JP2005280242A - Waste plastic processing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste plastic processing method which can efficiently supply waste plastic to recycling by less processes, and at a low cost. <P>SOLUTION: After measuring materials and a filler material, a horizontal rotating blade 3 in a tank 2 is rotated at a high speed, and the measured materials are thrown into the tank 2. The materials are crushed and sheared by a rotary blade 32, and at the same time, made to splash, and the splashed materials are further crushed and sheared by a fixed blade 18. After throwing in all the measured materials, the measured filler material is thrown in. The crushed and sheared materials are molten by the shearing heat of the horizontal rotating blade 3, and molded (granulated) into grains by being welded to the filler material while the volume reduction is accelerated. Thus, the materials can be granulated without being crushed, and therefore, the materials can efficiently be supplied to recycling by less processes and at a low cost. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a waste plastic processing method, and more particularly, to a waste plastic processing method for processing and recycling waste plastic.

  In recent years, from the viewpoint of effective use of resources, various studies have been made on recycling plastic waste materials (hereinafter referred to as “waste plastics”), which are being put into practical use.

As a method for treating such waste plastic, for example, after pulverizing the waste plastic, the crushed material is granulated by using a granulator having a container for receiving the material and a rotary blade provided in the container. Thus, a method of recycling waste plastic for recycling has been proposed (see, for example, Patent Document 1).
JP 2003-260707 A

  However, in the waste plastic processing method described in Patent Document 1, it is necessary to crush the waste plastic before putting the waste plastic into the granulator. Each process such as granulation, cooling and storage is required. Therefore, equipment costs, equipment maintenance costs, space, worker costs, and the like are inevitably necessary, and an increase in costs for recycling waste plastic is inevitable.

  An object of the present invention is to provide a waste plastic processing method capable of recycling waste plastic for recycling efficiently with a small number of steps and at low cost.

  In order to achieve the above object, the invention described in claim 1 is a processing tank, a horizontal rotating blade provided in the processing tank and having a movable blade that rotates horizontally, and a fixed blade provided in the processing tank. A waste plastic processing method using a waste plastic processing apparatus comprising: a charging step of charging waste plastic and a filler into the processing tank; and rotating the horizontal rotary blade to rotate the waste plastic and the filling It is characterized by having a granulation step for granulating the material.

  In such a method, if the waste plastic is granulated together with the filler in the treatment tank, the waste plastic can be granulated without crushing and introducing the waste plastic in advance. As a result, waste plastics can be recycled for efficient and low cost with a small number of processes.

  In addition, in the invention according to claim 2, in the invention according to claim 1, in the charging step, first, the waste plastic is charged into the processing tank, and then the filler is charged into the processing tank. It is characterized by being thrown in.

  In such a method, first, waste plastic is put into the treatment tank, the waste plastic is crushed by the rotation of the horizontal rotary blade, and then the filler is put into the treatment tank, so the waste plastic is efficiently crushed. Then, it can be granulated with the filler. Therefore, waste plastics can be processed more efficiently, and costs can be reduced.

  In addition, the invention according to claim 3 is the invention according to claim 1 or 2, wherein in the granulation step, the horizontal rotating blade is rotated at a peripheral speed of 30 to 50 m / s, When temperature becomes 130-180 degreeC, water is added in the said processing tank, and granulation is complete | finished, It is characterized by the above-mentioned.

  In such a method, since water is added near the end of granulation, the surface of the mixture of waste plastic and filler near the end of granulation can be cooled. Therefore, the mixture whose surface is cured by cooling is further granulated while being crushed by the movable blade and the fixed blade, so that efficient granulation can be achieved.

  According to the first aspect of the present invention, it is possible to recycle waste plastics efficiently and at low cost with fewer steps.

  According to the second aspect of the present invention, waste plastic can be processed more efficiently, and the cost can be reduced.

  According to the invention described in claim 3, since the mixture whose surface is hardened by cooling is further granulated while being crushed by the movable blade and the fixed blade, efficient granulation can be achieved.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a side sectional view showing a main part of an embodiment of a waste plastic processing apparatus used in the waste plastic processing method of the present invention, and FIG. 2 is a plan view of the main part of the waste plastic processing apparatus shown in FIG.

  In FIG. 1, the processing apparatus 1 includes a tank 2 as a processing tank, a horizontal rotary blade 3, a motor 4, and a support frame 5.

