crushed material is directly supplied to the extruder and supplied, the shape and size of the supplied raw material are not uniform, and the raw material cannot be supplied stably. There is a problem that occurs.

An object of the present invention is to solve such a problem. That is, first, according to the present invention, the raw material supply amount can be increased without changing the size of the extruder,
It is an object of the present invention to provide a method and an apparatus for treating used expanded polystyrene, which can improve the molding efficiency of an extruder and significantly improve the productivity of pellets. Secondly, an object of the present invention is to provide a method and an apparatus for treating a used expanded polystyrene which can supply a raw material to an extruder with high accuracy and prevent strand breakage due to surging and can operate stably. is there.

A third object of the present invention is to provide a method and an apparatus for treating used polystyrene foam which can form high-quality pellets having a low residual ratio of air or gas and no deterioration in physical properties. . Fourth, the present invention provides:
An object of the present invention is to provide a method and an apparatus for processing used polystyrene foam, which can reduce the size of an extruder and the size of a warehouse before supplying raw materials to the extruder, thereby significantly reducing the equipment occupation area. It is.

[0013]

The present invention solves the above-mentioned problems by pre-compressing used expanded polystyrene and then degassing with an extruder to form pellets. That is, according to the first aspect of the present invention, the used expanded polystyrene is previously compressed to remove air and gas inside the expanded polystyrene to have a predetermined bulk density and a predetermined size, and then melt-kneaded and further deaerated. And removes air and gas from expanded polystyrene to form pellets. According to such a method, in order to compress and mold in advance, the crushed expanded polystyrene is directly
The bulk density can be significantly increased by removing air and gas in the expanded polystyrene in advance by compressing and extruding air into the extruder. The raw material supply weight can be increased, and the molding efficiency of the pellet is dramatically improved.

According to a second aspect of the present invention, there is provided a crushing means (2) for crushing used expanded polystyrene to a predetermined size;
Volume reducing means (8) for compressing the expanded polystyrene crushed by the crushing means (2) to remove air and gas inside the expanded polystyrene and granulating the expanded polystyrene to a predetermined bulk density and a predetermined size; A quantitative supply means (1) for quantitatively supplying the expanded polystyrene compressed and granulated by (8).
0) and the expanded polystyrene supplied quantitatively by the quantitative supply means (10) are melt-kneaded in a short time by an extruder (11), and further extruded after removing air and gas inside the expanded polystyrene by degassing. And pellet forming means (12, 18) for forming into a pellet after cooling and solidifying. With such a configuration, the melt extruder can be sufficiently degassed by short-time melt-kneading, so that the time during which the expanded polystyrene is exposed to a high temperature is extremely short. It can be formed into high quality pellets having a small residual ratio of air or gas.

According to a third aspect of the present invention, there is provided a crushing means (2) for crushing used expanded polystyrene from which impurities have been removed in advance to a predetermined size, and pneumatic transportation of the expanded polystyrene crushed by the crushing means (2). (3, 6, 9, 16a, 16b, 16c), wind separation means (5) for removing impurities from the transferred expanded polystyrene by weight separation by wind force, and wind separation means (5) (8) volume reduction means for compressing the expanded polystyrene from which impurities have been removed by removing air and gas inside the expanded polystyrene and granulating the expanded polystyrene to a predetermined bulk density and a predetermined size.
A quantitative supply means (10) for quantitatively supplying the expanded polystyrene compressed and granulated by the volume reducing means (8);
An extruder (11) which melts and kneads the expanded polystyrene supplied in a fixed amount by the fixed amount supply means (10) in a short time, and extrudes as a strand after removing air and gas of the expanded polystyrene almost completely by degassing; An impurity removing means (17) provided on the discharge side of the extruder (11) for removing impurities by filtration, and a water tank (18) for cooling and solidifying the strand extruded from the extruder (11);
And a pelletizer (12) for forming the cooled and solidified strand into pellets. With such a configuration, the empty feeding means (3, 6, 9, 16a, 16b, 16c)
As a result, the crushed expanded polystyrene can be reliably and efficiently transported without scattering. As a means of air transport,
Fans (16a, 16b, 16c) blow air in the pipe,
It is preferred to capture with cyclones (3,6,9).

