JP2002001794A - Kneading adjusting apparatus for twin-screw extruder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate a gear pump by obtaining an enough discharge pressure by increasing the diameter of the discharge screw of screws to be equivalent to the diameters of the other parts and bringing them into an engaged state. SOLUTION: A kneading adjusting apparatus for a twin-screw extruder is composed of two screws (30) which are arranged to be rotatable in an engaged state and to be parallel in a parallel state, a cylinder (20) in which a through inner hole into which each screw (30) can be inserted is formed, each conical hole (28) corresponding to the taper fitting (36) of each screw (30), a kneading adjusting plate (27) which makes the taper fitting (36) penetrate the conical hole (28) concentrically and is inserted into the through inner hole of the cylinder (20) to cross it, and a kneading adjusting driving apparatus which makes the cylinder reciprocate in the axial direction in relation to the screws (30).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kneading and adjusting apparatus for a twin screw extruder for reforming a plastic material by melt-kneading and discharging the same to a granulator, and in particular, to obtain a high extrusion pressure without using a gear pump. Regarding new improvements.

[0002]

2. Description of the Related Art Conventionally, plastic materials produced by a synthesizer, plastic materials having improved functions, or plastic materials to which additives are added for coloring, are usually used for modifying and homogenizing materials. And kneaded by a screw type extruder. As a screw-type extruder used for this purpose, a twin-screw extruder having a high kneading function is generally used. Also, the twin-screw extruder is provided with a kneading adjusting device so that the optimum kneading can be performed according to the physical properties of the plastic material. There are devices to change.

FIG. 4 shows a conventional example of such a kneading adjusting device for a twin-screw extruder. In FIG. 4, what is indicated by reference numeral 10 is a screw-type twin-screw extruder. The screw-type twin-screw extruder 10 includes a long cylindrical cylinder 20 having a through-hole formed therein, and It is constituted by two screws 30 rotatably inserted into the screw. The screw-type twin-screw extruder 10 includes a transporting unit 11, a kneading unit 12, a kneading unit 12, and a kneading unit.
It comprises a slot 13 and a discharge unit 14.

The screw 30 includes, from the upstream side to the downstream side, a transport screw 31 constituting the transport section 11, a kneading screw 32 constituting the kneading section 12, a taper fitting 36 constituting the slot section 13, and Discharge unit 1
4, the two screws 30 have the same length in each screw portion. The transport screw 31 and the kneading screw 32 have the same outer diameter, the taper fitting 36 has a conical shape whose diameter decreases in the downstream direction, and the discharge screw 34 has a smaller outer diameter than the transport screw 31 and the kneading screw 32. Is configured. Each of the screws 30 is in a non-meshed state because the transport screw 31 and the kneading screw 32 are meshed with each other in a state of being arranged in parallel, and the discharge screw 34 is located in two independent through holes. It is configured.

On the other hand, the cylinder 20 is provided with the transport unit 1.
1 and a first cylinder 21 forming the kneading section 12 and a second cylinder 22 forming the slot section 13 and the discharge section 14. The first cylinder 2
1 is formed so that each screw 30 can be rotatably inserted in a meshing state. The second cylinder 22
At the upstream end thereof, a conical inner hole 23 having a smaller diameter in the downstream direction is formed corresponding to the taper fitting 36, and the conical inner hole 23 extends from the conical inner hole 23 to the downstream end, that is, the tip. It is formed in the same small diameter as the small diameter of the tip part. In addition, two independent axial holes are formed corresponding to the discharge slots 34 so that the screws 30 can be rotatably inserted in a non-meshing state.

The screw-type twin-screw extruder 10 further includes a rotation driving device (not shown) for rotating the two screws 30, and an illustration for reciprocating the cylinder 20 with respect to each screw 30 in the axial direction. A kneading adjustment driving device is provided. A gear pump (not shown) is connected to a downstream end, that is, a tip of the screw-type twin-screw extruder 10, and a granulating device is further connected downstream thereof.

