JPH09207130A - Method and apparatus for granulating plastic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to increase the granulating amount of a granulating apparatus without raising the manufacturing cost and running cost. SOLUTION: A motor 15 is driven, a cutter support plate 9 is reciprocated by a cam 14 and spring 13 mounted at a cutter drive shaft 16 at a high speed. Thus, a cutter 10 is reciprocated along the surface of a die to cut the melted resin discharged from the nozzle hole of the die in a granular state.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic granulating method and apparatus, and more particularly to a die of a plastic granulating apparatus and a cutter unit provided opposite thereto. is there.

[0002]

2. Description of the Related Art Conventionally, as a plastic granulating apparatus, for example, the configurations shown in FIGS. 7 and 8 have been adopted. That is, what is indicated by reference numeral 21 in FIG. 7 is an underwater granulating apparatus which is an example of the granulating apparatus, and this underwater granulating apparatus 2l is equipped with the extruder 2 via the cutter box 24.
It is fixed to the tip portion of 2 or the die 23 attached to the tip portion. The die 23 has a disc shape,
A ring-shaped portion 23a surrounding the center thereof is provided with a large number of nozzle holes 25 penetrating in the axial direction.

As described above, one side of the cutter box 24 is fixed to the tip of the extruder 22 or the die 23, and the other side is fixed to the cutter unit 26. Further, a cooling water inlet 27 is provided at the lower part of the cutter box 24, and a cooling water outlet 28 is provided at the upper part so that the inside of the cutter box 24 is always filled with warm water.

Housing 2 of the cutter unit 26
A cutter drive shaft 30 is coaxially rotatable in the shaft 9 and is movable in the axial direction (longitudinal direction). At the tip of the cutter drive shaft 30, a cutter holder 3
1 is held, and a motor 32 is connected to the rear end of the motor. A plurality of cutters 33 are radially fixed and held on the end surface of the cutter holder 31 on the die 23 side.

In the above-mentioned underwater granulator 21, when the cutter drive shaft 30 is rotated by the motor 32, each cutter 33 is rotated at high speed and the nozzle hole 25 of the die 23 is rotated.
The molten resin discharged from is cut into particles by each cutter 33. The cut pellets are cooled water inlet 27
It is solidified by the cooling water supplied from the inside to the cutter box 24, and is sent together with this cooling water from the cooling water outlet 28 to a processing unit (not shown) and dried to be a product.

[0006]

Since the conventional underwater granulating apparatus is constructed as described above, there are the following problems. That is, in order to increase the granulation amount of the underwater granulator, it is necessary to increase the outer diameter of the ring-shaped portion of the die to increase the number of nozzle holes and lengthen the cutter. However, when the cutter is lengthened, the cutter is cantilevered and rotated, so that the strength of the cutter is insufficient and the contact with the ring-shaped portion of the die becomes uneven. Therefore, it is necessary to increase the size of each of the constituent members, which causes a problem of increased manufacturing cost and running cost.

The present invention has been made in view of the above problems, and it is made of plastics capable of increasing the granulation amount of the granulating device without increasing the manufacturing cost and the running cost. An object of the present invention is to provide a graining method and an apparatus thereof.

[0008]

The method of granulating a plastic according to the present invention is characterized in that a cutter reciprocates along the surface of a die to granulate.

The plastic granulator according to the present invention comprises:
It has a die having a nozzle hole on the entire surface and a cutter unit provided so as to face the surface of the die, and the cutter unit includes a pair of spaced cutter support plates and both ends of the pair of cutter support plates. Is supported, and a cutter driving device that reciprocates the cutter along the surface of the die.

A pressing rib is preferably provided on the back surface of the cutter. The surface of the die may be curved.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a granulating apparatus according to the present invention. In the figure, reference numeral 1 denotes an underwater granulating apparatus which is an example of a granulating apparatus. The underwater granulating apparatus 1 is attached to the tip of the extruder 2 or the tip thereof via the cutter box 4. It is fixed to the attached die 3. The die 3 has a flat plate shape or a disc shape, and a large number of nozzle holes 5 penetrating in the axial direction are provided on the entire surface thereof. In the cutter box 4, the die 3
A cutter unit 6 is provided so as to face the surface of the. In the lower part of this cutter box 4, cooling water inlet 7,
A cooling water outlet 8 is provided in the upper part so that the inside of the cutter box 4 is always filled with warm water.

FIG. 2 is a view showing the cutter unit 6 of the underwater granulating apparatus 1. The cutter unit 6 includes a pair of cutter support plates 9 spaced apart from each other, a plurality of linear cutters 10 each having a curved cross section and both ends thereof being supported by the cutter support plate 9, and the pair of cutter support plates 9 A pair of support bars 11 supported at the upper and lower ends of the
A plurality of pressing ribs 12, both ends of which are attached to the support rod 11 and are in contact with the back surface of the cutter 10 at right angles, and a cutter driving device 17 for moving the cutter support plate 9 up and down. The cutter driving device 17 comprises a spring 13 arranged at the upper ends of the pair of cutter support plates 9 and a cam 1 arranged at the lower ends.
4, a cutter drive shaft 16 to which the cam 14 is attached, and a motor 1 that rotates the cutter drive shaft 16.
And 5.

