KR101210768B1 - Granulation die, granulator, and method for producing foamable thermoplastic resin particle - Google Patents

Abstract

The assembling die 1 used in the assembling apparatus T to be assembled by the underwater hot cut method includes a resin discharge surface 13 provided in contact with a cooling medium, and a plurality of resin flow paths communicating with the extruder 2. 14, 14, ???, nozzles 15, 15, ??? which communicate with the resin flow passage 14 and open to the resin discharge surface 13, and a plurality provided in the vicinity of the resin discharge surface 13; Cartridge heater 17 and short heater 18 are provided.
The resin flow passage 14 is disposed along the circumference of the virtual circle on the resin discharge surface 13, and the cartridge heater 17 and the short heater 18 are disposed on both sides of the circumferential direction of the resin flow passage 14 in the circumferential direction. In addition, it is arrange | positioned in the state which crossed the circumference toward the radial direction of the circumference in the longitudinal direction. ADVANTAGE OF THE INVENTION According to this invention, in the assembly die by a hot cut method, clogging of a nozzle can be prevented and the particle | grains of uniform particle diameter can be produced efficiently.

Description

Granulation die, granulator, and method for producing expandable thermoplastic particles {GRANULATION DIE, GRANULATOR, AND METHOD FOR PRODUCING FOAMABLE THERMOPLASTIC RESIN PARTICLE}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a granulation die for granulating thermoplastic resin particles by a hot cut method, a granulation apparatus, and a method for producing expandable thermoplastic resin particles.

This invention claims priority based on Japanese Patent Application No. 2008-39116 for which it applied to Japan on February 20, 2008, and adopts the content here.

Background Art Conventionally, an apparatus (called a pelletizer) for molding pellets of thermoplastic resin is provided with an extruder, a die provided at the tip of the extruder, a carter, and the like, and is formed by an extruder. BACKGROUND ART An apparatus is generally known in which a melt-kneaded resin material is extruded from a die and cut into a cutter to produce pellets of a desired size.

There is a hot cut method as a method of cutting a resin material extruded from a nozzle of a die.

This hot cut method is a method of cutting a hot resin immediately after being extruded into a water stream by contacting it with a water stream circulating through a die end surface in which a plurality of nozzles are opened. In the granulation by the hot cut method, since the resin is cut in a state where the resin is not sufficiently cured, no powdering of the resin occurs and spherical particles can be obtained. There is an advantage.

However, in the hot cut method, since the resin discharge surface of the die is in contact with the water flow, heat may be taken away from the water flow side, and the inside of the die may be partially lowered to a temperature below the melting point of the resin. As a result, a nozzle is clogged and productivity falls. In addition, clogging of the nozzle may cause nonuniformity in the particle size of the particles, which may degrade the quality. In addition, when the blockage increases, the extrusion pressure of the resin from the die becomes abnormally high, and the extrusion may not be possible beyond the internal pressure limit of the die.

Conventionally, the technique disclosed in patent document 1 or 2 is proposed as a technique for preventing clogging of a nozzle in the assembly die used for granulation by a hot cut method.

Patent Literature 1 discloses a die for assembling in which a rod-shaped heater is arranged in the same direction as a resin flow path of a nozzle at a central position of a nozzle arranged in a circular shape. By arrange | positioning a rod-shaped heater, a heater and each nozzle become equidistant and each nozzle is heated uniformly. Therefore, clogging of the nozzle is less likely to occur, low pressure loss and extrusion start in water can be achieved, and high quality pellets can be obtained.

 Patent Document 2 discloses a structure in which a heat insulating material is provided on a die surface in a method for producing thermoplastic resin particles in which molten resin extruded by a die is cut by a rotary cutter to be resin particles.

Moreover, both patent documents 1 and 2 perform granulation which does not contain a foaming agent.

Patent Document 1: Japanese Patent Application Laid-Open No. 7-178726

Patent Document 2: Japanese Patent Application Laid-Open No. 5-301218

However, the conventional technique disclosed in patent documents 1 and 2 has the following problem.

That is, when mixing a foaming agent in a compressor and trying to obtain foamable resin particle, it is necessary to suppress foaming of the foaming agent containing resin composition discharged | emitted from dice | dies. Therefore, the water temperature of the circulating water (cooling water) in the cutting chamber (chamber) must be lower than that of the non-foamed resin particles (80 to 90 ° C) (30 to 40 ° C). In addition, since the melt viscosity of the resin decreases due to the foaming agent, it is difficult to assemble without contacting (pressing) the cutter blade to the die surface.

In the prior art disclosed in Patent Literature 1, the rod-shaped heater is arranged so that the tip of the rod-shaped heater is close to the resin discharging surface of the die, but the rod-shaped heater has a nichrome wire to the tip in terms of its structure. Since it cannot be installed, the heater tip does not generate heat. Therefore, when granulating the expandable resin particles, in this die structure, it is difficult to sufficiently warm the resin discharge surface of the tip portion of the die that needs the most heating, and the clogging cannot be prevented.

Moreover, in the prior art disclosed in patent document 2, it describes about manufacture of the simple resin pellet which does not mix a blowing agent. On the other hand, as described above, when granulating the expandable thermoplastic resin particles, unlike the case of simple resin pellets, it is preferable to suppress the foaming of the particles, so that the temperature of the circulating water is preferably 40 ° C or lower. As a result, the difference between the resin temperature and the circulating water temperature becomes large, and heat dissipation alone cannot sufficiently suppress the heat dissipation of the tip portion of the die due to water flow, and clogging of the nozzle easily occurs. In addition, as described above, in the production of the expandable thermoplastic resin particles, since the resin softens with the blowing agent, it is necessary to cut the discharged resin by contacting (compressing) the die on the die surface. In the die structure which covered the surface with the heat insulating material as disclosed in patent document 2, a heat insulating material wears off in a short time by a carbon blade, and there exists a problem in the durability of a die.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and includes an assembly die, an assembly apparatus, and foamability which prevent clogging of a nozzle and efficiently produce particles having a uniform particle size in an assembly die by the hot cut method. An object of the present invention is to provide a method for producing thermoplastic resin particles.

