JPH07205147A - Plastic waste treating apparatus - Google Patents

Abstract

PURPOSE:To improve biting and transporting power of a raw material by a biaxial first stage extruder, to continuously supply waste resin film, to connect to dispose two extruders in a folded or U-turned state, and to reduce an installation area. CONSTITUTION:Waste resins 6A, 6B are fed from a first stage extruder 1 to a pellet manufacturing unit 3 via a second-stage extruder 2. The extruder 1 is formed in a biaxial different-direction rotary type having two first screw shafts 22A, 22B disposed in parallel in a first barrel 21 having a first heater so that screw threads are engaged and rotatably driven in reverse directions. The extruder 2 is formed in a uniaxial type having one second screw shaft 42 disposed rotatably in a second barrel 41.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic waste processing apparatus for heating and melting plastic wastes and defective plastics discharged from factories and the like to form pellets for reuse.

[0002]

2. Description of the Related Art Conventionally, in order to effectively use and recycle plastics, defective plastic products and plastic wastes are pulverized and reused as they are by mixing with virgin raw materials at about 15 to 20%. Although this method is inexpensive, there are many problems especially due to its small apparent specific gravity and foreign substances contained, so crushed plastic defective products and plastic waste are pelletized using an extruder and granulator. The method of reuse is adopted.

As shown in FIG. 7, this processing apparatus feeds defective plastic products and plastic wastes to a tray 62a of a pushing device 62 by a carry-in conveyor device 61 and drives a pushing tool 62b provided at the bottom of the tray 62a. It is rotationally driven by the motor 62c and is forcibly fed into the supply port 63a of the single-screw extruder 63, and the barrel 6 of the extruder 63 is driven.
While being heated and melted by the heater 63c in the 3b, the screw 63d kneads and stirs the discharge port 63e
It is sent from the granulator to the granulator.

[0004]

However, the above processing apparatus has a problem that it is difficult to stably feed and crush waste resin pulverized products and waste resin films. In order to solve this problem, for example, a twin-screw extruder may be used to improve the feeding and transportation, but if a heating and melting function and a pressure increasing function are added, the total length of the extruder becomes longer and There is a problem that the area becomes large and the cost becomes high.

According to the present invention, the above problems can be solved, the waste resin film as well as the waste resin film can be stably fed and transported, and can be melt-kneaded efficiently, and the entire apparatus can be made compact. At the same time, it is an object of the present invention to provide a plastic waste treatment device which can be manufactured at a low cost.

[0006]

In order to solve the above problems, the plastic waste treatment apparatus of the present invention is a plastic waste treatment in which a plastic waste raw material is heated and melted, kneaded, and formed into pellets by a granulating device. In the object processing device, two first screw shafts, which are arranged parallel to each other in a first barrel having a heating device, mesh with each other and are driven to rotate in opposite directions, and an upstream end of the first barrel. The raw material charging port formed on the side that rotates in the direction in which the screw crests of the first screw shaft merge with each other;
A two-shaft relative direction rotary type first-stage extruder provided with a first resin discharge port formed on the downstream end side of the barrel is provided.
One second screw shaft rotatably arranged in the barrel, a resin supply port formed on the upstream end side of the second barrel and connected to the first resin discharge port, and a downstream end of the second barrel. A single-screw second-stage extruder having a second resin discharge port formed on the side and connected to the die of the granulator is provided.

In addition, in the above-mentioned structure, resistors which serve as resin feed resistance are provided at intermediate positions of the first screw shaft of the first-stage extruder, and the screw mountain outer circumference of the first screw shaft upstream of these resistors is provided. A plurality of notches for venting gas are formed in the portion.

Further, in the above structure, the first resin discharge port of the first-stage extruder is provided with the first screen member having a large diameter and rough surface capable of removing foreign matters in the resin, and the first-stage extruder has the second screen of the first-stage extruder. The second resin discharge port is provided with a fine second screen member capable of removing foreign matters in the resin.

