JPH0357850B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] Removal of volatile matter, etc., such as a vent statistics for removing large amounts of moisture and excess volatile matter (hereinafter simply referred to as volatile matter, etc.) in the extruder of the present invention Regarding equipment.

[Prior art]

When extrusion molding polymers containing volatile components, etc., the vented extruder normally removes the volatile components by providing an opening in the middle of the cylinder to reduce the pressure. Since it has the disadvantage of blocking the port and eliminating the vent effect, a device for removing volatile matter such as a vent stuffer is used, which forcibly pushes the foamed polymer back into the extruder and removes only the volatile matter. As shown in FIGS. 1 to 3, in this type of device, a cylinder 2 into which a single or double screw screw 1 is rotatably inserted by an electric motor 8 or the like is attached to an opening 5 of a main cylinder 4 of an extruder 3. , said cylinder 2
Volatile components and the like are discharged through an opening 6 provided in the chamber by reducing the pressure or to the atmosphere.

[Problems with conventional equipment]

However, due to the content of volatile matter, melt viscosity, polymer temperature, etc. of the polymer passing through the groove of the main screw 7, if foaming occurs rapidly, the flow rate of the generated gas will be very high. Become,
The polymer torn off due to foaming flows back through the screw 1 together with the generated gas and stays in the opening 6, or gets clogged in pressure reduction piping, etc., resulting in deterioration of the retained polymer, and this deteriorated polymer is returned to the main screw 7 by the screw 1, which has the disadvantage of adversely affecting the physical properties of the product.

[Structure of the invention]

This method eliminates the drawbacks of the conventional device as described above, separates the polymer and gas that fly out into the opening of the vent statue, exhausts only the gas, and returns the polymer to the main screw before it deteriorates. A cylinder in which a shaft or two-shaft screw is rotatably inserted by a drive device such as an electric motor is attached to the opening of the main cylinder of the extruder, and the above-mentioned cylinder is inserted into the opening of at least one cylinder attached to the extruder. A screen is provided that allows only the volatile matter in the cylinder to pass through, but not the polymer.

〔Example〕

One embodiment of the present invention will be described with reference to FIGS. 4 and 5. Reference numeral 11 denotes a vent staff in which a single-shaft screw 13 is rotatably inserted into a cylinder 12 via a drive system 15 by an electric motor 14. There is.

The cylinder 12 is provided with a notch 16 which is an opening through which the screw 13 is partially exposed. A screen 17 is provided that is almost flush with the screen 17 to prevent polymers and the like from accumulating between the screen 13 and the screen 13.
We have tried to prevent the creation of dead spaces as much as possible. The screen 17 is designed to allow gases such as volatile matter to pass through, but not to allow polymers and the like to pass through.

The atmosphere open type can be configured as described above, but
When reducing the pressure using a vacuum pump or the like, an airtight container 1 is provided to keep the area around this screen 17 airtight.
8 is provided, and the volatile matter is sucked in the direction of arrow a through a discharge pipe 19 using a vacuum pump or the like (not shown).

〔Effect of the invention〕

Since the present invention has the above-described configuration, only volatile components such as gas can pass through, and the polymer torn off by foaming cannot pass through the screen and is immediately extruded again by the screw 13. It is adapted to be pushed back into the machine (not shown).

Although the above embodiment was explained using a single shaft screw,
A two-shaft screw may be used as shown in FIGS. 7 and 8.

[Brief explanation of drawings]

Figure 1 is a schematic diagram of a conventional vent statue. FIG. 2 is a cross-sectional view of FIG. 1, and FIG. 3 is a diagram of another conventional device, showing the case of a two-shaft screw.
FIG. 4 is a diagram showing one embodiment according to the present invention. FIG. 5 is a cross-sectional view of FIG. 4. FIG. 6 is a diagram showing another embodiment according to the present invention. FIGS. 7 and 8 are diagrams showing still another embodiment of the present invention, in which a two-shaft screw is used. 12... cylinder, 13... screw, 16...
...Notch, 17...Screen, 18...Airtight container.

Claims (1)

[Claims] 1 At least one location on the cylinder in the vent statue that is attached to the opening of the extruder and rotates a single or twin screw to force the foamed polymer that pops out of the opening back into the extruder. An opening is provided, and a constant gap is provided in the opening, which is substantially the same as the gap between the outer diameter surface of the single-shaft or twin-shaft screw and the inner diameter surface of the cylinder, and serves as a substitute for the cylinder wall and as a vent stud. A device for removing volatile matter, etc. in a vent station, characterized in that it is provided with a screen that allows only moisture and volatile matter inside the vent tower to pass through.