In order to achieve the said objective, the following structures are employ | adopted in the die for assembly according to this invention. That is, this assembling die includes a resin discharge surface provided in contact with the cooling medium, a plurality of resin flow paths in communication with the resin supply device, a nozzle in communication with the resin flow path and opening to the resin discharge surface, and resin A plurality of cartridge heaters are provided near the discharge surface. Further, the resin flow path is arranged along the circumference of the virtual circle on the resin discharge surface, and the cartridge heater is disposed on both sides of the circumferential direction of the circumference of the resin flow path, and the longitudinal direction is oriented in the radial direction of the circumference. It is arrange | positioned in the state traversed.

In the die for assembly according to the present invention, eight or more cartridge heaters are provided, and each center angle is preferably 45 ° or less.

In the die for assembling according to the present invention, the cartridge heater is preferably provided at a position of 10 to 50 mm from the resin discharge surface.

In the die for assembling according to the present invention, it is preferable that the cross-sectional shape of the resin flow path has a straight portion at its periphery, and the straight portion is disposed substantially parallel to the longitudinal direction of the cartridge heater.

In the die for assembling according to the present invention, it is preferable that a plurality of nozzles are provided in the resin flow path along the cross-sectional shape.

Further, in the die for assembly according to the present invention, a temperature sensor is provided at least on the upstream side and the downstream side of the water flow direction of the cooling medium, and is configured to individually turn on and off the cartridge heater based on the measured temperature of the temperature sensor. It is preferable that it is done.

Moreover, the granulation apparatus which concerns on this invention accommodates the assembly die mentioned above, the resin supply apparatus which installed the assembly die at the front end, and the carter which cut | disconnects resin discharged from the nozzle of the assembly die, And a chamber for bringing the cooling medium into contact with the resin discharge surface of the die.

In addition, the method of manufacturing the expandable thermoplastic resin particles according to the present invention comprises the steps of supplying the thermoplastic resin to the resin supply apparatus provided with the above-mentioned assembling die and melt-kneading, and moving the thermoplastic resin toward the assembling die. And a step of forming a blowing agent-containing resin by injecting a blowing agent into the foaming agent, and a step of cutting the blowing agent-containing resin discharged from the nozzle of the granulation die into a cooling medium by a carter to obtain expandable thermoplastic resin particles.

Further, in the method for producing the expandable thermoplastic resin particles according to the present invention, at least the die temperatures of the upstream and downstream sides of the water flow direction of the cooling medium are measured, and each cartridge heater is turned on individually so that the measured values are the same. It is desirable to control off.

In addition, the manufacturing method of the thermoplastic resin foam particles according to the present invention is a step of supplying thermoplastic resin to the resin supply apparatus provided with the above-mentioned assembly dies and melt-kneading, while moving the thermoplastic resin toward the assembly die, Forming a foaming agent-containing resin by injecting a foaming agent into the resin, cutting the foaming agent-containing resin discharged from the nozzle of the granulation die into a cooling medium by a carter to obtain foamable thermoplastic resin particles, and preparing the foamable thermoplastic resin particles. Foaming to obtain thermoplastic resin foamed particles.

In addition, the manufacturing method of the thermoplastic resin foamed molded article according to the present invention comprises the steps of supplying a thermoplastic resin to the resin supply apparatus provided with the above-mentioned assembling die and melt-kneading, and moving the thermoplastic resin toward the assembling die, Injecting a foaming agent into the resin to form a foaming-agent-containing resin, cutting the foaming-agent-containing resin discharged from the nozzle of the assembling die into a cooling medium by a carter to obtain foamable thermoplastic resin particles, and heating the foamable thermoplastic resin particles. And preliminary foaming to obtain thermoplastic resin foamed particles, and thermoplastic resin foamed particles in a mold to form a thermoplastic resin foamed molded article.

In addition, the expandable thermoplastic resin particles according to the present invention are the expandable thermoplastic resin particles obtained by the method for producing the expandable thermoplastic resin particles described above.

The thermoplastic resin foamed particles according to the present invention are thermoplastic resin foamed particles obtained by prefoaming the above-mentioned expandable thermoplastic resin particles.

Moreover, the thermoplastic resin foamed molded article according to the present invention is a thermoplastic resin foamed molded article obtained by foam molding the above-mentioned thermoplastic resin foamed particles.

According to the granulation die, the granulation apparatus, and the manufacturing method of foamable thermoplastic resin particle of this invention, a resin flow path and a nozzle are heated in the state fitted in both sides by the cartridge heater. Therefore, only one side of the resin flow path can be heated evenly on both sides without heating. As a result, clogging of the nozzle can be suppressed, it is possible to improve the decrease in the production efficiency due to the clogging and to manufacture high quality particles having a uniform particle size.

1 is a configuration diagram of an assembling apparatus according to an embodiment of the present invention.
2 is a side cross-sectional view showing a schematic configuration of an assembly die according to an embodiment of the present invention.
It is a side view which shows the resin discharge surface of the dice main body of FIG.
4 is a diagram illustrating an example of an arrangement state of nozzles.
FIG. 5 is a diagram illustrating an example of an arrangement state of nozzles according to a modification of the present embodiment, which corresponds to FIG. 4.
It is sectional drawing of the dice used by the comparative example 1. FIG.
It is a side view which shows the resin discharge surface of the dice used by the comparative example 1. FIG.
It is sectional drawing of the dice used by the comparative example 2. FIG.
FIG. 7B is a side view illustrating the resin discharge surface of the dice used in Comparative Example 2. FIG.
It is sectional drawing of the dice used by the comparative example 3.
Fig. 8B is a side view showing the resin discharge surface of the dice used in Comparative Example 3;

BEST MODE FOR CARRYING OUT THE INVENTION

EMBODIMENT OF THE INVENTION Hereinafter, the assembly die, the granulation apparatus, and the manufacturing method of foamable thermoplastic resin particle which concern on embodiment of this invention are demonstrated based on FIG.

Fig. 1 is a configuration diagram of an assembling apparatus according to an embodiment of the present invention, Fig. 2 is a side cross-sectional view showing a schematic configuration of an assembly die according to an embodiment of the present invention. Fig. 3 is a resin discharge surface of the die body of Fig. 2. 4 is a side view showing the arrangement of the nozzles.

As shown in FIG. 1 and FIG. 2, the assembling apparatus T according to the present embodiment is an assembling apparatus T which is assembled by an underwater hot cut method, and an embodiment of the present invention. The die 1 for assembly is adopted.

