JP2001246661A - Extrusion device for extruding resin material with low apparent specific gravity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extrusion device for extruding a clamlike resin material or the like which shows a good bite performance as a clamlike material into a feed aperture. SOLUTION: In the extrusion device which feeds a resin material with a low apparent specific gravity to a biaxially extruding machine and extrudes the resin material after melting/kneading it, the device is characterized by that it comprises a feed barrel for receiving the resin material having a low apparent specific gravity, an air vent barrel, located in the downstream of the feed barrel, having a discharge aperture which vents the air separated from the resin material received by the feed barrel and a barrel, located in the downstream of the air vent barrel, consisting of a plurality of split barrels connected together in one piece including a vent barrel having a vent aperture for removing a volatile substance originating from the resin material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a twin screw extruder,
In particular, the present invention relates to an extruder for extruding a resin material having a small apparent specific gravity.

[0002]

2. Description of the Related Art Conventionally, twin-screw extruders have been widely used in many resin materials because of their good mixing and dispersing functions and the ability to discharge a stable amount of extrusion. When extruding a crumb-shaped material, etc., the bite state in the feed section is poor, so the screw speed is high, but the extrusion amount is small, so the resin becomes high temperature, causing thermal degradation, etc., and economical efficiency. It was not used very badly.

Referring to FIG. 6, a conventional twin-screw extruder will be described. The extruder 1 includes a feed barrel 3 having a hopper 2 attached to a feed port, and a forward (leftward in the figure) downstream of the feed barrel 3. When the crumb-shaped material 4 is transferred, a plurality of standard divided barrels 7a and 7b including a vent barrel 6 provided with a vent port 5 for removing air, generated volatile substances, and the like.
, And the resin material sent from the upstream (rightward in the figure) immediately before the vent port 5 is given a shearing heat generated at the meshing portion of the two screws. A two-axis screw 10 (only one of the two axes is shown) having a kneading disk 9 for melting and effective heating and ventilation is rotatably inserted into the barrel 8.

Accordingly, the crumb-shaped material 4 supplied from the hopper 2 is heated by a heater provided outside the barrel 8 (not shown) due to the shearing heat generated by the rotation of the screw 10 and transported forward while being melted and kneaded. Along with
Air, moisture, other volatile substances, and the like remaining from the vent port 5 are removed and pushed out from a nozzle 11 provided at the tip.

[0005]

However, the crumb-like material 4 supplied from the hopper 2 via the fixed-quantity feeder 22 is sent forward through the barrel 8 by the screw 10 and finely crushed and melted when reaching the kneading disk 9. As a result, the heated air separated from the crumb-shaped material 4 is blocked from going to the molten resin completely filled in the front kneading disk, and loses a refuge and returns to the feed port side. Is blown up, so that the crumb-shaped material 4 does not bite into the screw 10 at the feed port, and the extruded amount of the crumb-shaped material is small, and the screw rotation speed is relatively high. However, there is a drawback that the temperature becomes high to cause thermal deterioration and the like, and extruding is practically impossible.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the disadvantage that the crumb-like material is not bite well at the feed port in a conventional extruder and the crumb-like material is poorly pushed out. It is an object of the present invention to provide an extruder for extruding a crumb-shaped resin material or the like having a good bite of the material.

[0007]

According to the present invention, there is provided an extruder for supplying a resin material having a small apparent specific gravity to a twin-screw extruder, melting and kneading the resin material, and extruding the resin material. A feed barrel for receiving the material, an air vent barrel downstream of the feed barrel and having an outlet for discharging air separated from the resin material received by the feed barrel, and a resin material downstream of the air vent barrel An extrusion device for extruding a resin material having a small apparent specific gravity, comprising a barrel integrally connected to a plurality of divided barrels including a vent barrel having a vent port for removing volatile substances and the like coming out of did.

It is preferable that the air is discharged through a wire mesh, a plurality of slits in the axial direction, or a plurality of small holes.