  The tank 2 has a bottomed cylindrical shape that is open at the top, and is installed on the support frame 5. The tank 2 includes a substantially disc-shaped bottom wall 6 arranged in a substantially horizontal direction, a curved portion 7 that curves and rises from a peripheral end portion of the bottom wall 6, and a substantially vertical direction from the upper end portion of the curved portion 7. A cylindrical peripheral side wall 8 extending upward is continuously and integrally formed. A circular opening surrounded by the upper end portion of the peripheral side wall 8 serves as a loading port 9 for loading waste plastic (hereinafter simply referred to as “material”). It is closed by a possible top lid 91.

  A plurality of (four in this embodiment) fixed blades 18 projecting radially inward from the inner peripheral surface of the peripheral side wall 8 are provided at the lower end portion of the peripheral side wall 8 (upper end portion of the curved portion 7). (See FIG. 2).

  The fixed blade 18 is disposed slightly above an upper wing 32A described later in the vertical direction. Further, as shown in FIG. 2, the fixed blade 18 has an elongated shape and its longitudinal direction is directed radially inward of the peripheral side wall 8, and the four fixed blades 18 are arranged in the circumferential direction of the peripheral side wall 8. In FIG. 4, the intervals are approximately every 90 °. Further, the fixed blade 18 is arranged so that the tip end portion of the rotating upper wing 32A and the free end portion thereof overlap in the vertical direction in a plan view, and the upstream direction of rotation of the horizontal rotary blade 3 in each fixed blade 18 is fixed. A wedge-shaped blade is formed at the end on the side.

  The tank 2 is provided with a water supply pipe 21 that passes through the upper portion of the peripheral side wall 8 in a substantially horizontal direction and measures the temperature in the tank 2 and a temperature sensor (not shown) for measuring the temperature in the tank 2. .

  The tank 2 is provided with a discharge unit 10 for discharging the material. The discharge part 10 is provided from the lower side of the peripheral side wall 8 in the tank 2 to the bottom wall 6, and as shown in FIG. 2, a discharge port 11 that opens in the tank 2 in a substantially elliptic shape, and a discharge port 11. And an open / close gate 12 for opening and closing the door. A pressure cylinder 13 is connected to the opening / closing gate 12, and the opening / closing gate 12 is opened / closed by a forward / backward drive of the pressure cylinder 13.

  A suction duct 19 is inserted into the tank 2 through the upper lid 91. In the tank 2, the suction duct 19 is disposed in the vertical direction in the vicinity of the inner wall of the tank 2. The suction duct 19 is connected to a cyclone 20 outside the tank 2, and the cyclone 20 is connected to a blower 23 via an exhaust duct 22. The blower 23 is a suction type blower. When the blower 23 is operated, the inside of the tank 2 is sucked by the suction duct 19. Further, the gas sucked by the suction duct 19 and the solid (material) are separated by the cyclone 20, and the solid is removed by the cyclone 20, while the gas is discharged from the blower 23 to the atmosphere via the exhaust duct 22. .

  As shown in FIG. 1, the horizontal rotary blade 3 includes a rotary shaft 31 provided at the center of the tank 2 and a rotary blade 32 as a movable blade provided on the rotary shaft 31.

  The rotary blade 32 is composed of an upper blade 32A and a lower blade 32B, and is arranged so that the upper blade 32A is positioned upward and the lower blade 32B is positioned downward in a side view.

  The upper wing 32A is formed so as to extend in a substantially horizontal direction (radially outward) from the rotating shaft 31 in a side view, and a tip blade 32C is provided on the top surface of the tip portion. Further, the upper wing 32A extends in the radial direction from the rotating shaft 31 in a plan view, and then extends so that the distal end portion is bent, so that the upper blade 32A is formed in a substantially oblique N shape as a whole. A blade is formed at the upstream end of the upper wing 32A (horizontal rotary blade 3) in 32C in the rotational direction (see FIG. 2).

  The lower blade 32B is formed so as to extend in a substantially horizontal direction (radially outward) from the rotary shaft 31 in a side view, and to bend upward at a tip portion. Further, the lower blade 32B is arranged so as to overlap the upper wing 32A in plan view.

  The rotary shaft 31 penetrates the bottom wall 6 in the vertical direction (vertical direction) in the central portion of the tank 2, and a lower portion thereof is rotatably supported by the support frame 5 via a bearing 14 and an upper portion thereof. , Projecting into the tank 2. In the support frame 5, a driven pulley 15 to which power from the motor 4 is transmitted is provided below the rotating shaft 31 so as not to be relatively rotatable.