This granulation apparatus T is a resin discharged from the nozzle 15 of the extruder 2 (resin supply apparatus) with which the assembly die 1 was provided at the front-end | tip, and the granulation die 1 (foaming agent in this embodiment). The carter 3 for cutting the containing resin 20 is accommodated, and the chamber 4 for bringing the water flow into contact with the resin discharge surface 13 of the assembly die 1 is provided. The chamber 4 is connected with a conduit 5 for allowing circulating water to flow, and one end (upstream of the chamber 4) of the conduit 5 is connected to the water tank via the water supply pump 6. Connected. In addition, at the other end of the conduit 5 (downstream from the chamber 4), a dewatering treatment section 8 is provided for separating the deformable thermoplastic resin particles from the circulating water and dewatering and drying them. The expandable thermoplastic resin particles separated and dried in the dewatering treatment section 8 are sent to a container. Reference numeral 21 is a hopper, 22 is a blowing agent supply port, and 23 is a high pressure pump.

In the assembly apparatus T and the assembly die 1, the resin discharged side is referred to as "front side" and "front end", and the opposite side is referred to as "rear" and "back end". use.

As shown in FIG.2 and FIG.3, the assembly die 1 consists of the die main body 10 and the die holder 11 fixed to the front end side (right side of the figure) of the extruder 2, and the die main body 10 is fixed to the front end side of the die holder 11 by a plurality of holders 12 and 12 ???.

The die holder 11 is provided in communication with the cylinder of the extruder 2, and the rear end side flow path 11a and the front end side flow path 11b are formed in that order from the rear end side to the front end side. The die main body 10 has a conical concave portion 10a formed to protrude rearward from the rear end surface center portion thereof, and the die main body 10 is connected to the die holder 11 in a state where the die main body 10 is connected to the die holder 11. In the tip side flow path 11b, the conical concave portion 10a is inserted with a predetermined gap. That is, the foaming-agent-containing resin 20 which has passed through the rear end side flow path 11a of the die holder 11 flows along the circumferential surface of the conical concave part 10a in the front end side flow path 11b, and the die main body 10 Flows into a plurality of resin flow passages 14, 14,?, Which will be described later.

The die body 10 includes a plurality of resin discharge surfaces 13 in contact with the water flow at the tip end surfaces thereof, and a plurality of resins for transferring the blowing agent-containing resin 20 extruded from the extruder 2 toward the resin discharge surfaces 13. A plurality of nozzles 15, 15? Which are provided at the distal ends of the resin flow passages 14, 14, ??? and the plurality of resin flow passages 14, 14, ??? ), The heat insulating material 16 provided at the center position of the resin discharge surface 13, and the resin discharge surface 13 and the resin flow passage 14 at positions closer to the extruder 2 than the resin discharge surface 13. A cartridge heater 17 for warming up and a small heater 18 for warming up the die main body 10 are provided and outlined.

The cartridge heater 17 and the short heater 18 can be suitably selected and used according to the size and shape of the die main body 10 from the conventionally well-known cartridge heater 17. As shown in FIG. That is, as the cartridge heater 17 and the short heater 18, for example, a heating wire (nichrome wire) wound with a rod-shaped ceramic is inserted into the pipe (heat-resistant stainless steel), and the gap between the heating wire and the pipe is heated at high temperature. High-density rod-shaped heaters encapsulated with a material (MgO) excellent in conductivity and high insulation can be used.

The cartridge heater 17 and the short heater 18 may be the cartridge heater 17 having two lead wires on one side, or the cartridge heater 17 (sheathed heater) having one lead wire on each side, but one side The cartridge heater 17 having two lead wires is preferable because the power density is higher.

The heat insulating material 16 of a circular cross section is arrange | positioned at the center part of the resin discharge surface 13 of the dice main body 10, and the discharge opening of the some nozzle 15, 15 degree | times in the radial direction outer side of the heat insulating material 16. Is installed along concentric circles. And the center part of the resin discharge surface 13 in which the heat insulating material 16 and the nozzles 15 and 15 ??? are arrange | positioned contacts with water in the chamber 4 inside.

The resin flow passages 14, 14, ??? form a circular cross section, extend in a direction orthogonal to the resin discharge surface 13, and have a circumference (resin discharge about the center axis of the die body 10). It is arranged on the surface 13 at regular intervals along the circumference of the virtual circle. In this embodiment, eight resin flow paths 14 and 14 are provided, and the center angles of the resin flow paths 14 and 14 adjacent to the circumferential direction of the said circumference are 45 degrees. As described above, each resin flow passage 14 communicates with the front end side flow passage 11b of the die holder 11.

The nozzles 15 and 15 ??? are arranged on the resin discharge surface 13 at predetermined intervals along the circumference of the virtual circle. As shown in FIG. 4, specifically, in one nozzle 15, a plurality of single nozzles 15a, 15b, 15c ??? are arbitrarily arranged within the cross-sectional shape of the resin flow passage 14. The nozzle unit (this invention calls this "nozzle") is comprised. The arrangement of the group nozzles 15a, 15b, 15c ??? may be adopted, for example, by arranging a plurality of small nozzles on a plurality of small circumferences. .

And the heat insulating material 16 is provided in the resin discharge surface 13 of the inner side of the circumference which arrange | positioned the some nozzle 15, 15 degree | times, and the heat of the dice main body 10 with the water in the chamber 4 is carried out. The temperature drop of the die main body 10 is suppressed by preventing it from escaping. As this heat insulating material 16, it is preferable to use the heat insulating material of the structure which has water resistance and high surface hardness. For example, a heat insulating material which is excellent in heat resistance and heat insulating performance which does not cause deformation even when connected to a high temperature die body 10 is disposed, and is coated with a waterproof resin such as fluorine resin having excellent heat insulating performance, and further resin discharge. On the surface 13 side, the laminated type heat insulating material 16 which laminated | stacked materials with high surface hardness, such as stainless steel and ceramics, in order can be used.

The cartridge heater 17 and the short heater 18 each form a rod-shaped heater, and the cartridge heater 17 has a resin discharge surface 13 side in the front end end direction of the assembly die 1 than the short heater 18. Located in

The cartridge heaters 17, 17 ??? are disposed on both sides of the circumferential direction of the circumference of the resin flow passage 14, and are disposed in a state of crossing the circumference in the longitudinal direction in the radial direction of the circumference, and discharging the resin. In the vicinity of the surface 13, the resin discharge surface 13, the nozzle 15, and the resin flow passage 14 are heated. Eight cartridge heaters 17, 17 ??? of the present embodiment are provided in the circumferential direction, each having a predetermined center angle (here, 45 degrees).

