JPH035209B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention is applicable to each step of the kneading process in an internal kneading machine such as a batch-type Banbury mixer used for kneading rubber, plastic, etc. with additives. The present invention relates to the provision of a new kneading technology that allows optimum kneading contents to be obtained in response to the above.

(Prior Art) Internal kneading machines such as batch-type Banbury mixers used for kneading plastic materials such as rubber and plastics with necessary additives are well-known, needless to be exemplified, but their mechanism and The contents are as follows. In FIG. 1 and FIG. 6, a kneading chamber 1 equipped with a rotor 1a and a rotor 2 are shown.
The kneading chambers 2 equipped with the kneading chambers a are of a closed type and are arranged parallel to each other in the axial direction and communicated with each other by a communication section 3 along the axial direction.
A material input port 4 is formed together with a pushing ram 5 as a pushing member in the upper part of the machine, and a material discharge port 7 with a discharge door 6 that can be opened and closed is formed in the lower part.
At this time, the rotors 1a and 2a are of both non-meshing type and meshing type. Further, the discharge door 6 has a door top 8 formed in a protruding manner within the communication portion 3 to divide the left and right kneading chambers 1 and 2. Although the protrusion height of the door top 8 is determined empirically, conventionally As shown in FIG. 3, it is formed integrally with the discharge door 6, and the determined height remains constant. The materials kneaded by such an internal kneader are kneaded in the following manner. That is, the target kneading material (for example, rubber carbon black, etc.) is introduced all at once from the material input port 4, the pushing ram 5 is lowered to push the material into the kneading chambers 1 and 2, and the rotors 1a and 2a are moved in opposite directions. The kneading is started by rotating the kneading chamber, and at the beginning of the kneading, the input materials are crushed and divided in the kneading chambers 1 and 2. At this time, when the input material is rubber, plastic, etc., the input material is initially a highly elastic or highly viscous body at room temperature, so an excessive kneading torque is generated, and the rotor 1a is moved to withstand this high peak torque. , 2a are required to have a high horsepower motor as a rotational drive source, and the strength of the kneading machine body must be correspondingly increased.
Furthermore, at the beginning of this kneading, in addition to the main materials such as rubber and plastic, various additives with low bulk density are also added, so the apparent volume of the material is large, and the material is kneaded by the pushing ram 5. It takes time to push the material into the chambers 1 and 2, and the crushing, crushing and exothermic state of the material at the initial stage of kneading and the mixing of additives into the main material are generally unstable. In order to quickly achieve good kneading, it is necessary to complete sufficient mixing (macroscopic dispersion) of the main material and additives at the early stage of kneading. It is desirable to actively move between the two. As the kneading further progresses, the additive is completely mixed into the main material, so the material volume naturally decreases. At this stage, the temperature of the material increases and the material becomes fluid, and the additives are dispersed (microdispersion) under fluid shear. There appears to be some accumulation on the door top 8 of the discharge door 6 in the communication section 3 between the discharge doors 1 and 2. In order to promote kneading, this stagnation is suppressed and effective kneading is performed in the left and right kneading chambers 1 and 2.
It is necessary to increase the material filling volume. Such a kneading process is stopped when a certain kneading energy or material temperature is reached, and the kneaded material is discharged from the material discharge port 7 by opening the discharge door 6.

(Problems to be Solved by the Invention) Problems with the internal kneading machine as described above, as seen in the kneading process already mentioned, include generation of excessive peak torque at the initial stage of kneading, crushing of materials, and crushing of materials. It is easy to cause unevenness in the state, heat generation state, and mixing of additives into the main material, etc.
Furthermore, the energy efficiency of kneading decreases due to the accumulation of materials that occurs as kneading progresses, and the microdispersion of additives becomes uneven.In the conventional type, the shape of the kneading chamber remains constant, so the above-mentioned problems occur. Solving the problems is extremely difficult.

(Means for Solving the Problems) In order to solve the problems with the conventional closed-type kneading machine described above, the present invention makes it possible to change the shape of the left and right kneading chambers during the kneading process. This system is designed to obtain appropriate kneading contents corresponding to the kneading process from the beginning to the final stage, and specifically, a pair of kneading chambers, each equipped with a rotor, are parallel to each other in the axial direction and communicate with each other. When kneading target materials using a closed-type kneading machine, which has a material inlet in the upper part of the communication part together with the pushing member and a material outlet in the lower part together with the discharge door, the target material is kneaded. To perform kneading while changing the height of a door top projecting into a communicating part of a door according to the kneading process.

