JP2003164746A - Kneading device for rubber or rubbery composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a kneading device which can achieve continuous kneading treatment and enables setting of a proper kneading condition according to the change of state of a material to be kneaded during continuous kneading to achieve high kneading efficiency. <P>SOLUTION: This kneading device is provided with a barrel 7 having a chamber 6 that is a cylindrical hollow part, a twin-screw set 5 which rotates in the chamber 6 to extrude the material to be kneaded to the downstream side, and kneading blade parts (14, 15) which are incorporated in the screw set 5 and knead the material to be kneaded by applying shearing to the material to be kneaded in wedge-shaped spaces 20c and chip clearances (20a, 20b) which are formed between chip parts and an inner wall 6a of the chamber. The chip clearances 20a are formed so as to be narrowed from the upstream side in the extrude direction to the downstream side. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a kneading apparatus for kneading a kneading object for improving fluidity and processability of rubber or kneading a kneading object to which rubber and various compounding agents are added. And the kneading method.

[0002]

2. Description of the Related Art When producing a kneaded product of a rubber composition comprising rubber and various compounding agents, particularly when producing a rubber compound for tires mainly composed of natural rubber,
A batch method in which a predetermined amount of raw material is intermittently kneaded once is often used. In this case, the batch-type kneading treatment is repeated until the molding processability such as extrusion and the dispersity of the compounding agent reach a desired state, that is, a desired viscosity level and dispersity level. This kneading step is usually called a remill step, and a batch type kneading device such as an internal mixer is used.

However, when the kneading process is carried out by using such a batch type kneading device, it is necessary to carry it from the kneading device to the extruder by using a carrying device after the kneading step and form it into a desired form. However, the step of conveying the lump-shaped kneaded product occurs. Therefore, the device is likely to be complicated and large-sized, and the operator has to rely on the work performed by the operator's hand, which makes it impossible to save labor. Further, in kneading with a batch-type kneading device, in order to prevent deterioration and improve kneading efficiency, it is necessary to prevent the temperature from becoming too high during kneading, and once the kneaded block-shaped kneaded product is sheeted and cooled. It is customary to repeat the remill process again. This remilling step is performed until the viscosity is reduced to a desired value, and the remilling step is often performed about 5 times. Therefore, it is not desirable from the viewpoint of improving productivity.

On the other hand, from the viewpoint of improving the productivity and the like, a kneading apparatus for a rubber composition for continuously kneading is also disclosed (Japanese Patent Laid-Open No. 11-262945). this is,
A twin-screw extruder, which is a typical kneading extruder for plastic-based compositions, is used for kneading rubber.
A rubber input port is provided in the twin-screw extruder, and a rubber-feeding extruder is further connected thereto, and continuous kneading is performed by the twin-screw kneading extruder while continuously supplying the rubber composition. Is.

Therefore, in the continuous kneading apparatus described in the above publication, adjusting the kneading state, that is, the viscosity level and the dispersity level of the compounding agent is within a limited range that can be realized by the rotation of the twin screw. It is difficult to adjust the viscosity and the dispersity of a highly viscous rubber composition that is limited and adjusted by a batch-type kneading device. During kneading with the twin-screw extrusion screw, the kneading state changes with the progress of kneading such as acceleration of shearing and temperature rise. However, the kneading conditions should be adjusted appropriately according to the state change of the kneading target during kneading. It is difficult to set up.

[0006]

In view of the above situation, the present invention realizes a continuous kneading process capable of adjusting the viscosity and the dispersity of the compounding agent for a highly viscous rubber or a rubber composition. At the same time, it is an object of the present invention to provide a kneading device that enables setting of appropriate kneading conditions according to a change in the state of a kneading target during continuous kneading and that realizes high kneading efficiency.

[0007]

In order to solve the above problems, the kneading apparatus for rubber or rubber composition according to claim 1 comprises a kneading object made of rubber or rubber to which various compounding agents are added. A kneading apparatus for a rubber or a rubber composition, which is made to knead a rubber or accelerates dispersion mixing and distributive mixing of compounding agents by giving shear force while flowing, and a kneaded product in a desired kneading state, 1) a barrel having a chamber which is a cylindrical hollow portion; (2) a twin screw set for pushing a kneading target to a downstream side by rotating in the chamber; and (3) the screw set. And a kneading blade part for kneading an object to be kneaded by applying a shear in a wedge-shaped space formed between the inner wall of the chamber and the tip clearance, and Characterized in that it is formed to be narrower toward the downstream side from the extrusion direction upstream side of the object.

