JPH06285349A - Hermetic type kneading machine - Google Patents

Abstract

PURPOSE:To impart adequate shearing force to materials and to speed up fine segmentation so as to improve kneading performance by specifying the spacings between the outer peripheral end faces of the vane parts of respective rotors and the inside wall surface of a chamber, i.e., the ratio between a chip clearance and the bore of the chamber. CONSTITUTION:This kneading machine 1 consists of a casing 2, the chamber 3 for kneading closed by an end frame, two pieces of a pair of the vaned rotors 4A, 4B which are formed parallel with each other in this chamber and rotate reverse from each other, a material insertion ram 3 which is freely removably inserted into a material supply port 5 at the center in the central part of the chamber 3 and an opening/closing door 8 which is inserted freely removably into a similar kneaded matter discharge port 7. The casing 2 communicates both rotors 4A and 4B with each other over the entire part. The specified spacings S are formed between the inside wall surface of the chamber 3 and the outer peripheral surfaces in the vane parts of the rotors 4A, 4B, i.e., land surfaces 10. The kneading in a short period of time is made possible if the ratio S/D between the spacings S and the bore D of the chamber 3 is set at 0.1 to 0.02.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade type meshing type (batch type) kneader used for kneading a polymer material such as a rubber material.

[0002]

2. Description of the Related Art Generally, a polymer material, which is a raw material for tire products and general industrial products, is mixed with a compounding agent such as carbon or an oil during a process called a masterbatch for uniform physical properties of different materials. A closed kneader is used. There are a tangential type and an intermeshing type in this kind of closed type kneader, and as the intermeshing type kneader, those exemplified in FIGS. 7 to 10 are known.

A kneading machine (conventional example 1) shown in FIG. 7 is disclosed in Japanese Utility Model Laid-Open No. 63-136908, and has a kneading chamber 22 inside which is closed by a casing 21 and an end frame (not shown). A pair of bladed rotors 23 are arranged in the chamber 22 so as to be parallel to each other and rotatable in opposite directions, and a communicating portion 24 is formed between the rotors 23 over the entire length of the chamber 22. , In the center of the chamber 22 corresponding to the communication portion 24,
The material supply popper 25 is formed on the upper side so that the material pushing ram 26 can be freely inserted and removed, and the discharge port 2 for the kneaded material is provided on the lower side.
7 is provided so that the door 28 can be inserted and removed freely.

Although not shown, the rotor 23 is provided with a main wing and an auxiliary wing, and the auxiliary wing is arranged at the center of the rotor so as to be able to synchronize with the main wing of the counterpart rotor. The kneading machine (conventional example 2) shown in FIG.
The main configuration is the same as that of the conventional example 1 in FIG. 7, but a plurality of pins 29 are arranged on the body blades of both rotors 23 to take in the material into the chamber 22. I try to increase the ability (feeding ability).

Kneading machine shown in FIGS. 9 and 10 (conventional example 3)
Is disclosed in Japanese Examined Patent Publication No. 63-1093, and its main configuration is the same as that of the conventional example 1 in FIG.
The ratio of the length L to the chamber inner diameter D is 1.25 ± 0.1,
The ratio of the length 1 of the main wing 30 to the rotor length L is 0.5 to 0.
7. The ratio of the length a of the bladeless part to the rotor length L is 0.1.
5 to 0.35, the blade twist angle θ is 55 ° ± 5 °, and the ratio between the tip clearance S and the chamber inner diameter D is 0.0275.
It is set to ± 0.0075, and it is intended to make the temperature distribution uniform and accelerate the heat transfer by accelerating the movement of the material.

It is said that the intermeshing type kneading machine is inferior in productivity to the tangential type kneading machine, and is designed based on the ratio S / D of the tip clearance S and the chamber inner diameter D. Therefore, the material shearing force between the rotors 23 is restricted by the ratio S / D.

[0007]

In the above-mentioned prior art, the material digging ability is inferior to that of the tangential type kneader. This is due to the small gap between the rotors, but it is necessary for the material digging. If the time, that is, the ram sheet time is increased, there is a problem that the time for kneading all the input materials in the chamber is shortened and the variation between batches is increased. To overcome this problem, it is necessary to subdivide the material faster between the rotor and the chamber or between both rotors.

