JPH0422606A - Gate device of kneading machine - Google Patents

Abstract

PURPOSE:To remove the occurrence of turbulent flow, while the force intended to expand is converted into the force in flowing direction by forming the tapered area expanded with the advance in flowing direction on the side of the flowing out of the material to be kneaded of the recessed parts of upper and lower gates. CONSTITUTION:The tapered surface 11 expanded with the advance in the flowing direction of the material to be kneaded, is formed on the side of the flowing out of the material to be kneaded of the recessed parts 3a, 4a of upper and lower gates 3, 4. The material kneaded by the kneading part of a rotor 5 is apt to flow left and right through a gap (e), but then since the kneaded material is once throttled by the gates 3, 4, the material to be kneaded is intended to expand as its reaction force, whereby the force f1 outside in the radial direction of the rotor 5 acts on the recessed parts 3a, 4a of the gates 3, 4. Said force f1 is converted into the force f2 in the flowing direction of the material to be kneaded by the action of the tapered surface 11, and the flow near the side of flowing out of the gates 3, 4 becomes very smooth, whereby the turbulence of the flow 9 does not occur, and the occurrence of the burning of plastic material is avoided.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a gate device for a kneader.

(Prior art) Conventionally, for example, homogenization by cross-wire of brass tink, rubber, etc., production of masterbatches, compounds, etc.
There are two-shaft kneading machines used in processes such as polymer blending, and in order to adjust the flow rate of the liquid temperature wire in this type of kneading machines, there is a flumper installed on the discharge port side of the housing, or the There is a gate type that is installed either on the outlet side or in the middle of the housing.

Among these, the gate type, that is, the gate device of the kneading machine, as shown in FIG. 4, has a pair of upper and lower gates 3.
4, and substantially arc-shaped recesses 3a4a are formed on opposite end surfaces of the gates 3.4. Fifth
In the figure, a rotor 5 is rotatably inserted into the kneading chamber 2, and a ring portion is located between the kneading section 6 and the feed section 7 of the rotor 5, where the gate 3.4 is located. 8 is formed.

By appropriately changing the gap e between the concave portions 3a and 4a of the gates 3 and 4 and this ring portion 8, the opening degree of the material passage to be kneaded is adjusted, and the flow rate of the material to be kneaded is adjusted. It looks like this.

(Problem to be solved by the invention) By the way, LLDPE (linear low density polyethylene)
For resins with good heat sensitivity such as HDPE (high-density polyethylene), this gate device has a problem in that it is more likely to cause so-called burning of the resin than the above-mentioned flapper type. .

That is, in the case of the gate device, the flow rate is adjusted by the opening degree of the gap e, so the material to be kneaded (resin) becomes locally squeezed near the gates 3 and 4, and when the resin passes through the gap e, the flow rate is adjusted by the opening degree of the gap e. Turbulent flow 9 as shown in FIG. 7 occurs and the resin stagnates, and the heat generated by this turbulent flow 9 causes burning of the resin.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a gate device that can prevent the occurrence of burning of materials to be kneaded.

(Means for solving the problem) The technical means taken by the present invention to achieve the above object are as follows:
A rotor 5 is rotatably inserted into a kneading chamber 2 formed in the housing 1, and a pair of upper and lower gates 3 and 4 protruding into the kneading chamber 2 are provided so as to be able to approach and separate from each other. Recesses 3a and 4a formed on opposite end faces
In the gate device of the kneading machine, the opening degree of the passage of the material to be kneaded can be freely adjusted by appropriately changing the gap e between the material and the rotor 5. A tapered surface 11 is formed on the side, which widens toward the flow direction of the material to be kneaded.

(Function) As shown in FIG. 2, the material to be kneaded which has been narrowed down by the first gates 3 and 4 tries to expand when passing through the gap e between the recesses 3a and 4a and the ring part 8, and is moved by the rotor 5. However, the tapered surface 11 converts this force f1 into a force f2 in the flow direction of the material to be kneaded, and instead of generating turbulent flow 9, a smoother and larger flow than before is generated. Occur.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. Since the present invention is characterized by the shape of the gates 3 and 4 of the gate device, the same reference numerals are given to the members described in the conventional example for consistency, and the description thereof will be omitted and the characteristic points will be explained below. I decided to.