According to this structure, shearing is applied in the wedge-shaped space formed between the inner wall of the chamber and the tip clearance, so that even the highly viscous rubber or rubber-based composition has a viscosity and a dispersity of the compounding agent. It is possible to realize a continuous kneading process capable of adjusting. Usually, as the kneading progresses, the viscosity decreases due to shearing and the temperature decreases due to heat generation, but the tip clearance is narrowed from the upstream side to the downstream side of the kneading target in the extrusion direction. By forming it in the above manner, it is possible to set the tip clearance to which an appropriate shearing force can be applied according to the change in the viscosity of the object to be kneaded during the continuous kneading. That is, it is possible to set an appropriate kneading condition according to the state change of the object to be kneaded during kneading, and it is possible to obtain a continuous kneading device that can realize excellent kneading efficiency.

A kneading apparatus for rubber or a rubber composition according to a second aspect is the kneading apparatus according to the first aspect, wherein a rotor segment having two or three spiral blades is used as the kneading blade portion. The tip clearance formed between at least one of the spiral blades and the chamber inner wall is formed to be narrower than the tip clearance formed between the other spiral blade and the chamber inner wall. It is characterized by

According to this structure, by using the rotor segment, it is possible to realize a continuous kneading process capable of adjusting the viscosity and the dispersity of the compounding agent for a highly viscous rubber or rubber composition, and High kneading efficiency can be realized. Then, by forming the tip clearance formed by one spiral blade so as to be narrower than the tip clearance formed by another spiral blade, even when rotor segments are continuously incorporated, kneading is performed. During this, it is possible to prevent the screw shaft from being largely bent or the center of the shaft from being displaced, and it is possible to prevent uneven wear or damage of the rotor segment.
Further, the first spiral blade forming the narrow tip clearance can prevent the object to be kneaded from adhering to the inner wall of the chamber, accelerate the cooling of the object to be kneaded, and suppress the temperature rise of the object to be kneaded. An effect is obtained that the object to be kneaded does not easily stay therein.

A kneading device for rubber or a rubber composition according to a third aspect is characterized in that, in the first or second aspect, the kneading blade portion is divided into a plurality of zones.

According to this structure, by selecting various segments forming the kneading blades of each zone, it becomes possible to set kneading conditions that correspond in detail to changes in the state of the kneading object during kneading.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below for each embodiment with reference to the drawings. (Example 1) FIG. 1 shows a schematic cross-sectional view of a kneading device 1 for a rubber composition according to this example as seen from the side surface. As shown in the figure, the kneading device 1 includes a co-rotating mesh type twin-screw kneading extruder 2 and a rubber feeding device 3 for supplying a kneading object made of rubber to the two-axis kneading extruder 2. I have it.

First, the twin-screw kneading extruder 2 is provided with a pair of screw sets 5 and a barrel 7 having a chamber 6 which is a hollow cavity for rotating the screw sets 5. The pair of screw sets 5 are arranged such that their axes are parallel to each other so as to overlap each other in the side view of FIG. 1, and a drive unit (not shown) outside the barrel 7 (positioned on the left side in the figure). And are driven to rotate in the same direction. Further, the barrel 7 is provided with a chamber 6 formed as a cylindrical hollow portion having a cocoon-shaped cross section, and a pair of screw sets 5 is housed in the chamber 6 (A-A in FIG. 2). 'See the cross-sectional view taken along the line)

At one end side of the barrel 7, a supply port 8 (hopper) for supplying a kneading object made of rubber or a mixture of rubber and various compounding agents such as fillers and additives into the chamber 6 is provided. Section) is provided. Then, the object to be kneaded supplied by the rubber supply device 3 supplied from the supply port 8 is set in the chamber 6 by the screw set 5
By rotating, the resin is extruded toward the right side in the drawing in the axial direction and is continuously kneaded.

The barrel 7 has a structure as shown in FIG.
As shown in the cross-sectional views of FIGS. 3 (BB ′ line arrow) and FIG. 4 (CC ′ line arrow), a plurality of cooling liquid flow paths 9 surround the chamber 6. The screw set 5 is formed in the axial direction (hereinafter, simply referred to as “axial direction”). By passing a coolant such as cooling water through the cooling liquid channel 9, it is possible to prevent the kneading target during the continuous kneading from reaching a high temperature through the barrel 7.

