JP2003245534A - Kneader for rubber or rubbery composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a kneader for rubber or a rubbery composition, preventing the rubber or the composition from remainding improperly in the kneader in during kneading and applying sufficient kneading work to them. <P>SOLUTION: The kneader for the rubber or the rubbery composition is equipped with (1) a barrel 5 having a chamber 6 being a cylindrical cavity part, (2) a cooling route 8 formed in the barrel 5 and provided to the periphery of the chamber 6, (3) a twine-screw set 4 rotated in the chamber 6 to apply shearing force to the rubber and extruding the kneaded rubber to a downstream side and (4) kneading blades (11 and 14) incorporated in the screw set 4 as segment members to knead the rubber in the space formed along with a inner wall 6a of the kneader. The kneading blades (11 and 14) are partially notched at the top parts 19 thereof and has spriral blades each having a length not shorter than the outer diameter D of the screw set 4 axially provided thereto and is adjacent to another segment members (12 and 15) having parts discontinuously changed in shaft cross section on 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. It is about.

[0002]

2. Description of the Related Art It is known to use a twin-screw kneading extruder as a kneading device for rubber or a rubber composition.
This twin-screw kneading extruder is usually provided with a barrel having a chamber that is a cylindrical hollow portion, and a two-screw screw set that rotates in the chamber. Further, the screw set is generally configured by combining a plurality of segments such as a kneading rotor, a kneading disk, and a screw.

When kneading rubber or the like by using the kneading device composed of this extruder for biaxial kneading, first, a kneading object made of rubber or rubber to which various compounding agents are added is
Feed from one side of the barrel into the chamber. And
The object to be kneaded is kneaded while being extruded in the axial direction by the screw set while being given a shearing force in a space formed between the kneading rotor and the inner wall of the chamber by a kneading rotor or the like incorporated in the screw set. Further, simultaneously with the kneading, the compounding agents contained in the object to be kneaded are dispersed and mixed. In this way, a kneaded product having a desired kneading state, that is, a desired viscosity and a dispersity of the compounding agent adjusted, is produced.

In this case, it is necessary to appropriately select the type and number of segments to be incorporated in the screw set, depending on the type of the object to be kneaded and the kneading state to be adjusted. Usually, when a large amount of kneading work is to be given, a large number of kneading rotors are incorporated, and when it is desired to focus on dispersion of the compounding agent, a large number of kneading disks are incorporated. In general, the kneading rotor is provided with a spiral blade, and imparts a strong shearing force to the object to be kneaded by a tip clearance formed between the top of the spiral blade and the inner wall of the chamber, and The kneading disc is provided with blades whose tops are formed parallel to the axis, and connects relatively short segments in the axial direction in a blade surface discontinuous manner.

Particularly, when kneading is carried out by using a screw set incorporating a kneading rotor, the screw set is rotated so that the spiral blades provided on the kneading rotor are in the direction of feeding the object to be kneaded. A rotor is installed. As a result, the kneading work is given to the object to be kneaded and the object is extruded to the downstream side. However, in order to give sufficient kneading work to the object to be kneaded and to realize high kneading efficiency, it is necessary to fill the chamber with the object to be kneaded to some extent. Therefore, the kneading rotor is incorporated so that the spiral blades of the kneading rotor located on the downstream side of the kneading rotor that is continuously incorporated are in the opposite direction, that is, the direction in which the object to be kneaded is returned to the upstream side. . As a result, the object to be kneaded is filled, and high kneading efficiency is realized.

However, according to the above construction, the object to be kneaded is not discharged until the end even after the kneading work is completed,
A lot of rubber will remain in the chamber. The remaining rubber that has not been discharged is mixed with a different object to be kneaded at the next chance, or even if the next chance is the same kind of rubber, etc., the quality is deteriorated and the quality deteriorates. It also causes a decrease in yield and the like.

Further, in the case of kneading a highly viscous object to be kneaded with the above-mentioned structure, the object to be kneaded excessively stays in the chamber, which gives an excessive amount of kneading work to the object to be kneaded, Due to the high filling, the cooling from the inner wall of the barrel cannot catch up, and the heat generated during kneading tends to raise the material temperature. If the temperature of the object to be kneaded is too high, the viscosity of the object to be kneaded during kneading is lower than that at a low temperature, so the effect of breaking the molecular chains by mechanical shearing is not sufficiently exerted, and the kneading efficiency is reduced. As a result, the desired viscosity cannot be reduced. Further, when the temperature of the object to be kneaded exceeds a predetermined temperature due to a high temperature, the physical properties of the rubber material change, and the performance of the rubber deteriorates.