Furthermore, in the above-mentioned structure, in the first-stage extruder, at least the feed portion corresponding to the raw material supply port is a screw shaft having multiple thread ridges. Further, in the second-stage extruder arranged in the first-stage extruder in which the resistor and the notch for degassing are formed, a vent port for discharging the air in the resin is provided in the second barrel on the upstream side of the resin supply port. It is a thing.

[0010]

In the above structure, since the extruder is composed of the first stage extruder and the second stage extruder, the first stage extruder and the second stage extruder are used.
The length of each stage extruder can be halved, and both extruders can be arranged in a bent state even if the length of the extruder is the same as that of a single unit, so they can be connected in a narrow angle or U-turn state. As a result, the installation area can be significantly reduced, and the installation surface can be arranged on any installation surface such as an L-shape corresponding to the installation surface such as a factory. In addition, since the first-stage extruder is a twin-screw type, it is possible to improve the biting ability and the transporting power of the resin material and perform the melt-kneading efficiently, and even if the waste resin film is used, it can be continuously continuously satisfactorily. Can be supplied.

Further, since the resistor and the notch are provided on the first screw shaft of the first-stage extruder, the resin is compressed by the resistor and the water vapor and volatile matter contained in the resin are passed through the notch. As a result, the gas can be reliably prevented from being entrained in the raw material charging port, and the problem of the twin-screw extruder in which air is easily taken into the resin can be solved.

Further, since the foreign matter contained in the resin can be removed in two steps, that is, the first screen member having a large area and the coarse mesh and the second screen member having the fine mesh, a clean resin can be obtained and a large amount of foreign matter is contained. Even if a resin raw material is used, the number of times the screen member is replaced can be reduced.

Furthermore, since the feed portion of the first-stage extruder is formed as a multi-thread screw thread, the waste resin crushed product and the waste resin film can be more effectively bited, and more efficient extrusion can be performed. Can be expected.

Further, in the second-stage extruder arranged in the first-stage extruder in which the resistor and the notch for venting gas are formed, natural evacuation from the vent port makes it possible to sufficiently degas ordinary resin. . Further, by forcibly degassing, even a resin having high hygroscopicity can be sufficiently degassed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the plastic waste processing apparatus according to the present invention will be described below with reference to FIGS.

This plastic waste treatment device is shown in FIG.
As shown in FIG. 1, it comprises a first-stage extruder 1, a second-stage extruder 2 and a pellet manufacturing apparatus (granulating apparatus) 3.
And the second-stage extruder 2 are connected and arranged in an L-shape in a plan view, and the discharge water tank 4 of the pellet manufacturing apparatus 3 is the first-stage extruder 1
In parallel with this, they are arranged in a U-shape in plan view as a whole to shorten the total length and reduce the total installation area. Then, in the vicinity of the side portion of the raw material supply chute 5 of the first-stage extruder 1, a roll waste holding shelf 7 capable of rotatably supporting and feeding the roll-shaped waste resin film 6A,
A crushing raw material container 8 for storing a waste resin crushed product 6B of plastic waste is installed, a pellet take-out conveyor 9 and a dehydrator 10 are arranged at the outlet of the discharge water tank 4 of the pellet manufacturing apparatus 3, and a control panel is provided in the vicinity thereof. A dual-purpose operation panel 11 is arranged.

As shown in FIGS. 2 and 3, the first stage extruder 1 includes two first screw shafts 22A and 22B which are parallel to each other in a horizontal plane in a first barrel 21 having a horizontally long oval cross section.
Are arranged, and the screw threads (also referred to as screw threads or spiral flights) 23a, 23 formed on the first screw shaft
b and 23c are deeply engaged with each other, and the first drive device 24
Therefore, the rotation speed N ₁ = maximum 60 rpm or less, properly 60 rpm.
It is configured to be rotationally driven in mutually opposite inner directions (hereinafter referred to as inner relative directions) indicated by arrows E and F in the range of m to 50 rpm. The first drive device 24 is
It is composed of a first drive motor 24a, a speed reducer 24b, and a torque distributor 24c.