The barrel 7 is constructed by combining a plurality of units (not shown) that can be divided in the axial direction, and the tip 2a of the barrel 7 is open to the atmosphere.
In the kneading device 1 shown in FIG. 1, a kneaded product kneaded in a lump form is shown to be discharged, but a kneaded product molded into a predetermined cross-sectional shape at the tip 2a is discharged. The die part may be connected to.

The screw set 5 has a first screw segment 13 and a second screw segment 16 which are respectively arranged on the upstream side and the downstream side. And
The 1st kneading blade part 14 and the 2nd kneading blade part 15 are formed by incorporating in between them in the axial direction.

Barrel 7 and first screw segment 1
The screw portion 10 (10a, 10b) is formed with the third or second screw segment 16, respectively. Similarly, the barrel 7 and the first kneading blade portion 14 form the first kneading portion 11a (11), and the barrel 7 and the second kneading blade portion 1
5 and the second kneading section 11b (11) is formed respectively.

The screw segment 13 is formed from immediately below the supply port 8 toward the downstream side, and is shown in FIG.
As shown in the cross section taken along the line A '), the spiral blade has two threads. The tip 13a of the spiral blade and the inner wall 6a of the chamber 6
By arranging and so as to be close to each other so that the gap becomes small, it is possible to improve the biting of the kneading target that has been introduced. And the two screw segments 13
However, by rotating in the same direction as indicated by the arrow, the object to be kneaded is extruded in the right direction in FIG.

The first kneading blade portion 14 and the second kneading blade portion 1
5 includes a plurality of rotor segments (14a, 14b, etc.) each including two spiral blades. That is, the first kneading blade portion 14 includes six rotor segments (14a to 14f) having a twist angle ψ1.
5 is five rotor segments (15a
~ 15e). As described above, by using a rotor segment capable of exhibiting a strong shearing action as the kneading blade part, continuous kneading capable of adjusting the viscosity and the dispersity of the compounding agent, even in the case of a highly viscous rubber or a rubber composition. Processing can be realized.

Here, the twist angle means that the tangent line toward the spiral direction at the top of the spiral blade formed so as to advance in the axial direction along the circumferential direction of the screw set 5 and the axial direction are parallel to the axis. It is the angle that is projected on the surface. Then, the rotor segments (14a to 1) of the first kneading blade portion 14 are
4f), the twist angle ψ1 and the second kneading blade portion 15
Of the rotor segment (15a to 15e) is different from the twist angle ψ2.

In the kneading device 1 shown in FIG. 1, the twist angle ψ2
However, an example is formed in which the twist angle is smaller than the twist angle ψ1. In this way, by setting the twist angle ψ2 formed in the rotor segment incorporated on the downstream side to be small, the action of promoting the discharge of the kneading target on the downstream side is exhibited. Further, by setting a large twist angle formed in the rotor segment incorporated on the upstream side, the object to be kneaded can be easily filled on the upstream side, and the kneading can be performed efficiently.

During the continuous kneading, the temperature is low and the viscosity is high on the upstream side, but the temperature is high on the downstream side due to the heat generated during the kneading, and the viscosity is low because the kneading progresses further. In this case, by increasing the twist angle ψ1 of the first kneading blade portion 14 on the upstream side and decreasing the twist angle ψ2 of the second kneading blade portion 15 on the downstream side, an unbalanced load is generated depending on the viscosity during kneading. It can be configured to be difficult.

Incidentally, both the twist angles ψ1 and ψ2 are 4
It is preferably formed at 5 ° or less. By setting the angle to 45 ° or less, the filling rate of the object to be kneaded in the kneading section 11 is increased to an appropriate level, and the necessary shearing force is easily applied.

Here, FIG. 5 shows a schematic view of one rotor segment R (for example, the rotor segment 14a). As shown in the figure, a shaft hole 18 is formed in the rotor segment R, and the shaft of the screw set 5 is fitted into the shaft hole 18 to be incorporated in the screw set 5. A high-level tip portion 19a and a low-level tip portion 19b are formed alternately on the top portion 19 of the two-blade spiral blade while being divided in the axial direction.