That is, the individual nozzles 15 are arranged so as to be fitted in the circumferential direction of the circumference by the two cartridge heaters 17 and 17.

In addition, the cartridge heater 17 is provided in the range of the predetermined heater depth in the vicinity of the resin discharge surface 13, ie, toward the extruder 2 side from the resin discharge surface 13. Here, the heater depth is the distance from the resin discharge surface 13 to the center of the cartridge heater 17 for surface heating (symbol L shown in FIG. 2), and the cartridge heater ( 17) is shown. The heater depth is preferable in the range which does not interfere with the processing surface of die | dye, and durability, and the one whose distance is small has a large blockage suppression effect of a nozzle. That is, as a heater depth, the range of 10-50 mm is preferable. If it is less than 10 mm, there is a possibility that the machining surface and durability of the die may be impaired. If it exceeds 50 mm, the effect of blocking the nozzle may be reduced. A more preferable range is 15 to 30 mm.

Further, the diameter of the cartridge heater 17 is preferable because the smaller one can increase the cross-sectional area of the resin flow passage 14 within the range in which the heat generating capacity can be ensured, and the number of nozzles increases. That is, although the diameter of the cartridge heater 17 is preferably 15 mm or less, since it is difficult to secure the required heat generation capacity at less than 10 mm, and the heater is also expensive, 10 mm to 15 mm is preferable, and 10 mm to 12 mm is more preferable.

And the length of the cartridge heater 17 is the position which extended toward the center side rather than the nozzle 15 arrange | positioned in the radial direction of the die main body 10 (that is, at least the front-end | tip part of the cartridge heater 17 is centered more than the nozzle 15). Position to the side) to a position from the outer periphery of the die body 10.

The short heaters 18, 18 ??? are disposed at the rear side with predetermined intervals with respect to each cartridge heater 17, and the number and number of cartridge heaters 17 are equal to eight, and the resin flow path ( 14) has a function of heating the rear side. The length of the short heater 18 is shorter than that of the cartridge heater 17.

In addition, the die main body 10 includes temperature measuring bodies 19 (19A, 19B, 19C, 19D) such as thermocouples at four positions in the upper, lower, left, and right directions at the position close to the resin discharge surface 13 (temperature sensor). Is installed. That is, it is comprised so that the die main body 10 may be temperature-controlled by controlling the cartridge heater 17 on / off individually based on the measurement temperature of these thermostats 19. As shown in FIG. In addition, it is preferable that the installation position of the temperature measuring body 19 is behind the resin discharge surface 13, and is located ahead of the cartridge heater 17. As shown in FIG. The installation place is not limited to four places of top, bottom, left and right, and may be two places of top and bottom. Furthermore, it is preferable to provide a separate thermostat 19 '(refer to FIG. 2) for temperature control of the short heater 18 near the short heater 18. FIG.

Next, the manufacturing method of foamable thermoplastic resin particle, thermoplastic resin foamed particle, and thermoplastic resin foamed molded object using the granulation apparatus T provided with the above-mentioned assembly die 1 is demonstrated.

The extruder 2 (resin supply device) used for the granulation apparatus T shown in FIG. 1 can be suitably selected and used according to the kind of resin etc. which are granulated among various conventionally well-known extruders, For example, Either an extruder using a screw or an extruder without a screw can be used. As an extruder using a screw, a single screw extruder, a multi-screw extruder, a vented extruder, a tandem extruder, etc. are mentioned, for example. As an extruder which does not use a screw, a flanger type extruder, a gear pump type extruder, etc. are mentioned, for example. Moreover, any extruder can use a starting mixer. Among these extruders, an extruder using a screw is preferable in terms of productivity. Moreover, the conventionally well-known thing used by the hot cut method can also be used for the chamber 4 which accommodated the cart 3.

In the present invention, the kind of the thermoplastic resin is not limited, but for example, polystyrene resin, polyethylene resin, polypropylene resin, polyester resin, vinyl chloride resin, ABS resin, AS resin or the like alone or in two kinds. It can mix and use the above. Furthermore, a recovered resin which is a thermoplastic resin obtained by recovering once used once as a resin product can also be used. In particular, polystyrene resins such as polystyrene (GPPS) and high impact polystyrene (HIPS) are suitably used.

As the polystyrene resin, for example, homopolymers of styrene monomers such as styrene, α-methyl styrene, vinyltoluene, chlorostyrene, ethyl styrene, i-propyl styrene, dimethyl styrene, bromostyrene or the like A copolymer etc. are mentioned, The polystyrene resin containing 50 mass% or more of styrene is preferable, and polystyrene is more preferable.

Moreover, as said polystyrene resin, the copolymer of the said styrene monomer which has the said styrene monomer as a main component, and the vinyl monomer copolymerizable with this styrene monomer may be sufficient, As such a vinyl monomer, for example, methyl (meth) Alkyl (meth) acrylates, such as acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and cetyl (meth) acrylate, (meth) acrylonitrile, dimethyl mareate, dimethyl flumarate, and diethyl And bifunctional monomers such as divinylbenzene and alkylell glycol methacrylate, such as flumarate and ethyl flumarate.

If the polystyrene-based resin is a main component, other resins may be added, and as the resin to be added, for example, in order to improve the impact resistance of the foamed molded product, a polybutadiene, a styrene-butadiene copolymer, and an ethylene-propylene-non-conjugation Rubber modified polystyrene resin, ie, high-impact polystyrene, which added diene rubber polymers, such as a diene three-dimensional copolymer, is mentioned. Or a polyethylene resin, polypropylene resin, an acrylic resin, an acrylonitrile- styrene copolymer, an acrylonitrile- butadiene- styrene copolymer, etc. are mentioned.

In the expandable thermoplastic resin particles of the present invention, the expandable polystyrene resin particles using the polystyrene resin as the thermoplastic resin are newly produced by commercially available polystyrene-based resins, suspension polymerization methods and the like as the polystyrene-based resins used as raw materials. In addition to polystyrene resins (hereinafter referred to as virgin polystyrene) which are not recycled raw materials, such as polystyrene resins, recycled raw materials obtained by regenerating the used polystyrene-based resin foamed molded product can be used. As the recycled raw material, a recycled raw material recycled by limonene dissolving method or heating reduction method can be used by recovering a used polystyrene-based resin foamed molded product such as a meat box, a home appliance buffer, a food packaging tray, and the like. have. The recycled raw materials that can be used are not only those obtained by regenerating the used polystyrene-based resin foamed molded products, but also home appliances (e.g., televisions, refrigerators, washing machines, air conditioners, etc.) and office equipment (e.g., copiers, fax machines). , A non-foamed polystyrene-based resin molded product fractionated and recovered by a printer, etc. can be pulverized, melt-kneaded, and repelted.