[0018] The first barrel 21 is about short length of half the front and rear [L ₁ = 11 × D ₁ (screw diameter)] is formed, the first feed from the upstream side portion A ₁ of the case provided with a single , A phase transition section B ₁ and a sending section C ₁ are provided. Then, on the outer peripheral surface of the first barrel 21, first heating devices 25A, 25B, 25C are provided corresponding to the first feed portion A ₁ , the phase transition portion B ₁ and the delivery portion C ₁ , respectively.

The first feed section A ₁ has a first barrel 21.
The raw material supply port 26 is formed on the upper surface side where the screw crests 23a merge with each other, and the raw material supply chute 5 is provided.
The waste resin film 6A is carried in from the roll waste holding shelf 7 via the guide member 7a, and the waste resin crushed product 6B is carried in from the crushing raw material container 8 via the pneumatic pipe 8a. . Also, the first feed section A
₁ screw mountain 23a may be a Ichijo, but are formed in parallel grooves shaped multi-start example Article 2, jammed waste resin film 6A by positive motion feed mechanism based on the gear pump principle as compared to 1 Article reliably At the same time, the crushed capacity of the waste resin crushed product 6B is improved to improve the transportation capacity and the production capacity. The depth of the groove of the screw crest 23a is H ₁ = 0.2 × D ₁ (screw diameter).

The screw crest 23b of the phase transition part B _{1 has} a single parallel groove shape shallower than the screw crest 23a of the first feed part A ₁ , and has both first screw shafts 22 at its downstream end position.
Cylindrical resistors 27A, 2 which are displaced by A, 22B
7B are respectively projected. Generally, the inner-rotating relative-direction twin-screw extruder is more likely to entrain air together with the resin raw material due to the effect of enclosing the screw mountain compared to the single-screw extruder, but in this embodiment, as shown in FIG. As shown in FIG. 5, the first body 27A and the second body 27B are provided.
Screw mountain 23 of the feed section A ₁ and the phase transition section B ₁
By forming air venting notches 28 at four locations at constant circumferential intervals on the outer peripheral portions of a and 23b, respectively, solid and fluid resins are compressed by the resistors 27A and 27B and sheared. To prevent the entrainment of volatile impurities, absorbed moisture vapor, etc. in the air entrapped in the resin and the waste resin film 6A and the waste resin crushed product 6B by promoting plasticization and melting of Supply port 2
It is configured to discharge from 6.

The screw crest 23c of the delivery portion C ₁ is formed in a shallow parallel groove shape like the screw crest 23b of the phase transition portion B ₁ . The first resin discharge port 29 formed at the downstream end of the delivery section C ₁ has a first screw shaft 22A,
A first breaker plate 30 that supports the first screen member 31 is disposed on the upstream side, close to the end of 22B. The first breaker plate 30 has a large number of resin passage holes formed therein, and the first screen member 31 is made of a rough mesh such as mesh # 30 to # 40. Also the first
Each of the breaker plate 30 and the first screen 31 has the same shape as the inner cross section of the first barrel 21 and a wide resin passage area is secured, so that even if the resin raw material contains a large amount of dust or foreign matter, First screen member 3
1 contributes to reducing the frequency of replacement.

As described above, the first-stage extruder 1 is a twin-screw inner-rotating relative-rotation type, and has a barrel length L ₁
= 11 × D ₁ and formed as short as possible, screw shafts 22A, 22B
The rotation speed N _{1max of the} resin is reduced to a maximum of 60 rpm or less and the depth of the groove of the first feed portion A ₁ is deepened to H ₁ = 0.2 × D ₁ to increase the meshing clearance, thereby increasing the residence time of the resin. t
₁ and the shear rate γ ₁ = πD ₁ · N _1max / H ₁ are both small to realize low temperature extrusion. This is the residence time t ₁
× Shear rate γ ₁ = Residence time t ₁ × πD ₁ · N _{1m ax} / H
_The value represented by ₁ and the total amount of shear energy (calorific value)
Are very close to each other and can be considered as a measure of low temperature extrusion, and in this example, the residence time t ₁ and the shear rate γ ₁ are also small, so that the shear energy amount of the first-stage extruder 1 is extremely small, Therefore, the excellent effect that a cooling device for removing the internal heat generation due to shearing is unnecessary is provided, which is a factor promoting energy saving and low cost. Such a small amount of shear energy means that the specific power of the first stage extruder 1 (power consumption of the first drive motor 24a /
It is also clear that the extrusion amount) is 0.06 to 0.13, which is a small value of 1/2 or less as compared with the specific power 0.25 to 0.30 of the conventional twin-screw extruder.