The lower tip portion 19b is formed so that the distance from the shaft center to the top portion 19 is shorter than that of the higher tip portion 19a. Then, the high-ranking tip portion 19 is attached to the top portion 19 of one of the two spiral blades at the same axial position.
When a is formed, the top 19 of the other spiral wing is formed.
A low-level chip portion 19 is formed in the lower part. With this configuration, a wide tip clearance and a narrow tip clearance are alternately formed between the chamber inner wall 6a and the rotor segment R, as will be described later.

By combining the rotor segments R described above in the axial direction, as shown in FIG.
The kneading blade portion 14 and the second kneading blade portion 15 are configured. Each rotor segment (14a, 14b, ...
.) Are combined such that the spiral blades are continuously connected in the spiral direction in the axial direction. In particular, this is well illustrated in the second kneading blade portion 15.

Further, FIG. 3 is a sectional view taken along the line BB ′ of FIG. 3, but the rotor segments 14a provided in the biaxial screw sets 5 (the same applies to 14b to 14f),
Similar to the screw segment 13, they rotate in mesh with each other in the same direction (the rotation direction is indicated by an arrow in the figure). Two rotor blades are formed in each rotor segment 14a, and as described above, the high-order tip portion 19a is provided on the top of one of the spiral blades and the low-order tip is provided on the top of the other spiral blade. The chip portion 19b is formed.

The size of the tip clearance 20a formed between the high-rank tip portion 19a and the chamber inner wall 6a is relatively narrow as they approach each other. On the other hand, the size of the tip clearance 20b formed between the lower tip portion 19b and the chamber inner wall 6a is relatively wide. That is, 1 spiral blade and chamber inner wall 6
The tip clearance 20a formed between a and a is formed to be narrower than the tip clearance 20b formed between another spiral blade and the chamber inner wall 6a.

By forming in this way, the chamber 6 is always stably provided on the high-ranking tip portion 19a side through the object to be kneaded.
The screw set 5 will be supported therein. Therefore, even when the rotor segments are continuously incorporated, it is possible to prevent the screw shaft from being largely bent or the center of the screw being displaced during kneading. As a result, uneven wear and damage of the rotor segment can be prevented.

Since the narrow tip clearance 20a is formed by the high-order tip portion 19a formed on one spiral blade and the chamber inner wall 6a, it is possible to prevent the object to be kneaded from adhering to the chamber inner wall 6a. That is, the object to be kneaded adhering to the inner wall 6a of the chamber is scraped off by the high-order tip portion 19a, so that the releasability of the object to be kneaded is improved. This can prevent the kneading target from staying in the barrel 7.

Further, the high-order tip portion 19a is provided on one spiral blade.
By forming the low tip portion 19b on the other spiral blade, the narrow tip clearance 20a and the wide tip clearance 20b alternately appear. As a result, a strong shearing force can be applied to the object to be kneaded in the narrow tip clearance 20a and the wedge-shaped space 20c formed on the side thereof. Then, in the wide tip clearance 20a, it becomes possible to promote the passage of the object to be kneaded. Therefore, the shearing action can be easily and uniformly applied to the object to be kneaded, and sufficient kneading can be performed while feeding the object to be kneaded. According to this configuration, uneven distribution of the object to be kneaded is unlikely to occur in the chamber 6, so that the mechanical load applied to the screw set 5 can be reduced.

FIG. 4 is a sectional view taken along the line CC 'in FIG. 4. As with the rotor segments (14a to 14f) of the first kneading section 11a described in FIG. 3, the rotor segment shown in this figure is shown. A high-level chip portion 19a and a low-level chip portion 19b are also formed on 15a (the same applies to 15b to 15e). Then, the high-ranking tip portion 19a and the chamber inner wall 6
A narrow tip clearance 20a is formed between the lower tip portion 19b and the chamber inner wall 6a. These actions are qualitatively the same as in the case of the first kneading section 11a. However, in the case of the second kneading section 11b, the wide tip clearance 20b is formed to be narrower than that in the case of the first kneading section 11a.

