JPH0684010B2 - Pellet manufacturing equipment - Google Patents

Description

TECHNICAL FIELD The present invention relates to an apparatus for pelletizing a material such as thermoplastics, and more particularly to an apparatus for producing pellets by a hot cut method.

<Prior Art> As a device for pelletizing a molding material such as a thermoplastic, conventionally, there are various systems. Among them, the hot-cut method is one in which a material heated and melted by an extruder is passed through a die. A method of producing pellets by extruding and cutting while the extruded material is not cold, which requires less cutting power, less wear of the cutting tool, and rounded edges of the cut pellets. It is widely used because it has advantages such as easy handling as a molding material.

<Problems to be Solved by the Invention> On the other hand, however, the conventional pellet manufacturing apparatus using the hot-cut method requires a large-scale device such as a screw extruder, resulting in high equipment cost and is not suitable for large-scale molding plants. There was a drawback that it was not suitable for.

An object of the present invention is to improve a pellet manufacturing apparatus by the hot cut method having many advantages described above,
The structure is simplified and downsized, and the material can be efficiently pressed to grind and extrude, and vibration and noise during operation can be suppressed to a low level.
Accordingly, it is an object of the present invention to provide a pellet manufacturing apparatus which is inexpensive and can efficiently manufacture high quality pellets.

<Means for Solving the Problems> The structure of the present invention will be described with reference to FIGS. 1 and 2 which are drawings of an embodiment of the present invention.
A plurality of orifices 1a ... 1a are formed on the peripheral wall of a substantially cylindrical body, and openings are formed on both end surfaces of the cylindrical extrusion die 1, and the cylindrical extrusion die 1 is provided in the vicinity of both ends thereof. 2a for driving the cylindrical extruding die to rotate while being supported on the outer periphery, one extruding roll 3 disposed inside the cylindrical extruding die 1, and the cylindrical extruding die 1. A pressurizing mechanism (hydraulic cylinder) that is connected to both ends of the extrusion roll 3 through openings at both ends and presses the extrusion roll 3 from both ends in the radial direction of the cylindrical extrusion die 1.
4, 4), and a cutting member (cutting blade) 5 that is disposed close to the outer peripheral surface of the cylindrical extrusion die and cuts the molding material extruded from the orifices 1a ... 1a. Be attached.

<Operation> When the molten material is supplied to the inside of the cylindrical extrusion die 1 and the extrusion roll 3 is pressurized while rotating the cylindrical extrusion die 1, the material becomes the inner peripheral surface of the cylindrical extrusion die 1. Extrusion roll 3
1a ... 1a, and is rapidly pressurized by the wedge effect and discharged to the outside. The discharge amount becomes maximum at the closest portion between the inner peripheral surface of the cylindrical extrusion die 1 and the outer peripheral surface of the extrusion roll 3, and thereafter,
While the amount is maintained, the cutting member 5 reaches the disposition position, but here, due to the pressing mechanism, the material is almost completely distributed in the longitudinal direction of the die 1 at the maximum pressing part which is the closest part. Pressure is equalized and therefore the cut pellets are of uniform length and density.

Here, since the cylindrical extrusion die 1 and the extrusion roll 3 housed therein have a structure in which both ends are supported, the rigidity can be increased, and the pressing force of the extrusion roll 3 is increased to increase the material. Even if the cylindrical extrusion die 1 is rotated in a state in which a sufficient pressing force is applied, vibration and noise due to the bending of each part are less likely to occur.

Further, since only one extrusion roll 3 is housed in the cylindrical extrusion die 1, the degree of freedom in selecting the outer diameter is large,
By making the outer diameter of the extrusion roll 3 closer to the inner diameter of the cylindrical extrusion die 1, the wedge angle formed between the two can be reduced, and the wedge effect can be expected to efficiently press and grind the material.

<Examples> Examples of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of an essential part of an embodiment of the present invention, and FIG. 2 is a partially cutaway left side view thereof.

