JP3113879B2 - Continuous kneading extruder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous kneading and extruding apparatus for continuously melting, kneading, devolatilizing and extruding a synthetic resin material.

[0002]

2. Description of the Related Art Conventionally, melting, kneading,
As a continuous kneading and extruding apparatus of a type in which devolatilization and extrusion are continuously performed, there are the following apparatuses. First, in a casing, first and second shafts each having a screw portion are arranged in parallel, and devolatilization and extrusion are performed in a twin-screw kneader having a part of the first and second shafts facing each other. This is a combination with a single screw extruder.

[0003] As another conventional apparatus, there is a combination of a twin-screw kneader and a gear pump. This is one in which the single screw extruder of the above-mentioned conventional apparatus is replaced with a gear pump.

[0004]

However, in the above-mentioned conventional apparatus, there are disadvantages in that the entire apparatus becomes large and inefficient and consumes a large amount of energy because the two apparatuses which operate independently are combined. Was. In addition, the twin-screw kneading unit has a structure in which both ends of the first and second shafts are supported by bearings in order to prevent screw galling in a high rotation range. However, since the structure is complicated, resin change and color change are performed. Accordingly, it is difficult to disassemble and clean the screw and cylinder. In addition, there is a problem that cleaning requires time and labor equivalent to two twin-screw kneaders and single-screw extruders.

[0005] On the other hand, a conventional apparatus having a gear pump, which is another apparatus, has a problem that devolatilization operation cannot be performed. When disassembling and cleaning due to resin change, color change, etc., it takes the same time and effort for the twin-screw kneading machine as for the above-mentioned device. Cleaning time.

Further, in the above-mentioned conventional apparatus, there is no means for adjusting the stagnation of the resin material in the twin-screw kneading section, so that operation is not possible.
Depending on the rolling conditions (the number of rotations of the screw) and the amount and state of the resin material, the residence time may be reduced and the resin may be extruded before sufficient kneading is performed. SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and provides a continuous kneading and extruding apparatus which can adjust the kneading degree of a resin, is small in size, and is easy to disassemble and clean with resin change, color change, etc. Subject.

[0007]

According to the present invention, in order to solve the above technical problem, a first shaft 3 and a second shaft 4 having a screw portion 2 are arranged in a casing 1 in parallel. This is a twin-screw continuous kneading extruder in which a part of the single shaft 3 and a part of the second shaft 4 face each other, and has the following configuration.

That is, a two-axis screw portion 6 in which the first shaft 3 and the second shaft 4 are arranged in parallel and a single-axis screw portion 7 composed of the extended first shaft 3 are formed. A flow adjusting mechanism is provided at a communication portion between the shaft portion and the single-screw portion 7, and a material supply port 8 communicating with the twin-screw portion 6 is formed in the casing 1 and is connected to an end portion 9 of the extension shaft portion 5. A resin is supplied from the material supply port 8, the resin is melted and kneaded in the twin screw section 6, and the molten resin is devolatilized and extruded in the single screw section 7. It was configured as follows.

[0009] As the flow rate adjusting mechanism, a valve portion 11 that connects the biaxial screw portion 6 and the single-shaft screw portion 7 can be formed. Also, the biaxial screw portion 6 includes:
A plurality of opposing mixing rotor sections 12, 13 can be provided. The first shaft 3 and the second shaft 4 can be rotatably supported via a molten resin at portions inserted into independent casings 22 and 23 which do not communicate with each other.

[0010]

The resin material sent from the material supply port 8 is melted and kneaded by the biaxial screw unit 6, especially the mixing rotor units 12 and 13, and then the single shaft screw unit composed of the extended shaft unit 5 via the flow rate adjusting mechanism. 7 is sent. Then, the molten resin is sent by the single screw portion 7 and discharged from the discharge port 10 to the outside. Here, the resin is melted and kneaded in the biaxial screw portion 6, and the molten resin is devolatilized and extruded in the single screw portion 7.

When the casing 1 is provided with a valve portion 11 for communicating the twin screw portion 6 and the single screw portion 7, the molten resin from the twin screw portion 6 directly to the single screw portion 7 is provided. The amount can be adjusted by the degree of opening and closing of the valve. By adjusting the amount of the molten resin, the kneading state can be freely adjusted at the same time.
That is, if the flow rate passing through the valve 11 is reduced, the residence time of the resin in the twin screw section 6 increases, and kneading proceeds. Conversely, if the flow rate is increased, the kneading degree decreases.

Further, in the conventional apparatus, since only one pair of mixing rotors for melting and kneading the resin are provided, the melting and kneading of the resin is not sufficient, and a part of the material is hardly sheared by the biaxial kneader. In some cases, the mixture passed without receiving the mixture, causing non-uniform kneading. At this time, if a large amount of resin material is supplied in order to increase the resin extrusion amount, melting and kneading of the resin are further insufficient, and the quality is reduced. This device includes a mixing rotor unit 12 in the middle of the first shaft 3 and the second shaft 4.
By forming each of 13, the kneading performance of the molten resin is greatly improved. Thereby, the extrusion amount of the molten resin also increases.