As shown in Fig. 1 and Fig. 2, in the case of producing the expandable thermoplastic resin particles using the granulation apparatus T described above, the thermoplastic resin is placed in the extruder 2 provided with the assembly die 1 at the tip. It is fed from a hopper, melted and kneaded. Next, while blowing the thermoplastic resin toward the assembling die 1, the blowing agent is press-fitted into the thermoplastic resin from the blowing agent supply port 22 by the high pressure pump 23, the blowing agent and the thermoplastic resin are mixed, and the blowing agent-containing resin. 20 is formed.

The blowing agent-containing resin 20 passes through the die holder 11 at the tip of the extruder 2 and is sent to the resin flow passage 14 of the die body 10 of the die 1 for assembly. The blowing agent-containing resin 20 sent through the resin flow passage 14 is discharged from the nozzles 15 of the die body 10 and cooled in the water flow of the chamber 4 by the rotary blade of the carter 3 (cooling). In the medium).

The foaming-agent-containing resin 20 cut into granules in the chamber 4 thus becomes almost spherical foamable thermoplastic resin particles. The expandable thermoplastic resin particles are conveyed in the conduit 5 along the water flow to reach the dewatering treatment unit 8, where the expandable thermoplastic resin particles are separated from the circulating water, dehydrated and dried, and separated. Water is sent to the water tank (7). The dewatered and dried foamable thermoplastic resin particles separated in the dewatering treatment section 8 are sent to the container 9 and stored in the container.

In addition, although the said blowing agent is not limited, For example, normal pentane, isopentane, cyclopentane, cyclopentadiene, etc. can be used individually or in mixture of 2 or more types. Moreover, normal butane, isobutane, propane, etc. can also be mixed and used as said main component of the said pentane. In particular, pentane is suitably used because it is easy to suppress the foaming of particles when discharged from the nozzle into the water stream.

Incidentally, the expandable thermoplastic resin particles refer to resin particles molded into a granular shape, preferably a small spherical shape by containing a blowing agent in the thermoplastic resin. The foamed thermoplastic resin particles are pre-foamed by heating in a free space, and the pre-expanded particles are placed in a cavity of a mold having a desired cavity, steam heated to fuse the pre-foamed particles together, and then separated from the mold. It can be used for producing a desired foamed molded resin article.

Next, the temperature control method of the above-mentioned assembly die 1 is demonstrated.

As shown in FIG. 3, in the temperature control method of the assembly die 1, it respond | corresponds to the temperature measurement body 19A, 9B, 19B, 19D which installed the die main body 10 in the upper, lower, left, and right vicinity of the resin discharge surface 13. As shown in FIG. By dividing into two or four areas, and controlling the temperature of the cartridge heater 17 in the area on and off individually so that the measured values measured by the respective temperature bodies 19 are equal. 10) can be kept constant at a predetermined temperature. Here, the cartridge heaters 17 in the region are two cartridge heaters 17 approaching the temperature measuring body 19 in the case of four regions.

In the case where the die body 10 is divided into two regions, for example, when the measurement temperature of the temperature measuring body 19B located on the upstream side of the cooling water is lower than the predetermined temperature, the upstream side The four cartridge heaters 17 located are turned on to raise the temperature by heating them. Alternatively, when the measured temperature of the thermometer (19A) located on the downstream side is higher than the predetermined temperature set in advance, the four cartridge heaters (17) located on the downstream side are turned off to release the heating state. To lower the temperature.

By performing such a temperature control, the temperature difference which arises by the contact state of the circulating water by the rotation of the carter 3 in the chamber 4 can be made small, and the dice main body 10 (resin discharge surface 13) The temperature becomes constant at, so that particles having a more uniform particle size can be formed.

In the manufacturing method of the die | dye for granulation, granulation apparatus, and foamable thermoplastic resin particle which concern on this embodiment mentioned above, the resin flow path 14 and the nozzle 15 are heated by the cartridge heater 17 in the state fitted at both sides. Therefore, only one side of the resin flow passage 14 can be heated evenly at both distances without heating, and clogging of the nozzle 15 can be suppressed. As a result, it is possible to improve the decrease in production efficiency due to clogging and to manufacture high quality particles having a uniform particle size.

Next, although the modification of embodiment of this invention is demonstrated based on drawing, description is abbreviate | omitted using the same code | symbol to the member and the part of the same kind or same kind as embodiment mentioned above, and differs from embodiment. The configuration will be described.

FIG. 5 is a view showing an arrangement of nozzles according to a modification of the present embodiment, which corresponds to FIG. 4.

The resin flow passage 14A according to the modification shown in Fig. 5 has a trapezoidal cross-sectional shape, and has a plurality of single nozzles 15a, 15b, 15c within the range of the trapezoidal shape. The nozzle 15 in which () is arbitrarily arrange | positioned is provided. Incidentally, the inclined surfaces 14a and 14b (straight portion) forming the outer portion of the resin flow passage 14A constitute a configuration in which the cartridge heater 17 is substantially parallel to the longitudinal direction. In this modification, since the inclined surfaces 14a and 14b of the resin flow passage 14A having a trapezoidal shape are equidistant from the cartridge heater 17, the area heated evenly by the cartridge heater 17 increases. And compared with the resin flow path 14 of circular cross section, it heats uniformly and the clogging of the nozzle 15 can be reduced more.

In order to support the effect of the granulation die, the granulation apparatus, and the manufacturing method of foamable thermoplastic resin particle which concern on this embodiment, an Example is demonstrated below.

Example

Example 1

In Example 1, the granulation die 1 shown in FIG. 2 and FIG. 3 was installed in the granulation apparatus T shown in FIG. 1, and foamable polystyrene resin particle was manufactured. However, only the temperature measuring body 19A was used, all the cartridge heaters 17 were turned on and off, and the temperature of dice was adjusted.

