JPS6233052B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a resin pellet manufacturing apparatus that manufactures resin pellets by cutting resin extruded in a linear shape through a die mounted on the head of an extruder using the die portion.

In order to cut the extruded resin into linear resin, the above-mentioned resin pellet production equipment needs to cool the linear resin to a temperature that allows it to be cut into pellets, but conventional cooling means use the linear resin outlet of the die. The part between the side and the cutter installed opposite thereto is constructed into an airtight chamber, in which cooling water (hot water) is made to flow to cool the linear resin, and the resin pellets cut by the flow of the cooling water are collected. It was taken out of the airtight room.

With this configuration, the die side is affected by the high temperature of the extruder and becomes high temperature, so in order to cool it down to the temperature required to cut it into pellets,
It requires a large airtight chamber and enough cooling water (hot water) to fill it, which makes the equipment larger, and requires a large amount of cooling water and a large amount of heat to make this cooling water the appropriate temperature. .

In addition, when cutting polypropylene resin into pellets, it is necessary to cool it more strongly than with other resins, so it is impossible to produce pellets with the same cooling means, so it is necessary to use a powerful cooling means for this resin. A dedicated machine must be configured.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a resin pellet manufacturing apparatus that can sufficiently cool extruded linear resin with a small amount of water and heat.

In this invention, a die having a mold hole for molding resin into a linear shape is attached to the head of an extruder, and a cutter for cutting the linear resin into pellets is provided on the outer surface of the die. The resin pellet manufacturing apparatus is characterized in that each of the die and the cutter is provided with a nozzle that directs the ejection direction toward the cutting part, and a mixed cooling fluid source containing a mixture of cooling water and air is connected to these nozzles.

According to this invention, since the linear resin is cooled by jetting out a mixed cooling fluid that is a mixture of cooling water and air, the temperature of the cooling water decreases because air, or bubbles, in the fluid have significantly lower heat conduction than the cooling water. Although it tries to rise due to the influence from the die side, it becomes bubbles and is blocked, suppressing the temperature rise of the cooling water and maintaining the appropriate cooling temperature set for the mixed cooling fluid, and forming a good linear resin at this optimum cooling temperature. It is possible to produce all kinds of resin pellets including polypropylene with one model.

Moreover, by providing a nozzle on the die as well, the die itself can be cooled sufficiently, so the configuration of the cooling means can be downsized and the device can be made more compact.
Furthermore, since air is mixed in the mixed cooling fluid, the amount of cooling water is reduced accordingly, and the amount of cooling water and amount of heat is also small, which is economical.

An embodiment of the present invention having such characteristics will be described in detail below with reference to the drawings.

The drawing shows a resin pellet manufacturing apparatus, and in FIG. 1, the resin pellet manufacturing apparatus 1 is constituted by a head 3 of an extruder 2, and the extruder 2 is a well-known type consisting of a cylinder (not shown) and a screw (not shown). It is the composition.

A die 6 formed by joining two disks 4 and 5 is attached to the front surface of the above-mentioned head 3, and this die 6 extrudes the resin into a linear shape as described later.

In addition, a cover 7 is provided on the front side of the die 6,
Inside the cover 7 are constructed a linear resin cutting means and a cooling means which will be described later, and the cut resin pellets and cooling water are discharged from the lower surface of the cover 7. Further, on the front surface of the cover 7, an end of a cutter rotating shaft 8 constituting a cutting means is projected, and a sprocket 9 is fixed to the end of this shaft 8.

A support stand 10 is fixed to the upper front surface of the above-mentioned head 3, and a motor 11 is placed on this support stand 10, and a sprocket 13 fixed to its output shaft 12 and a sprocket 9 of the above-mentioned rotating shaft 8 are mounted on the support stand 10. A chain 14 is stretched between the two, and the motor 11 drives the cutter rotating shaft 8 in a predetermined direction.

In front of the central part of the aforementioned cutter rotation shaft 8 is a double pipe-shaped support shaft 15 that also serves as a bearing for this shaft 8.
is protruded, and a pipe joint 16 is attached to the shaft end of this support shaft 15.
is fixed, and a die-side pipe 17 for supplying a cooling medium to the die 6 side and a cutter-side pipe 18 for supplying a cutter side to be described later are connected to this pipe joint 16.

Note that the spring 19 urges the cutter toward the die 6 side.

In FIGS. 2 to 4, the disks 4 and 5 constituting the aforementioned die 6 have a mold hole 20 that passes through them in a joined state. A large number of them are formed in a predetermined circumferential range excluding the outer circumferential edge.

The disc 4 is a heating side for maintaining resin flow, and embedding holes 21 are formed in radial positions where the mold holes 20 described above are sewn, and sheathed heaters 22 for boosting are embedded in these holes. ing.

