JP5245166B2 - Plastic kneader and material supply device - Google Patents

Description

  The present invention relates to a recycled material supply apparatus mainly used for molding waste plastic recycled material by a plastic kneader.

  Used plastic products are crushed into small pieces, melted and kneaded by an extruder, partly used for recycled molding materials, partly used for construction materials such as piles, or fuel, but most are incinerated. It is customary to do this. In particular, a film or sheet having a large bulk coefficient or specific surface area is one of the causes that it is difficult to be used as a recycled material because it is easily soiled, but it is also one of the factors that crushing and kneading are difficult.

  That is, films and sheets (for example, supermarket shopping bags) are bulky even when pulverized, and the apparent specific gravity is very small. In order to produce pellets as recycled materials from these pulverized materials or to form construction materials such as piles, even if the recycled raw materials are loaded into the material supply hopper of a screw type extruder, the materials themselves Supplying to the extrusion screw by its own weight is almost zero, and in order to supply a certain amount of material to the cylinder, it is always necessary to apply some external force to the recycled material to forcibly bite it. is there.

  Normally, a method is generally used in which a screw S is mounted in accordance with the center axis of the material hopper and rotated by a driving device to cause the regenerated raw material in the hopper to be swirled into the cylinder of the extruder. Yes (see FIG. 4).

Further, there is a method in which an outlet of a recycled material hopper is provided above the material biting port of the extrusion molding machine, and a vibrator is attached to the outlet, and the recycled material is shaken off by giving a constant vibration to the outlet. . Furthermore, a method is also disclosed in which a forced suction device is provided in the cylinder of the screw extruder to suck the material in the hopper by air.

JP 2005-349838 A JP-A-11-58381

Even if the screw (FIG. 4) mounted in the hopper of the extruder is rotated, the pulverized or crushed material such as thin film is light enough to float in the hopper without being sufficiently caught in the screw of the extruder. It will be in a state like that. In such a state, even if the extruder is operated, the material entering the cylinder melts in a small amount but does not transfer normally, so the material stays in the cylinder and eventually pyrolyzes. . If this crushed material is, for example, vinyl chloride resin, it will corrode the screw and cylinder.

In order to improve the above-mentioned problem, that is, the bite of the material having a small apparent specific gravity into the extrusion molding machine, the present invention slidably contacts the inner peripheral wall surface of the hopper of the extrusion molding machine or maintains a slight gap. A rotating blade device is mounted on a central axis with a predetermined angle of twist in the vertical direction. The device is mounted and rotated.

In this case, the cylinder of the extruder (hereinafter sometimes referred to as a quantitative feeder) to which the hopper is attached is characterized in that it is not heated, so that the recycled material in the cylinder is compressed without melting. Only will be done. Further, the discharge port of this extrusion molding machine (quantitative feeder) is connected to the material biting port of a second non-heated extruder (hereinafter sometimes referred to as a pusher) and discharged into the cylinder. Further, the discharge port of the second pusher is connected to the material biting port of an extruder having a third heating device. Thus, in the present invention, a three-unit connection configuration is adopted.

By connecting the hopper and the extrusion molding machine as described above, the material with a large bulk coefficient put into the hopper is rotated and the material that comes into contact with the blade is rotated. A certain amount (depending on the twist angle θ of the blades) is forcibly pushed into the cylinder hopper port which is the bite inlet of the quantitative feeder through the material discharge port without being leaked from the upper end, and the remaining material is It escapes from between the blades and is rotated by the next blade (after half rotation), circulates in the hopper, and a predetermined amount of material is forced into the cylinder hopper port again. And the material which did not enter further rotates with the rotation of the blade plate, and a part of the material leaks out and goes around by the next blade. This operation is repeated until the end of the hopper material.

Thus, the material pushed into the cylinder of the metering feeder reaches the tip of the cylinder while being compressed by the screw without being melted, and is discharged from there to the material of the next (second) extrusion molding machine (pushing machine). The screw is fed into the cylinder through the inlet, and here, screw compression is performed under the condition of no heating. The material compressed by the two pushers in this way is fed into the cylinder of the extruder through the hopper port of the third cylinder. In this case, the discharge amount is almost sufficient for the cylinder of the third extrusion molding machine, where it is heated and melted for normal molding.

FIG. 1 is a side view of a partial cross section (AB in FIG. 2) showing an outline of connection of a quantitative feeder, a pusher and an extrusion molding machine equipped with a hopper according to the present invention. FIG. 2 is a plan view of the quantitative feeder and hopper portion of FIG. FIG. 3 is a three-side view of the blades in the hopper, where (a) is a plan view, (b) is a front view, and (c) is a side view. FIG. 4 shows a conventional example, which is an extruder having a structure in which a screw S is built in a hopper.