Further, if the first shaft 3 and the second shaft 4 are rotatably supported via a molten resin at portions inserted into independent casings 22 and 23 which do not communicate with each other, the shaft can be lubricated. Is performed by the molten resin passing through,
There is no need to provide bearings or the like for bearings.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. This device has a first casing inside a metal casing 1.
A shaft 3 and a second shaft 4 shorter than the shaft 3 are provided for melting, kneading, feeding, and discharging the resin material supplied from the base side to the distal end side.

FIG. 1 is a plan sectional view of the apparatus. The casing 1 is formed in a cylindrical shape as a whole, and is divided into two parts at the approximate center at right and left. The divided portion is rotatably supported by the hinge 1a and is bent in the direction of arrow F. Note that a connection member 1b, which is a separate member, is inserted in the divided portion of the casing 1. Such a bent structure is used to facilitate internal cleaning and maintenance.

In the casing 1, there are formed a cylindrical cylinder 21, a cocoon cylinder 20 connecting two cylindrical cylinders, and two bearing cylinders 22, 23 formed in the connecting member 1b. . In the eyebrow cylinder 20, a first shaft 3 and a second shaft 4 each having a screw portion 2 are arranged in parallel. The first shaft 3 and the second shaft 4 are fitted into the casing 1 via screw bases 30 and 31. The base ends of the first shaft 3 and the second shaft 4 are inserted into a gear box (not shown) installed outside the casing 1 and are rotatably supported by bearings.

Further, the delivery screw portion 4 at the tip of the second shaft 4
Since a is held at a predetermined position by the interposition of the molten resin between this portion and the cylinder 22, the entire second shaft 4 is rotatably supported. . Similarly, the sending screw portion 5a at the intermediate portion of the first shaft 4 is held at a fixed position by the interposition of the molten resin between this portion and the cylinder 23, so that the entire first shaft 3 is rotatable. Supported.

The central portions of the first shaft 3 and the second shaft 4 are opposed to each other so as not to contact each other, and a pair of mixing rotor portions 12 and 13 are provided in the middle of these. The mixing rotor sections 12 and 13 are formed by opposing first rotor sections 12 a and 12 b and second rotor section 13.
a and 13b, and are formed at positions separated from each other as shown in the figure. A second screw 2a is formed between the first rotor section 12a and the second rotor section 13a, and a second screw 2b is formed between the first rotor section 13b and the second rotor section 13b. ing.

The first shaft 3 has an extension shaft portion 5,
The extension shaft portion 5 is rotatably housed in the cylindrical cylinder 21, and a screw 5b is formed over the entire length thereof. The base end side of the extension shaft portion 5 is held in the connecting member 1b. In this portion, a flow regulating screw 5a having a small screw groove, a small gap with the casing 23, and a fine pitch is formed. Have been. In the flow rate regulating screw 5a, the flow rate of the passing resin is regulated to a minimum.

With the above configuration, a two-axis screw portion 6 in which the first shaft and the second shaft 4 are arranged in parallel and a single-axis screw portion 7 composed of the extension shaft portion 5 are formed in the casing 1. Have been. The first in the casing 1
In the vicinity of the base end of each of the shaft and the second shaft 4, a material supply port 8 communicating with the biaxial screw portion 6 is formed. A resin material is sent to the material supply port 8 from a resin supply device (not shown).

On the other hand, a resin outlet 10 is provided on the end portion 9 side of the extension shaft portion 5 in the casing 1. Further, a devolatilization port 32 is formed in the casing 1 on the base end side of the extension shaft 5. A valve portion 11 is provided in the casing 1 on the base end side of the extension shaft portion 5. The valve section 11 is configured as follows.

First, the empty room 1 is located at the tip end of the delivery screw 4a.
4 is formed, and a small-diameter passage 16 is provided in a part of the empty chamber 14 so that the empty chamber 14 communicates with the cylinder 21. A cylindrical valve element 15 is inserted into the vacant chamber 14 from the outside, and the valve element 15 is capable of moving forward and backward in the arrow H direction. The closer the valve body 15 is to the passage 16, the smaller the volume of the vacant space 14, so that the resin flow path is narrowed.

The valve section 11 communicates the twin-screw section 6 with the single-screw section 7, and adjusts the flow rate by bypassing the molten resin reaching the single-screw section 7. At one end of the second shaft 4, a delivery screw portion 4a is formed, and most of the molten resin blocked by the flow rate regulating screw portion 5a is collected, and the resin is pressure-fed into the casing 21 via the valve portion 11. It has become.