Further, by providing the wind separation means (5), impurities can be removed before being fed into the volume reducing means (8), so that impurities can be minimized during melt-kneading in the extruder (11). . In addition, since the separation is performed by wind power, impurities are removed in a dry atmosphere, so that moisture does not adhere to the expanded polystyrene. Also. There is no need for a large-scale water treatment facility unlike the removal of impurities by washing. Impurity removing means (17)
For example, a screen changer type impurity removing unit is suitable. By providing the impurity removing means (17), impurities that may remain are further removed after melt-kneading in the extruder (11), so that impurities can be almost completely removed and high-quality pellets can be formed. .

According to a fourth aspect of the present invention, in the apparatus for treating used polystyrene foam according to the second or third aspect, the extruder (11) is a twin-screw extruder. Since a twin screw extruder is used, the size of the apparatus can be further reduced, and the installation area can be reduced.
It is preferable to use a twin-screw extruder as a co-rotating screw. Thereby, the expanded polystyrene as a raw material can be reliably discharged by the self-screening property of the screw and the stability of operation. According to a fifth aspect of the present invention, in the processing apparatus of the used expanded polystyrene according to the fourth aspect, the extruder (11) is provided with an auxiliary raw material supply means (14) capable of quantitatively supplying an auxiliary raw material such as a pigment. It is. By supplying the pigment to the twin-screw extruder (11) from the auxiliary raw material supply means (14), the pigment is sufficiently kneaded by the twin-screw of the extruder (11), so that the molded pellet can be colored.

In the apparatus for treating used polystyrene foam according to any one of the above, the volume reducing means (8) has a bulk density of about 0.2 g / c.
It is preferable that the compression is made to be c or more. By setting the bulk density to about 0.2 g / cc or more, the extruder (1
The processing efficiency of 1) is remarkably improved, stable production can be performed without strand breakage, high-quality pellets can be formed, and downsizing of the warehouse and the extruder (11) can be particularly suitably performed. In addition, the code | symbol in a parenthesis etc. shows the corresponding member of embodiment, etc.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, an apparatus for treating used expanded polystyrene according to an embodiment of the present invention will be described in detail with reference to the drawings. Examples of used polystyrene foam include foam polystyrene (so-called polystyrene foam) used in packing materials for home appliances and electronic devices, as well as in freshness containers and food trays for fish boxes and fruits and fresh foodstuffs, as well as in civil engineering and construction materials. ). Since these expanded polystyrenes are expanded to a bulk density of about 30 to 50 times, the bulk specific gravity is very small. What is used as a packing material is foamed about 50 times (bulk density of about 0.02 g).
/ Cc), about 30 times that of food trays.

As shown in FIG. 1, the apparatus for treating used expanded polystyrene of the present embodiment basically includes a crushing means 2 for crushing used expanded polystyrene from which impurities have been removed to a predetermined size. The crushed expanded polystyrene was compressed to remove air and gas inside the expanded polystyrene and granulated to a predetermined size with a predetermined bulk density, and compressed and granulated by the volume reducing means 8. A fixed-quantity supply means 10 for quantitatively supplying the expanded polystyrene, and the foamed polystyrene quantitatively supplied by the fixed-quantity supply means 10 are melted and kneaded in a short time by an extruder 11, and the air inside the expanded polystyrene is further degassed, Pellet forming means 12 and 18 for extruding after removing the gas, solidifying by cooling, and then forming into pellets.

More specifically, as shown in FIG. 1, a belt conveyor 1, crushing means 2, cyclones 3, 6, 9 and fans 16a, 16b, 16c, which are air feeding means, 7, a wind sorting unit 5, a volume reducing unit 8, a feeder (quantitative feeding unit) 10, an extruder 11, a water tank 18, a pelletizer 12, a pellet sorter 13,
It comprises an auxiliary material feeder (auxiliary material supply means) 14 and a stock tank 15.

