JP2006035574A - Method for separately collecting waste plastic composite materials, collected plastics, reproduced plastics, and reproduced plastic products - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for separately collecting waste plastic composite materials which can separately collect plastics high in impact resistance, collected plastics, reproduced plastics, and reproduced plastic products. <P>SOLUTION: The method for separately collecting plastics from the waste plastic composite materials containing one or more plastics includes a process in which the waste plastic composite materials are crushed at temperatures higher than the brittle temperatures of the plastics contained in the waste plastic composite materials, and the obtained fragments 1 are classified according to their sizes and a process for selectively recovering large-sized fragments 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for separating and recovering a waste plastic composite material by separating and recovering plastic by crushing a waste plastic composite material such as a waste household electrical product or a part thereof, a waste automobile product or a part, and a separately recovered plastic, a recycled plastic and Recycled plastic products. In particular, the present invention relates to a method for separating and recovering a waste plastic composite material that separates and removes plastic with low impact resistance from the waste plastic composite material.

  Waste plastic recycling for effective use of resources, heat recovery, thermal recycling using plastic as fuel for electricity recovery, chemical recycling using waste plastic composites as a raw material for plastics, waste plastic There is material recycling that separates and collects plastics from composite materials and recycles them as plastic products.

  Here, as one method of material recycling, after crushing the waste plastic composite material, separating the metal-based crushing pieces from the crushing pieces using magnetic force and eddy current, and then gasifying the mixture of plastic pieces with different specific gravity Separation into a mixture of lightweight plastic pieces such as powdered plastic and foamed plastic and a mixture of heavy plastic pieces by specific gravity sorting by flow, and further sedimentation of the above mixture of heavy plastic pieces by specific gravity sorting with a liquid medium There has been proposed a method of separating a single material plastic by separating it into a suspended matter and a suspended matter (see, for example, Patent Document 1).

  However, the recovered plastic recovered by this separate recovery method is formed of almost one type of plastic, but it is easily broken by UV irradiation or air oxidation in the atmosphere, or cracked from the beginning. Easy plastics (hereinafter referred to as easy-to-break plastics) are included, and there is a problem that the impact resistance of recycled plastics obtained by recycling such recovered plastics is reduced.

  In addition, a method has been proposed in which a plastic formed from one kind of plastic is taken out by crushing below the embrittlement temperature of the plastic contained in the waste plastic composite and classifying the crushed pieces according to the particle size ( For example, see Patent Document 2). However, even with this method, a recovered plastic formed from one type of plastic can be obtained, but since the plastic that is easily broken cannot be removed, the impact resistance of the recycled plastic that has been recycled from the recovered plastic is reduced. was there.

  In addition, the collected plastic separated and collected by the above-described collecting method has a problem that foreign matter having the same specific gravity as the plastic is mixed, and physical properties similar to those of virgin plastic are not produced. For example, in specific gravity sorting using liquid media, foreign materials such as aluminum foil that is rolled up and encapsulating air and foaming agent, foamed urethane with a low foaming ratio, and plastic with foamed urethane attached to it should be collected separately. However, these foreign substances cannot be separated from the plastic to be separated and collected.

Therefore, it is necessary to remove foreign substances by manual sorting or machine sorting. However, many small pieces are contained in the crushed pieces of waste plastic composite material, and much time is required for manual sorting. .
Japanese Patent No. 3457619 JP-A-6-226241

  In view of the above situation, an object of the present invention is to provide a method for separating and recovering a waste plastic composite material capable of separating and recovering plastic having high impact resistance, and a separately recovered plastic, recycled plastic and recycled plastic product.

  The present invention is a method for separating and recovering plastic from waste plastic composites containing one or more types of plastics, wherein the waste plastic composites are treated at a temperature higher than the embrittlement temperature of the plastics contained in the waste plastic composites. This is a method for separating and collecting waste plastic composites, which includes a step of crushing, a step of dividing the obtained crushing pieces into coarse and fine particles, and a step of selectively collecting crushing and coarse pieces of coarse particles.

