JPH07102606B2 - Twin screw extruder - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention compresses (reduces volume) waste such as various plastics and discharges it as a high density material, or compresses and heats waste such as various plastics (self-heating or external heating). The present invention relates to a twin-screw extruder that softens and melts a thermoplastic processed product, mixes it with a non-melted product (wood waste, paper waste, etc.), solidifies it, reduces its volume, and discharges it.

[0002]

2. Description of the Related Art Conventionally, a single-screw or twin-screw extruder has been used as a method for compressing (reducing the volume of) bulky plastic waste. An example of this type of extruder is Japanese Utility Model Publication No. 2-33912.

However, in the above-mentioned one, as shown in FIG. 18, a small gap S ₀₁ for crushing, compressing and crushing waste is provided between the press bodies ₀₁ and ₀₁ 'and the wear resistant lining body 02. Since the waste is formed and the waste is allowed to pass through this gap, there is a problem that a relatively large waste (piece) that is not crushed may be stagnated at the front part thereof, resulting in a decrease in processing capacity. Also, if there is a fluctuation in the amount of waste supplied, crushing,
There is a problem that the compressing and crushing forces change and the performance becomes unstable.

[0004]

Therefore, the present invention solves the above-mentioned conventional problems, and does not reduce the treatment capacity of waste and crushes the waste even if the supply amount of the waste varies. An object of the present invention is to provide a twin-screw extruder capable of maintaining stable performance without changing compression and crushing forces.

[0005]

In order to achieve the above-mentioned object, the invention of claim 1 has an end provided with a raw material supply port at the upper part on one end side and a plurality of discharge holes on the other end side. The plate is attached to the body, a pair of rotary shafts rotatably provided in the body in opposite directions, and a feed screw provided on the rotary shaft. In a twin-screw extruder configured so as to be compressed while being conveyed by a feed screw and discharged as a high-density material from a discharge hole of an end plate, a return screw is provided at a part of the feed screw in the longitudinal direction and its end is adjacent. A scraping member is provided which is provided so as to be connected to the end of the feed screw, and has a notch in a part of the return screw in the longitudinal direction, and further has a scraping blade on the outer periphery at the end plate side end of the rotary shaft. Provided near the end plate

According to a second aspect of the present invention, a body having a raw material supply port provided at an upper portion on one end side and an end plate having a plurality of discharge holes attached to the other end side is opposed to the body. A pair of rotary shafts rotatably provided in a rotating direction and a feed screw provided on the rotary shaft are provided, and the raw material supplied from the supply port is compressed while being conveyed by the feed screw to obtain a high density product. In a twin-screw extruder configured to discharge from a discharge hole of an end plate, a return screw is formed in a part of the length of a feed screw, and a gap is formed between both ends of the feed screw and an end of an adjacent feed screw. And a notch is provided in a part of the return screw in the longitudinal direction, and a scraping member having a scraping blade on the outer periphery is provided near the end plate on the end plate side end of the rotary shaft. ing.

According to a third aspect of the present invention, in the first or second aspect, a concave groove inclined by a predetermined angle with respect to the radial direction is formed on the downstream side surface of the scraping member facing the end plate. According to a fourth aspect of the present invention, in the third aspect, a grinding plate is provided on the upstream side surface of the end plate facing the scraping member, and a concave groove inclined at a predetermined angle with respect to the radial direction is provided on the upstream side surface of the grinding plate. Is forming.

According to a fifth aspect of the present invention, in any one of the first to fourth aspects, the end plate is detachably attached to the body, and the end plate is attached to the body at the time of attachment. A hydraulic clamp mechanism for tightening is provided. According to the invention of claim 6, in any one of claims 1 to 5, the body liner is provided in the body, and the crushing protrusion is provided on the inner surface of the body liner immediately below the supply port, and the feed screw is viewed from a plane. It is designed to rotate outwards from each other. According to a seventh aspect of the present invention, in the sixth aspect, a cutout portion is provided in a part of the feed screw facing the crushing projection in the longitudinal direction.