  The motor 4 is installed on the side of the tank 2 on the support frame 5, and its pinion shaft 16 is inserted into the support frame 5. Further, a transmission pulley 17 is provided on the pinion shaft 16 so as not to be relatively rotatable.

  An endless belt 24 is wound around the transmission pulley 17 provided on the pinion shaft 16 and the driven pulley 15 provided on the rotating shaft 31.

  Therefore, when the pinion shaft 16 is rotated by driving the motor 4, the power is transmitted to the rotating shaft 31 via the transmission pulley 17, the endless belt 24 and the driven pulley 15, thereby the horizontal rotating blade 3. The rotary blade 32 is rotated at a high speed in the horizontal direction.

  Next, a method for processing waste plastic (material) by the processing apparatus 1 will be described.

  Although it does not restrict | limit especially as a material processed with this processing apparatus 1, Typically, polyethylene (PE: melting temperature 130 degreeC), polypropylene (PP: melting temperature 170 degreeC), polystyrene (PS: melting temperature 130 degreeC) ), ABS resin (ABS: melting temperature 140 ° C.), chlorinated thermoplastic resins such as polyvinyl chloride (PVC: melting temperature 200 ° C.), polyethylene terephthalate (PET: melting temperature 250 ° C.), polyacetal (POM: melting temperature 170). ° C), for example, waste plastic sheets (including packaging sheets such as air cap sheets) and waste plastics in the form of sheets (films) such as waste plastic films.

  In this method, the filler is charged into the tank 2 together with the material. The filler is a known filler and is not particularly limited, and examples thereof include wood flour, cellulose, starch, calcium carbonate, sludge and the like.

  In this method, first, the material and the filler are weighed. For example, these are weighed at a ratio of 30 parts by weight or more of the filler with respect to 100 parts by weight of the material, and preferably at a ratio of 40 to 80 parts by weight of the filler with respect to 100 parts by weight of the material.

  Thereafter, the horizontal rotating blade 3 is rotated at a peripheral speed of 30 to 50 m / s by driving the motor 4 of the processing apparatus 1, and then the upper lid 91 is opened, and the measured material is fed into the tank 2 from the inlet 9. In Thereby, processing is started.

  In the tank 2, the rotating blade 32 (upper blade 32 </ b> A and lower blade 32 </ b> B) crushes and shears the material due to the high-speed rotation of the horizontal rotating blade 3, and at the same time, the material is scattered. Furthermore, it is crushed and sheared. Thereby, the material is efficiently crushed and sheared.

  After all of the weighed material has been charged, the weighed filler is then charged. When the filler is introduced, the crushed and sheared material is melted by the shear heat of the horizontal rotary blade 3, and while being reduced in volume, it is welded to the filler and formed into granules (granulated).

And from the start of the process, the temperature in the tank 2 continues to rise due to the shear heat of the horizontal rotary blade 3, and when the temperature in the tank 2 becomes 130 to 170 ° C, preferably 140 to 150 ° C, The blower 23 is operated, and suction in the tank 2 by the suction duct 19 is started. Air volume of the blower 23, for example, 5 to 30 m ³ / min, preferably from 10 to 20 m ³ / min.

  Air in the tank 2 is sucked by the suction duct 19 and discharged from the blower 23 to the atmosphere via the cyclone 20 and the exhaust duct 22. At this time, a small amount of material and filler sucked together with the air by the suction duct 19 are separated from the air and collected by the cyclone 20. Thereby, the air contained in the mixture (material and filler) being granulated is degassed from the mixture, and as a result, volume reduction of the granulated mixture is further promoted.

  Note that the suction start timing by the blower 23 may be determined as appropriate, and may be, for example, simultaneously with the water supply timing described below.

  Then, water is supplied from the water supply pipe 21 into the tank 2 when the temperature in the tank 2 reaches 130 ° C. or higher, preferably 130 to 180 ° C., more preferably 140 to 150 ° C. Then, the mixture is cooled at once. The mixture whose surface is cured by cooling is further granulated while being crushed by the rotary blade 32 and the fixed blade 18. Therefore, efficient granulation is achieved. The supply amount of water is, for example, 3 to 8 parts by weight with respect to a total of 100 parts by weight of charged materials and fillers.