In a single screw extruder having a diameter of 90 mm (L / D = 35), a nozzle unit having 15 assembling dies having a structure shown in FIG. 2, that is, a diameter of 0.6 mm and a land length of 3.0 mm, has a circumference of eight resin discharge surfaces. Eight cartridge heaters (diameter 12 mm) are disposed on the resin discharge surface side and each resin flow path passing through the nozzle unit on both sides is provided with a heater depth (distance from the resin discharge surface, corresponding to symbol L in Fig. 2). A die is disposed radially across the circumference at a phosphorus position and provided with a die provided with a heat insulating material at the center of the surface thereof, and finely divided with 100 parts by weight of a polystyrene resin (manufactured by Toyo Styrene, product name "HRM10N"). talc) 0.3 parts by weight of a mixture previously uniformly mixed in a tumbler mixer was fed into the extruder at a rate of 130 kg per hour. After setting the maximum temperature in an injector to 220 degreeC, and melt | dissolving resin, 6 mass parts pentane (mixture of isopentane / normalpentane = 20/80) was pressed in the middle of an extruder with respect to 100 mass parts of resin as a blowing agent.

Cooling water of 30 degreeC is passed through the said dice | dies maintained at 280 degreeC provided in the front end of the extruder, cooling so that resin temperature in an extruder front end may be 170 degreeC, mixing resin and a foaming agent in the extruder 2. While extruding into the circulating chamber, a high-speed rotary cutter having 10 blades in the circumferential direction was brought into close contact with a die, cut at 3300 revolutions per minute, and dehydrated and dried to obtain spherical foamable polystyrene resin particles. The discharge amount of the expandable styrene resin particles at this time was 138 kg / h.

In Example 1, the pressure of the resin introduction portion into the die at 1 hour after the start of extrusion was 17.0 MPa, the mass of 100 particles of resin particles after drying was 0.0724 kg, and the porosity of the die was 80.2%. Was good.

It was confirmed that the pressure of the resin introduction portion into the die at 48 hours after the start of extrusion was 17.3 MPa, the mass of 100 particles was 0.0741 g, and the porosity of the die was 78.4%.

With respect to the expandable styrene resin particles collected at 48 hours of extrusion, pre-expanded particles having a bulk foaming multiple of 50 times (bulk density 0.02 g / cm 3) were produced by the method described below, and foamed using the pre-expanded particles. A foamed molded product having a multiple of 50 times (density 0.02 g / cm 3) was produced. The obtained foamed molded article was visually observed, and the filling property of the prefoamed particles into the molding die was evaluated.

<Opening rate of dice>

Opening rate (opening rate during extrusion of the discharge nozzle on the die surface) = Number of open holes / number of total nozzles x 100 (%).

Discharge mass (kg / h) = total mass of all foamable particles broken by Carter per 1h

= Number of holes × number of cuts × 1 mouth mass

= Number of openings × number of cutters × number of revolutions × 1 mass

Since the opening number = the discharge amount (kg / h) / [the number of Carter blades × the number of Carter rotations (rpm) × 1 mass (kg / piece)], the aperture ratio can be calculated by the following equation.

Opening rate (E) = numerical aperture / total number of ejection nozzles × 100 (%)

= [Q / (N × R × 60 × (M / 100) / 1000)] / H × 100 (%)

(Wherein Q is the discharge amount (kg / h), N is the longevity of the cutter, R is the number of revolutions of the Carter (rpm), and M is the 100 mouth mass (g)). The value measured by the electronic balance of g was made into 100 pieces of mass), H represents the total number of nozzles of a dice, respectively.)

<Evaluation Criteria for Opening Rate>

The porosity (E) was evaluated based on the following criteria (see Table 1 below).

◎: 50% ≤E,

○: 40% ≦ E <50%,

Δ: 30% ≦ E <40%,

X: E <30%.

<Production of Foamed Molded Product>

As described above, the expandable styrene resin particles obtained at 48 hours of extrusion were allowed to stand at 20 ° C for 1 day. Subsequently, 0.1 mass part of zinc stearate, 0.05 mass part of hydroxystearic acid triglyceride, and 0.05 mass part of stearic acid monoglycerides were added and mixed with respect to 100 mass parts of expandable styrene resin particles, and it coat | covered on the resin particle surface, It was put into a batch type preliminary foaming machine (inner volume 40L), heated by steam with a blowing pressure of 0.05 MPa (gauge pressure) while stirring, and 50 times the bulk foaming drainage (bulk density 0.02 g / cm 3). ) Prefoamed particles were prepared.

Subsequently, the obtained pre-expanded particles were aged at 23 ° C. for one day, and then an automatic molding machine provided with a mold having a center partition part having a thickness of 5 mm, 10 mm, and 25 mm inside with an external dimension of 300 × 400 × 100 mm (thickness 30 mm) The ACE-3SP type | mold made by an air mill was used, and it shape | molded on the following molding conditions, and obtained the foamed molded object of 50 times foaming density (0.02 g / cm <3>).

Molding condition (ACE-3SP QS molding mode)

Molding vapor pressure 0.08 MPa (gauge pressure)

Mold heating 3 seconds

One-way heating (pressure setting) 0.03 MPa (gauge pressure)

Reverse one-way heating 2 seconds

12 seconds heating on both sides

10 seconds of water cooling

Set surface pressure 0.02 MPa

Evaluation Criteria for Mold Filling of Pre-expanded Particles

The said foamed molded object was observed visually, and the mold filling property was evaluated as follows.

(Double-circle): It is filled tightly to the partition part in thickness 5mm.

(Circle): Filling of a partition part in thickness 5mm is not enough, and an excessive foaming mouth is recognized, but the center partition part is formed.

(Triangle | delta): The particle | grain defect by a defective filling is seen in the partition part among 5 mm of thickness, and the center partition part is not completely formed.

X: The partition part in 5 mm thickness is a charge failure, and the center partition is not formed at all.

<Total Mass of 100 Particles>

In expandable polystyrene resin particle, it is preferable that the sum total mass of 100 particle | grains arbitrarily selected is the range of 0.02-0.09g. When it exceeds 0.09 g, filling into a molding die detail becomes difficult, and there is a possibility that the mold which can be molded is limited to a simple shape. Moreover, when it is less than 0.02 g, there exists a possibility that productivity of particle | grains may fall. A more preferable range is 0.04 to 0.06 g. Moreover, in resin other than polystyrene resin, the value which multiplied the specific gravity of the said range to the said range becomes a range of the total mass of 100 particle | grains with preferable.