[0009]

As described above, since the return screw having the cutout portion is provided in a part of the lengthwise direction of the feed screw, the raw material fed by the feed screw is subjected to the reverse feed (return) action by the return screw, The space between the feed screw, the return screw, and the body fills up as the screws rotate, compressing and mixing, and becomes a consolidated state. The feed (pressure) force of the feed screw is less than the reverse feed (return) force of the return screw. Since it is slightly larger depending on the presence or absence of the notch, it is pushed into the notch by the difference (pressure) force and passes through the notch, and at the time of this passage, it is cut into pieces by the cutting action of the edge of the notch of the return screw. In addition, the tip of the notch of the return screw is cut into pieces by the edge of the upper surface and the edges of both sides, and the pair is further paired. By the reverse rotation of each other of the screw back to be cut receives shearing action between the screw and the screw. In this way, the raw material is reliably crushed by the cutting and shearing action and passes through the notch of the return screw, so that the raw material can smoothly pass through a relatively large piece without congestion. When the raw material sent to the end plate side of the body due to the above-mentioned action has a relatively long string-like shape, it may be caught in the discharge hole of the end plate or may be congested at a portion without the discharge hole. In this case, the long string-shaped raw material is scraped and cut by the scraping blade of the scraping member rotated by the rotating shaft, and is finely transferred to the discharge hole side smoothly.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially cutaway front view showing a twin-screw extruder according to an embodiment of the present invention, and FIG.
A partially broken plan view and FIG. 3 are partially broken side views of the same. In addition, in FIG. 3, A part is a partially broken part along the AA line in FIG. 1, B part is a partially broken part along the B-B line, and C part is a partially broken part along the CC line. .
A twin-screw extruder 1 has a body 3 installed on a base plate 2. The body 3 has an elongated shape having two substantially circular side cross-sections, and is divided into two parts in the length direction and the up-down direction, and is assembled by being connected by a bolt nut or the like. A supply port 4 for an object to be treated (raw material) such as a plastic waste is provided in the upper part of the closed end of the body 3. The other end of the body 3 is opened to form a discharge port, and the discharge port is closed by an end plate 5. The end plate 5 has a bracket 7 protruding from one side thereof connected to a bracket 8 provided on the body 3 by a connecting pin 9 (FIG. 3), and pivots with the pin as a fulcrum to open and close the discharge hole. In addition, the end plate 5 is clamped to the body 3 by the hydraulic clamp mechanism 11 in a closed state (FIG. 1).

The end plate 5 is provided with a plurality of through holes 13 on the same circumference centered on each circle of the body 3 and a similar through hole 14 at the center thereof. A split type body liner (lining material) 15 which is divided into a plurality of pieces in the length direction and the vertical direction and has wear resistance is attached to the inner surface of the body 3 by a cotter 16. Inside the body liner 15, a pair of rotating shafts 17 and 18 are provided so as to be parallel to each other and rotatable in opposite directions. The rotary shafts 17 and 18 have a hexagonal cross-section inside the body liner 15, and a split feed screw 20 on the outer surface thereof.
_{1 to} 20 ₃ , return screw 20 ₄ , and feed screw 20 ₅ ,
20 ₆ are sequentially fitted and fixed so as to mesh with each other. Feed screws 20 _{1 to} 20 ₃ and feed screws
20 ₅ and 20 ₆ are assembled so as to form a continuous spiral. The return screw 20 ₄ is arranged such that both ends thereof are connected to the ends of the feed screw 20 ₃ and the feed screw 20 ₅ . Notches 21 as the part of the length of the screw 20 ₄ shown more in FIGS. 13 and 14 return is provided. S ₁ is a manufacturing gap formed between the feed screw 20 _{1 to} 20 ₃ , 20 ₅ , 20 ₆ and the return screw 20 ₄ and the body liner 15. Although the rotary shafts 17 and 18 are hexagonal in cross section in this example, they are circular and the feed screw 20 ₁
~ 20 ₃ , 20 ₅ , 20 ₆ and the return screw 20 ₄ may be connected by a key or the like.