Generally, in the case of a kneading device incorporating a kneading rotor, although high kneading efficiency is easily realized,
When uneven distribution of the object to be kneaded occurs in the chamber, the screw set is difficult to hold evenly in the chamber,
The contact between the barrel and the screw set causes wear and the like, leading to problems such as shortening of equipment life.

[0009]

Therefore, in the conventional kneading apparatus, the object to be kneaded tends to cause excessive retention in the chamber during kneading. Therefore, the object to be kneaded tends to remain in the chamber even after the kneading, and the temperature tends to be high, which may cause deterioration of the rubber material and a decrease in the kneading efficiency, or the uneven distribution of the object to be kneaded may shorten the life of the kneading device. It has problems such as being easy.

The present invention has been made in view of the above circumstances.
An object of the present invention is to provide a kneading device for rubber or a rubber composition which can prevent the object to be kneaded during kneading from staying excessively in the chamber and can impart sufficient kneading work.

[0011]

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 cavity; (2) a cooling path formed inside the barrel and provided around the chamber; and (3) rotating in the chamber,
A biaxial screw set for extruding to the downstream side while kneading the object to be kneaded by applying shearing force,
(4) A kneading blade part that is incorporated as a segment member in the axial direction of the screw set and kneads in a space formed between the chamber inner wall and the chamber inner wall, and the kneading blade part has a top portion partially cut. A spiral blade having a length not less than the outer diameter of the screw set in the axial direction,
It is characterized in that it is adjacent on the downstream side to another segment member having a portion whose axial sectional shape changes discontinuously.

According to this structure, since the kneading blade portion is adjacent to the other segment member having the portion whose axial cross-sectional shape changes discontinuously on the downstream side, the discontinuous portion serves as a conveyance resistance, and this discontinuity occurs. The object to be kneaded fills the upstream side of the continuous portion. Sufficient kneading work is imparted to the object to be kneaded thus filled by the kneading blade portion. On the other hand, since the object to be kneaded can be filled with the required amount so as to be blocked at the discontinuous portion, the object to be kneaded is not pushed back to the upstream side and excessive retention does not occur. Therefore, it is unlikely to cause a problem that the object to be kneaded remains in the chamber even after the kneading, or a problem that the temperature is high and deterioration of the rubber material and deterioration of the kneading efficiency are likely to occur. And, at the top of the spiral blade of the kneading blade,
Since the notch is provided, the object to be kneaded easily passes through the notch, and the kneading is promoted at the part without the notch. That is, in the portion without the notch, sufficient kneading work can be given to the object to be kneaded, and by providing the notch portion, the flow state of the object to be kneaded in the chamber is complicated. It is also possible to efficiently carry out dispersion mixing and distribution mixing of the compounding agent. Furthermore, since the length of the spiral blade is equal to or larger than the screw set outer diameter, the effect of preventing uneven distribution of the object to be kneaded and the effect of efficient mixing of the compounding agent can be stably exhibited. Therefore, the object to be kneaded during kneading is
It is possible to provide a kneading device for a rubber or a rubber-based composition, which can prevent excessive accumulation in the chamber and can impart sufficient kneading work.

A kneading device for rubber or a rubber composition according to a second aspect is the kneading blade part according to the first aspect,
It is characterized by having a screw lead having a length of 5 times or more the outer diameter of the screw set.

According to this structure, the screw lead is
Since the length of the screw set is more than 5 times the outer diameter (the screw lead is 5D or more), the conveying force of the kneading material in the extrusion direction is weaker than that of a general screw, and the object to be kneaded is filled in the chamber. As a result, it is possible to secure a sufficient full length for stably holding the screw set. Therefore, it is possible to prevent problems such as wear and the like due to contact between the barrel and the screw set, which shortens the life of the equipment.

A kneading device for rubber or a rubber composition according to a third aspect is the kneading device according to the first or second aspect, wherein the other segment member adjacent to the kneading blade portion on the downstream side is outside the screw set in the axial direction. A plurality of segments, each having a length equal to or greater than ½ of the diameter and provided with blades whose tops are formed parallel to the axis, are assembled by alternately shifting the axial sectional shapes by 90 ° with respect to the axial center. It is characterized by being a thing.