In the present embodiment, as the used expanded polystyrene, a pre-treated one which has been cleaned by removing impurities such as labels, seals and foreign substances in advance is used. The belt conveyor 1 is formed of a wide conveyor, and can be charged with pretreated expanded polystyrene such as containers of various sizes and the like by a machine such as a shovel or manually. The crushing means 2 forcibly presses the expanded polystyrene conveyed from the belt conveyor 1 against a crushing rotor, which is a sharp blade, and crushes the polystyrene into a substantially predetermined size by low-speed rotation. Since the pulverization is performed at a low speed, the pulverization can be performed quickly without giving a heat change. The crushing means 2 is not a problem with an existing device, but is preferably a device capable of crushing the expanded polystyrene to a diameter of about 10 to 50 mm in order to remove the expanded polystyrene and impurities in the next step of air separation. As the crushing means 2, for example, a rotary press crusher RPC of Miike Iron Works Co., Ltd. is suitable.

The fan 16a pneumatically transports the pulverized expanded polystyrene with a blower or the like, and sucks and collects it with the cyclone 3. The cyclone 3 is configured so that the entire cyclone is constituted by a bag with a metal frame, so that an ultralight material such as expanded polystyrene can be reliably collected without scattering. When the foamed polystyrene is transported by air, it is transported through a pipe or the like. Although not shown, the air generated by the cyclones 3, 6, and 9 is returned to the inside of the pipe and circulated and used to air-feed the expanded polystyrene. By carrying out pneumatic transportation in this way, the expanded polystyrene can be supplied to the extruder 11 in a later stage in a dry state.

The wind power sorting means 5 sorts heavy and light materials by wind force, and removes impurities such as labels and adhesive tapes which could not be removed by the pretreatment as heavy materials to remove impurities. . The pulverized expanded polystyrene is sorted out as a lightweight material. In addition, since the wind separation is performed in a closed space, a bad smell is not released to the outside. As the wind power selection means 5, for example,
A wind separator of Oike Iron Works Co., Ltd. is suitable.

The quantitative feeders 4 and 7 are composed of screw conveyors, and forcibly and quantitatively pulverize and expand the expanded polystyrene by means of a wind separation means 5 and a volume reduction device 8.
Is to be transported. The volume reducing means 8 is for removing air and gas in the expanded polystyrene in advance to obtain a predetermined bulk density. For example, a compression granulating apparatus for compressing and granulating pulverized expanded polystyrene is preferable. is there. Specifically, the compression granulation apparatus includes a ring in which a number of holes having a diameter of the size of a pellet to be formed are formed, and a roller that can rotate while being inscribed in the ring. The raw material, pulverized expanded polystyrene, is supplied into the ring, compressed between the rotating roller and the inner surface of the ring, and the pulverized expanded polystyrene is discharged as pellets from the holes formed in the ring. . The pulverized expanded polystyrene is mechanically press-compressed by a roller and a ring, and there is only a temperature increase generated by frictional heat between the roller and the ring, so that the expanded polystyrene does not melt.
Therefore, air and gas in the expanded polystyrene cannot be completely removed, and the bulk density becomes about 0.2 g / cc. Since polystyrene has a low melting temperature of about 80 ° C., the roller is compressed at a low speed to minimize frictional heat. In the present embodiment, the roller is rotated, but the roller may be fixed and the ring may be rotated. As a compression granulation apparatus, for example, in a multipurpose granulator pellet mill of Miike Iron Works Co., Ltd., it is possible to granulate into a shape that can be easily supplied to an extruder and to have an appropriate bulk density (in this case, About 0.2g / c
c) is particularly preferred. By the way, in the present embodiment,
Although a compression granulation apparatus is used, the invention is not limited to this. Any apparatus can be used as long as it can compress the pulverized expanded polystyrene to an appropriate bulk density, and may be a hydraulic or screw press apparatus. By these volume reducing means 8, the material is compressed to an appropriate bulk density. (For example, a bulk density of about 0.02 g / cc
Expands the bulk density to about 0.2 g / cc. In the present embodiment, the expanded polystyrene that can be injected per unit time into the extruder 11 in the next process by being compressed by the volume reducing means 8 can be reduced to about 10 times, so that the molding processing efficiency is increased to about 10 times. Can be improved.
In addition, since the bulk is reduced to an appropriate bulk density by being compressed and granulated by the volume reducing means 8, it is not necessary to use a conventional pushing device when supplying the extruder 11.