<Measurement Method of Bulk Foamed Multiple of Pre-expanded Particles>

The sufficiently dry prefoamed particles were naturally dropped in a measuring cylinder (for example, 500 ml capacity) using a funnel, and then the prefoamed particles were charged by tapping the bottom of the measuring cylinder until the volume of the prefoaming particles became constant. The volume and mass of the prefoamed particle at that time were measured and calculated by the following equation. In addition, the volume was deciphered in 1 ml units and the mass was measured by an electronic balance with a minimum scale of 0.01 g. The resin specific gravity of the styrene resin was calculated to be 1.0, and the bulk expansion multiple rounded off to one decimal place.

Bulk foaming water (fold) = volume of pre-expanded particles (ml) / mass of pre-expanded particles (g) x resin weight

<Measurement Method of Foam Drainage of Foamed Molded Product>

The test piece for measurement (Example 300x400x30mm) was cut out from the foamed molded article sufficiently dried, the size and mass of this test piece were measured, the bulk of the test piece was calculated based on the measured size, and it was calculated by the following formula. . In addition, the resin specific gravity of styrene resin was 1.0.

Foamed drainage (fold) = Test piece bulk (cm3) / Test piece mass (g) x Resin specific gravity

[Example 2]

In Example 2, Example 1 was extended except that the resin flow path communicating with the nozzle unit of the dice used in Example 1 was increased (cross-sectional area was increased), and dice were added in which the number of nozzles per nozzle unit was increased from 15 to 25. In the same manner as the above, spherical expandable styrene resin particles were obtained at a discharge amount of 138 kg / h.

In this Example 2, the pressure of the resin introduction part of the dice at the time of extrusion start 1 hour was 14.0 Mpa, the mass of 100 particle | grains of the resin particle after drying was 0.0465 g, and the porosity of the dice was favorable at 75.0%.

The pressure of the resin introduction portion of the die at 48 hours after the start of extrusion was 14.0 MPa, the mass of 100 particles was 0.0465 g, and the porosity of the die was 75.0%.

With respect to the expandable styrene resin particles collected at 48 hours of extrusion, pre-expanded particles having a bulk foaming multiple of 50 times (bulk density 0.02 g / cm 3) were prepared in the same manner as in Example 1, and the foamed multiples of 50 were foamed using the pre-expanded particles. A foamed molded article having a double density (0.02 g / cm 3) was produced. The obtained foamed molded article was visually observed, and the filling property of the prefoamed particles into the molding die was evaluated.

[Example 3]

In Example 3, a die temperature measuring sensor (two of 19B (inflow side) and 19A (outflow side) disposed at an up-down position in the temperature measuring body 19 shown in Fig. 3) was used for the dice used in Example 2. The area is divided and controlled by four heaters on the circulating water inflow side (lower side, 4a side in FIG. 2) and four heaters on the circulating water outlet side (upper side, 4b side in FIG. 2). A spherical foamable styrene resin particle was obtained at the discharge amount of 138 kg / h in the same manner as in Example 2 except that the dice were kept at 280 ° C.

In Example 3, the pressure of the resin introduction portion into the die at 1 hour after the start of extrusion was 13.3 MPa, the mass of 100 particles of resin particles after drying was 0.0425 g, and the porosity of the die was good at 82.0%.

The pressure of the resin introduction portion into the die at 48 hours after the start of extrusion was 13.3 MPa, the mass of 100 particles was 0.0425 g, and the porosity of the die was 82.0%.

With respect to the expandable styrene resin particles collected at 48 hours of extrusion, pre-expanded particles having a bulk foaming multiple of 50 times (bulk density 0.02 g / cm 3) were prepared in the same manner as in Example 1, and foamed drainage was carried out using the pre-expanded particles. A 50-fold (density 0.02 g / cm 3) foamed molded article was produced. The obtained foamed molded article was visually observed, and the filling property of the prefoamed particles into the molding die was evaluated.

Example 4

In Example 4, spherical expandable styrene resin particles were obtained in the same manner as in Example 2, except that a die in which the heater depth of the dice used in Example 2 was changed from 15 mm to 30 mm was used.

In Example 4, the pressure of the resin introduction portion into the die at 1 hour after the start of extrusion was 16.1 MPa, the mass of 100 particles of resin particles after drying was 0.0524 g, and the porosity of the die was 66.5%, which was good.

The pressure of the resin introduction portion into the die at 48 hours after the start of extrusion was 16.8 MPa, the mass of 100 particles was 0.0581 g, the porosity of the die was 60.0%, and it was confirmed that the extrusion was possible for more than 48 hours.

With respect to the expandable styrene resin particles collected at 48 hours of extrusion, pre-expanded particles having a bulk foaming multiple of 50 times (bulk density 0.02 g / cm 3) were prepared in the same manner as in Example 1, and the foamed drainage was obtained using the pre-expanded particles. A 50-fold (density 0.02 g / cm 3) foamed molded article was produced. The obtained foamed molded article was visually observed, and the filling property of the prefoamed particles into the molding die was evaluated.

[Example 5]

In Example 5, spherical expandable styrene resin particles were obtained in the same manner as in Example 2, except that a die in which the heater depth of the dice used in Example 2 was changed from 15 nn to 45 mm was used.

In Example 5, the pressure of the resin introduction portion into the die at 1 hour after the start of extrusion was 16.9 MPa, and the mass of 100 particles of the resin particles after drying was 0.0670 g, and the porosity of the die was 52.0%.

The pressure of the resin introduction portion into the die at 48 hours after the start of extrusion was 18.1 MPa, the mass of 100 particles was 0.0871 g, and the porosity of the die was 40.0%.

With respect to the expandable styrene resin particles collected at 48 hours of extrusion, pre-expanded particles having a bulk expansion ratio of 50 times (bulk density 0.02 / cm 3) were produced in the same manner as in Example 1, and the expansion-expansion multiples were used using the pre-expanded particles. A foamed molded product having a double density (0.02 / cm 3) was produced. The obtained foamed molded article was visually observed, and the filling property of the prefoamed particles into the molding die was evaluated.

[Example 6]

In Example 6, spherical expandable styrene resin particles were obtained in a discharge amount of 138 kg / h in the same manner as in Example 2, except that only isopentane was used as the blowing agent.