A cylindrical extrusion die 1 having a plurality of orifices 1a ... 1a formed on a peripheral wall of a cylindrical body has annular side plates 1 at both ends thereof.
b and 1b are fixed. This cylindrical extrusion die 1 is rotatably supported on a total of four drive rollers 2a ... 2a provided at both ends of two drive shafts 2,2. Drive shaft 2,
A pulley 2d is attached to one end of each of the two, and is rotated by a motor (not shown) via a belt 2e. Each drive roller 2a ... 2a has a flange.
2b is formed, and the flanges 2b ... 2b are side plates 1b, 1b.
It is possible to regulate the axial position of the cylindrical extrusion die 1 by abutting against. With such a configuration, the cylindrical extrusion die 1 is rotationally driven while being supported by both ends of the outer periphery thereof.

Inside the cylindrical extrusion die 1, there is a spindle 3 on both end faces of the cylindrical body.
The extrusion roll 3 formed by forming a and 3a is housed. In this extrusion roll 3, both support shafts 3a, 3a thereof are projected to the outside of the die 1 from the openings of the side plates 1b, 1b at both ends of the cylindrical extrusion die 1 and fixed to the piston rods of the hydraulic cylinders 4, 4, respectively. It is supported by fasteners 4a, 4a, and can be displaced in the radial direction in the cylindrical extrusion die 1 by driving the hydraulic cylinders 4, 4.

A discharge port of a feeder 6 for supplying a material to be molded therein is inserted into an opening of one side plate 1b of the cylindrical extrusion die 1.

Further, slightly below the vertical direction of the cylindrical extrusion die 1 and to the right of FIG. 2, a cutting blade 5 is disposed adjacent to the outer peripheral surface of the circular extrusion die 1 and extending along the axial direction thereof. .

In the above-described embodiment of the present invention, a molding material such as thermoplastic is heated from the feeder 6 and supplied into the cylindrical extrusion die 1, and the extrusion roll 3 is pressed downward by the hydraulic cylinders 4 and 4, Drive shafts 2, 2 are shown in Fig. 2 by arrows A, A
The cylindrical extrusion die 1 rotates in the direction of arrow B in FIG. As a result, the internal material is rolled up between the inner peripheral surface of the cylindrical extrusion die 1 and the outer peripheral surface of the extrusion roll 3, and is ground by the abrupt pressure applied by the wedge effect formed on both surfaces of the orifice 1a. It is discharged to the outside of the cylindrical extrusion die 1 from 1a. At this time, the discharge amount becomes maximum at the closest portion between the inner peripheral surface of the cylindrical extrusion die 1 and the outer peripheral surface of the extrusion roll 3, and thereafter reaches the cutting blade 5 while maintaining the amount, It collides with this cutting blade 5 and is cut into pellets. Here, the material pressing mechanism is a mechanism for press-fitting the material into the wedge space that is uniformly in the axial direction and is formed by the extrusion roll 3 that is almost inscribed in the cylindrical extrusion die 1. At a certain maximum pressure portion, a pressure equalizing portion is formed along the longitudinal direction of the die 1, and the cut pellets have uniform length and density.

Particularly noteworthy in the above-mentioned embodiments is that the cylindrical extrusion die 1 is rotated while being supported at both outer peripheral ends thereof, and the extrusion roll 3 inside the cylindrical extrusion die 1 is opened at both ends of the cylindrical extrusion die 1. This is a point where pressure is applied from both ends of the extrusion roll 3 through the section, so that even if the pressing force of the extrusion roll 3 is increased, a substantially uniform stress is applied to the extrusion roll 3 and the cylindrical extrusion die 1 in the axial direction thereof. Therefore, both members will not be twisted to generate vibration or noise.