FIG. 4 shows a scraping member 23 fixed to the end portions of the rotary shafts 17 and 18 on the end plate 5 side by bolts 22 in the vicinity of the end plate 5. The scraping member 23 has a plurality of scraping blades 24 on the outer circumference for cutting a relatively long object to be closed or a flat object to be closed, which will be described later.
It rotates as shown by the rotation of 17 and 18. Further, the scraping member 23 fixed to the rotary shafts 17 and 18 has the same structure except that it is symmetrically arranged. Therefore, the scraping member 23 fixed to the rotary shaft 17 will be described below. The member 23 will be described with reference to FIGS. 6 is a sectional view taken along the line DD of FIG. 5, and FIG. 8 is a partially enlarged view taken along the line EE of FIG. Downstream side surface of the scraping member 23 (end plate 5
A concave groove 25 is formed on the surface (opposite to). This groove
The direction of 25 is inclined by a predetermined angle θ ₁ (6 ° in the case shown) to the rotation direction side of the scraping member 23 with respect to the radial axis line a passing through the center of the scraping member 23. The object to be processed cut by 24 is discharged by the discharge nozzle 33 as the scraping member 23 rotates.
Guide to the side and transfer.

FIG. 9 shows a grinding plate 28 having wear resistance, which is fitted and disposed in a recess 27 formed on the upstream side surface (surface facing the scraping member 22) of the end plate 5. The grinding plate is provided with through holes 30 and 31 communicating with the through holes 13 and 14 of the end plate 5. Between these through holes 30 and 31 and the through holes 13 and 14 of the end plate, as shown in FIGS.
The discharge nozzle 33 is attached as shown in FIG. Also grinding plate
Grooves 35 and 36 are formed on the upstream side surface of 28. Figure 10,
As also shown in 11, the direction of the groove 35 is inclined by a predetermined angle θ ₂ (60 ° in the case shown) to the opposite side to the rotation direction of the scraping member 23 with respect to the radial axis b passing through the center of the grinding plate 28. ), The direction of the groove 36 is substantially parallel to the radial axis b, whereby the groove of the scraping member 23 is rotated as the scraping member 23 rotates the workpiece.
In cooperation with 25, it guides and transfers to the discharge nozzle 33 side.

12A and 12B show the details of the hydraulic clamp mechanism 11 for the end plate 5. FIG. 12A shows a tightened state, and FIG. 12B shows a state before tightening. Reference numeral 40 denotes a tightening member disposed on the upper and lower portions of the flange 3a of the body 3 and the end plate 5, and is formed on the inclined side surfaces 41, 42 formed in the recess 43 of the tightening member 40 and the flange 3a of the body 3. The slanted surface 3b and the slanted surface 5a formed on the end plate 5 are engaged or disengaged in a wedge shape. A hydraulic cylinder 45 is arranged on the side of the tightening member 40 opposite to the recess 43. The rod of this hydraulic cylinder 45
46 is loosely fitted in the through hole 47 of the tightening member 40 and is connected to the connecting member 48 which is embedded and fixed in the end plate 5. 50, 51
Is a hole for supplying and discharging hydraulic pressure in the cylinder.
When hydraulic pressure is applied from 50, the inclined side surfaces 41, 42 of the recess 43 of the fastening member 40 are fitted to the inclined surface 3b of the flange portion 3a of the body 3 and the inclined surface 5a of the end plate 5 as shown in (A). When the flange portion 3a of the body 3 and the upper and lower portions of the end plate 5 are tightened and hydraulic pressure is applied from the supply / discharge hole 51, the inclined side surface of the recess 43 of the tightening member 40.
41 and 42 are released from the inclined surface 3b of the flange portion 3a of the body 3 and the inclined surface 5a of the end plate 5 as shown in (B) to release the tightening.

In FIGS. 1 to 3, reference numeral 55 denotes a slicing mechanism for the processed material. Reference numeral 56 is a support base that is arranged in parallel with the end plate 5 at appropriate intervals by bolts 57, and the base end of the bolts 57 is a bracket 58 protruding from one side of the end plate 5 and a connecting pin 59. It is rotatably connected. Therefore, if the bolt 57 is removed, the support base 56 rotates about the pin 59 as a fulcrum. This support 59
Two rotary blades 61 are rotatably provided at a position slightly deviated from the rotation axis of the rotary blade 61, and the sprockets on the shafts 62 of the rotary blades 61 are interlocked via a chain 63 or the like, and
A motor 65 is provided at 62 via a coupling or the like. 67 is a crushing protrusion provided on the inner surface of the body liner 15 immediately below the supply port 4 side, and is provided at a position corresponding to the feed screws 20 ₁ and 20 ₂ . Reference numeral 68 is a heating medium oil jacket formed on the downstream side surface of the end plate 5 by a cover plate 69. When the heat generation of the plastic is insufficient, the heating medium oil is supplied to semi-melt the plastic. 73 and 74 are the inlet and outlet of the heat transfer oil. Further, 71 is a cooling water injection port, and 72 is a thermocouple. The ends of the rotary shafts 17 and 18 on the side of the supply port 4 penetrate the body 3 and are driven to rotate by a prime mover (not shown) such as a motor.