Contact the first resin discharge port 29 of the first stage extruder 1.
The single-screw second-stage extruder 2 connected via the connecting pipe 32 is
As shown in FIG. 4, in the second barrel 41 having a circular cross section,
The 2 screw shaft 42 is rotatably arranged,
Second drive device 43 including a motor 43a and a speed reducer 43b
Therefore, the rotation speed N of the screw shaft 42₂= 70r.p.m or less
In particular, it is rotationally driven in the direction of arrow G in the range of 60 to 70 r.p.m.
Is configured to. This second barrel 41 is a single
Short length of about half of that provided by [L ₂= 12 x
D₂(Screw diameter)], and the second screw from the upstream side.
Feed part A₂, Compression section B₂And weighing unit C₂Is provided
ing. And the compression unit B₂And lightweight section C₂Second ba
The outer surface of the rel 41 corresponds to the temperature of the second barrel 41.
Cooling device 44A and heating device 44B used selectively and selectively
Is provided, and the second feed section A₂The vent member
45 connects the connecting pipe 32 to prevent leakage of the resin.
The upstream side position of the continuous resin supply port 40 (at the upper position
It is also possible).

The vent port member 45 is provided with a suction hose connection port 45a that faces downward (downstream in the rotational direction) of the second screw shaft 42, and serves as resistors 27A and 27B of the first-stage extruder 1. First feed section A ₁ and phase transition section B
_Since the gas is discharged to the raw material supply port 26 by the air vent notch 28 formed in the screw crests 23a and 23b of _1, the hose connection port 45a is often left open in the resin. The remaining gas can be sufficiently removed, but especially by connecting a vacuum pump to the hose connection port 45a and forcibly deaerating, even the resin having a high hygroscopicity is sufficiently removed. be able to.

The groove of the second feed portion A ₂ has a depth H
_2f = 0.15 × D ₂ is formed deeply to suck and stabilize the molten resin that is unstablely sent from the first-stage extruder 1, and to prevent the resin from rising at the vent port by starving the molten resin. Moreover, the resin is prevented from leaking from the upstream end of the second-stage extruder 2.

The second screw shaft 42 has a second feed portion A.
₂ to the compression section B ₂ and the weighing section C ₂ are formed screw threads 46a, 46b and 46c, which are shallow grooves in this order,
The groove depth of the second feed portion A ₂ is deep as H _2f = 0.15 × D ₂ and the groove depth H _{2m of the} weighing portion C ₂ is H _2m = 0.05.
× formed shallower and D _2, by a compression ratio _{(H 2f / H 2m) ≧} 3, the length of the second barrel 41 is configured to be stable extrusion be short. In addition, in this second stage extruder 2, the rotation speed of the second screw shaft 42 is 60 to 70.
rpm or less and length L ₂ of the second barrel 41
= 12 × D ₂ and then cooled by the cooling device 44A to realize low temperature extrusion and prevent deterioration of the molten resin.

A second breaker plate 48 for supporting a second screen member 49 on the upstream side is arranged at the second resin discharge port 47 at the downstream end of the second barrel 41. The second screen member 49 has a mesh. # 80- # 12 practically considering the fineness of # 80 or more, clogging and strength
0 wire mesh is used.