In Conventional Example 1, since the rotors have a small number of meshing portions that rotate with clearance, the subdivision ability between the rotors is inferior, and about 15% of the tangential type kneader is given to give the same energy. It takes a lot of time.
Further, in the conventional example 2, since the pin 29 is provided, the biting ability of the material can be enhanced to some extent, but the pin 29 is moved in the axial direction of the material in the material segmentation after the biting of the material and the carbon dispersion step. Since the flow and the flow in the direction of the opposite rotor are obstructed to form a stagnation portion, there is a high possibility that the material kneading becomes non-uniform due to partial internal heat generation or the like.

Further, in Conventional Example 3, the twist angle θ of the blade portion is
Is large, the force of flowing the material in the axial direction becomes large, the material flow between the left and right chambers is small, and the ratio S / D of the tip clearance S and the chamber inner diameter D cannot be made small, so that the tip clearance S becomes large. , Proper shear force between rotor and chamber cannot be expected,
Since it is necessary to secure the material biting ability, it is not possible to reduce the clearance between the blade and the counterpart rotor, and the shear force is small in any clearance, and the material subdivision ability is poor.

Further, in the prior art, in order to realize the low temperature kneading, the width of the blade is increased to design the cooling area of the rotor to be large, and the ratio S / D between the tip clearance S and the chamber inner diameter D is increased. However, the amount of power consumption is suppressed by reducing the generation of shearing force, and there is a problem in dispersibility even when kneading at low temperature is possible. The present invention has been made in view of the above situation, and an object thereof is to give an appropriate shearing force to a material between a rotor blade portion and a chamber to speed up subdivision and improve kneading performance. It is an object of the present invention to provide a closed kneading machine capable of improving the flow of the material in the chamber in the axial direction and between the left and right chambers and eliminating the uneven kneading of the material.

[0011]

In order to achieve the above object, the present invention takes the following technical means. That is, the invention of claim 1 has a material supply port in the upper part and a discharge port in the lower part, and each chamber is closed so that each port can be sealed, and the chamber is parallel to the chamber and rotatable. In a hermetic kneading machine comprising two pairs of bladed rotors arranged in a pair, the blades of the rotors meshing with each other, an outer peripheral end face of the blades of the rotor and an inner wall surface of the chamber. Ratio S of the gap S of the chamber to the inner diameter D of the chamber
The feature is that / D is set in the range of 0.01 to 0.02.

The invention of claim 2 is characterized in that the twist angle θ of the long blade of the rotor is less than 50 °. In the invention of claim 3, the ratio 1 / L of the long blade length l of the rotor to the axial length L in the chamber of the rotor is set to 0.6 or more, and the long blade tip and the rotor end of the rotor are The ratio (a / L) of the axial length a and the axial length L in the chamber of the rotor is set to 0.2 or less.

[0013]

According to the first aspect of the present invention, an appropriate shearing force acts on the material between the inner wall surface of the chamber and the land surface of the rotor blade portion to accelerate the subdivision of the material and cause abnormal heat generation. It becomes possible to knead in a short time. According to the invention of claim 2, the flow in both the axial direction and the direction between the left and right chambers in the chamber is averaged without being biased to one side, and uneven kneading is eliminated.

According to the invention of claim 3, the flow of the material in the chamber is smoothly branched at the end portion in the axial direction of the rotor, the kneading unevenness is eliminated, and the kneading performance is improved.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the present invention, in which a kneading machine 1 is used.
Is a kneading chamber 3 closed by a casing 2 and an end frame (not shown), and a pair of bladed rotors 4A, 4B arranged in the chamber 3 so as to be rotatable in parallel and in opposite directions. And a material pushing ram 6 which can be inserted into and removed from a material supply port 5 provided in the upper center of the chamber 3, and an openable door which can be inserted into and removed from a kneaded material discharge port 7 provided in the lower center of the chamber 3. 8 and the chamber 3 can be closed or opened by the ram 6 and the door 8.