  The waste plastic composite separation and recovery method according to the present invention may further include a step of separating the crushed pieces or the crushed coarse pieces according to the specific gravity difference, and a step of selectively removing the metal-based crushed pieces from the crushed pieces and the crushed pieces or The method may further include a step of separating the crushed coarse pieces according to the specific gravity difference. Here, the step of separating the crushed pieces or the crushed coarse pieces according to the specific gravity difference may be a step of separating the crushed pieces or the crushed coarse pieces by at least one of an air separation method and a liquid specific gravity separation method. Furthermore, it can classify | categorize for every 1 type of plastic according to the process of classifying a crushing piece or a crushing rough piece by specific gravity difference.

  Further, in the method of separating and collecting waste plastic composite according to the present invention, a step of selectively recovering crushed coarse particles having a grain size larger than the sieve mesh width of the sieve using a sieve in the step of dividing the crushed pieces into coarse particles. Can be included. Here, the sieve can be a vibrating sieve, the sieve mesh width can be set to one third or more of the crushing mesh width in crushing, and the sieve mesh width can be set to 7 mm or more.

  Further, in the method for separating and collecting waste plastic composites according to the present invention, a step of selectively removing the coarse foreign particles contained in the crushed coarse pieces may be included after the step of selectively collecting the crushed coarse pieces.

  The present invention is a separately collected plastic recovered by the method for separating and recovering waste plastic composites described above. Further, the present invention is a recycled plastic obtained by recycling the separately collected plastic described above. Furthermore, the present invention is a recycled plastic product using the recycled plastic described above.

  As described above, according to the present invention, it is possible to provide a method for separating and collecting a waste plastic composite material capable of separating and collecting a plastic having high impact resistance, as well as a separately collected plastic, a recycled plastic and a recycled plastic product.

  A method for separating and collecting waste plastic composites according to the present invention is a method for separating and recovering plastics from waste plastic composites containing one or more types of plastics with reference to FIGS. Select the step of crushing the waste plastic composite material at a temperature higher than the embrittlement temperature of the plastic contained in the material, the step of dividing the obtained crushed pieces 1 into coarse particles, and the crushed coarse particles 2 with coarse particles Recovery step.

  By crushing at a temperature higher than the embrittlement temperature of the plastic contained in the waste plastic composite material, regardless of the type of the plastic, the fragile plastic is finely crushed, and the plastic that is difficult to break is roughly crushed. By dividing the obtained crushed pieces 1 according to the coarseness of the particle size, it is possible to separate plastics that are easily broken and those that are difficult to break. Next, by selectively recovering the coarse crushed pieces, it is possible to selectively recover a plastic that is difficult to break, that is, a plastic having high impact resistance.

  Here, the temperature higher than the embrittlement temperature of the plastic contained in the waste plastic composite material is not particularly limited, but is preferably a temperature higher than 0 ° C, more preferably a temperature higher than 5 ° C, more preferably 10 ° C. A temperature higher than ℃. Waste plastic composite materials such as waste household electrical products, waste automobile products and their parts have a brittle temperature such as polypropylene (brittle temperature: 0 ° C.), polyethylene (brittle temperature: −100 ° C.), etc. This is because a large amount of plastic at about −100 ° C. to 0 ° C. is contained.

  The waste plastic composite separation and recovery method according to the present invention may further include a step of separating the crushed pieces 1 or the crushed coarse pieces 2 by specific gravity difference with reference to FIG. By separating the crushed pieces 1 and the like according to the specific gravity difference, it is possible to obtain a plastic having high impact resistance for each type of plastic. Here, although there is no restriction | limiting in particular in the method of classifying a crushing piece or a crushing rough piece by specific gravity difference, With reference to FIG. 2, the liquid which uses the wind specific separation method using the air classification device 30 and the liquid specific gravity separation device 40 A specific gravity fractionation method is preferred. The step of separating the crushed pieces or the crushed coarse pieces according to the difference in specific gravity includes the step of dividing the crushed pieces 1 into coarse particles, the step of selectively recovering the coarse crushed pieces 2 before and after any step. Can be done.

  The waste plastic composite separation and recovery method according to the present invention may further include a step of selecting and removing the metal-based crushed pieces 1c from the crushed pieces 1 with reference to FIG. By selecting and removing the metal-based crushed pieces 1c from the crushed pieces 1, it is possible to recover the plastic free from metal-based foreign matters, and to improve the impact resistance of the recovered plastic.

