JPH0659646B2 - Rubber-like material kneading device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a device for kneading a rubber-like material in a chamber by rotating a rotor.

2. Description of the Related Art In general, rubber used for tires and the like is put into a chamber of a kneading device together with chemicals such as sulfur and carbon, and then kneaded by rotation of a pair of rotors to reduce plasticity and dispersion of chemicals. Uniformity is achieved.

Conventionally, a kneading apparatus used for such a kneading operation includes a case in which a chamber having an eyebrow cross section is formed inside, and a pair of two long blades horizontally housed in the chamber and extending in a radial direction. And a rotor. Then, by rotating the roller so that the long blades mesh with each other, the block-shaped rubber and the chemicals introduced into the chamber are kneaded. Here, the kneading by the rotation of the rollers is, firstly, an action due to a shearing force which the rubber receives when the rubber passes between the radial outer end of the long blade and the inner surface of the chamber, and secondly, a traveling direction of the long blade. It is considered to be based on the twisting action by the front face, the third, the turning action in the axial direction of the rotor, and the fourth, the folding action by the long blades meshing with each other.

Problems to be Solved by the Invention However, in such a kneading device, the chemicals were not uniformly dispersed in a short time, and as a result, kneading had to be performed for a long time. However, when continuously kneading for a long time, the temperature of the rubber being kneaded rises and the quality of the vulcanization reaction or the like changes. Therefore, in the past, once the rubber had risen to a predetermined temperature by kneading, The rubber was removed from the chamber, cooled and kneaded again. As a result,
There was a problem that the efficiency of kneading work was low.

Means for Solving the Problems Therefore, as a result of intensive studies by the present inventor, the adhesive force (tackiness) of the rubber increases as the kneading progresses, so that the rubber is formed between the long blades of the rotor and the inner surface of the chamber. When passing between the long blades and the chamber, the rubber adheres to the inner surface of the chamber by the long blades and remains attached in a layered state.As a result, the adhering rubber is not kneaded and the rubber can pass between the long blades and the chamber. It was found that the shearing and kneading due to the passage were not performed and the progress of the dispersion of the chemicals was delayed, and further, the adhered rubber served as a heat insulating material and the cooling effect on the rubber from the casing was reduced. Therefore, the problem is that the rotor is provided with a case in which a chamber having a cocoon-shaped cross section is formed, and a pair of rotors housed in the chamber and having long blades extending in the radial direction. A rubber-like material kneading device configured to knead the rubber-like material charged into the chamber by rotating the long blades so as to mesh with each other. This can be solved by making the distance between the inner surface of the chamber smaller than the distance between the long blade and the inner surface of the chamber, and peeling off the layered rubber-like material adhering to the inner surface of the chamber with these scrapers.