According to the present invention, the crumb-like material supplied from the feed port is finely crushed by a kneading disk, and even if the air contained by being heated and melted is separated and returned, the air vent located downstream of the feed port is removed. Since the air was discharged from the barrel, there was no air blow-up to the feed port, and therefore, the bite of the material was improved. as a result,
Extruded amount also increased

[0010]

FIG. 1 is a block diagram showing an embodiment of the present invention.
This will be described with reference to FIG. The twin-screw extruder 20 feeds a crumb-shaped material 21 from the fixed-quantity feeder 22 into the twin-screw extruder 20 via a hopper 23 attached to a feed port, and a discharge port downstream thereof for discharging air. A nozzle 31 is provided at the tip of a barrel 30 which is integrally connected to an air vent barrel 26 provided with 25 and a vent barrel 28 for sucking volatile substances and the like by a vacuum pump 27 and a plurality of standard barrels 29a, 29b. .

As shown in FIG. 2, a pair of screws 32a and 32b are rotatably inserted into the barrel 30, and the power of a motor 33 as a driving source is transmitted through a gear box 34 and couplings 35 and 36. To the screws 32a and 32b.

As shown in FIG. 2, a wire mesh 37 is attached to the air discharge port 25 of the air release barrel 26 so as to be replaceable by attaching and detaching a spacer 38 to and from the air release barrel 26. To prevent the resin material from being discharged. The wire mesh 37 of the outlet 25 may be a plurality of slits 39 in the axial direction shown in FIGS. 3 and 4 or a plurality of small holes 40 as shown in FIG.

With the above-described structure, even if the crumb-shaped material is pulverized by the screw kneading disk (not shown) and the air contained by melting is separated and flows backward, Is discharged to the outside of the extruder 20 through the discharge port 25 of the air release barrel 26, and does not blow up to the feed port, so that the resin material is smoothly bitten.

A comparison of the extrusion rate between the conventional apparatus and the apparatus according to the present invention shows that when an irregular crumb-shaped material having an average size of about 15 mm is rotated at a screw diameter of 48 mm and a screw rotation speed of 50 rpm, the extrusion rate is reduced. The amount is 50K for the former
gf / h, the latter being about twice as large as 100 Kgf / h, and it is apparent that the latter has a good bite at the feed port and has a larger extrusion rate than the conventional apparatus without an air vent barrel.

[0015]

As described above, there is no air blow-up from the inside of the extruder to the feed port, the bite of the resin material is improved, and the capacity of the extruded amount is improved and improved.

[Brief description of the drawings]

FIG. 1 is an explanatory view of an extruder showing one embodiment of the present invention.

FIG. 2 is an explanatory view of an extruding apparatus showing one embodiment of the present invention, and is an enlarged view of a section AA in FIG.

FIG. 3 is an explanatory view of an extrusion apparatus showing another embodiment of the present invention, and is an enlarged front view when an air discharge port is formed with a plurality of slits in an axial direction.

FIG. 4 is an explanatory view of an extruding apparatus showing another embodiment of the present invention, and is a cross-sectional view taken along the line BB of FIG.

FIG. 5 is an explanatory view of an extrusion apparatus showing still another embodiment of the present invention, and is a view when an air outlet is formed of a plurality of small holes.

FIG. 6 is an explanatory view of a conventional extrusion device.

[Explanation of symbols]

 Reference Signs List 20 twin-screw extruder 21 crumb-shaped material 22 fixed-quantity feeder 23 hopper 24 feed barrel 25 air outlet 26 air vent barrel 27 vacuum pump 28 vent barrel 29a, 29b ... standard barrel 30 barrel 31 nozzle 32a, 32b screw 33 motor 34 gear box 35 , 36 Coupling 37 Wire mesh 38 Spacer 39 Slit 40 Small hole

Claims (4)

[Claims] 1. An extruder that supplies a resin material having a small apparent specific gravity to a twin-screw extruder, melts and kneads it, and extrudes the resin material. An air venting barrel having an outlet for discharging air emitted from the resin material received by the feed barrel, and a vent barrel downstream of the air venting barrel and having a vent port for extracting volatile substances and the like from the resin material. An extrusion apparatus for extruding a resin material having a small apparent specific gravity, comprising a barrel in which a plurality of divided barrels are integrally connected. 2. The extruder for extruding a resin material having a small apparent specific gravity according to claim 1, wherein the air is discharged from the discharge port through a wire mesh. 3. The extruder for extruding a resin material having a small apparent specific gravity according to claim 2, wherein the air is discharged from the discharge port by a plurality of slits in the axial direction instead of the wire mesh. 4. The extruder for extruding a resin material having a small apparent specific gravity according to claim 2, wherein the air is discharged from the discharge port by a plurality of small holes in place of the wire mesh.