The disk 5 described above is a cooling side for cooling the linear resin, and conductive passages 23 are formed at radial positions stitched through the cooling holes 20 described above, and each passage 2
3... communicates with a supply passage 24 formed in a circumferential shape on the center side. Also, each conduction path 23...
are in communication with die-side nozzles 25 formed in radial rows on the outer surface of the disk 5.

The inner end of a support shaft 15 is fixed to the front surface of the center of the die 6 consisting of the disks 4 and 5 described above with a screw.
This support shaft 15 has a die-side cooling passage 27 and a cutter-side cooling passage 28 formed by the interior of the pipe 26, and the end of the die-side cooling passage 27 is formed by a conduit passage 29 bored in the radial direction. The aforementioned supply passage 24
is connected to. The die side cooling passage 27 is connected to the die side pipe 17 described above.

The aforementioned cutter rotating shaft 8 is supported on the outer periphery of the support shaft 15 by bearings 30, 30, and a disc-shaped cutter block 31 is fixed to the inner end of the rotary shaft 8. It is in sliding contact with the outer periphery so that airtightness is maintained.

Cutters 32 are implanted on the inner surface of the cutter block 31 at four radial positions corresponding to the circumferential range of the die hole 20 of the die 6. comes into contact with the outer surface of the die 6, and this contact pressure is applied by the spring 19 described above.

Each cutter 32 described above is provided with a plurality of cutter-side nozzles 33 in a row, which are opened in the direction of rotation thereof, and the inner ends of the nozzles 33 are connected to the inner side of the cutter 33 and the cutter block 31. The conductive path 34...... formed in the conductive path 34...
. . communicates with a supply passage 35 formed circumferentially in the stop portion of the cutter block 31.

The inner end of the cutter side cooling passage 28 of the support shaft 15 communicates with the above-mentioned supply passage 35 via the conduction passage 36, and the outer end communicates with the above-mentioned cutter side pipe 18.

The resin pellet manufacturing apparatus 1 configured as described above uses a mixed cooling fluid, which is a mixture of cooling water (hot water) and air at a volume ratio of, for example, 1:1, as a cooling medium, and this fluid is pressurized with an appropriate pressure pump. The pressurized cooling water is mixed with compressed air pressurized by a suitable compressor and sent to the die side pipe 17 and the cutter side pipe 18 through on-off valves (not shown), respectively.

These mixed cooling fluids are supplied to the die side nozzle 25 via the die side cooling passage 27 and to the cutter side nozzle 33 via the cutter side cooling passage 28, and are supplied to the cut section by the die 6 and the cutter 32. It is ejected from the nozzles 25 and 33.

When the motor 11 is driven, the cutter rotation shaft 8 is rotated, and the cutter 32 is rotated in the cutting direction. When the extruder 2 extrudes the resin in this state, the resin is released from the mold hole 20 of the die 6. is formed into a linear shape and extruded, and the cutter 32 cuts this linear resin into pellets.

During this cutting, the resin is cooled by the mixed cooling fluid ejected from both nozzles 25 and 33, and the disk 5 of the die 6 is also cooled by each conductive path 23, so the resin is kept at a temperature suitable for cutting. is cooled to

Note that the heat conduction of mixed cooling fluid, i.e., air bubbles, is significantly lower than that of cooling water. As a result, the temperature rise can be suppressed and the appropriate cooling temperature set for the mixed cooling fluid can be maintained, and the cooling effect can be significantly enhanced.

The cut resin pellets are then discharged from the lower part of the cover 7 together with the mixed cooling fluid.

In the above embodiment, the mixed cooling fluid of air was ejected from both the die side nozzle 25 and the cutter side nozzle 33, but since this device 1 has a high cooling effect, it can be applied to different types of resin for producing pellets. It is possible to selectively use the mixed cooling fluid from one of the nozzles 25 or 33 and only cooling water from the other, and also adjust the amount of air mixed in the mixed cooling fluid.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is a side view of a resin pellet manufacturing apparatus. Figure 2 is an enlarged sectional view of the main part. FIG. 3 is a sectional view taken along the line A-A in FIG. 2. FIG. 4 is a sectional view taken along the line BB in FIG. 2. 1... Resin pellet manufacturing device, 2... Extruder,
3...Head, 6...Dice, 25...Dice side nozzle, 32...Katsuta, 33...Katsuta side nozzle.

Claims (1)

[Scope of Claims] 1. A method for manufacturing resin pellets, in which a die having a mold hole for molding resin into a linear shape is attached to the head of an extruder, and a cutter for cutting the linear resin into pellets is provided on the outer surface of the die. A device for producing resin pellets, wherein a nozzle is provided on each of the die and the cutter, and a mixed cooling fluid source containing a mixture of cooling water and air is connected to the nozzle, the jetting direction being directed toward the cut portion by the die and the cutter. Manufacturing equipment.