In the screw type twin screw extruder 10 configured as described above, the plastic material is kneaded as follows. That is, first, the temperature of the cylinder 20 is adjusted to an appropriate set temperature by a temperature adjustment device (not shown), and the kneading adjustment drive device applies the cylinder 2 to the screw 30.
0 is reciprocated in the axial direction to change the axial interval between the conical inner hole 23 and the taper fitting 36, and the cross-sectional area of the flow path is appropriately adjusted. Thereafter, while each screw 30 is being driven to rotate by the rotation driving device, the cylinder 20 is rotated.
The plastic material is continuously supplied at a constant rate from a material supply port (not shown) provided at the upstream end of the plastic material.

The plastic material supplied to the screw-type twin-screw extruder 10 is sequentially transported downstream by the transport action of the screw 30, heated and heated while moving in the transport section 11, and melted and kneaded in the kneading section 12. , Slot 13
And is discharged from the downstream end by the transport discharge operation of the discharge unit 14. The transporting unit 11 and the kneading unit 12 receive the transporting action of each screw 30 in the meshing state, and the discharging unit 14 receives the transporting action of each non-meshing screw 30. The molten plastic material discharged from the tip of the screw-type twin-screw extruder 10 is pressurized by a gear pump in order to obtain a necessary extrusion pressure to be extruded from the granulating device, and is converted from the granulating device into a strand or the like. Extruded.

In the slot 13, the narrow gap between the outer peripheral surface of the taper fitting 36 and the conical inner hole 23 of the second cylinder 22 restricts the flow of the molten plastic material. Due to the flow restriction on the downstream side of the kneading section 12, the plastic material temporarily stays in the kneading section 12 and the time for receiving the kneading action becomes longer. That is, the degree of flow restriction is changed by changing the gap of the slot portion 13 by the kneading adjustment driving device, and the degree of stagnant kneading of the plastic material in the kneading portion 12 is changed. By adjusting the gap of the slot portion 13 according to the change in the physical properties of the plastic material, the degree of kneading can be adjusted to an appropriate degree.

[0010]

Since the conventional kneading and adjusting device for a twin-screw extruder is constituted as described above, the following problems exist. That is, in the cylinder 20, the second cylinder 22 is formed with a small-diameter through hole continuous with the conical inner hole 23 on the upstream side.
Similarly, the discharge portion 14 has a small diameter at the discharge portion 14 and is in a non-meshing state. In such a small-diameter screw 30 in a non-meshing state, a discharge pressure required for extruding a molten plastic material from a granulating device cannot be obtained. Therefore, since a gear pump is arranged at the tip of the screw type twin screw extruder 10 to obtain the discharge pressure, the entire apparatus including the related devices of the screw type twin screw extruder 10 becomes large and it is difficult to reduce the size. Was.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. In particular, the diameter of a screw discharge screw is made as large as that of other parts, and a sufficient discharge pressure is obtained in a meshing state. Accordingly, it is an object of the present invention to provide a kneading adjusting device for a twin-screw extruder which eliminates a gear pump.

[0012]

The kneading adjusting device for a twin-screw extruder according to the present invention comprises a transport screw, a kneading screw, a taper metal fitting and a discharge screw in order from the upstream side. Two screws are formed in parallel with each other so that the screws have the same outer diameter and are rotatably driven in a meshing state and are arranged in parallel with each other. And a conical hole provided corresponding to the tapered metal fitting at a position corresponding to each of the cylinders where the tapered metal fitting is located. A kneading adjusting plate inserted across the inner hole, and a kneading adjusting drive for axially reciprocating the cylinder with respect to the screw. Device and, characterized in that it is constituted by.

More specifically, the kneading adjusting plate is vertically divided on a straight line connecting the centers of the two conical holes, and can be inserted and fixed through the upper and lower openings of the vertical through holes provided in the through holes. It is characterized by having been done.