  In the method for separating and collecting waste plastic composites according to the present invention, referring to FIG. 1 and FIG. 2, a sieve 14 is used in the step of dividing the obtained crushed pieces into coarse particles, and the particle size is more than 14 w. A step of selectively collecting the coarsely crushed coarse pieces 2 can be included. By using the sieve 14, it becomes easy to divide the crushed pieces into coarse particles. Hereinafter, an embodiment including a step of dividing the crushed pieces 1 into coarse particles using the sieve 14 will be described.

(Embodiment 1)
One waste plastic composite separation and recovery method according to the present invention is a method for separating and recovering plastic from a waste plastic composite with reference to FIGS. 1 and 2, and is contained in the waste plastic composite 9. Crushing the waste plastic composite material 9 at a temperature higher than the embrittlement temperature of the plastic, a step of dividing the crushed pieces 1 into coarse particles using a sieve 14, and a crushing coarse material having a coarse particle size of 14 w or more. Selectively collecting the pieces 2. The plastic having low impact resistance (that is, easily broken) contained in the waste plastic composite material is broken into fine pieces (hereinafter, the same). Therefore, the crushed pieces of waste plastic composite material are passed through a sieve, the crushed pieces having a particle size finer than the sieve width are removed, and the crushed coarse pieces having a particle size larger than the sieve width are selectively recovered, thereby providing impact resistance. High-quality plastic can be collected separately. Note that the crushed coarse pieces having a grain size larger than the sieve width means a crushed piece that does not pass through the sieve width, and the crushed fine pieces finer than the sieve width pass through the sieve having the sieve width. Say a piece.

  In this separation and recovery method, the sieve is preferably a vibrating sieve. When the sieve vibrates, it becomes easy to remove crushed pieces smaller than the sieve width and selectively collect crushed coarse pieces coarser than the sieve width.

  Further, in the present separation and recovery method, referring to FIG. 1, after the step of selectively recovering the crushed coarse pieces 2, a step of selectively removing the coarse foreign particles 2 c included in the crushed coarse pieces 2 may be included. preferable. By selecting and removing the foreign particle coarse piece 2c from the crushed coarse piece 2, plastic with high impact resistance can be separated and collected. Further, by removing the crushed fine pieces in the crushed pieces before the step of separating and removing the foreign piece, the foreign pieces are easily separated and removed. Here, the method for sorting and removing the foreign particle coarse piece 2c is not particularly limited, and there are a manual sorting method by a human hand, a machine sorting method for sorting using the foreign matter sorting apparatus 20 (not shown), and the like.

  Here, a preferred embodiment of the present sorting method will be described below with reference to FIG. The crushed pieces 1 obtained by pulverizing the waste plastic composite material are stored in a hopper 11, and the crushed pieces 1 coming out from the opening 11 a of the hopper 11 are vibrated in an oblique 45 ° direction by a vibration motor 15 (FIG. 1). The reciprocating vibration from the upper right to the lower left of the crushed pieces 3 is separated and removed by the sieve 14 and collected in the fine piece collection container 16, and the crushed coarse pieces 3 having a grain size larger than the sieve width are further formed on the sieve 14. As it is, it proceeds in the direction of the conveyor 12 and falls onto the conveyor 12. On the conveyor 12, the crushed coarse pieces 2 made of highly impact-resistant plastic are removed by separating and removing the foreign matter coarse pieces 2c in the crushed coarse pieces 2 by the above-described method by manual sorting or machine sorting. Separately collect into 13.

(Embodiment 2)
Another waste plastic composite material separation and recovery method according to the present invention is a method of separately collecting and recovering plastic from waste plastic composite material with reference to FIG. Including a step of crushing the waste plastic composite material 9 at a temperature higher than the embrittlement temperature and a step of separating the crushed pieces 1 or the crushed coarse pieces 2 by specific gravity difference, and after the step of crushing the waste plastic composite material, A step of dividing the crushed pieces 1 into coarse particles having a particle size, and a step of selectively recovering the crushed pieces 2 having a coarse particle size of 14 w or more.