FIG. 3 is a view taken along the line AA of FIG. 2 and shows a side surface of the cutter support plate 9. In addition, FIG. 4 shows B of FIG.
In the -B arrow view, the pressing rib 12 provided in contact with the back surface of the cutter 10 is shown. As shown in the figure, both ends of the pressing rib 12 are attached to the support rod 11 so as to penetrate therethrough, and fixed by bolts 18. The pressing ribs 12 are provided in order to allow the cutter 10 as shown in FIG. 5 to uniformly contact the surface of the die 3 and evenly wear the cutter 10. The nozzle holes 5 of the die 3 are provided above and below each cutter 10 and in parallel with the cutter 10.

Next, the operation of the above-mentioned underwater granulator 1 will be described.

When the motor 15 is driven, the cutter support plate 9 moves the cam 1 mounted on the cutter drive shaft 16.
4 and the spring 13 reciprocate at a high speed for a very short distance. As a result, the cutter 10 also has the pressing ribs 12 provided in contact with the back surface of the cutter 10, so that the die 3
Reciprocates by evenly contacting the surface of.

The molten resin discharged from the nozzle hole 5 of the die 3 is cut into particles by each cutter 10. The cut pellets are solidified by the cooling water supplied from the cooling water inlet 7 into the cutter box 4, and are sent together with this cooling water from the cooling water outlet 8 to a processing unit (not shown), dried and commercialized.

In the above-mentioned embodiments, the granulating apparatus has been described as the underwater granulating apparatus 1, but it may be an aerial granulating apparatus (so-called hot cutting apparatus). Further, in the above-described embodiment, the cutter 10 is reciprocally moved up and down, but the cutter unit 6 shown in FIG.
You may reciprocate the cutter 10 right and left.

Further, as shown in FIG. 6, the surface of the die 3 may be curved, and the cutter 10 may be similarly curved and reciprocated accordingly. In this way, the cutter 10 contacts the surface of the die 3 uniformly, and the wear of the cutter 10 also becomes uniform.

[0020]

Since the present invention is configured as described above, the following effects can be obtained. That is, (a) nozzle holes can be provided inside the ring-shaped portion as compared with the conventional disc-shaped die, so that three times or more nozzle holes can be provided. (b) Since the entire device can be made smaller, the manufacturing cost and running cost can be dramatically reduced. (c) By using a die with a row of nozzle holes formed between the cutters, the nozzle holes can be prevented from being cooled by water by placing the cutters above the nozzle holes at the start of operation. Therefore, the temperature of the plastic in the nozzle hole can be maintained at a temperature equal to or higher than the melting point. As a result, cutting can be started while the cutter box is filled with water.

[Brief description of drawings]

FIG. 1 is a perspective view showing a granulating device.

FIG. 2 is a perspective view showing a cutter unit of the granulating device.

FIG. 3 is a view as viewed in the direction of arrows AA in FIG. 2;

FIG. 4 is a view taken in the direction of arrows BB in FIG. 2;

FIG. 5 is a diagram showing a linear cutter.

FIG. 6 is a view showing a cutter unit according to another embodiment, and FIG. 6A is a perspective view showing the cutter unit.
FIG. 2B is a perspective view showing the cutter.

FIG. 7 is a perspective view showing a conventional granulating apparatus.

FIG. 8 is a diagram showing a contact state between a conventional die and a cutter.

[Explanation of symbols]

 1 Underwater granulator (granulator) 2 Extruder 3 Die 4 Cutter box 5 Nozzle hole 6 Cutter unit 9 Cutter support plate 10 Cutter 11 Support rod 12 Pressing rib 13 Spring 14 Cam 15 Motor 16 Cutter drive shaft 17 Cutter drive apparatus

Claims (4)

[Claims] 1. A method for granulating a plastic, which comprises reciprocating a cutter (10) along the surface of a die (3) to granulate. 2. A die (3) having a nozzle hole (5) on the entire surface, and a cutter unit (6) provided so as to face the surface of the die (3), and the cutter unit (6). ) Is a pair of spaced cutter support plates (9)
A plurality of cutters (10) whose both ends are supported by the cutter support plate (9), and a cutter driving device (1) that reciprocates the cutters (10) along the surface of the die (3).
7) and a granulating apparatus for plastics, characterized in that 3. The plastic granulator according to claim 2, wherein a pressing rib (12) is provided on a back surface of the cutter (10). 4. The plastic granulator according to claim 2, wherein the surface of the die (3) is curved.