More specifically, the taper fitting is characterized in that it has a conical shape whose diameter decreases in the downstream direction, and is provided with a small-diameter cylindrical portion having a predetermined length on the tip side of the cone.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a kneading adjusting device for a twin-screw extruder according to the present invention will be described below in detail with reference to the drawings. FIG. 1 is a plan sectional view showing a twin-screw extruder according to the present invention, and FIG. 2 is a sectional view taken along line AA of FIG. The same or equivalent parts as those of the conventional kneading and adjusting device for a twin-screw extruder shown in FIG. 4 will be described using the same reference numerals. In FIGS. 1 and 2, what is indicated by reference numeral 10 is a screw-type twin-screw extruder. This screw-type twin-screw extruder 10 includes a long cylindrical cylinder 20 having a through-hole formed therein, and a screw-type twin-screw extruder. It comprises a pair of screws 30 rotatably inserted into the cylinder 20. The screw-type twin-screw extruder 10 includes a transport unit 11, a kneading unit 12, a slot unit 13, and a discharging unit 14 from an upstream side to which a plastic material is supplied, in a downstream direction after kneading processing, and in a distal direction. It consists of.

Each of the screws 30 includes, from the upstream side to the downstream side, a transport screw 31 constituting the transport section 11, a kneading screw 32 constituting the kneading section 12, a taper fitting 36 constituting the slot section 13, and Each of the screws 30 is configured to have the same length in each of the screw portions. The transport screw 31, the kneading screw 32 and the discharge screw 37 have the same outer diameter, the taper fitting 36 has a conical shape having a small diameter in the downstream direction, and a small-diameter cylindrical portion 36a having a predetermined length at the distal end. I have. Each of the screws 30 includes a transport screw 31, a kneading screw 3
2 and the discharge screw 37 are mutually meshed in a state where they are arranged in parallel, and are configured to be rotatable.

On the other hand, the cylinder 20 is constituted by a first cylinder 21 having an inner hole having the same cross-sectional shape over the entire length except for a part corresponding to the taper fitting 36 of the screw 30. The first cylinder 21
Has an axial inner hole in which the two screws 30 can be rotatably inserted in a meshing state, and two portions corresponding to the taper fittings 36 are provided at positions corresponding to the taper fittings 36 of the cylinder 20. A kneading adjusting plate 27 having a conical hole 28 penetrating the taper fitting 36 in a concentric manner is inserted into the conical hole 28 (FIG. 2).

At the place where the taper fitting 36 of the cylinder 20 is located, the through-hole 26 in the vertical direction is perpendicular to the axial direction of the screw 30 as shown in FIG. The kneading adjusting plate 27 is vertically divided into first and second plates 27 a and 27 b on a straight line connecting the centers of the two conical holes 28, and is configured to be inserted and fixed in the through hole 26. I have. Further, the flange joint portion F of the first cylinder 21 is made to coincide with the position of the taper fitting 36, and the through hole 2
By forming 6, the kneading adjustment plate 27 can be attached and detached.

The screw-type twin-screw extruder 10 includes a rotary driving device (not shown) for driving the respective screws 30 to rotate, and a kneading adjustment drive (not shown) for reciprocating the cylinder 20 with respect to the respective screws 30 in the axial direction. A device is provided. A well-known granulator (not shown) is connected to the downstream end, that is, the tip of the screw-type twin-screw extruder 10.

In the screw type twin screw extruder 10 configured as described above, the plastic material is kneaded as follows. That is, first, the temperature of the cylinder 20 is adjusted to an appropriate set temperature by a temperature adjusting device (not shown).
The kneading adjustment driving device reciprocates the cylinder 20 in the axial direction with respect to the screw 30 to change the axial distance between the conical conical hole 28 and the taper fitting 36, and to change the vertical distance of the conical surface, that is, the flow path disconnection. The area is appropriately adjusted. Thereafter, in a state where the two screws 30 are rotationally driven by the rotary driving device, a constant amount of plastic material is continuously supplied from a material supply port (not shown) provided at the upstream end of the cylinder 20.

