JP3010264U - Cooling device for thermoplastic resin granulator - Google Patents

Abstract

(57) [Summary] [Purpose] Good quality pellets can be obtained continuously. [Structure] The die nozzle 4 is formed on the male side taper portion 30 of the die plate 3, and the male side taper portion 3 is formed on the rotary cutter 6.
A female side taper portion 60 which is externally fitted to 0 is formed, and the cutter blade 7 is arranged on the inner surface of the female side taper portion 60. A primary cooling water supply pipe 301 is provided at the axial center of the rotary cutter 6, and a secondary cooling compressed air supply device U and a third cooling water supply device V are provided. The molten resin discharged from the die nozzle 4 is cut into pellets by the cutter blade 7, cooled and solidified by the primary cooling water, and discharged from between the tapered portions 30 and 60 to the outside. It is moved to the rear of the rotary cutter 6 by the next cooling compressed air, and then the pellet discharge port 1 is moved by the third cooling water.
Moved to 2.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a cooling device for a thermoplastic resin granulator. More specifically, the molten resin (plastic material) continuously discharged from multiple die nozzles of the die plate is cut with a cutter blade that rotates at a predetermined cycle, and the resin (plastic) pellets are cooled with a cooling medium such as cooling water. The present invention relates to a cooling device of a granulator for cooling.

[0002]

[Prior art]

 Generally, as a granulation method for a thermoplastic resin granulator (pelletizer), (1) the molten resin extruded from the die at the tip of the extruder is introduced into a cooling water tank and cooled and solidified into a strand with a substantially circular cross section. After that, a strand cutting method in which a fixed blade and a rotating blade are used to cut through a take-up roller. (2) A cutter blade of a rotary cutter that brings molten resin extruded from the die plate at the end of the extruder into close proximity to the die plate. Air-cooling cutting method in which cooling gas is sprayed to the cutting portion when cutting with (3) When cutting as in (2) above, mist cutting method in which mist-like water is sprayed into the cutting portion, (4) Extrusion The hot cut method, which is an underwater method in which molten resin is extruded from the die plate at the machine tip into cooling water and cut in water, is usually used.

Each of the above methods has its own advantages and disadvantages. For example, in the so-called cold cut method such as the strand cut method, the granulating machine (pelletizer) is not directly connected to the extruder, and when cutting or trouble occurs. It is relatively easy to deal with, but on the other hand, there is a problem with the stability of cooling during extrusion. Further, the so-called hot cut method such as the underwater method has a good cooling effect, but has a problem in supplying cooling water or operating in cooling water. These granulation cooling methods are used properly depending on the purpose and the resin material, but attempts have also been made to combine them utilizing the characteristics of these methods.

[0004]

[Problems to be solved by the device]

 By the way, according to the air cooling cutting method, the mist cutting method, and the hot cutting method of the above (2) to (4), molten resin having a high viscosity in the cylinder of the extruder passes through the die nozzle of the die plate and gas or There is no problem as long as it is an ideal material that is completely solidified immediately by a cooling medium such as mist. However, since the molten resin usually remains viscous even after passing through the die nozzle, pellets that have been once cut have the property of easily sticking or fusing again to form a mass. However, in the extruder, a die nozzle is provided in the vertical wall portion of the tip of the die plate, and the cutter blade of the rotary cutter is opposed to the die nozzle in a positive plane in the axial direction.

Therefore, when the resin is cut into pellets (chips) by the cutter blade, it is difficult to continuously supply the cooling medium, that is, to spray the cooling medium to the cutting region between the die nozzle and the cutter blade. However, due to the above characteristics of the resin, pellets that have been cut once are re-adhered or fused to each other to form particles. Further, as described above, since it is difficult to continuously supply the cooling medium, it is difficult to discharge the cut pellets from the cutting area, which causes a problem that the cut pellets are cut again by the cutter blade. . As described above, there is a problem that pellets are dumped or cut again and it is difficult to obtain good pellets. Especially, when cooling water is used as the cooling medium, the solidification effect of the molten resin can be increased. Instead, since it becomes more difficult to continuously supply the cooling medium to the cutting area, both of the above problems are remarkable.