(Function) According to the technical means of the present invention, as shown in FIG. 1 and FIG. A door top 8 protruding into the portion 3 is formed separately from the discharge door 6, and the door top 8 is provided on the discharge door 6 so that it can be vertically raised and lowered, for example, by a lifting means such as a hydraulic cylinder 9 and a piston 10.
By making the height of the door top 8 that protrudes into the communication section 3 variable, the shape of the kneading chamber including the communication section 3 can be made variable, thereby changing the kneading content in the kneading chamber depending on the kneading process. It is easily possible to change it appropriately. That is, by changing the height of the door top 8, it is possible to adjust the peak torque, speed up the kneading process, and moreover, achieve efficient kneading.

Figures 4 and 5 are experimental graphs showing that it is possible to reduce peak torque by lowering the door top height. The results are shown using a small experimental kneading machine with variable height. Figure 4 shows the case where a block-shaped material is used as the input material, and Figure 5 shows the result when a small piece-shaped material is used as the input material. The vertical axis shows the peak torque value, and the horizontal axis shows the height value of the door top 8. Also, the mark indicates the door top 8 whose upper end is round, the mark indicates the upper end of which is flat, and the mark indicates the height of the door top 8. The square shape is shown, but as is clear from the figure, all of them have a door top of 8.
It is possible to lower the peak torque by lowering the height of. In addition, by changing the height of the door top 8, the pushing ram 5 can be
Similar experimental results also show that the time required to lower the kneaded material to the lowest limit, the pulverized state of the main material for kneading at the initial stage of kneading, the state of additives mixed in, and the variation in the viscosity of the kneaded material within one batch, etc. Therefore, it was confirmed that each of them changes.
Therefore, by making the height of the door top 8 variable and changing the height of the door top 8 as needed according to the kneading process, it is possible to provide more efficient kneading in a shorter time. For example, when adding carbon black or the like as an additive to rubber, which is the main material, the power normally changes over time as shown in FIG. In the figure, the vertical axis shows power and the horizontal axis shows time. Starting from the input of materials, the rubber crushing process is carried out, and parallel to this, the additive mixing process begins, and then the additive dispersion process continues. ,
A series of kneading processes is completed, and the power change process corresponds to each process in the kneading process.

Therefore, first, the height of the door top 8 is set to the lowest limit, rubber and additives are introduced into the material input port 4, and the pushing ram 5 is lowered to push the materials into the kneading chambers 1 and 2. At this time, since the door top height is low, kneading is started at a low power peak. At the same time, since the kneading chamber space is wider, the push-in ram 5 descends more quickly than when the door top height is high, and the active movement of rubber crushing and additives between the left and right kneading chambers 1 and 2 is promoted well. It is. In this way, the rubber becomes pulverized and the material temperature increases,
When the power decreases to a certain extent, the height of the door top 8 can be increased and the space of the communication section 3 directly above it can be narrowed to strongly increase the effect of mixing additives in the left and right kneading chambers 1 and 2. It is. Furthermore, after a suitable period of time has elapsed, the door top 8 is lowered again to widen the space in the communication section 3, thereby increasing the movement of each material in the left and right kneading chambers, thereby promoting overall mixing. Following this, the door top 8 is raised again, and in order to further enhance the dispersion effect of the mixed additives in the left and right kneading chambers 1 and 2, each kneading process is adjusted in response to changes over time and power changes. Accordingly, the height of the door top 8 can be changed appropriately to improve the efficiency and content of kneading and mixing of the target materials, and the problems in kneading that occur in the conventional technology can be solved. It is.

(Example) Specific examples of the present invention will be described. In Figures 1 and 2, left and right kneading chambers 1 and 2 equipped with rotors 1a and 2a, a material input port 4 and a pushing ram 5 are shown.
Since this is the same as that of a conventional internal kneading machine, the explanation will be omitted and only the necessary structure of the door top 8 will be described. In this example, a hydraulic cylinder 9 is installed inside the discharge door 6, and a piston 10 of the cylinder 9 is installed.
The lower part of the door top 8 provided separately with the discharge door 6 is integrally formed or connected to the discharge door 6, and the guide hole 6a provided in the center top of the discharge door 6 allows the door top 8 to
It is installed so that it can be raised and lowered vertically. In the illustrated example, the upper end of the door top 8 has a round shape such as an arcuate surface or a hemispherical surface, but it can be equally effective as a flat shape with a flat straight surface or a square shape with a triangular chevron shape. Further, it is preferable that the axial length of the door top 8 is approximately the same as the length of the discharge door 6 (depth of the kneading chamber). That is, the variable door top 8 according to the present invention can have some effect even if it is provided partially over the entire length of the door top, but it is even more effective when it is provided over the entire length of the door top. The reason for this is that the height of the door top 8 is changed to suppress material retention in the communication section 3 above the door top 8 or to promote material movement between the left and right kneading chambers 1 and 2 during kneading. The control effect on the material movement increases as the length and width of the vertical movement of the door top 8 increases, and therefore, it is best for the axial length to cover the entire length as much as possible. However, as illustrated in FIG. 7, each of the rotors 1a and 2a in the left and right kneading chambers 1 and 2 has long blades 11 and short blades 12 symmetrically, and serves to collect the input material to the center,
Regarding the blade length on the rotors 1a and 2a, the length l ₁ of the long blade 11 and the length l ₂ of the short blade 12 are l ₁ /L.
When the relationship is 0.6~0.7=2/3 and _l2 /L0.3~0.4=1/3, the effect of the variable door top 8 in the present invention is to control the movement of the material collected to the center. Therefore, in such a case, if the variable door top 8 is provided in the center with a length of L ₁ /L = 1/3 or more, the function of collecting material to the center by the long and short wings 11 and 12 will be hindered or Therefore, the effect of controlling the kneading content according to the present invention can be similarly expected. In the figure, arrows indicate the movement of the material.

