JPS5944093B2 - Continuous kneading machine - Google Patents

Description

[Detailed description of the invention] This invention relates to an improvement of a continuous kneader.

Conventionally, various continuous kneading machines have been used to knead rubber and plastic materials, etc., but in conventional kneading machines, the shape of the space formed between the rotor and the wall of the kneading chamber is similar to that of the rotor. Kneading is performed by taking advantage of the changes caused by rotation.

Kneading that takes advantage of changes in the shape of the kneading chamber is suitable for mixing and dispersing materials, and is good for kneading viscous substances such as rubber, plastics, and foods, but it is not suitable for kneading carbon and a small amount of Teflon. When kneading a powder and a very small amount of additives, such as Ai, the fluidity is large and sufficient kneading cannot be expected. This invention was made to solve these conventional drawbacks, and improves the compression shearing effect by improving the shape of the rotor, thereby improving the mixing of powder and trace additives. This is to ensure that it is carried out well.

That is, in the kneading section of the kneading rotor in a two-shaft continuous kneading machine, the distance between the rotor axes is set to be smaller than twice the maximum radius of the rotor, and the rotational speed of both rotors is set to be the same. , at least one of the rotors is formed in a cross-sectional shape such that the front side in the rotational direction protrudes more from the centerline than the rear side in the rotational direction.

In this way, the rotors are formed into a so-called meshing type, and the rotational speeds of both rotors are made the same so as not to interfere with each other. Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a motor, 2 is a gear reducer, 3 is a feed screw, 4 is a rotor of the kneading section, and 5 is a trough. As shown in FIG. 2, the rotor 4 is composed of two blades attached to a rotating shaft 6, and each blade has an edge 7 at the front in the rotational direction with respect to the center line 40 that expands more than an edge 8 at the rear in the rotational direction. It is designed to come out. Further, an annular spacer 9 is attached to the other rotating shaft 6. The front edge 7 in the rotational direction has a constant curvature, and the angle between this tangent and the tangent of the trough 5 at the opposite position is the penetration angle of the material.

That is, as shown in FIG. 3, point D on edge 7 and trough 5
The angle θ formed between the upper point C and the tangent line is the penetration angle θ, and is expressed as follows.

Furthermore, since the edge 7 is bulged out more than the center line 40, the penetration angle is smaller. Conventionally, as shown in FIG. 7, the amount of protrusion of the rotor 41 from the center line 40 was small, and therefore the angle of bite was large. In the conventional rotor configuration, mixing and dispersion are difficult because the kneading chamber formed between the pair of rotors 41, 41 and the trough 5 changes as the rotor 41 rotates. Although it performed well, there was little compression shear action. On the other hand, in the rotor 4 shown in FIG. 2, the penetration angle is constant and small, so that the compressive shearing action is mainly performed. It is only when this compression-shearing action is performed that the powder and a small amount of additives are properly kneaded. The compressive shear action increases as the penetration angle becomes smaller, but in order to reduce the penetration angle, the edge 7
If the amount of swelling becomes large, the volume of the kneading chamber will become smaller and the residence time of the material will become shorter, which may result in insufficient kneading. Therefore, the amount of bulge of the rear edge 8 in the rotational direction is made as small as possible. When a material containing carbon with a very small amount of Teflon added was kneaded, the relationship between the penetration angle θ and the degree of kneading, that is, the quality of the product, was as shown in FIG. That is, in the conventional device shown in FIG. 7, the point 20 was far below the quality limit line 30, but when using the rotor shown in FIG. A good product was obtained. From the same figure, it can be seen that good kneading can be achieved if the penetration angle θ is set to 25 mm or less. In the configuration shown in FIG. 2, the raw materials will remain in the kneading chamber on the side of the spacer 9,
This acts as a weir to prevent raw materials from passing through.

FIG. 5 shows an example in which a single-blade rotor 44 is applied to both,
Each rotor 44 is configured such that the front edge 7 in the rotational direction has a small biting angle. This configuration has the advantage that since the moving space of the rotor 44 is large, the material flows easily and the stirring effect is also increased. FIG. 6 shows a two-blade rotor 45,
An example is shown in which a pair of rotors 46 are used, and the shape of each rotor is basically the same as each rotor described above.

In the case of this rotor, the outer diameter of one rotor 46 is set to be somewhat small so that the rotors can perform a mutual cleaning action, and the rotors do not interfere with each other. Although there is no cleaning action between the rotor 46 and the trough 5, which have a smaller outer diameter, the inner diameter of the trough 5 may be made smaller in order to produce this cleaning action. Any of the rotors shown in FIGS. 2, 5, and 6 may be used, but a combination of these may also be used.

For example, in FIG. 1, the rotor 4 in FIG. 2, the rotor 44 in FIG. 5, and the rotor 45 in FIG.
, 46 may be arranged in sequence to find the most appropriate arrangement depending on the material. As explained above, the rotor of this invention is configured so that the compression-shearing effect is sufficiently exerted, and it exhibits an excellent effect in kneading materials in which small amounts of additives are mixed into powder. It is.

[Brief explanation of the drawing]

Fig. 1 is a vertical sectional view of a device showing an embodiment of the present invention;
The figure is a cross-sectional view taken along the - line, and Figure 3 is an explanatory diagram of the rotor penetration angle.
FIG. 4 is a diagram of the relationship between the penetration angle and product quality, FIGS. 5 and 6 are diagrams corresponding to FIG. 2 showing other embodiments, and FIG. 7 is a diagram corresponding to FIG. 2 of a conventional rotor. 4, 44, 45, 46... Rotor, 5...
...Trough, 7... Front edge in the direction of rotation, θ...
...Engraving angle.

Claims (1)

[Claims] 1. In the kneading section of the kneading rotors in the two-shaft continuous kneading machine, the distance between rotor axes is set to be smaller than twice the maximum radius of the rotors, and the rotational speeds of both rotors are set to be the same. A continuous kneading machine characterized in that at least one of the rotors is formed in a cross-sectional shape such that the front side in the rotation direction protrudes more from the center line than the rear side in the rotation direction. 2. A continuous kneading machine according to claim 1, characterized in that the other rotor is constituted by a spacer that projects evenly in the circumferential direction from the rotating shaft. 3. A continuous kneading machine according to claim 1, characterized in that the other rotor has the same shape as the one rotor.