That is, a wider tip clearance 20b formed in the second kneading section 11b located downstream than a wider tip clearance 20b formed in the first kneading section 11a located upstream in the extrusion direction of the object to be kneaded. Is formed to be narrower. During the continuous kneading, as described above, the temperature is low and the viscosity is high on the upstream side, but the temperature is high on the downstream side due to the heat generated during the kneading and the viscosity is low because the kneading progresses further. In this case, if the tip clearance can be set according to the change in the viscosity of the object to be kneaded during kneading, an appropriate shearing force can be applied. Therefore, by forming the tip clearance 20b so as to narrow from the upstream side to the downstream side in the extrusion direction as in the kneading device 1, it is possible to provide an appropriate chip clearance according to the state change during continuous kneading, High kneading efficiency can be realized.

A screw segment 16 is incorporated in the screw set 5 on the downstream side of the second kneading section 11b. The kneaded material kneaded through the kneading section 11 is discharged from the tip 2a of the screw section 10b as the screw segment 16 rotates.

As described above, the biaxial kneading extruder 2 is configured, and the object to be kneaded supplied from the supply port 8 is kneaded in the biaxial kneading extruder 2 and adjusted to a desired viscosity and dispersity. And then discharged. Then, as described above, the rubber is supplied to the supply port 8 provided on one end side of the twin-screw kneading extruder 2 by the rubber supply device 3 provided above the supply port 8.

The rubber supply device 3 is a device for quantitatively supplying a sheet-shaped object to be kneaded to the biaxial kneading extruder 2, and is provided with a feeder roll 21 and a cutter roll 22.

The feeder rolls 21 are a pair of rolls that rotate in mutually opposite directions and feed a sheet-like object to be kneaded between the rolls. The supply rate (supply amount per unit time) can be adjusted.

The cutter rolls 22 are a pair of rolls which are arranged below the feeder roll 21 and rotate in opposite directions with a rubber sheet sandwiched between them. A cutter blade 22a is provided at a predetermined position on the outer circumference of the rolls. Has been. With this cutter blade 22a, a cut is made in advance in the rubber sheet each time the cutter roll 22 rotates, and even if the rubber sheet is pulled in by the screw segment 13 of the twin-screw kneading extruder 2, it is cut at the cut portion and quantitatively cut. Then, the object to be kneaded is supplied to the biaxial kneading extruder 2.

The above is the configuration of the kneading apparatus 1 according to the first embodiment. Next, the operation mode will be described based on FIG. First, various compounding agents such as fillers and additives such as carbon black are added, and a kneading target formed into a sheet shape is fed by the rubber feeding device 3 from the feeding port 8 to the chamber 6 of the biaxial kneading extruder 2. Is supplied inward. The sheet-shaped kneading target is quantitatively supplied into the chamber 6 by the feeder roll 21 and the cutter roll 22.

At this time, in the chamber 6, the pair of screw sets 5 are meshed and rotated in the same direction by a driving unit (not shown) (see FIGS. 2 to 4). Then, the object to be kneaded supplied into the chamber 6 is supplied to the first kneading section 1 by the two spiral blades provided in the screw segment 13.
Extruded into 1a.

In the first kneading section 11a, the extruded object to be kneaded is filled so as to be retained between the first kneading blade section 14 and the chamber inner wall 6a, and while being filled, the tip clearance (20a , 20b) are kneaded so that they flow and are subjected to shearing force to be mixed and dispersed.

At this time, as described above, in the narrow wedge-shaped space formed between the high-order tip portion 19a and the chamber inner wall 6a and the narrow tip clearance 20a, a strong shearing force is applied to the object to be kneaded and the viscosity is lowered. Be promoted.
Then, in the wide tip clearance 20b formed between the lower tip portion 19b and the chamber inner wall 6a, uniform shearing is promoted by the passage of the kneading target in the high shearing region.

The object to be kneaded in the first kneading section 11a is extruded as it is to the second kneading section 11b. At this time, the object to be kneaded, which has reached the second kneading section 11b, has a reduced viscosity due to the above-mentioned influence of heat generation and the like. But,
The wide tip clearance 20b of the second kneading section 11b is
Since it is formed so as to be narrower than the wide tip clearance 20b of the first kneading section 11a, it is possible to apply a sufficient shearing force to the object to be kneaded. Therefore,
As the twin-screw kneading extruder 2, high kneading efficiency can be realized.

Finally, the kneaded material kneaded in the second kneading section 11b is extruded through the screw section 10b and discharged from the tip 2a. The above is the description of the kneading device 1 according to the first embodiment.