In the present embodiment, the volume reducing means 8
Although the compression is made about 10 times, the processing efficiency can be further improved by making the compression more than that, depending on the performance of the volume reducing means 8 used. In the present embodiment, the bulk density is compressed to about 0.2 g / cc. However, the present invention is not limited to this. The performance of the extruder 11 in the next process, the properties of expanded polystyrene, and the like are not limited to this. Of course, it may be set to decrease or increase depending on the above conditions.

The fan 16 b pneumatically transports the expanded polystyrene compressed and granulated by the volume reducing means 8 and collects the expanded polystyrene by the cyclone 9. The supply feeder 10 serving as a quantitative supply means supplies the collected pellets to a hopper to quantitatively extrude the extruder 1.
1 hopper. The supply feeder 10 is, for example,
The weight type feeder JSW-TF of Japan Steel Works, Ltd. is suitable, and it is possible to supply the extruder 11 with highly accurate expanded polystyrene pellets. Since it is compressed and granulated by the volume reducing means 8 and has an appropriate bulk density, it can be precisely and quantitatively supplied. For this reason, since the fixed amount can be supplied to the extruder 11 in the next process with a certain precision, the supply amount and the bulk density of the raw material can be made uniform, and it is possible to prevent strand breakage due to surging when the strand is discharged from the extruder 11. . Although not shown in front of the supply feeder 10, since the storage warehouse is provided, even when the extruder 11 is stopped for maintenance or the like, the compressed and granulated expanded polystyrene is stored. I can put it. Since compression granulation has already been performed, it is about 1 /
A low capacity of about 10 is sufficient.

In the extruder 11, the supplied pellets of the pulverized expanded polystyrene are melt-kneaded, and the air and gas remaining in the expanded polystyrene are evacuated through a plurality of vent ports 19 provided in the extruder 11. As described above, since the evacuation is sufficiently performed by the plurality of vent ports 19, deaeration can be sufficiently performed, and high-quality pellets with a very low residual ratio of air and gas can be formed. Also air,
Since the gas has a small residual ratio, no air bubbles enter the strand, and when the strand is extruded as a strand, the conventional strand break can be prevented. Further, by evacuating from the vent port 19, no odor is released. In the present embodiment, a plurality of vent ports 19 are provided to reliably perform deaeration. However, the pump capacity for evacuating is further increased, the number of vent ports is increased, It is also possible to improve the deaeration efficiency by lengthening the mouth and the like.

In the present embodiment, the extruder 11 is a twin screw extruder. For example, T of Japan Steel Works, Ltd.
An EX twin screw extruder or the like is preferred. The extruder 11 is a twin-screw extruder, and can sufficiently knead with an internal twin-screw, so that the deaeration efficiency is good.
It can be formed into high quality pellets without bubbles. Furthermore,
In the twin screw extruder, the equipment can be downsized,
The installation area can be reduced.

Further, since the mixture is efficiently kneaded by the twin-screw extruder, it can be sufficiently deaerated by melt-kneading for about 30 seconds, and the residence time in the extruder, that is, the time of exposure to high temperature can be shortened. Therefore, a decrease in the molecular weight of the polystyrene resin is small, a decrease in the physical properties of the resin can be prevented, and high-quality pellets can be formed. According to the results of the experiment, the molecular weight reduction rate is about 3%, which is a reduction in error.
It results in very high quality pellets. On the other hand, when melted by the conventional solvent treatment, the molecular weight is reduced by about 10%, and the quality of the pellet is reduced.

