JPH071553A - Filtrating mechanism of extruder - Google Patents

Abstract

PURPOSE:To prevent a foreign matter such as fiber form mixing in by a method wherein a rotary body is provided wherein a material extruded in front of a screen is divided into sections while it is being rotated, and sent into the screen. CONSTITUTION:A screen 1 fixed to a breaker plate 2 is provided between a tip of screw 11 and a die. One sheet or at least two sheets of fine mesh wire nets are used as the screen 1. A fitting shaft 3 extending from the breaker plate 2 is provided at a center of the screen 1, and a rotary body 4 is freely rotatably fitted to the fitting shaft 3. In the rotary body 4 a propeller screw 43 is provided between a bearing part 41 and an outer frame 42, and the shaft 3 is inserted into a hole 41A of the bearing part 41. Since a rotary body 4 wherein a material extruded in front of the screen thus is divided into sections while it is being rotated and sent into the screen is provided, foreign matter such as fiber or the like is also prevented from penetrating by rotation of the rotary body 4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an extruder used for extrusion molding of a thermoplastic resin, and more particularly to a filtration mechanism for an extruder having a screen between a screw tip and a die.

[0002]

2. Description of the Related Art In a conventional extruder, as shown in FIG. 5, material is fed from a hopper 10 to a die 12 side by a screw 11. The material sent by the screw 11 is pressurized, air intervening between the materials is discharged, and heated by the heater 14 on the outer periphery of the barrel 13 and internal friction heat to be plasticized or melted. A screen 1 is provided between the tip of the screw 11 and the die 12 (see FIG. 6). The screen 1 is fixed to the breaker plate 2. In addition, it is general to use a fine mesh as the screen 1, the breaker plate 2 is a metal mesh holder, and a large number of holes 21 are formed, and the material passes through these holes 21 (see FIG. 5). ). In addition, a wire mesh having a coarse wire diameter and a large wire diameter is often provided on the die 12 side of the breaker plate 2. Even if the material comes directly from a well-controlled material factory, there is a possibility that dust will enter during opening and during operation, and if the material is mixed with dust, the physical properties will not be uniform. Not only that, but the appearance also deteriorates, so filtration is performed.

[0003]

This type of filtering mechanism is also used when extruding the insulating layer of a power cable. One or more wire nets are used as the screen 1, and even if the eyes are made fine, elongated foreign matters 100 such as fibers,
For example, a cotton monofilament has a diameter of 10 to 20 μm and a length of 10
0 to 5000 μm, and such a foreign matter 100 is shown in FIG.
As shown in (3), if the wire mesh (screen 1) was seen vertically from the thin side, it might pass through. If such foreign matter 100 is mixed into the insulator of the power cable while standing in the thickness direction, the withstand voltage characteristic of the cable deteriorates.

Therefore, an object of the present invention is to provide a filtering mechanism of an extruder which prevents foreign matters such as fibers from being mixed.

[0005]

In order to achieve the above-mentioned object, the present invention is a filter mechanism of an extruder in which at least a screen is provided between a screw tip and a die, and a material extruded on the front surface of the screen. It is provided with a rotating body that divides while rotating and sends it to the screen.

[0006]

Since the members constituting the rotating body act so as to be orthogonal to the advancing direction of the material, even if the fiber foreign matter tries to enter parallel to the advancing direction, that is, perpendicularly to the eyes of the screen, this will be blocked.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing the head portion of an extruder. In this figure, a die 12 similar to the conventional one is provided on the left side. A screen 1 fixed to a breaker plate 2 is provided between the tip of the screw 11 and the die 12. As the screen 1, one or two or more fine meshes are used. At the center of the screen 1, there is a mounting shaft 3 extending from the breaker plate 2.
The rotator 4 is rotatably attached to the.

The rotating body 4 has a bearing portion 41 as shown in FIG.
A propeller screw 43 is provided between the outer frame 42 and the outer frame 42, and the shaft 3 is inserted into the hole 41A of the bearing portion 41.

The rotating body 4 may have a punching metal 44 attached thereto as shown in FIG. Alternatively, as shown in FIG. 4, a rod member 45 may be provided radially between the outer frame 42 and the bearing portion 41. Furthermore, a wire mesh with coarse mesh may be provided instead of the punching metal 44 or the bar 45.

The rotating body 4 is a propeller screw 43.
In the case of 1, the screw rotates by the pressure of the material pushed out by the screw 11, but it may be driven by a motor or the like. Furthermore, the screen 1 can also be rotated in the opposite direction to the rotating body 4.

[0012]

As described above, according to the present invention, since the material extruded on the front surface of the screen is provided with the rotating body which divides the material while rotating and sends the material to the screen, the material tries to get into the eyes of the screen. Intrusion of fiber foreign matters and the like is also blocked by the rotation of the rotating body.

[Brief description of drawings]

FIG. 1 is a sectional view of a head side of an extruder showing a preferred embodiment of the present invention.

FIG. 2 is an exploded perspective view of a screen and a rotating body.

FIG. 3 is a front view showing another example of the rotating body.

FIG. 4 is a front view showing still another example of a rotating body.

FIG. 5 is an explanatory diagram of an entire conventional general extruder.

FIG. 6 is a sectional view of a head portion of a conventional extruder.

FIG. 7 is a front view of a breaker plate.

FIG. 8 is an explanatory diagram of a state in which a fiber foreign matter passes through the screen.

[Explanation of symbols]

 1 screen 4 rotating body 11 screw 12 die

Claims (1)

[Claims] 1. A filtration mechanism of an extruder having at least a screen provided between the tip of a screw and a die, wherein a rotating body for dividing the material extruded in front of the screen while rotating and feeding it into the screen is provided. The filtration mechanism of the extruder.