According to this structure, a plurality of segments are
Since the axial cross-sectional shapes are alternately shifted by 90 ° with respect to the axial center, the segment members themselves do not have a feeding action or a returning action to the object to be kneaded.
Therefore, it is possible to surely fill the object to be kneaded so as to block the required amount. Further, the length of the other segment member is ½ or more of the outer diameter of the screw set, so that the effect of blocking a required amount of the object to be kneaded can be stably obtained.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view of a kneading device 1 for a rubber composition according to the present embodiment as seen from a side surface. As shown in the figure, the kneading device 1 is configured as a co-rotating mesh type twin-screw kneading extruder.

The kneading device 1 which is an extruder for biaxial kneading has one
It is provided with a pair of screw sets 4 and a barrel 5 having a chamber 6 which is a cylindrical hollow portion for rotating the screw sets 4. 1 pair of screw set 4
Are arranged such that their axes are parallel to each other so as to overlap each other in the side view of FIG. And this one
The pair of screw sets 4 are connected to a drive unit 7 (shown on the left side in the drawing) provided on one end side of the barrel 5 and having a motor and a speed reducer (not shown), and are rotationally driven in the same direction.
Further, the chamber 6 is formed as a cylindrical hollow portion having a cocoon-shaped cross section, and a pair of screw sets 4 are provided in the chamber 6 as shown in a cross sectional view taken along the line AA ′ of FIG. It is stored.

At one end of the barrel 5, a supply port 3 for supplying an object to be kneaded, which is made of rubber or a mixture of rubber and various compounding agents such as fillers and additives, into the chamber 6.
(Hopper part) is provided. In this supply port 3,
The object to be kneaded is supplied from the rubber supply device 2 or the like. Figure 1
Is a feeder roll 2a for feeding a raw material rubber (object to be kneaded) molded into a sheet, and a chuck roll 2b.
1 illustrates a rubber supply device 2 including Then, the object to be kneaded supplied from the supply port 3 by the rubber supply device 2 or the like is moved from the right side (upstream side) to the left side (downstream side) in the drawing as the screw set 4 rotates in the chamber 6. The kneading is carried out continuously while being conveyed in the axial direction.

As shown in FIG. 3 (a sectional view taken along the line AA ') and FIG. 4 (a sectional view taken along the line BB'), the barrel 5 has a plurality of chambers 6 surrounding the chamber 6. The cooling path 8 is formed in the axial direction of the screw set 4 (hereinafter, simply referred to as “axial direction”). By passing a coolant such as cooling water through the cooling liquid path 8, it is possible to prevent the object to be kneaded during the continuous kneading from reaching a high temperature through the barrel 5.

The barrel 5 has openings 9 (9a, 9a) for deaeration and observation at a plurality of axial positions.
b) is provided. Through this opening 9, it is possible to discharge the gas generated during kneading and observe the kneading state of the kneading object during kneading. In FIG. 1, the opening 9a,
Although 9b shows an example in which it is open to the outside, a lid or the like (not shown) may be attached.

The barrel 5 is constructed by combining a plurality of units that can be divided in the axial direction (the dividing line is not shown), and the tip 5a of the barrel 5 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 5a is discharged. You may connect a die part to.

Next, as shown in FIG. 1, the screw set 4 includes a first screw portion 10, a first kneading blade portion 11, a first kneading disc portion 12, a second screw portion 13,
The second kneading blade portion 14, the second kneading disk portion 15,
Each segment member of the third screw portion 16 is configured by being assembled in this order in the axial direction.

First, the first to third screw parts (10, 13,
16) is a screw segment incorporated in the screw set 4, and is provided with two spiral blades, one of which is shown in the sectional view taken along the line AA ′ of FIG. The tip of the spiral blade (the tip 14a is shown in FIG. 3) and the inner wall 6a of the chamber 6 are provided so as to be close to each other so that the gap becomes small. It can be extruded without leaking. The two screw sets 4 rotate in the same direction as shown by the arrows in FIG.
Is pushed to the right side of. By the way, supply port 3
Directly above the first screw portion 10, the openings 9a and 9a
b is provided so as to be located directly above the second screw portion 13 and the third screw portion 16, respectively.