Further, since the screw inside the twin screw extruder is a co-rotating screw, it has self-screening properties and extrusion stability such as vent-up, so that the polystyrene as a raw material can be reliably discharged. Further, in the twin-screw extruder, particularly, since the backflow of the raw material hardly occurs inside the cylinder, the flow state inside the cylinder becomes uniform, and strand breakage due to surging is further less likely to occur. In this embodiment, the extruder is a biaxial co-rotating extruder. However, the extruder may rotate in different directions depending on the application, the properties of the raw materials, and the like.

Further, since the kneading property is good by using a twin screw extruder, the pellets such as pigments can be colored by supplying pellets such as pigments from the auxiliary material feeder 14 which is an auxiliary material supply means. . For this reason,
In the single-screw extruder, it is difficult to color the pellets. Conventionally, containers and the like of colored used expanded polystyrene were removed in the pretreatment. Because a screw extruder is used,
It becomes possible to color the pellets. Thereby, when a large amount of colored used expanded polystyrene is used, or when highly stained expanded polystyrene is recycled, it can be molded as a colored pellet, and the recycling efficiency is significantly improved.

In the twin screw extruder, since the cylinder and the screw can be exchanged, even if the properties of the raw material to be supplied in the future are changed, it can be easily dealt with. This makes it possible to minimize equipment costs even when the properties of the raw materials are changed. In this embodiment, the twin-screw extruder is used. However, when the expansion ratio of the expanded polystyrene is small, or it is necessary to use an existing facility, or depending on the application, a single-screw extruder is used. It is of course possible to use it. Even when a single-screw extruder is used, since it is compressed in advance, the residual ratio of air or gas is small, so that the melting time can be shortened and the extruder can be downsized. .

Although not shown, the extruder 11 is directly water-cooled, so that the heat generation of the raw material can be suppressed. On the discharge side of the extruder 11, there is provided an impurity removing means 17 for filtering through a screen to further remove impurities that may remain. In the present embodiment, a screen changer type impurity removing means 17 is used. Thus, the screen can be replaced while the extruder 11 is operating, and since the air is removed when the screen is replaced, it is possible to prevent the strand from being broken by the entrained air. Also, the extruder 11
Since the size of the screen can be selected irrespective of the size of the filter, the filtration area can be increased. For example, as a screen changer, NSC-
A DB type dual bar screen changer is preferred.

The strand extruded from the extruder 11 is
A die with about 30 holes formed in a horizontal row, about 3
It is continuously extruded in a round bar shape of about -5 mm. Thereafter, the mixture is cooled and solidified in the water tank 18, and
Pellets are cut into a predetermined length by a cutter. As described above, in the present embodiment, the extruded strands are supplied uniformly by supplying a constant amount of the raw material to the extruder 11 by the constant-quantity supply means 10, and the vent port 1
9 prevents the bubbles from being mixed into the strand by sufficient deaeration, and furthermore, by sufficiently removing impurities, prevents the strand from breaking due to surging.

In the pellet sorter 13, the pelletizer 12
The pellets cut in the above are sorted out by a sieve or the like, and those having a predetermined size or less are collected and not shown,
It is supplied to the hopper of the extruder 11 again. Stock tank 1
Reference numeral 5 stores pellets of a predetermined length selected by the pellet sorter 13. Furthermore, it is packed at a predetermined weight and recycled as pellets.