The pellet manufacturing apparatus 3 has a resin pressure inlet 51a.
The second resin discharge port 47 of the second-stage extruder 2 is connected to the die 51, and a die 51 having a plurality of extrusion molding passages 51c branched from one resin inlet 51a, and an extrusion port 51b of the die 51. Rotary cutter 54 for forming pellets by cutting a small-diameter columnar resin which is arranged facing the air and is continuously extruded from the extrusion port 51b into an appropriate length.
And, the cutting blade motor 52 that rotates the rotary cutter 54 via the drive shaft 53, the die 51 and the rotary cutter 54 are covered, and cooling water is sent inside to cool the cut pellets with water. It is composed of a cooling casing 55.

The operation of the above configuration will be described. (1) In the first stage extruder 1, the first barrel 21 is heated by the first heaters 25A to 25C, and the screw shafts 22A and 22B are rotationally driven by the first driving device 24, so that the roll waste holding shelf 7 is provided. The waste resin film 6A held in the above is supplied to the raw material supply chute 5 through the guide member 7a, and the waste resin crushed product 6B is supplied from the crushed raw material container 8 to the raw material supply chute 5 through the pneumatic pipe 8a. It

(2) In the first-stage extruder 1, the waste resin film 6 is produced by the positive feeding effect based on the principle of the gear pump by the two screw threads 23a provided in the first feed section A _1.
Make sure that A is bitten, and that the waste resin crushed product 6B is bite with a high biting force, and with a high transport capacity
It is sent from the feed section A ₁ to the phase transition section B ₁ .

(3) In the phase transition portion B ₁ , the resistors 27A,
The solid and fluid resin is compressed and sheared by 27B to accelerate the plasticization and melting of the resin.
The entrainment effect of a and 23b prevents entrainment of air, volatile impurities in waste resin film 6A and waste resin crushed product 6B, moisture vapor absorbed, and the like, and outer peripheral portions of screw mountains 23a and 23b. It is extruded rearward through the air vent notch 28 formed in and is discharged from the raw material supply port 26.

(4) In the delivery section C ₁ , the first resin discharge port 2
The first breaker plate 30 and the first screen 31, which are arranged at 9 and have a wide resin passage area, remove relatively large dust and foreign matter mixed with the waste resin raw material.

(5) First resin discharge port 29 to connection pipe 32
The resin delivered to the resin supply port 40 of the second-stage extruder 2 via the deep feed groove A ₂ sucks the molten resin to alleviate the unstable feeding, and also causes the starvation state. As a result, the resin is prevented from rising at the vent port, and the gas remaining in the resin is naturally or forcibly degassed from the vent member 45.

(6) The molten resin is sent from the second feed section A ₂ to the compression section B ₂ and the metering section C ₂ in this order, and the compression ratio is 3
With the above settings, the second barrel 41 is stably extruded even if the length of the second barrel 41 is short. And the second screw shaft 42
Low speed (60-70r.pm or less) and short second barrel 4
By the length of 1 (L ₂ = 12 × D ₂ ) and the cooling device 44A, low temperature extrusion is performed to prevent deterioration of the molten resin. Further, the second breaker plate 48 of the second resin discharge port 47
By the second screen member 49 having a fine mesh, fine foreign matters mixed in the resin are removed and pushed out.

(7) The resin supplied from the second resin discharge port 47 to the die 51 of the pellet manufacturing apparatus 3 is sent from a single resin inlet 51a to a plurality of branched extrusion passages 51c, and the extrusion port 51b. Is formed into a small diameter cylindrical body and continuously extruded. Then, the rotary cutter 54 cuts the resin into an appropriate length to form pellets, and the pellets are dropped into cooling water in the cooling casing 55 to be cooled and solidified. Furthermore, from the drainage tank 4 to the dehydrator 1
0 and is discharged to the product tray 56.