In the quantitative feeder 1 of the plastic kneader (20) of the present invention, the material replenishing hopper 2 has a cylindrical shape, the flat bottom plate 3 of the hopper 2 has a shaft hole 4 at its center, and a material near its periphery. A discharge port 5 is provided, and a rotary shaft 11 of the rotary blade device 10 is rotatably supported by the shaft hole 4. An upper portion of the rotary shaft 11 is supported by a bearing 6, and a rotational driving device M is provided above the shaft 6. Is connected and driven by a motor or the like. In the rotary blade device 10, a horizontal beam 12 having a bottom surface notched in a concave and convex shape 12 a below the rotary shaft 11, that is, immediately above the intersection with the hopper bottom plate 3 is orthogonal to the rotary shaft 11 (therefore, a concave shape). The upper beam 13 is at an angle θ (above the horizontal beam 12 above the horizontal beam 12 at a position above the horizontal beam 12 and about 1/3 lower than the upper end of the hopper 2 in the depth direction. (5 degrees to 45 degrees) It is fixed in a twisted state advanced in the rotation direction of the rotating shaft and orthogonal to the rotating shaft 11. .., Several (four in FIG. 2 and FIG. 3) are joined between the horizontal beam 12 and the upper beam 13 in an interleaved manner at an appropriate interval.

The cylinder of the quantitative feeder 1 is not attached with a heat source such as a heater so as not to cause a bridge under the hopper. The tip of the cylinder 1c of the quantitative feeder 1 is connected to the material supply port 7e of the pusher 7. A heat source is not attached to the cylinder 7c of the pusher 7 as well. Further, these screws 1s and 7s are formed such that the depths of the screw grooves are made shallower or the pitch of the screws is changed so that the material is compressed as it goes to the tip side.

The tip of the cylinder 7c of the pusher 7 is connected to a material supply port 8e of the extruder 8 with heaters 8h, 8h,. A required die 9 is attached to the tip discharge port of the extrusion molding machine 8, and the molten resin is extruded while being formed into a required shape (for example, a strand for pellets).

The cylindrical material replenishing hopper 2 in the plastic kneader 20 has an inner diameter of 600 mm and a depth of 1000 mm. The flat bottom plate 3 has a shaft hole 4 in the center and a material discharge provided in the bottom plate 3 near the periphery. The outlet 5 was a 130 × 260 mm square or elliptical shape. The width (130 mm) of the material discharge port 5 is substantially the same as the screw diameter of the quantitative feeder 1.

The rotary blade device 10 was made rotatable by inserting the lower end of the rotary shaft 11 into the shaft hole 4, inserting the upper portion into the bearing, and connecting the drive source M to the upper portion thereof. In this embodiment, the horizontal beam 12 and the upper beam 13 are made of a stainless steel (SUS) plate having a thickness of 3 mm and a height of 30 mm and a length of 580 mm, and the twist angle of both (the horizontal beam 12 and the upper beam 13) is 15 degrees. As shown in FIG. On the lower surface of the horizontal rail 12, notches 12a having a length of 70 mm and a depth of 5 mm are arranged at almost equal intervals and symmetrically from the center position to the left and right. In addition, blade rods (round bars with a diameter of 30 mm) 14, 14,. In addition, the gap between the lower surface of the horizontal rail 12 and the upper surface of the hopper 2 in the rotary blade device 10 is 1 to 5 mm at a portion where there is no notch. It should be noted that the numerical values shown here are for the embodiment and are not limited to these.

  A crushed piece of polyethylene or polypropylene plastic bag (0.001 to 0.04 mm thick and about 5 mm to 10 mm square (regardless of shape) discarded in a supermarket or the like in this hopper 2. Recycled raw material R.) was introduced and allowed to bite into the extruder. The rotary blade device 10 was rotated 15 to 30 times per minute.

  This regenerated raw material R has a small apparent specific gravity and is in a state close to being fluffy and floating in the hopper 2, but when the blade plate is rotated, a part thereof is compressed at the bottom of the hopper, and a part of the blades 14 and 14 ... And a part thereof slips through the notch 12a portion on the lower surface of the horizontal rail 12, and no excessive load is generated on the rotary blade device 10. Then, a certain amount of the regenerated raw material was caught in the screw of the quantitative feeder 1 from the material discharge port 5 under the hopper. Since the quantitative feeder 1 is not heated by a heater or the like as described above, no bridging occurs in the vicinity of the material supply port 5, and the regenerated raw material R is smoothly entrained.