The flow rate adjusting mechanism may have another structure. For example, the first shaft 3 can be moved in the axial direction, and the valve body is formed by the first shaft 3 and the uneven portion formed on the inner surface of the casing around the first shaft 3. It is also possible to form such a structure that the degree of opening and closing of the flow path is adjusted. Next, the operation of the continuous kneading and extruding apparatus will be described. The resin material supplied from the material supply port 8 is sent in the direction of arrow G by the screw portions 2 of the first shaft and the second shaft 4, and the first rotor portions 12a and 13a.
This causes coarse kneading, whereby the resin is in a semi-molten state and the density of the resin material is increased. By increasing the density of the resin in this way, the ability to transport the resin in the second screws 2a and 2b can be increased, and the amount of extrusion can be increased. At this time, the number of rotations of the first shaft 4 and the second shaft 4 is 300 to 100.
0 rpm.

The resin material fed by the second screws 2a and 2b is completely melted and kneaded by the second rotor portions 12b and 13b. The melted and kneaded resin is sent into the empty chamber 14 by the delivery screw portion 4a, passes through the passage 16 while the flow rate is adjusted by the valve body 15, and the casing 2
Sent within 1. By adjusting the flow rate in this way,
Since the kneading residence time of the resin and the filling degree of the resin in the biaxial kneading section 6 can be adjusted, the degree of kneading can be freely set by operating the valve section 11. Therefore, the degree of opening and closing of the valve unit 11 is controlled according to the state of the resin,
The resin can always be uniformly kneaded.

Also, two sets of first and second rotor sections 12, 1
3, the melting and kneading actions of the resin are strengthened, and the extruded amount is greatly increased. Further, the flow rate regulating screw portion 5a and the sending screw portion 4a in the connecting member 1b are independently supported, and the resin is filled between these and the cylinders 22 and 23 so that a bearing action is generated. It is possible to prevent each screw from causing galling in the rotation range.

The resin that has been melted and kneaded and adjusted as described above is sent to the single-screw screw section 7 and
After the necessary devolatilization is performed, it is sequentially fed by the extension shaft 5 and extruded from the discharge port 10. In addition, when changing resin or changing color, it is necessary to disassemble and clean the inside,
In this case, the entire first shaft 3 is withdrawn from the discharge port 10 side. Then, after opening the casing of the single screw 7 portion with the hinge 1a as a fulcrum, the second shaft 4 is removed. The inside of the apparatus can be opened by such a simple operation, and cleaning can be performed in a short time.

This continuous kneading and extruding apparatus is greatly reduced in size compared to a conventional apparatus combining a twin-screw kneader and a single-screw extruder or an apparatus combining a twin-screw kneader and a gear pump. The energy consumed can be significantly reduced. In addition, by providing the valve portion 11 for the purpose of adjusting the flow rate of the molten resin, the kneading time of the molten resin can be set optimally, and uniform kneading can always be performed.

Further, since the first shaft 3 and the second shaft 4 are supported by a bearing lubricating action of a molten resin, bearings or the like are not required, and the inside can be easily cleaned.

[0030]

According to the present invention, the degree of kneading of the resin in the biaxial kneader can be adjusted.
The most suitable kneading can be selected and carried out. Further, since the structure of the apparatus is simplified and downsized, the handleability is improved and the space can be saved. In particular, there is an advantage that it is easy to disassemble and clean the inside due to resin change, color change, and the like.

Further, since the entire apparatus operates by rotating the first shaft and the second axis, the energy consumption can be reduced more efficiently than in the conventional apparatus.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of the present invention.

FIG. 2 is a sectional view taken along the line AA in FIG. 1 showing one embodiment of the present invention.

FIG. 3 is a sectional view taken along line BB in FIG. 1 showing one embodiment of the present invention.

[Explanation of symbols]

 1. Casing, 2. Screw part, 3. First shaft, 4. Second shaft, 5. Extended shaft part, 6. Double screw part, 7. Single screw part, 8. · Material supply port, 9 · · · end, 10 · · · discharge port.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B29C 47/40 B29B 7/46 B29B 7/80 B29C 47/58

Claims (4)

(57) [Claims] 1. A twin-screw continuous kneading and extruding apparatus in which first and second shafts each having a screw portion are arranged in a casing in parallel, and a part of the first and second shafts is opposed to each other. In the above, a biaxial screw portion in which the first shaft and the second shaft are arranged in parallel, and a monoaxial screw portion composed of the extended first shaft are formed, and a communication portion between the biaxial screw portion and the monoaxial screw portion is formed. Providing a flow rate adjustment mechanism, also in the casing, forming a material supply port communicating with the biaxial screw portion and forming a discharge port communicating with the end of the extension shaft, supplying resin from the material supply port, Melt and knead the resin in the twin screw section,
A continuous kneading and extruding apparatus characterized in that devolatilization and extrusion of the molten resin are performed in the single screw portion. 2. The continuous kneading and extruding apparatus according to claim 1, wherein a valve section that connects the twin screw section and the single screw section is provided as the flow rate adjusting mechanism. 3. The continuous kneading and extruding apparatus according to claim 1, wherein a plurality of a pair of mixing rotor portions facing each other are provided on the biaxial screw portion. 4. The apparatus according to claim 1, wherein the first shaft and the second shaft are rotatably supported via a molten resin at a portion inserted into an independent casing that does not communicate with each other. The continuous kneading extruder according to the above.