Next, an explanation will be given of the experimental results of producing pellets from a plurality of kinds of waste resins by using the plastic waste treatment equipment having the following specifications. The first-stage extruder 1 used here is: 2-shaft type inner-rotating relative direction type-Outer diameter of the first screw shafts 22A, 22B: D ₁ = 70
mm ・ Length of the first barrel 21: L ₁ = 11
× D ₁ = 770 mm ・ First breaker plate 30: Oval ・ First screen member 31: # 40 × 1 Further, the second stage extruder 2 is: ・ Single screw type ・ Outer diameter of the second screw shaft 42: D ₂ = 70
mm ・ Length of second barrel 41: L ₂ = 12
× D ₁ = 840 mm ・ Depth of groove of the second feed portion A ₂ : H _2f = 12
mm ・ Depth of groove of measuring section C ₂ : H _2m = 4
mm ・ Compression ratio: H _2f / H _2m
= 3 ・ Vent port: Open or vacuum suction on the upstream side of the second feed section A ₂・ Second breaker plate 48: Diameter 70 mm
Circle-Second screen member 49: # 30x1, #
80 × 1, # 40 × 1.

Experiment A In this experiment, pellets were manufactured by simultaneously supplying an OPP defective film (polypropylene biaxially oriented film) having a thickness of 25 μm and a crushed OPP defective film (apparent specific gravity ρ = 0.05 g / cm ³ ). The results are shown in Tables 1 and 2.

[0038]

[Table 1]

[0039]

[Table 2]

According to Tables 1 and 2, a good quality pellet without deterioration of physical properties could be manufactured. Experiment B In this experiment, pellets were manufactured by supplying a defective trimmed EVOH film (ethylene vinyl alcohol copolymer) having a thickness of 25 to 40 μm. The results are shown in Tables 3 and 4.

[0041]

[Table 3]

[0042]

[Table 4]

The EVOH film is a resin having a high gas barrier property but also a high water absorption property. According to Tables 3 and 4 above, even if it is an open vent, good quality pellets without bubbles are formed. Was manufactured.

Experiment C Pellets were manufactured by supplying a crushed product of PC (polycarbonate resin) film having an apparent specific gravity of 0.18 g / cm ³ . The results are shown in Tables 5 and 6.

[0045]

[Table 5]

[0046]

[Table 6]

The PC film has a water absorbability of about 0.3% at room temperature and is a resin that is easily oxidized and deteriorated in the melting process. However, by vacuum suction from the vent port, it is possible to obtain good quality pellets without physical deterioration. did it.

Experiment D Pellet was prepared by supplying a crushed product of PET-G resin (polyethylene lalephthalate copolymer) having an apparent specific gravity of 0.43 g / cm ³ . The results are shown in Table 7 and Table 8.
Shown in.

[0049]

[Table 7]

[0050]

[Table 8]

PET-G resin has a high water absorbability of about 0.4% at room temperature, is hydrolyzed in the melting process to cause a rapid decrease in viscosity, and is a resin which is difficult to be pelletized. A good quality pellet free from air bubbles was obtained by the typical vent port suction.

According to the above-described embodiment, (1) the two extruders of the first-stage extruder 1 and the second-stage extruder 2 are connected in series, so that the first-stage extruder 1 and the second-stage extruder 1 Two
The multi-stage extruder 2 and the multi-stage extruder 2 each can be formed to have a barrel length that is about half that of a single-stage extruder, and both extruders can be connected together via a connecting pipe 32. Can be arranged at an angular position of, and the area and length required for installation can be halved.

(2) Since the first-stage extruder 1 is of the inner-rotating, relative-direction rotating type, that is, a twin-screw type, the positive feed mechanism based on the principle of the gear pump improves the biteability and transport ability of the waste resin crushed product 6B. At the same time, the waste resin film 6A can be continuously fed and fed, and the waste resin film 6A and the waste resin pulverized product 6B can be supplied simultaneously or separately.

Further, the first feed portion A _{1 is provided} with a deep groove (H ₁ = 0.
2 × D ₁ ) and in the form of multiple grooves, for example, two grooves, so the waste resin film 6
It is possible to bite A more reliably and improve the bite ability of the waste resin crushed product 6B to increase the production capacity.