In this embodiment, as shown in FIG.
A tapered surface 11 is formed on the outflow side of the material to be kneaded in the recesses 3a, 4a of the upper and lower recesses 3a, 4.
It is formed by notching both left and right ends of a at a constant depth (height) from the joint end surfaces of the upper and lower gates 3 and 4.

Furthermore, this child bar surface 11 is not sloped in the entire thickness direction of the gates 3 and 4, but is sloped from the middle of the thickness direction as shown in FIG. The surface is a straight surface 12 as before.

The gate 3.4 having such a tapered surface 11
In this embodiment, which employs the following, it is possible to effectively prevent the resin from burning due to local constriction of the gate 3.4.

That is, as shown in FIG. 2, the materials to be kneaded by the kneading section 6 of the rotor 5 try to flow to the left in the figure through the gap e, but at this time, the gate 3, 4 (squeezing effect), the material to be kneaded tends to expand as a reaction force against the squeezing, and a force f on the outside in the radial direction of the rotor 5 acts on the recesses 3a and 4a of the gates 3 and 4. .

This force f is converted into a force f2 in the flow direction of the material to be kneaded by the Taber surface 11, and the flow near the outflow side of the gate 3.4 becomes very smooth, and the turbulent flow 9 is reduced as in the conventional case. This prevents resin burn from occurring.

In the above embodiment, the tapered surface 11 is formed into a recessed portion 3a.

The reason why the recesses 3a, 4 are provided only at both left and right ends of the gates 4a is that the recesses 3a, 4 are provided only at the left and right ends of the gates 4a.
This is because the gap e between a and the ring portion 8 is not so large. Therefore, in the case of a sensitive resin in which a sufficient effect cannot be obtained by providing the tapered surface 11 only in that portion, the tapered surface 11 is provided around the entire circumference of the recesses 3a and 4a, as shown in FIG. It is preferable to form the shape according to the resin to be handled in this manner.

In addition, the tapered surface 11 is formed into an inclined shape starting halfway in the thickness direction of the gates 3 and 4, so that a straight surface 12 is left in the area where the tapered surface 11 is provided, but this is different from the original aperture of the gates 3 and 4. This is for the purpose of exhibiting the effect, and in this case as well, depending on the resin being handled, all the surfaces forming the recesses 3a and 4a may be made into the tapered surface 11 (not shown).

Furthermore, it goes without saying that the present invention can be applied to devices other than twin-screw kneaders.

(Effects of the Invention) As explained above, according to the present invention, the upper and lower gates 3.
Since a tapered surface 11 that widens in the flow direction of the material to be kneaded is formed on the outflow side of the material to be kneaded in the concave portions 3a and 4a of 4, the resin flows smoothly and burns due to the turbulent flow 9 are prevented. Therefore, even resins with good heat sensitivity can contribute to the production of homogeneous resin materials.

[Brief explanation of the drawing]

Figures 1 to 3 show one embodiment of the present invention, with Figure 1 being a perspective view of the gate, Figure 2 being an explanatory diagram of the effect of the flow of materials to be kneaded, and Figure 3 showing a modification of the tapered surface. 4 to 7 show a conventional example, FIG. 4 is a front view illustrating main parts of the gate device, FIG.
The figure is a perspective view of the gate, and FIG. 7 is an explanatory diagram of the flow of the materials to be kneaded. DESCRIPTION OF SYMBOLS 1... Housing, 2... Kneading chamber, 3.4... Gate, 3a, 4a... Recessed part, 5... Rotor, 11...
...Tapered surface, e...gap.

Claims (1)

[Claims] (1) A rotor (5) is rotatably inserted into a kneading chamber (2) formed in the housing (1), and the kneading chamber (2)
A pair of upper and lower gates (3) and (4) protruding inward are provided so as to be able to approach and separate from each other, and recesses (3a) and (4a) formed in opposite end faces of the gates (3 and 4) and the rotor (
5) In a gate device for a kneading machine in which the opening degree of the material passage to be kneaded can be adjusted by appropriately changing the gap (e) between the upper and lower gates (3) and (4), the recesses (3a) ( 4a) A gate device for a kneader, characterized in that a tapered surface (11) is formed on the outflow side of the materials to be kneaded, the tapered surface (11) expanding toward the flow direction of the materials to be kneaded.