  This separation and recovery method is suitable when the waste plastic composite material contains two or more types of plastics having few foreign substances other than plastic and different specific gravities. That is, by combining the step of separating the crushed pieces 1 or the crushed coarse pieces 2 by the specific gravity difference and the step of separating and collecting the crushed coarse pieces 2 having a grain size larger than the sieve width in the crushed pieces 1 in the first embodiment. , High impact resistance plastic can be separated and recovered for each specific gravity.

  Here, the step of separating the crushed pieces 1 or the crushed coarse pieces 2 by the difference in specific gravity and the step of separating and collecting the crushed coarse pieces 2 from the crushed pieces 1 may be performed from either step. That is, the crushed piece 1 may be separated and collected from the crushed piece 1 after the crushed piece 1 is separated by the specific gravity difference. You may sort by difference.

  In this separation and recovery method, referring to FIG. 2, the step of separating the crushed pieces 1 or the crushed coarse pieces 2 according to the specific gravity difference is performed by the crushed pieces 1 or the crushed pieces by at least one of the wind separation method and the liquid specific gravity separation method. It is preferable to be a step of separating the coarse pieces 2. By the air separation method or the liquid specific gravity separation method, the crushed pieces or the crushed coarse pieces can be easily separated according to the specific gravity difference.

  In the separation step based on the specific gravity difference in the present fraction collection method, for example, adjustment of the wind force in the wind separation method or adjustment of the specific gravity of the liquid for separation in the liquid specific gravity separation method and / or appropriate combination of the wind separation method and the liquid specific gravity separation method For example, it is possible to separate and collect each type of plastic.

  Further, in this separation and recovery method, as in Embodiment 1, the foreign matter coarse piece 2c included in the crushed coarse piece 2 after the step of selectively collecting the crushed coarse piece 2 is selected as the vibrating sieve. It is preferable to include a step of selecting and removing.

  Here, a preferred embodiment of the present separation and recovery method will be described below with reference to FIG. First, the waste plastic composite material 9 is crushed by the crushing device 71 to obtain a crushed piece 1. This crushed piece 1 includes a crushed coarse piece 2 having a grain size larger than the sieve width and a crushed fine piece 3 having a grain size finer than the sieve width in the subsequent separation by a sieve. These crushed pieces 1 are stored in a hopper 31.

  The crushed pieces 1 stored in the hopper 31 are supplied to the wind power separating device 30 by the conveyor 32. Of the crushed pieces 1, the light crushed pieces 1 a (including the light crushed coarse pieces 2 a and the light crushed pieces 3 a, the same applies hereinafter) are blown off by the wind 33 from the blower fan (not shown) of the wind power separating device 30. The remaining crushed pieces 1 (including the crushed coarse pieces 2 and the crushed fine pieces 2, the same applies hereinafter) are stored in the lightweight piece collection container 35, and sent to the liquid specific gravity separator 40.

  In the liquid specific gravity fractionating device 40, the weight crushing piece 1b (including the weight crushing coarse piece 2b and the weight crushing fine piece 3b, which is the same hereinafter) heavier than the specific gravity of the sorting liquid 41 settles in the sorting liquid 41, and the liquid specific gravity It is taken out from the lower part of the separation device 40, and the separation liquid is removed when it passes through the liquid draining part 51 and the liquid removal tank 61, and is stored in the weight piece collection container 45. The remaining crushed pieces 1 having a specific gravity equal to or lower than the specific gravity of the separation liquid 41 are removed from the separation liquid when passing through the liquid draining part 52 and the liquid removal tank 62 together with the separation liquid 41 to the hopper 11 which is a recovery container. Be contained. The separation liquid 41 separated in the liquid draining parts 51 and 52 and the deliquid tanks 61 and 62 is stored in the liquid storage layer 44 provided in the lower part, and is circulated to the liquid specific gravity separation device 40 by the pump 43. .

  The crushed pieces 1 accommodated in the hopper 11 are separated and recovered from the crushed pieces 1 by using the vibrating sieve 14 and the conveyor 12 in the same manner as in the first embodiment. Further, the foreign matter coarse piece 2 is sorted and removed from the crushed coarse piece 2 by manual sorting, and the crushed coarse piece 2 made of plastic having high impact resistance is separated and collected in the coarse piece collection container 13.