(Example 2) Next, a kneading apparatus 50 for a rubber composition according to Example 2 will be described. FIG. 6 shows a schematic diagram of the kneading device 50. The kneading device 50 has a biaxial kneading extruder 51 and a rubber feeding device 52. In FIG. 6, a barrel 53 and a screw set 54 included in the biaxial kneading extruder 51 are shown separately. There is. Note that the screw set 54 is provided as a pair of same-direction rotational meshing type as in the case of the first embodiment. Further, the barrel 53 is provided with a supply port 53a.

The kneading device 50 is almost the same as the kneading device 1 according to the first embodiment, but the screw segment 57 is incorporated between the first kneading blade portion 56 and the second kneading blade portion 58s of the screw set 54. Is different. That is, the screw set 54 includes the first screw segment 55, the first kneading blade portion 56, the second screw segment 57, the second kneading blade portion 58, and the third screw segment 59 in this order.

An opening 53b is provided in the barrel 53 corresponding to the second screw segment 57, and the state inside the barrel 53 can be seen through this opening 53b. This allows
The object to be kneaded in the state after kneading in the first kneading section 60 formed by the first kneading blade section 56 and the barrel of the corresponding section can be observed and sampled, and the kneading state is determined. be able to. Therefore, the segment to be incorporated in the second kneading blade portion can have an appropriate configuration according to the result of this determination.

The first kneading blade portion 56 and the second kneading blade portion 5
8 is composed of a plurality of two-blade rotor segments as in the case of the first embodiment. And the first
Regarding the configuration of the tip clearance and the configuration of the twist angle formed between the kneading blade portion 56 and the second kneading blade portion 58 and the chamber inner wall (not shown), the number of the arranged segments is different. The same as in Example 1.

(Example 3) Finally, a kneading apparatus 80 for a rubber composition according to Example 3 according to Example 3 will be described. FIG. 7 shows a schematic diagram of the kneading device 80. The kneading device 80 is
It has a biaxial kneading extruder 81 and a rubber supply device 82. In FIG. 6, the barrel 83 and the screw set 84 provided in the biaxial kneading extruder 81 are shown separately. The screw set 84 is provided as a pair of same-direction rotary meshing type as in the case of the first embodiment. Further, the barrel 83 is provided with a supply port 83a.

The biaxial kneading extruder 81 is different from that of the first embodiment in that the first to the third kneading sections (85, 86, 87) 3 are provided.
It is equipped with two zones, and each of the first to third kneading blades (88, 89, 9) in the screw set 84 is provided.
0) corresponds. Each of these kneading blades (88-9
0) is configured by incorporating a plurality of two-blade rotor segments. The first kneading section 85 and the second kneading section
At the downstream end of the kneading section 86, kneaded material discharge ports 91 and 92 are provided, respectively. The screw set 84 is provided with the screw segment 94 only on the upstream side.

A discharge port (91, 9 provided on the barrel 83
When 2) is not used as a discharge port, it is closed by a closing member (not shown). When it is used as a discharge port, the blocking member is removed only from the corresponding discharge port, and the kneaded product is discharged from there. In addition, when a closing member is attached to both the discharge ports 91 and 92, the kneaded product is discharged from the tip end 83 a of the barrel 83 on the downstream side of extrusion.

With the above structure, the position at which the kneaded material is discharged is selected according to the type of the material to be kneaded, or the level of the degree of dispersion of the various compounding agents mixed or the degree of decrease in viscosity. You can That is, the discharge port 91 may be selected when kneading a low-viscosity kneading target, or when the viscosity reduction width or the dispersity of the compounding agent to be adjusted is small. In this case, since the kneading is performed only by the first kneading section 85, the length of the kneading section is shortened and a kneaded product in a desired kneading state can be obtained. Further, when kneading a highly viscous kneading target, or when the viscosity reduction width or the dispersity of the compounding agent to be adjusted is large, the kneaded product may be discharged from the discharge port 92 or the tip 83a. In this case, since the kneading is performed using the first and second kneading sections, or the first to third kneading sections, the length of the kneading section becomes long,
A kneaded product in a desired kneading state is obtained.