Action As described above, the adhesive force (tackiness) of the rubber-like material increases as the kneading progresses, and the rubber-like material remains in a layered manner on the inner surface of the chamber, but the scraper rotates along the inner surface of the chamber due to the rotation of the rotor. Most of the adhered layered rubber-like material is peeled off from the inner surface of the chamber every one rotation of the rotor. As a result, the amount of rubber-like material that is not kneaded is significantly reduced, and since rubber can pass between the long blade and the chamber, strong kneading is performed by the shearing that occurs during passage,
The rate of progress of chemical dispersion is increased. Further, when the rubber-like material being kneaded is cooled from the case, the layered rubber-like material for heat insulation is removed, and the cooling effect is improved.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 1, 2, and 3, 1 is a kneading device generally called a Banbury mixer, and this kneading device 1 has a case 2 in which a chamber 3 having a cocoon-shaped cross section is formed. A cooling medium passage (not shown) is formed. This chamber 3 contains a pair of horizontal rotors 4 and 5, which are the case 2
It is rotatably supported by. Each of the rotors 4 and 5 has a cylindrical shaft portion 6 and two long blades 7 and 8 formed integrally with the shaft portion 6 and extending in the radial direction. Each long wing 7 is a rotor
It extends from one end in the axial direction of 4 and 5 to the vicinity of the other end in the axial direction, and is approximately about the plane 9 including the rotation axes of the rotors 4 and 5.
They intersect at a twist angle A of about 45 degrees. On the other hand, the long blade 8 is at the position 180 degrees away from one end of the long blade 7
While extending from the other axial ends of 4 and 5 to the vicinity of one axial end, the long blade 7 intersects the plane 9 at a twist angle A of about 45 degrees, although the inclination direction is opposite. Here, the long blade means a blade whose axial length L is 1/2 or more of the axial length M of the rotor 45. And these long wings
The distance N between the radial outer ends of 7, 8 and the inner surface of the chamber 3 is generally 5 mm to 8 mm. In addition, each rotor 4, 5
Two scrapers 16 and 17 are integrally formed on the shaft portion 6 of the shaft 6, and the scrapers 16 and 17 are arranged behind the long blades 7 and 8 in the same inclination direction as the long blades 7 and 8 respectively. Has been done. The scrapers 16 and 17 extend from one end in the axial direction of the rotors 4 and 5 to the central portion in the axial direction, and from the other end in the axial direction of the rotors 4 and 5 to the central portion, respectively. These two scrapers are made by overlapping the tips.
16 and 17 cover all axial positions of rotors 4 and 5. The scrapers 16 and 17 intersect the plane 9 at a helix angle B, which is a long blade 7,8.
It is preferable that the twist angle is not less than A and not more than 70 degrees. The reason is that if the helix angle B is less than the helix angle A, the rubber 18 passing through the gap 19 between the radially outer ends of the long wings 7, 8 and the inner surface of the chamber 3 is scraped by the scrapers 16, 17.
Since it is scraped off by the blades, it gathers between the long blades 7 and 8 and the scrapers 16 and 17, and the amount increases, but it is sent toward the axial center, but the flow passage area of the rubber 18 at this time decreases. The rubber 18 has long wings 7, 8 and scrapers 16, 17
Because it will stay between and. On the other hand, if it exceeds 70 degrees, the force of the scrapers 16 and 17 for sending out the rubber 18 in the axial direction becomes small, and the scrapers 16 and 17 interfere with the long blades 8 and 7 located rearward in the traveling direction, respectively. Is. The distance P between the outer ends of the scrapers 16 and 17 in the radial direction and the inner surface of the chamber 3 is smaller than the distance N and is preferably in the range of 1 mm to 4 mm. The reason is,
If the distance P is less than 1 mm, the radial outer ends of the scrapers 16 and 17 may slide on the inner surface of the chamber 3 due to manufacturing error. On the other hand, if the distance P exceeds 4 mm, the rubber 18 is peeled off. Is almost eliminated.
The circumferential width R of the radial outer end faces of the scrapers 16 and 17 is narrower than the circumferential width S of the radial outer end faces of the long blades 7 and 8 and is 1/2 or less of S. Then, the rotors 4 and 5 are rotated in the direction of the arrow by a driving device (not shown), and the rubber 18 charged into the chamber 3 is kneaded by the long blades 7 and 8.

Next, the operation of the embodiment of the present invention will be described.