  In this fraction collection method, it is preferable that the mesh width 14w of the sieve 14 is equal to or more than one third of the crushing mesh width 71w in crushing. By making the mesh width more than one-third of the crush width, the crushing coarse particles having a grain size coarser than one-third of the crush width can be separated and collected by the sieve, and high impact-resistant plastic. Is obtained.

  Moreover, in the collection | recovery method classified by text, it is preferable that the sieve width 14w of the sieve 14 is 7 mm or more. By setting the sieve width to 7 mm or more, crushed coarse pieces having a particle diameter of 7 mm or more can be separated and collected, and a high impact-resistant plastic can be obtained. It becomes.

(Embodiment 3)
Another waste plastic composite material separation and recovery method according to the present invention is a method for separating and recovering plastic from waste plastic composite material with reference to FIG. A step of crushing the waste plastic composite material 9 at a temperature higher than the embrittlement temperature, a step of selecting and removing the metal-based crushing pieces 1c from the crushing pieces 1, and a step of separating the crushing pieces 1 or the crushing coarse pieces 2 by the difference in specific gravity. After the step of crushing the waste plastic composite material, a step of separating the crushed pieces 1 into coarse particles using a sieve 14 and a crushed coarse piece 2 having a particle size coarser than the sieve width are selectively recovered. Process.

  This separation and recovery method is suitable when the waste plastic composite material contains foreign matters other than plastic, particularly metal foreign matters, and two or more kinds of plastics having different specific gravities. That is, the step of selecting and removing the metal-based crushed pieces 1 c from the crushed pieces 1, the step of separating the crushed pieces 1 or the crushed coarse pieces 2 in the second embodiment according to the specific gravity difference, and the particle size of the crushed pieces 1 beyond the sieve width. By combining with the step of separating and collecting the coarsely crushed coarse pieces 2, it is possible to remove metal-based debris and to separate and collect plastics with high impact resistance for each specific gravity.

  Here, the method for selectively removing the metal-based crushed pieces is not particularly limited, but a method using magnetic force or eddy current is preferable. In addition, any of the steps of selecting and removing the metal-based crushed pieces 1c from the crushed pieces 1, the step of separating the crushed pieces 1 or the crushed coarse pieces 2 by the specific gravity difference, and the step of separating and collecting the crushed coarse pieces 2 from 1 are any steps. It may be done from.

  Further, in this separation and recovery method, as in Embodiment 1, the foreign matter coarse piece 2c included in the crushed coarse piece 2 after the step of selectively collecting the crushed coarse piece 2 is selected as the vibrating sieve. It is preferable to include a step of selecting and removing. Moreover, it is preferable that it is 1/3 or more of the crushing width | variety 71w in crushing similarly to Embodiment 2, and the screen width | variety of the sieve 14 is 7 mm or more.

  Further, in the separation step based on the specific gravity difference in the present separation and recovery method, for example, the adjustment of the specific gravity of the liquid for separation in the wind separation method or the specific gravity adjustment in the liquid specific gravity separation method and / or the wind separation method, as in the second embodiment. It is also possible to separate and collect each kind of plastic by an appropriate combination of the liquid specific gravity separation method and the like.

  Here, a preferred embodiment of the present separation and recovery method will be described below with reference to FIG. First, the waste plastic composite material 9 is crushed by the crushing device 71 to obtain a crushed piece 1 (crushing step). This crushed piece 1 includes a crushed coarse piece 2 having a grain size larger than the sieve width and a crushed fine piece 3 having a grain size finer than the sieve width in the subsequent separation by a sieve. From these crushed pieces 1, the metallic crushed pieces 1 c are sorted and removed by using a metallic crushed piece sorting and removing device 72 using magnetic force or eddy current. The crushed pieces 1 from which the metal-based crushed pieces have been selected and removed are stored in a hopper 31.

  Thereafter, in the same manner as in the second embodiment, the crushed pieces 1 stored in the hopper 31 are separated and collected by the difference in specific gravity, and the crushed coarse pieces 2 having a grain size larger than the sieve width are separated and collected by a sieve, The coarse foreign particles 2 can be selected and removed from the fragments 2 to separate and collect the crushed coarse particles 2 made of high impact resistance plastic.