It should also be noted that the configuration of the variable door top 8 in the present invention is completely different from the inserts used in known continuous kneading machines. That is,
In the FCM type continuous kneading machine, as illustrated in FIG. 8, inserts 15, 15 are inserted between the left and right chambers 13, 14 between the left and right chambers 13, 14 formed by a pair of rotors 13a, 14a, in the upper and lower middle of the kneading section. Although the kneading effect is enhanced, both inserts 1
The main effect of 5 and 15 is that the left and right chambers 1
This is to prevent material (so-called short pass material) from moving in the axial direction through the communication portion between 3 and 14 without being subjected to any shearing action, and both inserts are completely fixed and immovable during operation. This is completely different from the present invention in which the movement of materials between the left and right kneading chambers 1 and 2 is controlled during kneading.
In the figure, 13b and 14b are rotors 13a,
A material feed screw follows 14a, and the material input port is located at the top thereof, and 16 indicates the discharge ports at the front ends of the left and right chambers 13, 14.

Although a hydraulic cylinder method is shown in FIG. 1 to change the height of the variable door top 8, mechanical means such as those illustrated in FIGS. 9A and 9B may be used as the elevating mechanism. You can also do it. That is, as shown in both figures, a slide guide chamber 17 is provided inside the door following a guide hole 6a opened at the center top of the discharge door 6, and a base 8a of the door top 8 is inserted into the guide hole 6a so as to be able to rise and fall. A screw hole 18 is fitted into the slide guide chamber 17 so as to be able to move up and down and not rotate, and is formed in the base portion 8a.
A screw shaft 21 is screwed into the slide guide chamber 17 so as to be rotatable from the outside of the discharge door 6 via a motor 19 and a bearing 20. According to this, the base portion 8a of the door top 8 moves up and down within the slide guide chamber 17 by forward and reverse rotation of the screw 21, so that the door top 8 can freely adjust the height L of protruding into the communication portion 3 from the guide hole 6a. The means for raising and lowering the door top 8 can be freely designed.

Changing the height of the door top 8 in response to the kneading process is automatically controlled by remote control, and various programs can be cited as examples of the control method. Basically, in the curve diagram showing the kneading process of one batch shown in the power one hour chart where the vertical axis shows the power change and the horizontal axis shows the kneading time elapsed, as explained in FIG. time
After ti, when the set power P becomes Pi, the height L of the door top 8 (see FIG. 9A) is set to Licm. However, i means that the door top 8 is raised and lowered n times from i=1 to n. That is, specifically, when loading the material, set L = 0 (lowest limit position), power P becomes P ₂ ,
When the kneading time reaches _t2 , the door top with L=0 is raised from the _L1 position to the predetermined _L2 position as shown in the figure, and in this state, the kneading process reaches the position of power _P3 and time _t3 . For example, the door top 8 is held at L ₂ until L ₃ , and then the door top 8 is lowered from L ₃ to L ₄ , and while the L ₄ is maintained, the kneading process is powered.
When P ₄ and time t ₄ come, the door top 8 is automatically moved up and down corresponding to the kneading process by changing the power and elapsed time so that the door top 8 is raised from L ₅ to L ₆ . That is clear. Of course, the program setting conditions include not only power but also
For example, the required kneading time t for one batch may be sufficient.
Alternatively, it may be based on the kneading material temperature T, or furthermore, when a motor is used as rotor rotational power, it is also possible to use the integrated power ΣP associated with power consumption, etc. In Fig. 11, only the kneading time t is set. A case is shown in which the height L of the door top 8 is automatically changed up and down from L ₁ to _{L 8} according to the change in time t as a condition, and FIG. 12 shows the material temperature as the kneading time t changes. A case is shown in which the height L of the door top 8 is automatically changed up and down from _L1 to _L8 in response to changes in T over time. The same effect can also be achieved by changing the height L of the door top 8 by combining the setting conditions exemplified above.