As described above, by providing a plurality of discharge ports in the barrel 83 toward the downstream side of extrusion, the types of kneading objects that can be continuously kneaded are expanded, and further, viscosity adjustment and compounding agent dispersity over a wide range are performed. Can be adjusted.
Further, according to this, since it is possible to easily realize the viscosity adjustment over a wide range only by attaching / detaching the closing member, it is possible to reduce a labor-intensive and time-consuming work of changing various segments incorporated in the screw set.

Further, as described above, each of the kneading blade portions (88 to 90) incorporates a plurality of two-blade rotor segments (88a, 88b, etc.). Each rotor segment incorporated in each kneading blade portion (88 to 90) includes a high-level tip portion 93a and a low-level tip portion 93b, as in the example described in Example 1 with reference to FIG. Then, as in the first embodiment, the high-rank chip portion 9
A narrow tip clearance (not shown) is formed between 3a and the chamber inner wall (not shown) in the barrel 83,
A wide tip clearance (not shown) is formed between the lower tip portion 93b and the chamber inner wall.

In the twin-screw kneading extruder 81, wide tip clearances and narrow tip clearances are alternately formed. Then, the kneading section (85
.About.87), the rotor segment is incorporated so that the size of the wide tip clearance is narrowed from the upstream side to the downstream side. Further, the size of the wide tip clearance in each kneading section is also narrowed from the upstream side to the downstream side. That is, in each kneading section, the wide tip clearance is formed so as to become narrower toward the downstream side, and when the kneading sections are compared with each other, the size of the wide tip clearance is the kneading point located on the downstream side. The part is configured to be narrower. With this configuration, as in the case of Example 1, it becomes possible to set appropriate kneading conditions according to changes in the viscosity of the object to be kneaded during continuous kneading.

Further, the twist angle formed in each rotor segment is large on the upstream side for each kneading section.
It is set to be smaller on the downstream side. That is, for example, in the twist angles (ψ1 to 3) of the first kneading blade portion 88, the relation of ψ1>ψ2> ψ3 is established. With such a configuration, on the upstream side of each kneading unit, the filling degree of the object to be kneaded is increased and a high shearing force is applied. Then, on the downstream side, the discharging action of the kneading target is promoted, and the kneading target is quickly extruded. In addition,
With respect to the rotor segment at the position corresponding to the portion where the discharge ports (91, 92) are provided, the twist angle is set to be small so that discharge of the kneaded product from the discharge ports (91, 92) is likely to be facilitated. Play an action.

The above is the description of the kneading apparatus according to Examples 1 to 3. Note that the embodiment is not limited to the above-described embodiments, and may be modified and implemented as follows, for example.

(1) In each of the embodiments, an example in which a rotor segment including two spiral blades is used as the kneading blade portion is shown, but the same applies to a rotor segment including three spiral blades. The present invention can be applied to.

(2) The combination of the tip clearance and the twist angle is not limited to the one described in this embodiment, and various combinations are possible. For example, it is possible to adjust a wide range of viscosity by setting variously according to the kind of the object to be kneaded, the width of decrease in viscosity to be adjusted, or the adjusted dispersity of the compounding agent.

(3) The kneading section does not necessarily have to be divided into a plurality of zones as shown in this embodiment. That is, it may be one kneading section which is continuously formed for a long time. According to the kneading device of the present invention, it is possible to carry out sufficient kneading while feeding the object to be kneaded even if there is only one kneading section, so that the entire length of the screw set can be effectively utilized.

(4) In Examples 1 and 3, the respective kneading sections were continuously combined, and in Example 2, the first
Although the example in which the screw segment is disposed between the second kneading section and the second kneading section is shown, the position is not limited to these examples, and the position at which the screw segment is disposed can be variously selected. Further, not only the rotor segment but also a kneading disc may be combined.

(5) In this embodiment, the rubber feeding device uses a single-stage feeder roll, but the present invention is not limited to this, and a rubber feeding device having a plurality of stages of feeder rolls may be used. Good. Further, it is not limited to those supplied by a feeder roll, and may be an extrusion screw type (such as a single-screw extrusion screw or a twin-screw taper screw feeder) or a gear pump. The form of the kneading target to be supplied is not limited to the sheet form, and various forms such as a ribbon form, an agglomerate form, and a powder form may be used as long as the kneading target form can be continuously supplied.