  The separately collected plastic according to the present invention is, for example, plastic collected by the waste plastic composite material separating and collecting method according to any of the first to third embodiments. By using the above-described method for separating and collecting waste plastic composite materials, it is possible to separate and collect plastics with high impact resistance.

  The recycled plastic according to the present invention is a recycled plastic obtained by recycling the above-described separated and collected plastic. Recycled plastic with high impact resistance can be obtained by reprocessing the separately recovered plastic recovered by the above-described separate recovery method. Here, the regeneration process refers to a process of melting, kneading, and re-molding the separately collected plastic separated and collected from the waste plastic composite material. Recycled plastic refers to plastic that is recycled as a plastic raw material for molding by melting and kneading the separately collected plastic, and plastic that is recycled as a plastic molded product by molding this plastic raw material for molding. There is no particular limitation on the method and apparatus for melting and kneading the separately collected plastic, but an extrusion molding method and an extrusion molding machine are preferably used. Further, there is no particular limitation on the method and apparatus for molding the plastic material for molding, but an injection molding method, an injection molding machine and the like are preferably used. In addition, the separately collected plastic can be continuously melted, kneaded and molded, and a plastic molded product can be obtained directly without taking out the plastic material for molding once.

  A recycled plastic product according to the present invention is a recycled plastic product having high impact resistance, such as a household electric product such as an air conditioner, a television, a refrigerator, and a washing machine, or an automobile product, using the recycled plastic.

  As an embodiment of the present invention, waste plastic composite materials constituting waste household electrical appliances (waste refrigerators, waste washing machines, waste air conditioners, waste TVs, etc.) are converted into plastics (specific gravity: 0.9) and polyethylene (specific gravity: specific gravity: An example in which 0.9) is separately collected will be described below. In addition to the above polypropylene and preethylene, this waste plastic composite contains iron (specific gravity: 7.9), brass (specific gravity: 8.4), copper (specific gravity: 9.0), curled air and foaming agent. Metal foil such as aluminum (specific gravity: 0.9 to 1.5), urethane foam (specific gravity: 0.04 to 0.32), foamed styrene (specific gravity: 0.01 to 0.2), hot melt (Specific gravity: 0.9; hot melt refers to adhesive plastic, the same applies hereinafter), copper wire (specific gravity: 8.9), stainless steel screws (specific gravity: about 8), and other foreign matters such as dust, Micronized plastic, ABS resin (specific gravity: 1.05), polystyrene (specific gravity: 1.08), polyurethane resin (specific gravity: 1.2), polyvinyl chloride (specific gravity: 1.3), polyvinylidene chloride (specific gravity) : 1.7) And for which was subjected to treatment according to the third embodiment.

  Referring to FIG. 2, the waste plastic composite material 9 was crushed at 20 ° C. using a crushing device 71 having a crushing width 71 w of 35 mm to obtain a crushed piece 1. Using a metal-based crushed piece sorting / removing device 1c using magnetic force or eddy current, the crushed pieces 1c, such as iron, brass, and copper, were sorted and removed and stored in the hopper 31.

  Next, the crushed pieces 1 stored in the hopper 31 were supplied to the wind power separation device 30 by the conveyor 32. Of the crushed pieces 1, the pulverized plastic pieces, the foamed urethane pieces, the foamed styrene pieces, the dust, and the like are blown off by the wind 33 from the blower fan (not shown) in the air separation device 30. The remaining crushed pieces 1 were accommodated in the lightweight piece collection container 35 and sent to the liquid specific gravity separator 40. In this embodiment, a cyclone type wind power separating apparatus is used as the wind power separating apparatus.

