JPH08332630A - Closed kneader - Google Patents

Abstract

PURPOSE: To provide in a short time a closed kneader for providing a kneaded material in which the dispersion properties of a blending agent is good. CONSTITUTION: In a closed kneader provided with two rotors 5 and 6 rotating in the different directions respectively in a closed chamber 1 and a drop door 4 to be opened and closed and set on the lower section of a closed space, the ratio α(=h/r) between the height (h) of the drop door 4 and the radius R of the chamber 1 is set to be 0.6<=α<=0.8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a closed type kneader used for kneading rubber, plastics and the like.

[0002]

2. Description of the Related Art A cross-sectional view of a conventional closed type kneading machine is shown in FIG. In FIG. 3, 1 is a chamber and 2 is a chamber 1.
The kneading chamber 3 closed by 3 is a floating weight that can be moved up and down, 4 is a drop door that can be opened and closed, and these constitute a part of the chamber. 2 inside the chamber
The two rotors 5 and 6 are arranged in parallel, and the rotors rotate in different directions, while the material to be kneaded with a compounding agent from a hopper (not shown) is lowered into the chamber by lowering the floating weight 3. Knead by press-fitting.

When the kneading is completed, the drop door 4 in the lower part of the chamber is opened to discharge the material to be kneaded to the outside.

[0004]

In the conventional closed type kneading machine, the drop ratio such that the ratio α (= h / R) of the drop door height h to the chamber radius R is empirically α≈0.5. It is composed of a door. However, in such a conventional technique, there is a problem that the material to be kneaded stays together with the compounding agent in the space formed between the upper portion of the drop door and the rotor in the kneading chamber, and in some cases, it is fixed as it is. Therefore, there are problems that the compounding agent is not sufficiently dispersed, the kneading time becomes long, and a uniform kneaded product cannot be obtained.

The present invention is proposed in view of the above problems, and an object thereof is to provide a closed-type kneading machine capable of obtaining a kneaded product having a good dispersibility of a compounding agent in a short time. There is a point to try.

[0006]

In order to achieve the above object, according to the present invention, two rotors which rotate in different directions from each other are provided inside a sealed chamber, and the rotor can be opened and closed at the bottom of a sealed space. In a hermetic kneader equipped with a drop door, the ratio α (= h / R) between the height h of the drop door and the radius R of the chamber is 0.6 ≦ α ≦ 0.8.
The drop door is arranged so that

[0007]

As described above, the closed type kneading machine of the present invention has a ratio α (= h / R) between the height h of the drop door and the radius R of the chamber.
By setting 0.6 ≦ α ≦ 0.8, the branched flow of the material to be kneaded at the top of the drop door to the left and right is promoted, and the shearing action on the material to be kneaded and the transfer function between the left and right rotors are improved. Therefore, the mixing / dispersing action in the kneading chamber is improved, and a kneaded product having good dispersibility can be obtained in a short time. In addition, the space formed by the upper portion of the drop door and the rotor is reduced, so that the amount of the compounding agent or the material to be kneaded, retention and sticking is reduced.

[0008]

FIG. 1 shows an embodiment of the closed type kneading machine of the present invention. In FIG. 1, 1 is a chamber and 2 is a chamber 1.
Kneading chamber closed by 3; 3 is a floating weight that can be raised and lowered; 4 is a drop door that can be opened and closed;
Has a height ratio α of 0.6 ≦ α ≦ 0.8, and the top of the drop door has an arc shape in the illustrated example, but it can have a flat shape or a sharp chevron shape. Also, the effect is the same and is adjusted to the optimum shape.

Using a lab mixer with an inner diameter of 128 mm in the chamber 1, a conventional drop door (α≈0.5)
Then, a comparative experiment was performed on the drop door height ratio α according to the present invention. In the experiment, carbon blending was carried out for natural rubber and synthetic rubber, and the carbon dispersity of the kneader was measured. FIG. 2 shows the relationship between the drop door height ratio α and the carbon dispersity. The greater the degree of carbon dispersion, the greater the shearing action in the kneading chamber and the passing action between rotors,
It shows that the mixing and dispersibility is good.

From FIG. 2, the drop door height ratio α is 0.6.
In the above case, the carbon dispersibility is dramatically improved as compared to the conventional drop door height ratio α≈0.5, and the larger the drop door height ratio, the better the mixing / dispersing property. I understand. However, when the height of the drop door becomes high, there is a risk of contact with the rotor and a problem in strength, and α≈0.8 is set in view of the working accuracy and the accuracy maintenance of the movable part of the drop door. There is a need. Therefore, the drop door height ratio α is preferably set to 0.6 ≦ α ≦ 0.8 as a value that maximizes the effect of the invention.

[0011]

As described above, the hermetic kneading machine of the present invention has a ratio α of the drop door height h to the chamber radius R of α.
Since (= h / R) is set to 0.6 ≦ α ≦ 0.8,
The branched flow of the material to be kneaded to the left and right at the top of the drop door is promoted, and the shearability to the material to be kneaded and the transferability between the rotors can be improved. Therefore, the mixing / dispersing action in the kneading chamber is improved, and a uniform kneaded product can be obtained in a short time. In addition, the space formed by the upper portion of the drop door and the rotor is reduced, so that the amount of the compounding agent or the material to be kneaded, retention and sticking is reduced.

[Brief description of drawings]

FIG. 1 is a sectional view of a closed kneading machine showing an embodiment of the present invention.

FIG. 2 is a graph showing the effect of drop door height ratio.

FIG. 3 is a cross-sectional view of a conventional closed kneader.

[Explanation of symbols]

 1 chamber 4 drop door 5, 6 rotor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Toshikazu Shojima 5-717-1, Fukahori-cho, Nagasaki-shi, Nagasaki Sanhishi Heavy Industries Ltd. Nagasaki Research Institute (72) Inventor Shuichi Hanada 1-1, Atsunoura-cho, Nagasaki-shi, Nagasaki No. Mitsubishi Heavy Industries, Ltd. Nagasaki Shipyard (72) Inventor Kazuo Miyasaka No. 2 Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber Co., Ltd. Hiratsuka Works (72) Inventor Katsumi Hayashida No. 2 Oiwake, Hiratsuka-shi, Kanagawa Yokohama Rubber stock company Hiratsuka factory

Claims (1)

[Claims] 1. A closed-type kneading machine, comprising two rotors that rotate in different directions inside a closed chamber, and a drop door that can be opened and closed at the bottom of a closed space. The ratio k (= h / R) of the radius h of the chamber h to the radius R of the chamber is 0.6 ≦ α ≦ 0.8.