Next, the kneading blade portion will be described. The first kneading blade portion 11 and the second kneading blade portion 14 are respectively incorporated in the screw set 4 so as to be positioned immediately downstream of the first screw portion 10 and the second screw portion 13.
The segment members that form these kneading blades are a plurality of kneading rotor segments (hereinafter, simply referred to as "kneading rotors") having a twist angle in the direction of pushing the object to be kneaded downstream.
Are assembled in the axial direction. That is, an example is shown in which three kneading rotors are combined in the first kneading blade portion 11, and five kneading rotors are combined in the second kneading blade portion 14. The first kneading blade portion 11 and the second kneading blade portion 11
The mating surfaces of the most upstream side of the kneading blade part 14 and the most downstream side of the first screw part 10 and the second screw part 13 should be superposed in substantially the same shape (so that they have the same phase).
Are combined. As a result, it is possible to prevent the object to be kneaded from staying in the gap between each screw section and each kneading blade section, and prevent the screw section and the kneading blade section from interfering with each other.

Each kneading rotor (11a to 11c, 14a to 14e) incorporated in the kneading blade portion (11, 14) is provided with two spiral blades formed so as to have a constant twist angle ψ. ing. By using this two-blade kneading rotor, a strong shearing force can be applied to the object to be kneaded, and even in the case of highly viscous rubber or rubber-based composition, the viscosity and the dispersity of the compounding agent can be adjusted. It is possible to realize a continuous kneading process capable of

The twist angle means the screw set 4
The tangent line toward the spiral direction at the apex of the spiral blade formed so as to advance in the axial direction while traveling along the circumferential direction and the axial direction are angles formed by being projected on a plane parallel to the axis. In addition,
1 shows an example in which the twist angle of the first kneading blade portion 11 and the twist angle of the second kneading blade portion 14 are the same ψ, but different twist angles may be formed. For example,
By setting the twist angle of the second kneading blade portion 14 on the downstream side to be smaller than the twist angle of the first kneading blade portion 11 on the upstream side, the discharge action of the kneading target is promoted on the downstream side, On the side, the kneading efficiency can be improved by making it easy to fill the object to be kneaded. However, it is important to prevent the twist angle from pushing the kneading target back to the upstream side.

Here, the kneading rotor used in this embodiment will be described in more detail. FIG. 5 shows a front view (FIG. 5A) and a side view (FIG. 5B) of one kneading rotor R (for example, the kneading rotor 11a). As shown in the figure, a shaft hole 18 is formed in the kneading rotor R, and the shaft of the screw set 4 is inserted into the shaft hole 18, whereby the kneading rotor R is incorporated into the screw set 4. Be done.

As shown in FIGS. 5A and 5B, the tops 1 of the two spiral blades formed on the kneading rotor R are formed.
9 has a shape that is partially cut away. The cutout portion constitutes the low-order tip portion 19b, and the portion other than the cutout portion constitutes the high-order tip portion 19a.
That is, the high-rank tip portions 19a and the low-rank tip portions 19b are axially sectioned and alternately formed.

In the lower chip portion 19a, the higher chip portion 1
It is formed so that the distance from the axial center to the top portion 19 is shorter than that of 9b. Then, when the high-level tip portion 19a is formed on one apex portion 19 of the two spiral blades at the same axial position, the low-level tip portion 19b is formed on the apex portion 19 of the other spiral blade. With this configuration, wide tip clearances and narrow tip clearances are alternately formed between the chamber inner wall 6a and the kneading rotor R, as will be described later.

As shown in FIG. 1, the respective kneading rotors R described above are axially combined to form the segment members of the first kneading blade portion 11 and the second kneading blade portion 14. . The kneading rotors (11a, 11
(b, ...) are combined such that the spiral blades are continuously arranged in the spiral direction in the axial direction.

Further, both the first kneading blade portion 11 and the second kneading blade portion 14 are provided with spiral blades having a length equal to or larger than the screw set outer diameter D (shown by double-ended arrows on the left side of FIG. 1).
Then, both the first kneading blade portion 11 and the second kneading blade portion 14,
It is configured to have a screw lead of 5 times or more the outer diameter D of the screw set (that is, a length of 5 D or more).

As one of the sectional views of the kneading blade portion, a sectional view taken along the line BB 'in FIG. 3 is shown. As is well understood in this figure, the biaxial screw set 4 is used. The kneading rotor 14c provided (as well as other kneading rotors) is adapted to rotate in mesh with each other in the same direction (the rotation direction is indicated by an arrow in the figure). Then, as described above, the kneading rotor 14c is formed with two spiral blades, the high-order tip portion 19a is formed on one spiral blade top portion, and the low-order tip portion 19b is formed on the other spiral blade top portion. ing.

The size of the tip clearance 20a formed between the high-ranking tip portion 19a and the chamber inner wall 6a is relatively small as they approach each other (hereinafter, referred to as "narrow").
"Narrow tip clearance 20a"). 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 (hereinafter, "wide tip clearance 20b").
That).