[0006]

[Means for Solving the Problems]

 The present invention forms a die nozzle for extruding a molten thermoplastic resin into a granulation chamber on a die plate provided at the tip of an extruder, and uses a rotary cutter that rotates in the vicinity of the tip of the die plate. In the cooling device of the granulator (pelletizer), the resin extruded from the die nozzle is cut into pellets, the cut pellets are cooled and solidified with cooling water, and the pellets are discharged from the pellet discharge port of the granulation chamber housing. These problems can be solved all at once by combining multiple cooling media and causing the flows of the cooling media to function in their respective roles in order without causing such problems. It is intended to provide a cooling device for a granulator. Note that the peripheral wall portion on the tip side of the die plate is tapered, and the tip portion of the rotary cutter corresponding thereto is also tapered, so that the cooling water is supplied from the hollow rotary shaft of the rotary cutter. There is a patent application (reference number = OMY628-1) which has been filed by a person at the same time, and the present invention is the one improved by applying this. That is, the feature of the present invention is that the peripheral wall portion on the tip side of the die plate is made into a taper shape and the male side taper portion in which the die nozzle is arranged, and the tip end portion of the rotary cutter is made into a taper shape. The female side taper part that is externally fitted to the male side taper part, the cutter blade is arranged on the inner surface of the female side taper part, and the primary part between the rotary cutter and the die plate is located at the center of the rotary cutter. A cooling water supply pipe for supplying the cooling water is installed, and a star-shaped frame cage that is covered with a mesh and covers the inner surface of the granulation chamber housing is rotatably arranged with respect to the rotating cutter. Equipped with driving means for intermittent rotation in the forward and reverse directions, (1) Secondary cooling compressed air is supplied to the granulation chamber to move the secondary compressed compressed air behind the rotary cutter. Feeding device, (2) Granulation chamber Third-order by supplying cooling water, is that the pellet behind rotating cutter with a tertiary cooling water supply device for moving the pellets discharge port.

[0007]

[Action]

 The molten resin discharged from the die nozzle of the extruder is hot-cut (cut) into pellets (chips) by a cutter blade of a rotating cutter that rotates at a predetermined speed. The hot-cut pellets are cooled and solidified by the primary cooling water supplied to the cutting area, that is, between the tapered parts, and the pressure of the primary cooling water and the force acting from the rotary cutter By this, it is easily blown out radially and scattered in the granulation chamber. The pellets scattered in the granulation chamber are moved to the back of the rotary cutter while being cooled by the secondary cooling compressed air, and then further cooled by the tertiary cooling water and aggregated. In this state, it is dropped downwards, moved smoothly to the pellet discharge port, and the pellets are taken out together with the cooling water.

[0008]

【Example】

 Hereinafter, one embodiment of the present invention will be described in detail with reference to FIG. FIG. 1 shows the overall arrangement of an apparatus according to an embodiment of the present invention. An extruder 1 is provided with a screw 2 exemplified as an extruding member inside the extruder. The screw 2 is rotationally driven to melt and knead the thermoplastic resin. 3 is a die plate, 4 is a dynozzle, 5 is a granulation chamber, 6 is a rotary cutter, 7 is a cutter blade, 9 is a granulation chamber housing, and 12 is a pellet discharge port. A peripheral wall portion on the tip side (extrusion side) of the die plate 3 is a tapered male side taper portion 30, and the male side taper portion 30 has a plurality of die nozzles 4 which penetrate the male side taper portion perpendicularly to the outer surface thereof. Are arranged in a star-shaped pattern at equal intervals in the circumferential direction.