  The regenerated raw material kneaded and compressed in the cylinder 1c of the quantitative feeder 1 is discharged to the cylinder 7s of the pusher 7 through the material supply port 7e. The cylinder 7c is also unheated and the screw 7s rotates to discharge the recycled raw material to the material supply port 8e of the extruder 8 while compressing and kneading the recycled material. In this extrusion molding machine 8, the cylinder 8c is heated, and the regenerated raw material R is melted, formed into a predetermined shape from the die 9, and extruded. At this stage, the amount of the regenerated raw material R from the hopper 2 is judged. In Example 1, the amount of the crushed material was not sufficient, but the discharge amount from the pusher 7 was stable at a substantially constant amount.

Of the conditions in Example 1, the number of blade rods (round bars with a diameter of 30 mm) 14 and 14 to be passed between and fixed between the horizontal beam 12 and the upper beam 13 was six, and the other conditions were the same, and extrusion molding was performed. The amount of the recycled raw material R is improved. Also, the rotation of the rotary blade device 10 was stable.

  Next, the blade blade twist angle θ is set to 30 degrees (the upper beam is first), and four blade rods (round bars with a diameter of 30 mm) 14 and 14 are arranged between the upper beam 13 and the horizontal beam 12. The material was molded under the above conditions. With this rotary blade device 10, a good extrusion efficiency was obtained. Similarly, the blade was twisted at a twist angle θ of 45 degrees, but the biting amount was slightly increased, which was insufficient for the material biting amount required for a normal extruder. When the twist angle is too large, the rotation of the rotary blade device 10 becomes unstable (rotational resistance is large).

  In the third embodiment, the twist angle θ of the horizontal beam 12 and the upper beam 13 is set to 20 degrees in the hopper 2 of the second example, and six blade bars (round bars with a diameter of 30 mm) 14, 14,. The above material was molded under the above conditions. In this case, the extrusion molding machine was supplied with sufficient material, and the shape of the product extruded from the die 9 was good. From these examples, it was considered that the twist angle (θ) was 5 to 45 degrees, preferably 15 to 30 degrees, and the number of blades 14 to be mounted should be 4 to 6.

  As described above, since the quantitative feeder 1 and the pusher 7 of the plastic kneader according to the present invention do not heat the cylinder, there is no phase change due to the transfer by the rotation of the screw, and only the compression effect that reduces the gap. Therefore, the ideal compression ratio of the screw has to be on a case-by-case basis.

By providing a sufficient space between the blades 14 and 14 in the rotary blade device 10, the recycled material R can be smoothly rotated without excessive compression, and a cut provided on the lower surface of the horizontal beam 12 is provided. The regenerated raw material R is not clogged between the horizontal rail 12 and the bottom plate 3 of the hopper 2 due to the notch 12a. Therefore, the rotational speed of the rotary blade can be freely selected, and the amount of the regenerated raw material to be fed into the quantitative feeder 1 can be easily adjusted.

The plastic kneader and the material supply apparatus according to the present invention are intended for plastic films having a thickness of 1 to several hundred microns. When these films are crushed, the bulk becomes very large, and even if they are put into the hopper of the molding machine as described above, they hardly bite by their own weight. Therefore, it can be used for the regeneration treatment of such a pulverized or crushed state bulky material, for example, industrial films and sheets used in agriculture and the like.

DESCRIPTION OF SYMBOLS 1 Fixed feeder 2 Material replenishment hopper 3 Hopper bottom plate 4 Shaft hole 5 Material discharge port 6 Bearing 7 Forced pushing device 8 Extruder 9 Die 10 Rotary blade device 11 Rotating blade 12 Horizontal crosspiece 12a Irregular notch 12a
M rotation drive device 13 upper crosspiece 14 wing rod

Claims (1)

A plastic kneader (20) for melting and kneading and forming a recycled raw material consisting of a crushed (pulverized) product of a plastic film or sheet, a quantitative feeder (1) with a hopper (2), a pusher (7) and an extrusion In the configuration that is connected to the molding machine (8),
The hopper (2) has a cylindrical shape with a bottom and has a rotating shaft (11) in the inside thereof, and a horizontal beam (12) and an upper beam (13) having a concave and convex bottom surface (12a) perpendicular to the rotating shaft. ) Are spaced apart and fixed with a torsion angle of 5 to 45 degrees, and a plurality of blades (14, 14) are passed between the horizontal beam (12) and the upper beam (13) at intervals of 5 to 20 cm. secured to it by either the vane rod fixed to the outermost periphery during the rotation of the rotary shaft (11) is in sliding contact with the inner peripheral wall surface of the hopper (2), or a circumferential diameter clearance is maintained in 10mm rotary A plastic kneader (20) characterized in that the blade device (10) is mounted so as to be rotationally driven by rotational power.

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