The casing 2 includes both rotors 4A and 4B.
A communication portion 9 is provided so that the spaces communicate with each other over the entire length of the chamber 3. A constant clearance (chip clearance) S is formed between the inner wall surface of the chamber 3 and the outer peripheral surface of the blades (also referred to as chips) of the rotors 4A and 4B, that is, the land surface 10. The ratio S / D between the gap S and the inner diameter D of the chamber 3 is set in the range of 0.01 to 0.02.

The rotor 4A has long blades 11, auxiliary blades 12 and two short blades 13, as shown by the solid line in FIG.
The two short blades 13 are twisted in opposite directions, and each of the blades 11 to 1
The twist angles θ of 3 are the same, but less than 50 °. As shown by the dotted line in FIG. 2, the rotor 4B has long blades 14 and auxiliary blades 15, the twist angle θ is the same as that of each of the blades 11 to 13 of the rotor 4A, and the twist direction is opposite. The long wings 11 and 14 are meshed with each other.

The long blades 11 of both rotors 4A and 4B are
14 has the same axial length l, and the rotor 4
The ratio 1 / L with the length L of A and 4B is set to 0.6 or less, and the axial length a of the bladeless portions at both axial ends of the long blades 11 and 14 (that is, the distance from the rotor end). The ratio a / L of the length L of the rotors 4A and 4B is 0.2 or less. Also,
The lengths of the auxiliary blades 12 and 15 of both rotors 4A and 4B are the same, and are 1/2 or less of the length L of rotors 4A and 4B.

The reason for setting the ratio S / D between the tip clearance S and the chamber inner diameter D in the range of 0.01 to 0.02 is that when the ratio S / D is less than 0.01, the shearing force of the material is reduced. However, if the ratio S / D is made larger than 0.02, the tip clearance S becomes large and the shearing force cannot be obtained. Also,
The reason why the twist angle θ of each blade of the rotors 4A and 4B is less than 50 ° is that when θ exceeds 50 °, the force of flowing the material in the axial direction increases due to the rotation of the rotors 4A and 4B, and
This is because the flow between A and 4B, that is, between the left and right chambers 3 becomes poor, and uneven kneading of the material occurs.

Then, the long blades 11 of each rotor 4A, 4B,
The kneading effect is obtained by setting the length l of 14 and the ratio l / L, a / L of the axial length a to the rotor end and the axial length L of the rotor to 0.6 or more and 0.2 or less. In addition, the flow of the material is branched from both ends of the long blades 11 and 14, so that the material can be taken in smoothly and in a short time, and uneven kneading in the chamber 3 can be eliminated.

In the above embodiment, the fixed amount of the material and the compounding agent fed from the material supply port 5 are pushed into the chamber 3 by the pushing ram 6 between the rotors 4A and 4B rotating in the opposite directions. From the time when all the materials are taken in and pushed into the chamber 3 by the ram 6, the blades 11 to 15 of both rotors 4A and 4B start uniform kneading of the entire material.

Then, a certain optimum shearing force acts between the material and the inner wall surface of the chamber 3 of the rotors 4A and 4B and between the rotors 4A and 4B, and the temperature becomes appropriate. Depending on the optimum length and the distance from the rotor end, the distribution in the axial direction and between the rotors 4A and 4B is carried out on average, and the kneading is speeded up and evenly and efficiently carried out. Further, since the material take-in time is shortened and the kneading performance is improved, the kneading time can be shortened and the productivity can be improved.

3 to 6, the S / D is 0.014,
The kneading machine of the present invention in which θ is 40 °, l / L is 0.7, and a / L is 0.15, and Conventional Example 1 or Comparative Example (using a rotor having a twist angle θ of 50 ° in the example of the present invention) 3 shows the results of a kneading test of a tire compounding material (NBR-based carbon masterbatch) according to. As is apparent from FIG. 3, the degree of decrease in Mooney viscosity with respect to the kneading time is faster in the present invention than in Conventional Example 1, and the specific energy with respect to the kneading time is also in the present invention as shown in FIG. Faster than Example 1,
It is clear that it is efficient. And the time required to take the material into the chamber 3 with respect to the material filling rate,
That is, as shown in FIG. 5, the ram sheet time (seconds) of the present invention is faster than that of the comparative example, and the Mooney viscosity of the material with respect to the filling rate is lower than that of the comparative example as shown in FIG. It is clear that the kneading performance is good.