The rotary cutter 6 is disposed inside the granulation chamber 5, is located on the extension axis of the die plate 3, and faces the tip of the die plate 3 in the axial direction. A cooling water storage chamber 13 is defined between the plate 3 and the rotary cutter 6. The rotary cutter 6 is rotationally driven by a drive motor (not shown) via the pulley portion 306. A tip portion (die plate side) of the rotary cutter 6 is a tapered female side taper portion 60, which is externally fitted to the male side taper portion 30 so that the outer surface of the male side taper portion 30 and the female side taper portion 30 are fitted. The inner surface of the super portion 60 faces. On the inner surface of the female taper portion 60, a plurality of cutter blades 7 are arranged at equal intervals in the circumferential direction. Both the tapered portions 30 and 60 form a suitable angle with respect to the rotation axis of the screw 2, and the cutter blade 7 faces the male tapered portion 30 with a predetermined clearance.

The rotary cutter 6 is waterproofed by the bearings 304 a and 304 b and the seal 305 on the primary cooling water supply pipe 301 located at the shaft center (rotation shaft center, rotation center) of the rotary cutter 6. It is rotatably supported (as watertight). The cooling water supply pipe 301 is made of a hollow pipe, through which the primary cooling water passes, and its tip is fitted to the axial center (center) of the tip of the die plate 3. . A hole 303 that opens to the cooling water storage chamber 13 is formed through the peripheral wall portion on the front end side of the cooling water supply pipe 301. A primary cooling water supply device W for supplying primary cooling water to the inside thereof is connected to the base end portion (the end portion on the side opposite to the die plate) of the cooling water supply pipe 301.

A pair of upper and lower intake ports 311 are formed on the outer peripheral portion on the right side of the granulation chamber housing 9, and the secondary cooling air supply device U is connected to the intake ports 311. The supply device U supplies secondary cooling compressed air (cooling medium) into the granulation chamber 5 to move the cut pellets P to the rear of the rotary cutter 6. At the upper part of the granulation chamber housing 9, an intake port 312 is formed behind the female side taper portion 60 of the rotary cutter 6, and the third cooling water supply device V is connected to the intake port 312. ing. This supply device V supplies the third cooling water into the granulation chamber 5 to move the pellets P behind the rotary cutter 6 to the pellet discharge port. The pellet discharge port 12 is located below the intake port 312.

The cage 308 is a star-shaped cage, and as shown in the figure, a stainless mesh 309 is stretched except for the intake ports 311 and 312, the pellet discharge port 12 and the vicinity of the shaft center (rotation center). It is disposed inside the granulation chamber housing 9 and covers the inner surface of the granulation chamber housing 9. The cage 308 is rotatably and waterproofly (watertightly) rotatably supported by the rotary cutter 6 and the granulation chamber housing 9 via bearings 314, 315, and seals 316, 317, and via a cage rotation pulley 310. The cage 308 is connected to the drive motor 320, and is intermittently driven to rotate in a fixed direction or a forward or reverse direction at a low speed such that pellets do not adhere to the inner surface of the cage 308.

According to the embodiment configured as described above, the thermoplastic resin melt-kneaded by the screw 2 is discharged from the die nozzle 4 of the die plate 3 and the cutter blade 7 of the rotary cutter 6 that rotates at a predetermined speed. Is hot cut (cut) into pellets (chips). In addition, the primary cooling water is jetted from the primary cooling water supply device W through the hole 303 of the cooling water supply pipe 301 into the cooling water storage chamber 13 between the die plate 3 and the rotary cutter 6. Thus, the pellets P are radially and continuously supplied between the tapered portions 30 and 60, that is, between the die nozzle 4 and the cutter blade 7 which are cutting regions, and the pellet P cut as described above is cooled and solidified. In this way, cooling water with a high solidification effect in the cooling medium can be continuously supplied to the cutting area, and the pellets can be cooled well, so that pellets once cut can be re-adhered or fused again. Then, there is no dumpling.