  In a liquid specific gravity separation apparatus 40 using water as a separation liquid 41 for separating the crushed pieces 1, ABS resin pieces, polystyrene pieces, polyurethane resin pieces, polyvinyl chloride pieces, polyvinylidene chloride pieces, copper wire, stainless steel Since the weight crushing pieces 1 b such as screws were settled, they were taken out from the lower part of the liquid specific gravity separation device 40, dehydrated when passing through the liquid draining part 51 and the liquid removal tank 61, and stored in the weight piece collection container 45. The remaining crushed pieces 1 having a specific gravity equal to or lower than the specific gravity of water (specific gravity: 1.0) as the separation liquid 41 are dehydrated when passing through the liquid draining part 52 and the deliquid tank 62 together with the water as the separation liquid 41. It was accommodated in the hopper 11 which is a collection container. Here, the crushed pieces 1 accommodated in the hopper 11 include, in addition to polypropylene pieces and polyethylene pieces, metal foil such as aluminum that is rolled up and entrained with air or a foaming agent, foamed urethane, foamed styrene, hot melt, and the like. It was.

  Next, referring to FIG. 1, the crushed pieces 1 stored in the hopper 11 are crushed by a sieve 14 that vibrates in an oblique 45 ° direction by a vibration motor 15 (reciprocating vibration from upper right to lower left in FIG. 1). After the pieces 3 were separated and removed, the crushed coarse pieces 2 larger than the mesh width were dropped onto the conveyor 12 while being layered on the sieve 14. On the conveyor 12, by the above-mentioned method of manual sorting, the foamed urethane coarse piece, the foamed styrene coarse piece, the hot-melt coarse piece, and the metal foil coarse piece such as aluminum in which air or a foaming agent is involved. The foreign matter coarse pieces 2c such as the above were sorted and removed, and the crushed coarse pieces 2 made of high impact-resistant plastic were separated and collected in the coarse piece collection container 13.

  At this time, the sieve width in the step of separating and collecting crushed coarse pieces from the crushed pieces by the sieve, the sieve residual mass ratio (crushed coarse pieces / crushed pieces), and 1 kg of crushed pieces (ie, 1 × (residual) Table 1 shows the relationship with the time required for sorting the foreign matter coarse pieces from the mass ratio (kg coarse pieces).

  As is clear from Table 1, by using a sieve having a sieve width of 7 mm or more, there is no fine piece in the crushed coarse pieces that are separated and collected, and the number of pieces to be sorted and the target of the selection. Since the number of foreign material coarse pieces is reduced, the efficiency of manual sorting is greatly improved.

  The crushed coarse pieces (the one after the foreign substance coarse pieces were selectively removed) collected and collected as described above contained polypropylene and polyethylene in a mass ratio of 99: 1. This mass ratio is the same as the mass ratio of polypropylene and polyethylene contained in waste household electrical appliances, and material recycling is possible as a polypropylene material as one kind of plastic if the mixing ratio is at this level.

  In this embodiment, when the weight fragment 1b accommodated in the heavy material collection container 45 is further supplied into the liquid specific gravity separation device 40 using the separation liquid 41 having a specific gravity of 1.1, the specific gravity is 1.0. A polystyrene piece, an ABS resin piece, etc. can be separated and collected as a suspended piece as a crushed piece between .about.1.1.

The crushed pieces (separately collected foreign matter pieces) obtained as described above were first melted at 220 ° C. using a twin-screw extruder, and then a twin-screw. A plastic raw material for molding was obtained by kneading at a diameter of 25 mm. Next, this plastic raw material for molding is melted at 230 ° C. using an injection molding machine, and a mold having an injection primary pressure of 200 kg / cm ² and an injection secondary pressure of 150 kg / cm ² and a surface temperature of 40 ° C. To obtain a sheet-like plastic molded article for testing having a thickness of 3.2 mm. Table 2 shows the relationship between the ratio of the sieve mesh width to the crushing mesh width and the 50% fracture height in the drop weight impact test (based on JIS K 7211) of the test plastic molded product. Here, the 50% fracture height in this example is the number of test pieces of a test plastic molded product by allowing a 1 kg weight (sphere 2 type weight in JIS K 7211) to fall freely on a test plastic molded product. Means the average free fall height (cm) when 50% of the material is crushed. For reference, Table 2 shows general numerical values of 50% fracture height of impact-resistant plastic molded products using virgin plastic. Here, the 50% fracture height of the impact-resistant plastic molded article using virgin plastic takes a numerical value that varies depending on the target product, but is approximately in the range of 50 cm to 200 cm.

  As shown in Table 2, when the sieve width is 1/3 or more of the crushing width, the 50% fracture height in the falling weight impact test is 56 cm or more, and an impact-resistant plastic molded article using virgin plastic The impact resistance was equivalent or better.