[0065]

According to the first aspect of the present invention, even if a highly viscous rubber or rubber-based composition is viscous, shearing is applied in the wedge-shaped space formed between the chamber inner wall and the tip clearance. Further, it is possible to realize a continuous kneading process capable of adjusting the dispersity of the compounding agent. Usually, as the kneading progresses, the viscosity decreases due to shearing and the temperature decreases due to heat generation, but the tip clearance is narrowed from the upstream side to the downstream side of the kneading target in the extrusion direction. By forming it in the above manner, it is possible to set the tip clearance to which an appropriate shearing force can be applied according to the change in the viscosity of the object to be kneaded during the continuous kneading. That is, it is possible to set the appropriate kneading conditions according to the state change of the kneading target during kneading,
It is possible to obtain a continuous kneading device that can realize excellent kneading efficiency.

According to the second aspect of the present invention, by using the rotor segment, it is possible to realize a continuous kneading process capable of adjusting the viscosity and the dispersity of the compounding agent for a highly viscous rubber or a rubber composition. And high kneading efficiency can be realized. Then, by forming the tip clearance formed by one spiral blade so as to be narrower than the tip clearance formed by another spiral blade, even when rotor segments are continuously incorporated, kneading is performed. inside,
It is possible to prevent the screw shaft from being largely bent or the center of the shaft from being displaced, and it is possible to prevent uneven wear or damage of the rotor segment. Further, the first spiral blade forming the narrow tip clearance can prevent the object to be kneaded from adhering to the inner wall of the chamber, accelerate the cooling of the object to be kneaded, and suppress the temperature rise of the object to be kneaded. An effect is obtained that the object to be kneaded does not easily stay therein.

According to the third aspect of the present invention, by selecting various segments constituting the kneading blade portion of each zone, it is possible to set kneading conditions that correspond finely to changes in the state of the kneading object during kneading. Become.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a kneading device for a rubber composition according to an example of the present embodiment as seen from a side surface.

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

FIG. 3 is a sectional view taken along the line BB ′ of FIG.

FIG. 4 is a sectional view taken along the line CC ′ of FIG.

FIG. 5 is a schematic view showing one rotor segment in the kneading device for a rubber composition according to the embodiment.

FIG. 6 is a schematic view of a kneading device for a rubber composition according to a modification.

FIG. 7 is a schematic view of a kneading device for a rubber composition according to another modification.

[Explanation of symbols]

1 kneading device 2 twin-screw kneading extruder 3 rubber feeding device 5 screw set 6 chambers 6a Chamber inner wall 7 barrels 8 supply ports 11 Kneading department 11a First kneading section 11b Second kneading section 14 First kneading blade 14a-f rotor segment 15 Second kneading blade 15a-e rotor segment 20a Narrow tip clearance 20b wide tip clearance 50 kneading equipment 80 kneading equipment

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Norifumi Yamada             2-3-3 Niihama, Arai-cho, Takasago, Hyogo Prefecture             Takasago Works, Kobe Steel, Ltd. F term (reference) 4F207 AA45 KA01 KA17 KF12 KK13                       KK30 KK34 KL23 KL34                 4G078 AA01 AB07 BA01 BA07 CA01                       CA06 CA12 CA17 DA09 DA17                       DB01 DC08 EA03

Claims (3)

[Claims] 1. A rubber or a rubber to which various compounding agents have been added is flowed and a shearing force is applied to the material to masticate the rubber or accelerate the dispersion mixing and distribution mixing of the compounding agents to obtain a desired mixture. A kneading device for a rubber or a rubber-based composition to be a kneaded product in a kneaded state, comprising: (1) a barrel having a chamber that is a hollow cylindrical portion; and (2) kneading by rotating in the chamber. (3) Kneading of the object to be kneaded by shearing by a wedge-shaped space formed between the screw set for pushing the object to the downstream side and (3) the screw set and formed in the chamber inner wall and the tip clearance. And a kneading blade part for performing the kneading, and the tip clearance is formed so as to become narrower from the upstream side to the downstream side in the extrusion direction of the kneading target. There the kneading apparatus of a rubber-based composition. 2. A rotor segment including two or three spiral blades is used as the kneading blade portion, and a tip clearance formed between at least one of the spiral blades and the chamber inner wall. Is formed so as to be narrower than the tip clearance formed between the other spiral blade and the inner wall of the chamber. . 3. The kneading device for rubber or rubber-based composition according to claim 1, wherein the kneading blade portion is divided into a plurality of zones.