The present invention is not limited to the above embodiment, but may be, for example, a rotor without the short blades 13, a rotor with the short blades 13 provided on both rotors, and the auxiliary blades 12, The twist angle θ of 15 does not have to be the same as that of the long blades 11 and 14, and the design can be appropriately changed.

[0025]

As described above, according to the present invention, in the hermetic kneader, the ratio S / D between the tip clearance S and the chamber inner diameter D, which is the gap between the outer peripheral end face of each rotor blade and the chamber inner wall surface, is set. Since it is set in the range of 0.01 to 0.02, an appropriate shearing force is applied to the material between each rotor blade and the chamber inner wall surface, the subdivision is accelerated, and the material feeding ability is increased. The kneading performance can be improved.

Further, in the present invention, since the twist angle θ of the long blades of each rotor is set to less than 50 °, the material flow in the chamber becomes uniform both in the axial direction and in the direction between both rotors, resulting in uneven kneading. It can be lost. Further, in the present invention, the ratio 1 / L of the long blade length l of each rotor and the axial length L of the rotor in the chamber axial direction is set to 0.6 or more, and the axis between the long blade tip and the rotor end of the rotor is set. Since the ratio a / L of the length a in the direction of the rotor and the length L in the axial direction of the rotor in the chamber is set to 0.2 or less, an effective kneading action by the long blades can be secured, and
The material flow can be optimally branched from the gap at the axial end of the long blade, the kneading unevenness can be eliminated, and the material pushing capacity and the kneading performance can be improved.

[Brief description of drawings]

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

FIG. 2 is a developed plan view of a rotor in the embodiment.

FIG. 3 is a graph showing the relationship between the material kneading time and the Mooney viscosity in the material kneading tests of Example of the present invention and Conventional Example 1.

FIG. 4 is a graph showing the relationship between material kneading time and specific energy in the material kneading test of the same example and Conventional Example 1.

FIG. 5 is a graph showing a relationship between a material filling rate and a ram sheet in a material kneading test of the example and the comparative example.

FIG. 6 is a graph showing the relationship between the Mooney viscosity and the material filling rate in the material kneading tests of the same example and the comparative example.

FIG. 7 is a vertical sectional view showing Conventional Example 1.

FIG. 8 is a vertical sectional view showing a second conventional example.

FIG. 9 is a vertical sectional view showing Conventional Example 3.

FIG. 10 is a plan view showing a rotor of Conventional Example 3.

[Explanation of symbols]

 1 Closed Kneader 3 Chamber 4A Rotor 4B Rotor 5 Material Supply Port 7 Discharge Port 10 Outer Blade End Face 11 Long Blade 12 Auxiliary Blade 13 Short Blade 14 Long Blade 15 Auxiliary Blade D Chamber Inner Diameter L Rotor Chamber Axial Length S Gap (tip clearance) a Axial length between long blade tip and rotor end l Axial length of long blade θ Long blade twist angle

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sumio Hayashida 2-3-1, Niihama, Arai-cho, Takasago-shi, Hyogo Inside Takasago Works, Kobe Steel, Ltd. (72) Katsunobu Hagiwara 2-chome, Niihama, Arai-cho, Takasago-shi, Hyogo No. 3-1 Takasago Works, Kobe Steel, Ltd.

Claims (3)

[Claims] 1. A chamber having a material supply port in the upper part and a discharge port in the lower part, each port being closed so as to be hermetically sealed, and arranged in the chamber in parallel and rotatable with each other. In a hermetic kneader comprising two pairs of bladed rotors, the blades of the rotors meshing with each other, a gap S between the outer peripheral end surface of the rotor blades and the chamber inner wall surface , Ratio of chamber inner diameter D to S
/ D is set in the range of 0.01 to 0.02. 2. The twist angle θ of the long blade of the rotor is 50 °.
The closed type kneading machine according to claim 1, wherein the amount is less than 1. 3. A ratio 1 / L of the length 1 of the long blade of the rotor and the axial length L in the chamber of the rotor is set to 0.6 or more, and the long blade end of the rotor and the rotor end are arranged in the axial direction. 3. The hermetic kneading machine according to claim 1, wherein the ratio (a / L) of the length a to the axial length L of the rotor in the chamber is 0.2 or less.