13 and 14 show an example of a system for practically performing the above-mentioned remote control. As shown in FIG. The kneading time t is input from the motor 23 via the wattmeter 24, the kneading time t is input via the timer 25, and the material temperature T is input via the temperature sensor 26 installed in the kneading chamber as pulse signals etc. A displacement meter 27 is installed and its vertical displacement is similarly input to the unit 22, and the calculation results from the temperature sensor 22 under each condition are sent to the servo valve 28 side as an output for the door top up and down. By operating the hydraulic unit 29, the vertical movement of the door top 8 can be controlled according to the program.
An example of a hydraulic system circuit is shown in which a power signal P', a time signal t', or a temperature signal T' is inputted to a power/displacement calculation circuit 31 in which a setting condition 30 is incorporated, and a door top 8 is detected by a displacement meter 27. In conjunction with the position search, the hydraulic unit 29 is actuated via the servo valve 28 via the servo amplifier 32, and in any case, the door top 8 is automatically controlled up and down by remote control (depending on the kneading process). can easily employ various known automatic control systems.

According to each of the embodiments exemplified above, as already explained in principle in the operation section, when kneading various plastic materials using a closed kneader, the door top protruding into the communication portion 3 is used. 8 height L
is adjusted up and down to obtain the appropriate kneading content required in each kneading process in one batch of kneading process, thereby reducing the peak torque at the initial stage of kneading and making it easier to start kneading with low power. In addition, the active movement or suppression of main materials and additives as kneading progresses can be accurately and easily controlled in accordance with the kneading process, and it is expected that the content and efficiency of kneading and mixing will be improved. Become.

(Effects of the Invention) According to the present invention, when kneading various materials and additives in an internal kneading machine such as a batch-type Banbury mixer, the door top can be moved up and down during kneading to perform the kneading. This makes it possible to avoid problems with conventional technology, such as the requirement for excessive kneading torque at the initial stage of kneading, and the need to increase the strength of a high-horsepower motor or the kneader main body in order to withstand high peak torque. Stable and uniform initial kneading can be achieved by eliminating material crushing, fragmentation, heat generation, and uneven mixing of additives during the initial stage of kneading due to the active movement of materials and additives. At the same time, by early completion of sufficient mixing of materials and additives during initial kneading, good kneading can be quickly achieved. Furthermore, as the kneading progresses, it is possible to suppress the phenomenon in which materials accumulate in the communicating parts and on the door top, and it is possible to eliminate the decrease in energy efficiency of kneading and uneven dispersion of additives caused by the accumulation. Moreover, this is extremely advantageous in that both can be achieved reliably and easily by changing the height of the door top 8 and by making the shape of the kneading chamber variable. The height of the door top 8 can be changed depending on the material crushing process, additive mixing process, and dispersion process of the mixed additives, so that the appropriate kneading content can be adjusted throughout the kneading process. By applying it over the course of the process, it is possible to ensure a qualitative improvement in kneading.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a kneading machine as an embodiment of the present invention, Fig. 2 is a slope view of the same door top, Fig. 3 is a slope view of a conventional door top, and Figs. 4 and 5 are a variable door top and peak torque according to the present invention. Figure 6 is a power hour chart of the kneading process.
Fig. 7 is an explanatory diagram of a modified embodiment of the variable door top according to the present invention, Fig. 8 is an explanatory diagram of an insert in a continuous kneading machine, and Figs. 9A and 9B are general views of an embodiment of the lifting mechanism of the variable door top of the present invention. FIGS. 10, 11, and 12 are flow sheet diagrams of an embodiment of the door top up/down operation program according to the present invention, and FIGS. 13 and 14 are flow sheet diagrams of each embodiment of the remote control system. 1a, 2a...rotor, 1, 2...kneading chamber, 3
...Communication section, 4...Material input port, 5...Pushing ram, 6...Discharge door, 7...Material discharge port, 8...
Door top, 9...hydraulic cylinder, 10...piston, 18...screw hole, 21...screw shaft.

Claims (1)

[Claims] 1 A pair of kneading chambers, each equipped with a rotor, are provided in parallel and in communication with each other in the axial direction, a material input port is provided together with a pushing member in the upper part of the communication part, and a material discharge port is provided in the lower part with a discharge door. A closed kneading method characterized in that when kneading target materials using a kneading machine, the kneading is carried out while changing the height of a door top protruding into the communication portion of the discharge door according to the kneading process. Machine kneading method.