In the present embodiment, no water washing device is used. However, when a foamed polystyrene used in the market and the like is used, it is difficult to remove foreign matter sufficiently by the wind separation means 5. In this case, the crushing means 2
The water washing device may be provided before the water washing device. The foamed polystyrene having a large amount of dirt may be washed by providing a water washing device before crushing. At this time, since the washing water can circulate the cooling water in the water tank 18 for cooling the strand discharged from the extruder 11, there is no need to provide a water treatment facility. Before crushing means 2,
The provision of the water washing device is performed when the extruder 11 is charged.
Since the air can be dried by the air transport means 3, 6, 9 and the wind separation means 5, the adhesion of moisture to the crushed and compressed polystyrene is prevented. This is because if moisture is adhered, an enormous amount of steam is generated when the moisture is put into the high-temperature extruder 11.

As described above, in the present embodiment,
By compressing the crushed expanded polystyrene and removing the internal air and gas by compression in advance, the bulk density of the pulverized expanded polystyrene to be charged into the extruder 11 can be increased, so that the processing efficiency of the extruder 11 is significantly improved. Therefore, the molding efficiency of the pellet is very good, and the productivity is remarkably improved.

Further, by pre-compressing and granulating the expanded polystyrene, it is possible to supply the extruder 11 quantitatively with high accuracy by the quantitative supply means 10, so that the supply amount can be stabilized, thereby preventing strand breakage due to surging. be able to. Further, a conventional pushing device is not required. In addition, by pre-compressing and granulating the expanded polystyrene, air and gas having a reduced residual ratio can be supplied to the extruder 11, so that the extruder 11 melts in a short time and no air or gas remains. Thus, high quality pellets can be formed without deterioration in physical properties. Since high-quality pellets are regenerated in this way, there is no need to mix virgin pellets as in the conventional case, and pellets can be formed from nearly 100% of used expanded polystyrene, thereby achieving a high recycling rate. It becomes possible.

Further, a warehouse (not shown) for storing the expanded polystyrene granulated and compressed by the volume reducing means 8 can be significantly reduced in size. In the present embodiment, the floor area of the warehouse is about 1 /
It is about 10 and a large warehouse as in the prior art is not required, and the area occupied by the equipment can be greatly reduced. In addition, since the extruder 11 can be made smaller than the conventional one, the occupied area of the equipment can be remarkably reduced. The warehouse and the extruder 11 can be further reduced in size by the performance of the volume reducing means 8.

In the present embodiment, used foamed polystyrene from which impurities have been removed in advance by pretreatment is reduced in volume by means 8.
Before being put into the extruder, the extruder 11 sorts out the impurities by wind force to remove impurities, and the extruder 11 further removes impurities which may remain even after the melt-kneading by the extruder 11. The impurities can be almost completely prevented from being mixed into the pellets, and high-quality pellets can be formed.

The method and the apparatus for treating used polystyrene foam according to the present embodiment can, of course, already treat compression-molded polystyrene foam. For this reason, department stores,
It can not only collect and process expanded polystyrene packing materials, containers, trays, etc. discharged widely in supermarkets, public municipalities, etc., but also efficiently process used expanded polystyrene already compressed in various places. For example, it can be used in combination with a vehicle-mounted foam polystyrene compression volume reduction device. With the widespread use of such a method and apparatus for treating used polystyrene foam, it is possible to easily treat a huge amount of used polystyrene foam. Contributions are possible.

[0043]

As described above, according to the present invention, used foamed polystyrene is pre-compressed to remove air and gas inside to obtain a predetermined bulk density and a predetermined size, and then melt-kneaded. Since the pellets are formed into pellets, the bulk density of the granulated, compressed and expanded polystyrene to be supplied can be increased, so that there is an effect that the efficiency of the pellet forming process is improved and the productivity can be significantly improved.

In the present invention, the expanded polystyrene compressed and granulated by the volume reducing means (8) is quantitatively supplied to the extruder (11) by the quantitative supply means (10). Since the raw material can be supplied quantitatively with high accuracy, strand break due to surging can be prevented and stable operation can be performed. Furthermore, in the present invention, the extruder (11) can sufficiently deaerate by short-time melting by compression granulation of expanded polystyrene, so that high-quality pellets with a low residual ratio of air or gas and no deterioration in physical properties can be formed. Can be. Furthermore, high-quality pellets can be formed by removing impurities by using the air separation means (5) and the impurity removing means (17) together.