Now, after putting a certain amount of block-shaped rubber into the chamber 3 together with chemicals such as sulfur and carbon,
When 5 is rotated in the direction of the arrow so that the long wings 7 and 8 mesh with each other, the rubber 18 is strongly kneaded, the plasticity of the rubber 18 is lowered, and the chemical is dispersed. At this time, long wings
Since 7 and 8 are inclined at an angle A with respect to the plane 9 as described above, the rubber 18 moves in the circumferential direction by the rotation of the rotors 4 and 5 and is fed to the other axial direction or one axial direction. To be In addition, at this time, between the radial outer ends of the long wings 7 and 8 and the inner surface of the chamber 3, as described above,
Since there is a gap 19 of 8 mm, a part of the rubber 18 moves rearward in the traveling direction of the long blades 7 and 8 while passing through this gap 19 while being sheared and kneaded. For this reason, the rubber 18 located in front of the long wings 7, 8 in the traveling direction gradually decreases in amount while moving in the axial direction along the long wings 7, 8. here,
If the kneading as described above is continued, the adhesive force (tackiness) of the rubber 18 increases, so that the rubber 18 does not move into the gap 19
When it passes through, it adheres to the inner surface of the chamber 3 and remains as a layer. However, in the present invention, the rotor
Since scrapers 16 and 17 are provided on 4 and 5,
By the rotations of 4 and 5, the outer ends of the scrapers 16 and 17 in the radial direction move along the inner surface of the chamber 3 in the immediate vicinity thereof. For this reason, most of the layered rubber 18 attached to the inner surface of the chamber 3 is rotated by the scrapers 16 and 17 into the rotor.
Stripped every 4 or 5 revolutions. As a result, the amount of the rubber 18 that does not proceed with kneading is significantly reduced, and the rubber 18 can always pass through the gap 19.
It is possible to knead by giving shear to the rubber 18 passing through
The progress speed of chemical dispersion can be increased. Moreover,
As described above, the refrigerant passes through the case 2, but since the layered rubber that performs the heat insulating action is removed, the cooling effect by the refrigerant is improved. Also, the scraper 1
The layered rubber 18 stripped off by 6, 17 is pushed toward the center in the axial direction by the front faces of the scrapers 16 and 17 in the traveling direction because the scrapers 16 and 17 are inclined at an angle B. Moving. Here, the rubber 18 that has moved to the end along the long blade 7 is captured by the long blade 8 on the downstream side after moving away from the other end of the long blade 7, and subsequently moves along the long blade Mu 8. . On the other hand, the rubber 18 that has moved along the scraper 16 is attached to the front side of the long blade 8 by the rubber 18.
Since it already exists, it will overlap in front of this rubber 18. As a result, the rubber 18 that was not subjected to strong kneading because the gap 19 between the long blade 7 and the inner surface of the chamber 3 could not pass through is long in the long blade 8 because it is located immediately before the long blade 8. Gap 19 between wing 8 and chamber 3
Can be passed first and the opportunity to be kneaded is given first. In this way, the inclination directions of the two long wings 7 and 8 with respect to the plane 9 are made opposite to each other, and
By installing scrapers 16 and 17 that are inclined in the same direction as the long blades 7 and 8 behind the traveling direction of 7 and 8, the rubber 18 that was not kneaded very strongly by one long blade is strengthened by the next long blade. Thus, the rubber 18 can be repeatedly kneaded depending on the strength and weakness as a whole.

FIG. 4 is a graph showing how the carbon dispersion ratio in the rubber 18 changes when the filling ratio of the rubber 18 in the chamber 3 is changed. It can be seen that even if the filling rate becomes high, the dispersion rate does not decrease so much that the chemicals can be dispersed with higher efficiency than in the rotor having no scraper. Further, FIG. 5 is a graph showing how the temperature of the rubber 18 changes when the kneading power (specific energy) per unit volume of rubber is changed. In the case where the scrapers 16 and 17 are provided, Since the cooling effect is hardly reduced, the temperature hardly rises, and the kneading operation can be performed without stopping until the desired plasticity and dispersion rate are achieved.

In the present invention, the rotors 4 and 5 are long blades 7,
8 may have short wings outside.

EFFECTS OF THE INVENTION As described above, according to the present invention, the progress speed of chemical dispersion can be improved, and when the rubber-like material being kneaded from the case is cooled, the cooling is performed. The effect can be improved.

[Brief description of drawings]

1 is a schematic sectional view showing an embodiment of the present invention, FIG. 2 is a developed view of a rotor, FIG. 3 is an enlarged sectional view in the vicinity of the rotor,
FIG. 4 is a graph showing the relationship between the amount of rubber in the chamber and the carbon dispersion ratio, and FIG. 5 is a graph showing the relationship between specific energy and rubber temperature. 1 …… Kneading device, 2 …… Case 3 …… Chamber, 4, 5 …… Rotor 7, 8 …… Long blade, 16, 17 …… Scraper 18 …… Rubber-like material

Claims (1)

[Claims] 1. A case having a chamber having a cocoon-shaped cross section formed therein, and a pair of rotors housed in the chamber and having long blades extending in a radial direction, the rotor having the long blades meshing with each other. In a rubber-like material kneading device adapted to knead a rubber-like material charged into a chamber by rotating, a scraper extending in a radial direction is provided on each rotor, and a scraper between each scraper and the inner surface of the chamber is provided. A kneading device for a rubber-like material, characterized in that the distance between the long blade and the inner surface of the chamber is made smaller, and the layered rubber-like material adhering to the inner surface of the chamber is peeled off by these scrapers.