  In the present embodiment, the high impact-resistant recycled plastic obtained in this way is used to produce highly impact-resistant recycled plastic products such as air conditioners, televisions, refrigerators, washing machines and other household electrical appliances or automobile products. Can be produced. In this way, recycling material recycling can be established.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

  As described above, the present invention can be widely used in a method for separating and recovering a waste plastic composite material capable of separating and collecting a plastic with high impact resistance, as well as a separately recovered plastic, recycled plastic, and recycled plastic product.

It is a schematic diagram explaining the separate collection method of the waste plastics composite material concerning this invention. It is a schematic diagram explaining the separate collection method of another waste plastics composite material concerning this invention.

Explanation of symbols

  1 crushed pieces, 1a lightweight crushed pieces, 1b weight crushed pieces, 1c metal crushed pieces, 2c crushed coarse pieces, 2a lightweight crushed coarse pieces, 2b heavy crushed coarse pieces, 2c foreign matter crushed coarse pieces, 3 crushed fine pieces, 3a lightweight Crushed pieces, 3b weight crushed pieces, 9 waste plastic composite, 11, 31 hopper, 12, 32 conveyor, 13 coarse piece collection container, 14 sieve, 14w sieve width, 15 vibration motor, 16 piece collection container, 30 Wind separation device, 33 wind, 35 Light-weight piece collection container, 40 Liquid specific gravity separation device, 41 Liquid for separation, 43 Pump, 44 Liquid storage layer, 45 Weight piece collection container, 51, 52 Liquid drainage part, 61, 62 Detachment Liquid tank, 71 crushing device, 71w crushing mesh width, 72 metal-based crushing piece sorting and removing device.

Claims (13)

A method for separating and recovering plastic from a waste plastic composite containing one or more types of plastic,
A step of crushing the waste plastic composite material at a temperature higher than the embrittlement temperature of the plastic contained in the waste plastic composite material, a step of dividing the obtained crushed pieces into coarse particles, and a coarse particle size crushing A method for separating and collecting waste plastic composites, comprising a step of selectively collecting coarse pieces.   The method for separating and collecting waste plastic composite materials according to claim 1, further comprising a step of separating the crushed pieces or the crushed coarse pieces according to a specific gravity difference.   The method for separating and collecting a waste plastic composite according to claim 1, further comprising a step of selecting and removing metal-based crushed pieces from the crushed pieces, and a step of separating the crushed pieces or the crushed coarse pieces according to a specific gravity difference.   The step of separating the crushed pieces or the crushed coarse pieces by specific gravity difference is a step of separating the crushed pieces or crushed coarse pieces by at least one of an air separation method and a liquid specific gravity separation method. Item 4. A method for separating and collecting the waste plastic composite material according to Item 3.   The method for separating and collecting a waste plastic composite material according to any one of claims 2 to 4, wherein the crushed pieces or the crushed coarse pieces are separated for each kind of plastic by a step of separating the crushed pieces or coarse pieces by specific gravity difference.   6. The method according to claim 1, further comprising: using a sieve in the step of dividing the crushed pieces into coarse particles, and selectively collecting the crushed coarse pieces having a particle size larger than a sieve mesh width of the sieve. To separate and collect waste plastic composites.   The method for separating and collecting waste plastic composite material according to claim 6, wherein the sieve is a vibrating sieve.   The method for separating and collecting a waste plastic composite material according to claim 6 or 7, wherein a mesh width of the sieve is not less than one third of a crush width in the crushing.   The method for separating and collecting a waste plastic composite material according to any one of claims 6 to 8, wherein a sieve width of the sieve is 7 mm or more.   The waste plastic composite material separation according to any one of claims 1 to 9, further comprising a step of selectively removing the coarse foreign particles contained in the crushed coarse pieces after the step of selectively collecting the crushed coarse pieces. Collection method.   The separated collection plastics collect | recovered by the waste collection method of the waste plastic composite material in any one of Claims 1-10.   A recycled plastic obtained by recycling the separately collected plastic according to claim 11.   A recycled plastic product using the recycled plastic according to claim 12.

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