Further, according to the present invention, a large warehouse is not required before the raw materials are supplied to the extruder (11), and the extruder (11) can be downsized, so that the equipment occupied area can be significantly reduced. . In addition, by using a twin screw extruder, the extruder (11) can be further reduced in size, so that the equipment occupation area can be further reduced. Further, by providing the auxiliary material supply means (14), the pigment can be supplied to the twin-screw extruder, so that the molded pellet can be colored.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a processing apparatus for used expanded polystyrene showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Belt conveyor 2 Crushing means 3,6,9 Cyclone (pneumatic conveying means) 16a, 16b, 16c Fan (pneumatic conveying means) 4,7 Quantitative feeder 5 Wind separation means 8 Volume reduction means (compression granulator) 10 Supply Feeder (quantitative supply means) 11 Extruder (pellet forming means) 18 Water tank (pellet forming means) 12 Pelletizer (pellet forming means) 13 Pellet sorter 14 Auxiliary raw material feeder (auxiliary raw material supplying means) 15 Stock tank 17 Screen changer (impurities) Removal means) 19 Vent port

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI B29B 15/00 B09B 3/00 301W // B29K 25:00 303G 105: 04 105: 26

Claims (5)

[Claims] 1. The used polystyrene foam is previously compressed to remove air and gas inside the polystyrene foam to a predetermined bulk density and a predetermined size, and then melt-kneaded and further degassed to form a polystyrene foam inside the polystyrene foam. A method for treating used expanded polystyrene in which air and gas are removed to form pellets. 2. A crushing means (2) for crushing the used expanded polystyrene to a predetermined size, and removing the air and gas inside the expanded polystyrene by compressing the expanded polystyrene crushed by the crushing means (2). Volume reduction means (8) for granulating to a predetermined size with a predetermined bulk density; and a quantitative supply means (10) for quantitatively supplying the expanded polystyrene compressed and granulated by the volume reduction means (8); The extruded polystyrene supplied quantitatively by the quantitative supply means (10) is melted and kneaded in a short time by an extruder (11), and the air inside the expanded polystyrene is further degassed by kneading.
An apparatus for treating used expanded polystyrene, comprising: pellet forming means (12, 18) for extruding after removing gas, solidifying by cooling, and then forming into pellets. 3. A crushing means (2) for crushing the used expanded polystyrene to a predetermined size, and an air feeding means (3,6,9) for conveying the expanded polystyrene crushed by the crushing means (2) by pneumatic transportation. , 16a, 16
b, 16c); a wind separation means (5) for removing impurities from the conveyed expanded polystyrene by weight separation by means of wind; and an expanded polystyrene from which the impurities have been removed by the wind separation means (5) are compressed to form an interior of the expanded polystyrene. A volume reducing means (8) for removing air and gas and granulating to a predetermined size with a predetermined bulk density, and quantitatively supplying the expanded polystyrene compressed and granulated by the volume reducing means (8). A quantitative supply means (10); and the foamed polystyrene quantitatively supplied by the quantitative supply means (10) is melted and kneaded in a short time, and the air and gas of the expanded polystyrene are almost completely removed by deaeration, and then the strand is formed as a strand. An extruder (11) for extruding; an impurity removing means (17) provided on a discharge side of the extruder (11) for removing impurities by filtration; A water tank (18) to a strand extruded cooled and solidified from the processing apparatus used foamed polystyrene cooled and solidified strands consisting a pelletizer (12) for shaping into pellets. 4. The processing apparatus for used polystyrene foam according to claim 2, wherein the extruder (11) is a twin-screw extruder. 5. An apparatus for treating used polystyrene foam according to claim 4, wherein said extruder (11) is provided with an auxiliary raw material supply means (14) capable of quantitatively supplying auxiliary raw materials such as pigments. Processing equipment.