Further, since one extrusion roll 3 is housed in the cylindrical extrusion die 1, by setting the outer diameter of the extrusion roll 3 closer to the inner diameter of the die 1, the wedge angle formed between them is increased. Can be made extremely small, and the material can be efficiently pressed and ground by a sufficient wedge effect. This means that if a granular or lumpy material remains in the material fed into the cylindrical extrusion die 1, it will be sufficiently ground and extruded, which has the effect of improving the quality of the obtained pellets. Connect.

In the above-mentioned examples, the pressing die 1 and the extrusion roll 3 are used.
In the above, the example in which the outer peripheral surface is formed into a right circular cylinder shape is shown, but it is also possible to form each of them into a curved circular cylinder shape having a substantially convex curvature, and in this case, the grinding effect of the material is further improved. It will be. When using this curved cylindrical extrusion die and extrusion roll, press the extrusion roll by alternately applying pressure to both ends of the extrusion roll with a hydraulic cylinder that supports and extrudes both ends of the extrusion roll. With a slight rocking inside, the grinding effect is further enhanced.

Further, as a cutting member, it is needless to say that a rotating cutter, a knife cutter, or the like can be used instead of the cutting blade 5 that collides with the material discharged from the orifices 1a ... 1a and shears into pellets.

<Effects of the Invention> As described above, according to the present invention, pressure is applied in the radial direction of a cylindrical extrusion die having a plurality of orifices formed in the peripheral wall of a substantially cylindrical body. An extrusion roll is arranged, the pressing roll is pressed while rotating the cylindrical extrusion die, the material supplied inside the extrusion die is pressed by the wedge effect, and the extruded material is discharged from the orifice. Since it is cut into pellets, it is possible to obtain a pellet manufacturing apparatus with a simple structure and a small hot-cut method without using a large apparatus such as a screw extruder as in the past. Moreover, due to the pressurizing mechanism, the obtained pellets have good length and density.

Further, the cylindrical extrusion die is rotated while being supported at both ends of the outer periphery thereof, and the extrusion roll inside thereof is also extended in the radial direction of the cylindrical extrusion die from both ends through the openings at both ends of the cylindrical extrusion die. Since a structure that is pressurized is used, vibration and noise are less likely to occur due to twisting of each part during operation, that is, rotation in a pressurized state, and pellet manufacturing with high rigidity while having a simple structure The device is obtained.

In addition, since one extrusion roll is housed in the cylindrical extrusion die, there is a large degree of freedom in selecting the outside diameter of the extrusion roll. If necessary, the outside diameter can be set to the inside diameter of the cylindrical extrusion die. By making them close to each other, the wedge angle formed between them can be made extremely small, and it is possible to wrap the material between them and exert a great grinding effect, and with a simple and small device The resulting pellets are of high quality.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an embodiment of the present invention, and FIG. 2 is a partially cutaway left side view thereof. 1 ... Cylindrical extrusion die 1a ... 1a ... Orifice 2 ... Drive shaft 2a ... 2a ... Drive roller 2d ... Pulley 2e ... Belt 3 ... Extrusion roll 4,4 ... Hydraulic cylinder 5 ... For cutting Blade 6 ... feeder

Claims (1)

[Claims] 1. A cylindrical extrusion die in which a plurality of orifices are formed in a peripheral wall of a substantially cylindrical body and openings are formed in both end surface portions thereof, and the cylindrical extrusion die is provided in the vicinity of both end portions thereof. A plurality of drive rollers that rotate and drive the cylindrical extrusion die while being supported on the outer periphery, one extrusion roll disposed inside the cylindrical extrusion die, and openings at both ends of the cylindrical extrusion die. A pressure mechanism that is connected to both ends of the extrusion roll through the pressing roll and presses the extrusion roll in the radial direction of the cylindrical extrusion die from both ends thereof, and is arranged close to the outer periphery of the cylindrical extrusion die, A pellet manufacturing apparatus provided with a cutting member for cutting a molding material extruded from an orifice.