First kneading blade portion 11 and second kneading blade portion 14
Has a configuration in which the notch portion is provided as described above. Therefore, since the object to be kneaded easily passes through the wide tip clearance 20b, a part of the material is moved toward the blade surface of the other blade. On the other hand, the narrow tip clearance 20a facilitates the kneading while sending the material to the downstream side. Therefore, it is possible to prevent the object to be kneaded from being unevenly distributed in the chamber 6 and to stay therein, and it is possible to uniformly hold the screw set 4 in the chamber 6. Therefore, it is possible to suppress the occurrence of wear and the like due to the contact between the barrel 5 and the screw set 4, and prevent the shortening of the equipment life. Then, sufficient kneading work can be applied to the object to be kneaded.

Further, by providing the notch portion, the flow state of the kneading object in the chamber 6 can be complicated, and the mixing and dispersing of the compounding agent can be efficiently performed. Furthermore, since the length of the spiral blade is equal to or more than the screw set outer diameter D, the effect of preventing uneven distribution of the object to be kneaded and the effect of efficient mixing of the compounding agent can be stably exhibited.

Further, since the screw lead of the kneading blade portion is 5 times or more of the screw set outer diameter D, the object to be kneaded is filled in the chamber 6 and is sufficient for stably holding the screw set 4. The filling section length can be secured.

Finally, referring to FIG. 1, the first kneading disc portion 12 and the second kneading disc portion 15 which are the segment members remaining in the screw set 4 will be described. The first kneading disc portion 12 and the second kneading disc portion 15 are respectively incorporated in the screw set 4 so as to be located immediately downstream of the first kneading blade portion 11 and the second kneading blade portion 14. The segment member forming the kneading disc portion is configured by a plurality of kneading disc wings (hereinafter, simply referred to as “kneading disc”) being combined in the axial direction. That is, an example is shown in which the first kneading disc portion 12 and the second kneading disc portion 15 are combined with five kneading discs.

Each kneading disk (12a-12)
e, 15a to 15e) are cross-sectional shapes of the kneading rotor or screw segment (see FIGS. 3 and 4).
Is formed as an axially short segment having two cross-sections having substantially the same cross-sectional shape and a top portion formed parallel to the axis.

Then, the first and second kneading blade portions (11, 1)
4) The most downstream side of the first and second kneading disc parts (12, 15) and the most upstream side of the second and third screw parts (13, 16). The mating surfaces of the first and second kneading disk parts (12, 15) with the most downstream side are combined so as to be superposed in substantially the same shape (in phase). As a result, the object to be kneaded stays in the gap between each kneading blade portion and each screw portion or each kneading blade portion, and the screw portion or kneading blade portion and the kneading disc portion interfere with each other. Can be prevented.

In the first and second kneading disc portions (12, 15), the plurality of kneading discs (12a-12a, 15a-15e) each have an axial sectional shape of 90 ° with respect to the axial center. It is staggered alternately and combined in the axial direction. Here, the segments (12a, 15a) on the most upstream side of the first and second kneading disc portions (12, 15) are, as described above, the first and second kneading blade portions (11, 14), respectively. They are combined so that the axial cross-sectional shape changes continuously. However, since the segments (12b, 15b) whose 90 ° axial cross-sectional shapes are displaced are combined on the downstream side,
First and second kneading disc parts (12, 15)
Has a portion whose axial cross-sectional shape changes discontinuously. That is, the first and second kneading blades (11, 14)
On the downstream side is adjacent to another segment member having a portion whose axial cross-sectional shape changes discontinuously.

The first and second kneading discs (1
2, 15) in each segment (12a-12e, 1
5a to 15e) are combined by shifting the phase by 90 ° as described above. If the phase difference is gradually provided so that the object to be kneaded is fed by the rotation of the screw set 4 instead of the phase difference of 90 °, the object to be kneaded is not sufficiently filled in the upstream side and the downstream side is not filled. Will be sent to. In this case, sufficient kneading work is not given to the object to be kneaded. Further, if a phase difference is gradually provided so that the object to be kneaded is returned by the rotation of the screw set 4, this time, the object to be kneaded will be excessively filled on the upstream side thereof. As described above, the problem that the kneading target remains without being discharged to the end and the problem that the temperature becomes too high will be induced. However, by setting the phase difference of 90 °, the first and second kneading disk parts (12, 15) themselves act only as a material transport resistance, and a feeding action and a returning action to the object to be kneaded may occur. Absent. Therefore, it is possible to surely fill the object to be kneaded so as to block the required amount.