(3) Generally, a relative direction twin-screw extruder has a screw thread sealing effect as compared with a single-screw extruder.
Although it is easy to entrain air together with the resin raw material, in this embodiment, due to the resistors 27A and 27B formed on the first screw shafts 22A and 22B and the air vent notch 28,
The air, volatile impurities, absorbed moisture vapor, etc., which have been compressed by the resin being compressed into the resin, can be extruded backward and discharged from the raw material supply port 26, and at the same time, the resistor 27
The resin can be sheared by compression with A and 27B to promote plasticization and melting.

Since the resistors 27A and 27B and the air vent notch 28 allow the gas in the resin to be sufficiently degassed, the degassing in the second extruder 2 is performed by the resin supply port 40. In many cases, the vent member 45 penetrating on the upstream side need only be opened, and the gas in the resin can be sufficiently removed by vacuum suction only for a resin having a particularly high hygroscopicity.

(4) First resin discharge port 2 of first stage extruder 1
9 and the second resin discharge port 47 of the second stage extruder 2 are provided with the first and second breaker plates 30 and 48 and the first and second screen members 31 and 49, respectively. It is possible to remove dust and foreign matters and obtain clean pellets. Further, since the first screen 31 has the same shape as the inner cross section of the first barrel 21 and has a wide resin passage area, the screen member 3 can be formed even if the resin raw material contains a large amount of dust and foreign matters.
The frequency of replacement of 1,49 can be reduced, and maintenance becomes easier.

(5) In the first-stage extruder 1, the barrel length is shortened, the rotational speeds of the screw shafts 22A and 22B are reduced, and the depth of the groove of the first feed section A ₁ is increased to make a meshing gap. By increasing the residence time and shear rate of the resin to realize low temperature extrusion, the second extruder 2 shortens the length of the second barrel 41 and reduces the length of the second screw shaft 42. By lowering the rotation speed and further cooling by the cooling device 44A, low temperature extrusion is realized, and unnecessary deterioration of the molten resin can be prevented, and the product characteristics of the pellets can be improved.

(6) In the second extruder 2, by forming the groove of the second screw shaft 42 of the second feed portion A ₂ deep, the molten resin sent unstablely from the first-stage extruder 1 Can be sucked and stabilized, and can prevent starvation of resin at the vent port and prevent resin from leaking from the upstream end of the second-stage extruder 2. Also, the second feed section A ₂
By forming the groove of (1) deep and the groove of the measuring section C ₂ shallow, the compression ratio is set to 3 or more,
Even if the length of the second barrel 41 is short, stable extrusion can be performed.

[0060]

As described above, according to the present invention, since the extruder is composed of the first stage extruder and the second stage extruder, the first stage extruder and the second stage extruder are constituted. The length can be reduced to half, and even if the total length is the same as one unit, both extruders can be arranged in a bent state, so by connecting in a narrow angle or U-turn state,
The installation area can be greatly reduced, and it can be arranged on any installation surface such as an L-shape corresponding to the installation surface of a factory or the like. In addition, since the first-stage extruder is a twin-screw type, it is possible to improve the biting ability and the transporting power of the resin material and perform the melt-kneading efficiently, and even if the waste resin film is used, it can be continuously continuously satisfactorily. Can be supplied.

Further, since the resistor and the notch are provided on the first screw shaft of the first-stage extruder, the resin is compressed by the resistor and the water vapor and volatile matter contained in the resin are passed through the notch. As a result, the gas can be reliably prevented from being entrained in the raw material charging port, and the problem of the twin-screw extruder in which air is easily taken into the resin can be solved.

Furthermore, since the foreign matter contained in the resin can be removed in two steps, the first screen member having a large area and the rough surface and the second screen member having a fine mesh, a clean resin can be obtained and a large amount of foreign matter is contained. Even if a resin material is used, the number of times the screen member is replaced may be reduced.

Furthermore, since the feed section of the first-stage extruder is formed as a multi-thread screw thread, the waste resin crushed product and the waste resin film can be more effectively bited, and more efficient extrusion can be performed. Can be expected.