The plastic material supplied to the screw type twin screw extruder 10 is transported sequentially downstream by the transport action of the screw 30, heated and heated while moving in the transport section 11, and melt-kneaded in the kneading section 12. And slot part 1
3 and is discharged from the downstream end by the discharge operation of the discharge unit 14. During this time, the plastic material is transported by the transport unit 11,
In the kneading section 12 and the discharge section 14, the molten plastic material discharged from the tip of the screw type twin-screw extruder 10 under the strong transport action by the two meshing screws 30 is discharged from the discharge section 14. Extrusion pressure is obtained by the transport action and extruded from the granulator.

In the slot 13, the flow of the molten plastic material is restricted by the narrow gap between the outer peripheral surface of the taper fitting 36 and the conical hole 28 of the kneading adjusting plate 27, Due to the flow restriction, the plastic material temporarily stays in the kneading section 12, and the time for receiving the kneading action becomes longer. That is,
By changing the gap of the slot portion 13 by the kneading adjustment drive device, the degree of flow restriction changes, and the degree of stagnant kneading of the plastic material in the kneading portion 12 changes.
By adjusting the gap of the slot portion 13 in accordance with the change in the physical properties of the plastic material, an appropriate degree of kneading can be adjusted.

It should be noted that a small-diameter cylindrical portion 36a having a predetermined length is provided on the tip end side of the taper fitting 36, so that
The forward movement of the cylinder 20 with respect to the screw 30, that is, the forward movement of the downstream small-diameter hole portion of the kneading adjustment plate 27 can be performed without any trouble. This small-diameter cylindrical portion is not limited to being provided on the tip end side of the taper fitting 36, but is provided at the rear end of the discharge screw 37, that is, the taper fitting 36.
May be provided continuously at the conical end of the.

[0024]

The kneading and adjusting device for a twin-screw extruder according to the present invention has the following effects by being configured as described above. (1) A large-diameter meshing screw can be provided in the discharge section 14, and a high discharge pressure, that is, a high extrusion pressure of the twin-screw extruder can be obtained, and a gear pump is not required. (2) Since a high extrusion pressure was obtained, extrusion granulation became possible by directly connecting to a granulation device without the need for a gear pump of a pressure increasing device. (3) As a whole equipment including the twin screw extruder related equipment,
The need for a booster is eliminated, the size is reduced, the device area is reduced, and the energy efficiency is improved.

[Brief description of the drawings]

FIG. 1 is a plan sectional view showing a twin-screw extruder according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is an enlarged view of a main part of FIG. 1;

FIG. 4 is a plan sectional view showing a conventional twin-screw extruder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Screw-type twin-screw extruder 20 Cylinder 21 1st cylinder 27 Kneading adjustment plate 28 Conical hole 30 Screw 36 Taper fitting 37 Discharge screw

Claims (3)

[Claims] 1. A transport screw (31), a kneading screw (32), a taper fitting (36), and a discharge screw (3) are sequentially arranged from an upstream side.
7), the transport screw (31), the kneading screw (3
2) and the discharge screw (37) are formed with the same outer diameter, and are rotatable and driven in a meshing state, and two screws (30) arranged in parallel, and each of the screws (30) can be inserted. A cylinder (20) in which a through-hole having the same cross-sectional shape is formed along the entire length, and a taper fitting (36) is provided at a position corresponding to each of the cylinders (20) where the taper fitting (36) is located. The conical hole (28) and the kneading adjustment plate () inserted through the conical hole (28) concentrically with the taper fitting (36) and inserted across the through-hole of the cylinder (20). 27) and a kneading adjustment drive device for a twin-screw extruder, comprising: a kneading adjustment driving device that reciprocates the cylinder (20) in the axial direction with respect to the screw (30). 2. The kneading adjusting plate (27) has two conical holes (2).
8) is vertically divided on a straight line connecting the centers of the through holes (2
The kneading adjustment device for a twin-screw extruder according to claim 1, wherein the kneading adjustment device for a twin-screw extruder is configured to be capable of being inserted and fixed from upper and lower openings of a vertical through hole provided in 6). 3. The taper fitting (36) has a conical shape having a small diameter in the downstream direction and a small-diameter cylindrical portion (36a) having a predetermined length provided on a tip side of the cone. The kneading adjustment device for a twin-screw extruder according to claim 1 or 2.