  In the temperature detection, the temperature in the tank 2 may be directly detected by a temperature sensor (not shown), or when the material is melted and welded to the filler, the viscosity rapidly increases. The load of the motor 4 at that time (the generated current value of the motor or the torque of the motor) may be detected.

  Then, after supplying water into the tank 2, after 20 to 60 seconds, preferably 30 to 40 seconds, the blower 23 is stopped and the tank 2 is opened to the atmosphere, and then the pressure cylinder 13 is operated. Then, by opening the open / close gate 12, the granulated product obtained by granulating the mixture is discharged out of the tank 2 through the discharge port 11, and is conveyed to a storage tank (not shown) through a belt conveyor or the like. And store in the storage tank.

  And, if necessary, the granulated product stored in the storage tank can be obtained by selecting the particle size with a sieve (not shown) to obtain a granulated product having a particle size according to the purpose and application. Can be used for recycling.

  As described above, in this method, if the material is granulated with the filler by using the processing apparatus 1 described above, the material can be granulated without crushing and adding the material in advance. . As a result, since the treatment process can be a measurement process, a granulation process, a conveyance process, and a storage process, it is possible to recycle the material efficiently and at low cost with fewer processes. For example, the granulated product can be recycled as a molding material such as extrusion molding, injection molding or press molding. More specific applications include, for example, synthetic wood materials, decorative materials, and writing materials.

  Further, in this method, the material is put into the tank 2, the material is crushed by the rotation of the horizontal rotary blade 3, and then the filler is put into the tank 2, so that the material is efficiently crushed and filled. Can be granulated with the material. Therefore, the material can be processed more efficiently, and the cost can be reduced.

  Moreover, in this method, since water is added into the tank 2 near the end of granulation, the surface of the mixture of the material and filler near the end of granulation can be cooled. Therefore, the mixture whose surface is hardened by cooling is further granulated while being crushed by the rotary blade 32 and the fixed blade 18, so that efficient granulation can be achieved.

Test example

As waste plastic to be processed, 14 kg of PE air cap sheet that was not crushed was weighed, and 6 kg of wood powder (200 mesh) was weighed as a filler. Then, as the processing apparatus shown in FIG. 1 described above, a super add-on mixer EM-100 type (manufactured by Kawata Co., Ltd.) is used, and the rotational speed of the horizontal rotary blade is rotated to 1050 min ⁻¹ (circumferential speed 38 m / s). The PE air cap sheet weighed in the processing apparatus was charged over 3 minutes and 20 seconds. The temperature in the tank before the start of the introduction of the PE air cap sheet was 40 ° C., and the temperature in the tank after the completion of the introduction of the PE air cap sheet was 72 ° C. Then, after 40 seconds, the weighed wood powder was put into the processing apparatus over 1 minute 30 seconds. In addition, the temperature in the tank after completion of the wood powder input was 85 ° C. Then, after 8 minutes and 55 seconds, when the temperature in the tank of the processing apparatus reached 150 ° C., the air in the tank was discharged outside the processing apparatus by operating the blower, and at the same time, 1 L of water Was introduced. Further, 30 seconds after the water was put into the processing apparatus, the blower was stopped, the material was discharged from the processing apparatus, and the granulated material was recovered.

  The average particle diameter of the collected granulated product was 1 to 5 mm. The average moisture content of the granulated product was 0.5% by weight.

It is a principal part sectional side view which shows one Embodiment of the waste plastic processing apparatus used for the waste plastic processing method of this invention. It is a principal part top view of the waste plastic processing apparatus shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Processing apparatus 2 Tank 3 Horizontal rotary blade 18 Fixed blade 32 Rotary blade

Claims (3)

A waste plastic processing method using a waste plastic processing apparatus comprising a treatment tank, a horizontal rotary blade having a movable blade that rotates horizontally provided in the treatment tank, and a fixed blade provided in the treatment tank. ,
A charging step of charging waste plastic and filler into the treatment tank,
A waste plastic treatment method comprising a granulation step of granulating the waste plastic and the filler by rotating the horizontal rotary blade. In the charging step,
The waste plastic treatment method according to claim 1, wherein the waste plastic is first put into the treatment tank, and then the filler is thrown into the treatment tank. In the granulation step,
The horizontal rotating blade is rotated at a peripheral speed of 30 to 50 m / s, and when the temperature in the processing tank reaches 130 to 180 ° C., water is added to the processing tank to complete the granulation. The method for treating waste plastic according to claim 1 or 2, wherein:

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