By changing the axial lengths of the first and second kneading disc parts (12, 15) and the number of segments to be incorporated, the first and second kneading blade parts (11, 14) on the upstream side. It is possible to appropriately adjust the amount of the object to be kneaded to fill the side. In this case, it is desirable that the axial length of the first and second kneading disc portions (12, 15) is 1/2 or more of the screw set outer diameter D. As a result, the effect of blocking the required amount of the kneading target can be stably achieved.

FIG. 2 is a schematic view showing that the first screw part 10, the first kneading blade part 11, the first kneading disk part 12, and the second screw part 13 are incorporated into the screw set 4 as segment members. Is shown in. As can be understood from this figure, the first screw section 10 and the first kneading blade section 11, the first kneading blade section 11 and the first kneading disk section 12, the first kneading disk section 12 and the second screw section. 13 continuously change, but in the first kneading disc portion 12 adjacent on the downstream side of the first kneading blade portion 11, a portion (segment 12a and segment Between 12b)
Is provided.

The above is the configuration of the kneading device 1 according to the present 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 the object to be kneaded, which is molded into a sheet, is fed to the kneading device 1 which is a twin-screw kneading extruder by the rubber feeding device 2 and the like. Supplied with. The object to be kneaded is supplied from the supply port 3 into the chamber 6.

At this time, in the chamber 6, the pair of screw sets 4 are meshed and rotated in the same direction by the drive unit 7 (see FIGS. 3 and 4). Then, the object to be kneaded supplied into the chamber 6 is extruded toward the first kneading blade portion 11 side by the two-blade spiral blades provided in the first screw portion 10.

The object to be kneaded extruded to the first kneading blade portion 11 side is conveyed to the downstream side while undergoing the kneading action between the first kneading blade portion 11 and the chamber inner wall 6a. At this time, due to the presence of the portion of the first kneading disc portion 12 adjacent to the first kneading blade portion 11 on the downstream side and having the discontinuous axial cross-sectional shape, the kneading target to be conveyed to the downstream side is provided. On the other hand, the conveyance resistance acts. As a result, the object to be kneaded is filled between the first kneading blade portion 11 and the chamber inner wall 6a so as to be appropriately retained. Then, the filled kneading object is kneaded so as to be sufficiently mixed and dispersed in the tip clearances (20a, 20b) by being flowed and given a shearing force.

At this time, the first kneading disc portion 1
Since the object to be kneaded can be filled with the required amount in the discontinuous portion of 2, the object to be kneaded is not pushed back to the upstream side, and excessive retention does not occur. Therefore, the problem that the object to be kneaded easily remains in the chamber 6 even after the kneading and the problem that the temperature is high and the rubber material is easily deteriorated or the kneading efficiency is lowered are unlikely to occur. In addition, the spiral blade top portion 1 of the first kneading blade portion 11
Since the cutout portion 9 is provided in the chamber 9, as described above, the problem that the object to be kneaded is unevenly distributed and accumulated in the chamber 6 and the life of the kneading device is shortened is unlikely to occur.

The object to be kneaded by the first kneading blade portion 11 passes through the first kneading disk portion 12 and is further extruded to the downstream side by the second screw portion 13. The object to be kneaded extruded to the downstream side by the second screw portion 13 reaches the second kneading blade portion 14. And the first
The second kneading blade portion 14 and the second kneading disc portion 15 add the same action as the action received by the kneading blade portion 11 and the first kneading disc portion 12. The object to be kneaded that has passed through the second kneading disc portion 15 is further pushed to the downstream side by the third screw portion 16, and finally, as the kneaded material, the tip portion 5a is formed.
Emitted from.

Here, in order to describe the effects of the present invention in more detail, the present invention will be described in more detail with reference to Examples. The embodiments described below are merely examples of application of the present invention.

(Example) In this example, in the kneading apparatus 1 (see FIG. 1) which is the twin-screw kneading extruder according to the above-described embodiment, only one kneading blade portion and one kneading disk portion are provided. A kneaded product manufacturing experiment was conducted with a screw blade configuration. The kneading device 1 has a screw diameter of 5
The ratio (L / D) between the length of the screw set 4 and the screw set outer diameter D was 9 mm, and L / D was 10.8. During continuous kneading, cooling water is introduced into the cooling liquid passage 8 provided in the barrel 5 to perform kneading while adjusting the temperature so that the barrel temperature is kept substantially constant at around room temperature. The kneaded product was discharged from the tip 5a of No. 5 in the form of a lump.