Next, the operation of the embodiment will be described. When the object to be processed is dropped from the supply port 4 to the supply zone of the feed screws 20 _{1 to} 20 ₃ , the object to be treated first has the feed screws on the rotating shafts 17 and 18 that rotate in opposite directions, which are outside each other when viewed from the plane. is crushed by 20 _1, 20 ₂ a solution砕用protrusion 67. After crushing,
Further, it is transferred to the end plate 5 side by the feed screws 20 _{1 to} 20 ₃ . The transferred object is the return screw.
20 ₄ receives the reverse feed (return) action. That is, FIG.
As in 3, the space C between the feed screw 20 ₃ , the return screw 20 _4, and the body liner 15 is sequentially compressed and mixed with the rotation of these screws to fill and become a consolidated state. Then, the compacted work piece is fed by a screw 20 ₃
The feed (pressure) force of the return screw 20 ₄ reverse feed (return)
Since the force is slightly larger than the force depending on the presence or absence of the notch portion 21, it is pushed into the notch portion 21 by the (pressure) force of the difference and passes through the notch portion 21. At this time, the object to be processed is the return screw
The edge of the notch 21 of 20 ₄ is cut into pieces by receiving the cutting action. Further, the small pieces undergoing cutting action by an edge and the edge of the both side surfaces of the tip top of the notch 21 of the screw 20 returns the processing object of filling the space C _4. further,
Since the object to be treated which is filled in the space C is screw 20 ₄ back faces are rotated reversely to each other, it is cut sheared acting between d and the screw 20 ₄ and the screw 20 _4. In this way, the object to be processed is reliably crushed by cutting and shearing action, and the cutout portion 21 of the return screw 20 ₄ is cut.
Since the object to be processed passes through, even a relatively large piece can be smoothly passed through without being congested. This improves the processing capacity. Furthermore, filling by the screw 20 ₄ returns an object to be processed,
Since it is made compact, it is not affected even if the supply amount of the object to be processed varies, and therefore the object to be processed is always subjected to a constant compressive force and a cutting action (by crushing).

The object to be treated is further fed with feed screws 20 ₅ and 20 _6.
Is transferred to the end plate 5 side, and during this time is compressed and crushed by the rotating force of the rotary shafts 17 and 18, and is ground by the grinding plate 28. Then, it reaches the vicinity of the end plate 5 and is sequentially discharged from the discharge nozzle 33. However, when the object to be processed is a relatively long string-like object, it is caught on the discharge nozzle or a portion without the discharge nozzle 33. There may be congestion. In such a case, the long string-shaped object to be processed has rotating shafts 17, 18
Is scraped off and cut by the scraping blade 24 of the scraping member 23 rotated by, and after being finely divided, it is guided to the concave groove 25 and transferred to the discharge nozzle 33 side. At this time, there are concave grooves 35 and 36 on the facing surface of the grinding plate 28, and the grinding by the cooperation of the gap between the concave groove 25 and the concave grooves 35 and 36 (about 5 mm in the case shown). Since the milling effect on the object to be treated is further enhanced by the mortar action and the object is transferred to the discharge nozzle 33 side, the discharge becomes extremely smooth. In addition, an internal frictional action is generated in the meltable raw material to induce self-heating, which enables efficient softening and melting, and also an efficient mixing action with the non-meltable raw material, which results in a return of bulk after discharge. It is possible to achieve sufficient volume reduction and solidification that do not occur.