Further, in the second-stage extruder arranged in the first-stage extruder in which the resistor and the notch for venting gas are formed, natural evacuation from the vent port allows the ordinary resin to be sufficiently degassed. It is possible to prevent air bubbles from being embedded in the resin.
Further, by connecting a vacuum pump or the like and forcibly degassing, even a resin having a high hygroscopicity can be sufficiently degassed.

[Brief description of drawings]

FIG. 1 is an overall perspective view showing an embodiment of a plastic waste processing apparatus according to the present invention.

FIG. 2 is a partially cutaway perspective view showing the configuration of the processing apparatus.

FIG. 3 is a cutaway perspective view showing a first stage extruder of the processing apparatus.

FIG. 4 is a cutaway perspective view showing a second stage extruder of the processing apparatus.

5 is a cross-sectional view taken along the line I-I shown in FIG.

6 is a sectional view taken along line II-II shown in FIG.

FIG. 7 is a configuration diagram showing a conventional plastic waste treatment device.

[Explanation of symbols]

 1 1st stage extruder 2 2nd stage extruder 3 Pellet manufacturing device 5 Raw material supply chute 6A Waste resin film 6B Waste resin crushed product 7 Roll waste holding shelf 8 Crushing raw material container 21 1st barrel 22A, 22B Screw shaft 23a- 23c Screw mountain 24 1st drive device 25A-25C 1st heater 26 Raw material supply port 27A, 27B Resistor 28 Air vent notch 29 1st resin discharge port 30 1st breaker plate 31 1st screen member 32 Connection pipe 40 Resin Supply port 41 Second barrel 42 Second screw shaft 43 Second drive device 44A Cooler 44B Second heater 45 Vent member 46a to 46c Screw mountain 47 Second resin discharge port 48 Second breaker plate 49 Second screen member 51 Die 54 rotary cutter 55 water-cooled casing

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sadao Sumigaki 1-470 Jomi Chuo-ku, Osaka City, Osaka Prefecture Hitachi Shipbuilding Industry Co., Ltd.

Claims (5)

[Claims] 1. A plastic waste treatment apparatus for melting and kneading a plastic waste material by heating and kneading, and forming into pellets by a granulating apparatus, which are arranged in parallel in a first barrel having a heating apparatus. Two first screw shafts, which are screw-engaged with each other and are rotationally driven in opposite directions, are formed on the side of the upstream end of the first barrel, where the screw mountains of the first screw shaft rotate in the direction in which they merge with each other. 2 provided with a raw material charging port and a first resin discharge port formed on the downstream end side of the first barrel 2
An axial relative rotation type first-stage extruder is provided, and one second screw shaft rotatably arranged in the second barrel and the first screw shaft formed on the upstream end side of the second barrel.
Single-screw second-stage extruder equipped with a resin supply port connected to the resin discharge port and a second resin discharge port formed on the downstream end side of the second barrel and connected to the die of the granulating device. A plastic waste treatment device provided with. 2. A resistor, which serves as a resin feed resistance, is provided at an intermediate position of the first screw shaft of the first-stage extruder, and at the screw thread outer peripheral portion of the first screw shaft on the upstream side of these resistors, The plastic waste treatment device according to claim 1, wherein a plurality of air vent notches are formed. 3. A first screen member having a large diameter and a rough surface capable of removing foreign matters in the resin is provided at the first resin discharge port of the first stage extruder, and the second resin discharge port of the second stage extruder is provided. The plastic waste treatment device according to claim 1 or 2, wherein a fine second screen member capable of removing foreign matter in the resin is provided at the outlet. 4. The plastic waste treatment device according to claim 1, wherein in the first stage extruder, at least the feed portion corresponding to the raw material supply port is a screw shaft having multiple thread ridges. 5. The plastic waste processing apparatus according to claim 2, wherein a vent port for discharging air in the resin is provided in the second barrel on the upstream side of the resin supply port of the second-stage extruder.