The screw rotation speed was 300 rpm,
The temperature of the object to be kneaded (rubber material) to be supplied is 25 ° C., the supply rate is 200 kg / hr, the Mooney viscosity decrease value and the temperature after kneading (the temperature of the kneaded material immediately after being discharged from the tip portion 5a) and the second The amount of screw deflection of the screw part was measured (experimental condition). For comparison, a kneaded product was produced by a kneading machine using a rotor having a screw lead of 3D and not having a notched top (experimental condition). A rotor having a screw lead of 3D and not having a notched top was used. , Production of kneaded material by kneading device using kneading disc in feed direction (experimental condition), kneading device using kneading disc in returning direction, using rotor with 3D screw lead and notched top The kneaded product was produced (experimental condition) according to the above, and the Mooney viscosity decrease value and the kneaded product temperature were measured in the same manner as the experimental condition. The experimental results are shown in Table 1 below.

[0053]

[Table 1]

As shown in Table 1, the experimental conditions using the return kneading disk have the highest kneading degree (the Mooney viscosity lowering value) and the smallest screw runout amount, but the material temperature is high, and in some cases, the material deterioration may occur. . Moreover, a large amount of residual material is generated, which makes it difficult to adopt. On the other hand, under the experimental conditions using the feed kneading disc, the material temperature is the lowest because the material retention amount is small, but the kneading degree is small, the screw runout amount is large, and there is little advantage to be adopted. The experimental conditions using the kneading disc with the phase shifted to 90 ° and the favorable values for both the temperature and the kneading degree were obtained. The temperature and Mooney viscosity decrease value can be adjusted by the kneading blade length and rotation speed,
The amount of screw runout, which is difficult to adjust under these operating conditions, is small under experimental conditions. Therefore, it can be judged that the experimental conditions are the best, and the effectiveness of the present invention can be confirmed.

Each constituent winglet of the kneading disk section is
If it is thin, the stirring ability and conveyance resistance will increase, but mechanical rigidity is required, so it is generally 0.1D-0.3.
It is produced in about D. In the example, five 0.2D winglets are used.
Although used in combination with one another, functionally, a phase discontinuous surface can be formed with a minimum of two. However, it is considered that about 5 sheets are required to realize sufficient conveyance resistance. Also,
Since it is expected that basically the same performance will be achieved even with a small wing of 0.1D, it is estimated that a minimum kneading disk length of 0.5D or more is sufficient.

The above is the description of the kneading apparatus 1 according to the present embodiment. According to the kneading apparatus 1, it is possible to prevent the object to be kneaded during the kneading from staying excessively in the chamber, and to sufficiently perform the operation. It is possible to provide a kneading device for rubber or rubber-based composition capable of imparting kneading work.

The embodiment is not limited to the above, but may be modified as follows.

(1) In the present embodiment, an example in which a kneading rotor having two blades is used is shown, but the same applies to a kneading rotor having three blades. The present invention can be applied.

(2) In the present embodiment, the first and second kneading blades are provided, but this need not always be the case, and one or three or more kneading blades may be provided. The present invention can be applied.

(3) In this embodiment, an example in which three kneading rotors are incorporated in the first kneading blade portion and five kneading rotors are incorporated in the second kneading blade portion is shown, but this is not always the case. The present invention can be applied even if various numbers are incorporated.

(4) The shape of the cutout portion formed on the top of the spiral blade of the kneading rotor is not limited to that shown in FIG. 5, but various shapes (length and position of the cutout portion,
The present invention can be applied by selecting the number, the height of the chip portion, etc.).

(5) In this embodiment, another segment member adjacent to the kneading blade on the downstream side and having a portion whose axial cross-sectional shape changes discontinuously has a plurality of kneading discs as an example. However, the present invention is not necessarily limited to this. For example, it may be a screw portion having a spiral blade formed so that a discontinuous portion can appear.