FIG. 15 shows another embodiment. In the above-described embodiment, the return screw 20 ₄ is arranged with its both ends connected to the ends of the feed screw 20 ₃ and the feed screw 20 ₅ as shown in FIG. 13, but this embodiment is shown in FIG. by changing the incorporation angle of the screw 20 ₄ back to the feed screw 20 _3, 20 _5, to form a slight clearance S ₂ between the end of the screw 20 ₅ and the feed screw 20 ₃ sends its ends It is arranged. In the case of this embodiment, the object to be processed is caused to flow out from the gap S ₂ to prevent excessive consolidation due to congestion of the object to be processed.

16 and 17 show still another embodiment, which is a cutout portion in a part of the feed screw 20 ₂ facing the crushing protrusion 67 in the embodiment shown in FIGS. 1 to 14. 76 is provided. The other structure is the same as that of the above embodiment. The position of the cutout portion 76 is not limited to the illustrated position. In this embodiment, the object to be processed is wound by the notch portion 76, and after being wound, the object to be processed is further crushed in cooperation with the crushing projection 67. That is, the object to be processed that has entered the notch portion 76 is scraped into the gap between the tip of the notch portion and the body liner 15 (about 5 mm in the case shown) to cut the object. receive. Although not shown, may be provided with a notch 76 in a part of the feed screw 20 ₂ opposed to the solution砕用protrusion 67 in the embodiment shown in FIG. 15.

The feed screws 20 ₁ to 2 of the above-mentioned respective embodiments
An optimum example of the assembling positions of 0 ₃ , 20 ₅ , 20 ₆ and the return screw 20 ₄ is shown, but it goes without saying that the assembling positions may be changed as needed according to the object to be processed.
Further, in each of the above-mentioned embodiments, the crushing protrusion 67 is provided to rotate the rotary shaft 17,
Although the 18 are rotated outward from each other when viewed from the plane, the rotation shafts 17 and 18 may be rotated inward when viewed from the plane when the crushing protrusion 67 is not provided.

[0021]

As described above, the invention according to claim 1 or 2 connects the return screw to a part of the longitudinal direction of the feed screw, connects the end portion to the end portion of the adjacent feed screw, or connects both end portions thereof. A gap is formed between the ends of adjacent feed screws, and a cutout is provided in a part of the length of the return screw, so that the raw material sent by the feed screw is fed backward (returned) by the return screw. Since it was made to act, the raw material is cut into small pieces by cutting the edges of the notches of the return screw, and the pieces are cut into small pieces by the edges of the notch of the returning screw and the edges of both side surfaces. It is possible to shear and cut between the screws by the opposite rotation of the opposing return screws, and the raw material is reliably crushed by the shearing action. Preparative it is, back can pass notch of the screw can also be smoothly pass without congestion in relatively large pieces. Therefore, the processing capacity is improved and the processing capacity of the raw material does not decrease as in the past, and the crushing, compression and crushing force do not change even if the supply amount of the raw material changes, and stable performance is maintained. can do. Further, even a relatively long string-shaped raw material or a flat-shaped raw material can be scraped by a scraping blade to be crushed and cut, so that there is no congestion of the raw material in the vicinity of the discharge hole, and the raw material is smoothly and reliably discharged. The discharge capacity can be improved from the above.
In addition, meltable material such as plastic containing meltable material or non-meltable material such as plastic can be melted by the grinding action by relative movement between the scraping member and the end plate or between the scraping member and the grinding plate. Not only can internal softening be induced in the raw material of the melt to induce self-heating to efficiently soften and melt it, but also efficient mixing with the non-melt to prevent bulk recovery after discharge. It is possible to realize a large volume reduction and solidification.

According to the third aspect of the invention, the raw material scraped by the scraping blade of the scraping member can be effectively guided to the discharge hole of the end plate by the concave groove formed on the downstream side surface of the scraping member.

In the invention of claim 4, the raw material can be further ground and effectively guided to the discharge hole by the concave groove. According to the invention of claim 5, when the end plate is attached, the end plate can be fastened and fixed to the body by the hydraulic clamp mechanism. Claim 6
In the invention, the raw material dropped from the supply port can be roughly crushed before being sent to the end plate side by the feed screw. Claim 7
The raw material can be crushed more effectively.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing a twin-screw extruder according to an embodiment of the present invention.

FIG. 2 is a plan view of the above, partially omitted and partially broken.