Further, since the pressure flow of the cooling water is radially supplied to the cutting region from the rotating shaft center portion and the cut pellets are also subjected to the force and the like acting from the rotary cutter 6, the pellets are cut from the cutting region. Radially blown out easily (discharged). Moreover, since the secondary cooling compressed air is supplied from the secondary cooling compressed air supply device U into the granulation chamber 5 through the intake port 311, the blown pellets are While being cooled by the next cooling compressed air, it is moved behind the rotary cutter 6. Therefore, the once cut pellets are not cut again by the cutter blade 7.

Further, since the third cooling water is supplied from the third cooling water supply device V into the granulation chamber 5 through the intake port 312, it is moved to the back of the rotary cutter 6. The pellets thus obtained are further cooled by the third cooling water, moved downward in a collective state, smoothly moved to the pellet discharge port 12, and taken out from the pellet discharge port 12 together with the cooling water. It Further, since the inner surface of the granulation chamber housing 9 is almost entirely covered with the star-shaped frame cage 208, pellets are unlikely to adhere to the inner surface of the granulation chamber housing 9. Further, the stainless mesh 309 is stretched over most of the cage 308, and the cage 308 is intermittently rotated by a drive motor 320 at a low speed such that pellets do not adhere to the inner surface of the cage 308 in a fixed direction or a forward or reverse direction. Therefore, there is little risk that the pellets will adhere to the cage 308.

[0016]

[Effect of device]

 According to the present invention, it is possible to obtain good quality pellets without causing the cut pellets to adhere to each other again and to be fused and fused to form a dumpling, and the cut pellets are not cut again. it can. Further, the pellets can be smoothly moved to the pellet discharge outlet of the granulation chamber housing and taken out, and high-quality pellets can be continuously obtained. In addition, the star-shaped frame cage can prevent pellets from adhering to the inner surface of the granulation chamber housing, and the possibility of pellets adhering to the cage itself is low.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Extruder 2 ... Screw 3 ... Die plate 4 ... Die nozzle 5 ... Granulation chamber 6 ... Rotating cutter 7 ... Cutter blade 9 ... Granulation chamber housing 12・ ・ ・ Pellet discharge port 13 ・ ・ ・ Cooling water storage room 30 ・ ・ ・ Male side taper part 60 ・ ・ ・ Female side taper part 301 ・ ・ ・ Primary cooling water supply pipe 303 ・ ・ ・ Primary cooling Water hole 308 ... Star-shaped frame cage 311 ... Secondary cooling compressed air intake 312 ... Third cooling water intake 320 ... Drive motor W ... Second Primary cooling water supply device U ... Secondary cooling compressed air supply device V ... Third cooling water supply device

Claims (1)

[Scope of utility model registration request] 1. A die nozzle for extruding a molten thermoplastic resin into a granulation chamber is formed on a die plate provided at a tip portion of an extruder, and a rotary cutter that rotates in proximity to the tip portion of the die plate is used. , The resin extruded from the die nozzle is cut into pellets, and the cut pellets are cooled and solidified with cooling water and taken out from the pellet discharge port of the granulation chamber housing. And the die nozzle is arranged on the male side taper part, and the tip of the rotary cutter is the female side taper part which is tapered and is externally fitted to the male side taper part, and the inner surface of the female side taper part A cutter blade is installed in the center of the rotary cutter, and a cooling water supply pipe for supplying the primary cooling water is provided between the rotary cutter and the die plate. The star-shaped frame cage covering the inner surface of the granulation chamber housing is rotatably arranged with respect to the rotary cutter, and provided with a drive means for intermittently rotating the cage in a fixed direction or in forward and reverse directions. Supply secondary cooling compressed air,
A secondary cooling compressed air supply device that moves the cut pellets to the back of the rotary cutter, and (2) a third cooling water is supplied to the granulation chamber to feed the pellets behind the rotary cutter to the pellet discharge port. Third to move
A cooling device for a thermoplastic resin granulator, comprising a secondary cooling water supply device.