[0063]

According to the invention of claim 1, the kneading blade portion comprises:
Since it is adjacent to another segment member that has a portion whose axial cross-sectional shape changes discontinuously on the downstream side, the discontinuous portion acts as conveyance resistance, and the object to be kneaded fills the upstream side of this discontinuous portion. become. Sufficient kneading work is imparted to the object to be kneaded thus filled by the kneading blade portion. On the other hand, since the object to be kneaded can be filled with the required amount so as to be blocked at the discontinuous portion, the object to be kneaded is not pushed back to the upstream side and excessive retention does not occur. Therefore, it is unlikely to cause a problem that the object to be kneaded remains in the chamber even after the kneading, or a problem that the temperature is high and deterioration of the rubber material and deterioration of the kneading efficiency are likely to occur. Further, since the spiral blade top portion of the kneading blade portion is provided with the notch, the object to be kneaded easily passes through the notch portion, and the kneading is promoted in the portion without the notch. That is, in the portion without the notch, sufficient kneading work can be given to the object to be kneaded, and by providing the notch portion, the flow state of the object to be kneaded in the chamber is complicated. It is also possible to efficiently carry out dispersion mixing and distribution mixing of the compounding agent. Furthermore, since the length of the spiral blade is equal to or larger than the screw set outer diameter, the effect of preventing uneven distribution of the object to be kneaded and the effect of efficient mixing of the compounding agent can be stably exhibited. Therefore, it is possible to provide a kneading device of rubber or a rubber composition capable of preventing the object to be kneaded during the kneading from staying excessively in the chamber and imparting sufficient kneading work.

According to the invention of claim 2, since the screw lead has a length of 5 times or more the outer diameter of the screw set (because the screw lead is 5D or more), the extrusion direction of the kneading material is larger than that of a general screw. It is possible to secure a sufficient filling part length for the object to be kneaded to be filled in the chamber and the screw set to be stably held, because the feeding force is weak. Therefore, it is possible to prevent problems such as wear and the like due to contact between the barrel and the screw set, which shortens the life of the equipment.

According to the third aspect of the present invention, since the plurality of segments are combined by shifting the axial sectional shapes by 90 ° alternately with respect to the axial center, the segment member itself also feeds the object to be kneaded. There is also no return action. Therefore, it is possible to surely fill the object to be kneaded so as to block the required amount. The length of the other segment member is 1 / outer diameter of the screw set.
When there are two or more, the effect of blocking a required amount of the kneading target can be stably achieved.

[Brief description of drawings]

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

FIG. 2 is a partial schematic view of a kneading device for a rubber-based composition according to the present embodiment as seen from a side surface.

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

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

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

[Explanation of symbols]

1 kneading device 4 screw set 5 barrels 6 chambers 6a Chamber inner wall 8 Coolant path 11 First kneading blade 11a-11c Kneading rotor 12 1st kneading disc 12a to 12e kneading disc segment 14 Second kneading blade 14a to 14e Kneading rotor 15 Second Kneading Disc 15a to 15e kneading disc segment 19 spiral wing top 19a Higher chip section 19b Lower chip part R kneading rotor

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ identification code FI theme code (reference) B29B 7/46 B29B 7/46 F term (reference) 4F201 AA45 AB00 BA01 BC02 BK02 BK13 BK14 BK26 BK36 BK38 BK40 BK48 BK49 BQ52 4G035 AB48 AE13 AE15 4G037 AA03 CA03 EA03 4G078 AA26 AB07 BA01 BA07 BA09 CA01 CA05 CA12 CA17 DA09 DA17 DA28 DA30 EA03 EA10

Claims (3)

[Claims] 1. A desired object to be kneaded, which is made of rubber or rubber to which various compounding agents are added, is flowed and shearing force is applied to masticate the rubber or to accelerate the dispersion mixing and distribution mixing of the compounding agents. 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 which is a cylindrical hollow portion; and (2) a barrel formed inside the barrel, A cooling path provided in the periphery, and (3) a biaxial screw set that pushes to the downstream side while kneading by shearing the object to be kneaded by rotating in the chamber.
(4) A kneading blade portion that is incorporated as a segment member in the axial direction of the screw set and performs kneading in a space formed between the chamber inner wall and the chamber inner wall, and the kneading blade portion has a top portion partially cut. It is provided with a spiral blade having a length not less than the screw set outer diameter in the axial direction and adjacent to another segment member having a portion whose axial sectional shape changes discontinuously on the downstream side. A kneading device for rubber or a rubber composition, which is characterized. 2. The kneading device for rubber or rubber-based composition according to claim 1, wherein the kneading blade portion has a screw lead having a length of 5 times or more the outer diameter of the screw set. 3. The other segment member adjacent to the kneading blade portion on the downstream side has an outer diameter of 1 of the screw set in the axial direction.
A plurality of segments each having a length equal to or greater than ½ and having a blade whose top is formed parallel to the axis are combined by alternately shifting the axial cross-sectional shapes by 90 ° with respect to the axial center. The kneading device for rubber or rubber-based composition according to claim 1 or 2.