FIG. 3 is a partially cutaway side view of the same.

FIG. 4 is a side view of a scraping member.

FIG. 5 is a side view of an upstream side surface of the scraping member.

6 is a cross-sectional view taken along the line DD of FIG.

FIG. 7 is a side view of a downstream side surface of the scraping member.

FIG. 8 is a partially enlarged view taken along the line EE of FIG.

FIG. 9 is a side view of an upstream side surface of a grinding plate incorporated in an end plate.

10 is a partially enlarged side view of FIG.

FIG. 11 is a partial view taken along the line F of FIG.

FIG. 12 is an enlarged cross-sectional view of a hydraulic clamp mechanism, where (A) shows a tightened state and (B) shows a state before tightening.

FIG. 13 is an enlarged plan view of an essential part of a portion having a return screw.

14 is a vertical cross-sectional side view taken along the line GG of FIG.

FIG. 15 is an enlarged plan view of an essential part corresponding to FIG. 13 showing another embodiment.

FIG. 16 is a plan view corresponding to FIG. 2 showing still another embodiment.

FIG. 17 is a side view corresponding to part of FIG. 3 above.

FIG. 18 is a vertical sectional side view of a conventional example.

[Explanation of symbols]

1 2-screw extruder 3 Body 4 Supply port 5 End plate 15 Body liner 17,18 Rotating shafts 20 _{1 to} 20 ₃ , 20 ₅ , 20 ₆ Feed screw 20 ₄ Return screw 21,76 Notch 33 Discharge nozzle 67 Crushing Projection

Continuation of front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location B29C 47/40 9349-4F

Claims (7)

[Claims] 1. A body having a raw material supply port provided at an upper portion on one end side and an end plate having a plurality of discharge holes at the other end side, and a body rotatable in a direction opposite to the body. A pair of rotating shafts provided on the rotating shaft and a feed screw provided on the rotating shaft, and the raw material supplied from the supply port is compressed while being conveyed by the feed screw, and is discharged as a high-density product from the end plate. 2 configured to be discharged from
In the axial extruder, a return screw is provided in a part of the feed screw in the longitudinal direction, and both ends thereof are provided to be connected to ends of adjacent feed screws, and a cutout part is provided in a part of the return screw in the longitudinal direction. A twin-screw extruder characterized in that a scraping member having a scraping blade on the outer periphery is provided in the vicinity of the end plate on the end plate side of the rotary shaft. 2. A body having a raw material supply port provided at an upper portion on one end side and an end plate having a plurality of discharge holes at the other end side, and a body rotatable in a direction opposite to the body. A pair of rotating shafts provided on the rotating shaft and a feed screw provided on the rotating shaft, and the raw material supplied from the supply port is compressed while being conveyed by the feed screw, and is discharged as a high-density product from the end plate. 2 configured to be discharged from
In the axial extruder, a return screw is provided in a part of the feed screw in the longitudinal direction, and both ends thereof are provided with a gap between the end of an adjacent feed screw, and a part of the return screw in the longitudinal direction. A twin-screw extruder characterized in that a notch portion is provided in the end portion, and a scraping member having a scraping blade on the outer periphery is provided in the end portion of the rotary shaft on the end plate side in the vicinity of the end plate. 3. The twin-screw extruder according to claim 1, wherein a concave groove inclined at a predetermined angle with respect to the radial direction is formed on the downstream side surface of the scraping member facing the end plate. 4. The grinding plate is provided on the upstream side surface of the end plate facing the scraping member, and a concave groove inclined at a predetermined angle with respect to the radial direction is formed on the upstream side surface of the grinding plate. Twin screw extruder. 5. The end plate is detachably attached to the body, and a hydraulic clamp mechanism is provided for tightening the end plate to the body at the time of attachment.
The twin-screw extruder according to any one of 1. 6. A fuselage liner is provided in the fuselage body, and a crushing protrusion is provided on the inner surface of the fuselage liner immediately below the supply port, so that the feed screws can rotate outward with respect to each other when viewed from a plane. The twin-screw extruder according to any one of items. 7. The twin-screw extruder according to claim 6, wherein a notch is provided in a part of the feed screw facing the crushing protrusion in the longitudinal direction.