In Example 6, the pressure of the resin introduction portion into the die at 1 hour after the start of extrusion was 15.1 MPa, and the mass of 100 particles of resin particles after drying was 0.0458 g, and the porosity of the die was 76.1%, which was good.

The pressure of the resin introduction portion into the die at 48 hours after the start of extrusion was 15.0 MPa, the mass of 100 particles was 0.0461 g, and the porosity of the die was 75.6%.

With respect to the expandable styrene resin particles collected at 48 hours of extrusion, pre-expanded particles having a bulk foaming factor of 50 times (bulk density 0.02 / cm 3) were prepared in the same manner as in Example 1, and foamed times 50 times using the pre-expanded particles. A foamed molded article (density 0.02 g / cm 3) was produced. The obtained foamed molded article was visually observed, and the filling property of the prefoamed particles into the molding die was evaluated.

[Comparative Example 1]

6A is a cross-sectional view of the dice used in Comparative Example 1, and FIG. 6B is a side view showing the resin discharge surface 13 of the dice.

In Comparative Example 1, the dies 20 of the known structure shown in Figs. 6A and 6B, that is, 16 nozzle units (reference numeral 15) having 15 nozzles having a diameter of 0.6 mm and a land length of 3.0 mm are arranged on the circumference, A spherical foamable styrene resin with a discharge amount of 138 kg / h was discharged in the same manner as in Example 1 except that the cartridge heater 17 was replaced with a die without the cartridge heater 17 (that is, only the short heater 18 was disposed). The particles were obtained.

In this comparative example 1, the pressure of the resin introduction portion into the die at 1 hour after the start of extrusion was high at 21.7 MPa, the mass of 100 particles was 0.1322 g and the porosity of the die was 22.0%.

As time went by, the pressure rise of the resin introduction part was seen, and since the upper limit of the internal pressure of the die reached 25 MPa at 6 hours after the start of extrusion, extrusion was stopped for 6 hours.

Comparative Example 2

7A is a cross-sectional view of the dice used in Comparative Example 2, and FIG. 7B is a side view illustrating the resin discharge surface 13 of the dice.

In Comparative Example 2, four cartridge heaters (17, 17, ???, diameter 12mm) and a heater depth of 15mm were placed on the die 30 having the structure shown in Figs. 7A and 7B, that is, the resin discharge surface 13 side. Spherical foamed styrene resin particles were obtained in the same manner as in Example 1 except that the nozzle units were arranged crosswise across the circumference and replaced with a die having a heat insulating material 16 mounted on the surface center thereof. .

In this comparative example 2, the pressure of the resin introduction portion into the die at 1 hour after the start of extrusion was slightly high at 20.0 MPa, the mass of 100 particles was 0.1030 g, and the porosity of the die was 28.2%.

Over time, the pressure rise of the resin introduction part was seen, and since the upper limit of internal pressure of die | dye (25 MPa) was reached 10 hours after the start of extrusion, extrusion was interrupted by 10 hours.

Comparative Example 3

8A is a cross-sectional view of the dice used in Comparative Example 3, and FIG. 8B is a side view showing the resin discharge surface 13 of the dice.

In Comparative Example 3, the die 40 of the known structure shown in Figs. 8A and 6B, that is, there is no heat insulator, and the oil passage 41 is provided in the die, and hot oil is removed from the die top and bottom 41a and 41a. It is made into a die of the structure which flows in and flows out to right and left (41b, 41b) through a central annular flow path, and returns to an oil heater, and the die was maintained at 280 degreeC by indirect heating using oil as a heat medium. A spherical foamable styrene resin particle was obtained in the same manner as in Example 1 except the discharge amount of 138 kg / h.

In this Comparative Example 3, the pressure of the resin introduction portion into the die at 1 hour after the start of extrusion was 18.0 MPa, the mass of 100 particles was 0.0907 g, and the porosity of the die was 32.0%.

The pressure of the resin introduction portion into the die at 48 hours after the start of extrusion was 21.8 MPa, the mass of 100 particles was 0.0994 g, and the porosity of the die was 29.2%.

With respect to the expandable styrene resin particles collected at 48 hours of extrusion, pre-expanded particles having a bulk foaming multiple of 50 times (bulk density 0.02 g / cm 3) were prepared in the same manner as in Example 1, and the foamed drainage was obtained using the pre-expanded particles. A 50-fold (density 0.02 g / cm 3) foamed molded article was produced. The obtained foamed molded article was visually observed, and the filling property of the prefoamed particles into the molding die was evaluated.

The results of Examples 1 to 6 and Comparative Examples 1 to 3 described above are summarized in Table 1 and described.

According to the results of Table 1, in Examples 1 to 6 according to the present invention, the die pressure at the first hour from the start of assembly was 13.3 to 17.0 MPa, and the pressure at the 48 hour hour was 13.3 to 18.1 MPa. It became lower than 1-3, and continuous operation was possible. In addition, the opening rate of the nozzle is also 52% or more after 1 hour and 40% or more after 48 hours, and in particular in Examples 1 to 3 and 6, 75% or more after 1 hour and 75% after 48 hours As mentioned above, it was confirmed that porosity E hardly changes with time.

And in Example 5 with a heater depth of 45 mm, since a porosity is inferior compared with Example 4 with a heater depth of 30 mm, as a heater depth, 10-50 mm is preferable and 15-30 mm is more preferable. can do.

On the other hand, in the comparative examples 1 and 2, the rise of the die pressure by nozzle blockage was seen remarkably, and it reached the upper limit of the die internal pressure by operation for about 6 to 10 hours. The porosity of the nozzle was already low at 22.0 to 32.0% at one hour.

In Comparative Example 3, compared with Examples 1 to 6, as the annular oil flow path is provided in the die, the structure of the die becomes complicated, an oil heater and a circulation pump are required, and heat retention is required for the piping for circulating the oil. Installation cost is high. In addition, when the flow path becomes clogged by the deteriorated oil and foreign matter or the flow becomes difficult, the heat balance is broken, and the die temperature cannot be maintained uniformly.

As mentioned above, although embodiment of the granulation die, the granulation apparatus, and the manufacturing method of foamable thermoplastic resin particle by this invention was described, this invention is not limited to the said embodiment, It is suitably in the range which does not deviate from the meaning. It is deformable.

For example, in this embodiment, eight resin flow paths 14 and eight cartridge heaters 17 and eight short heaters 18 are each, but are not limited to the quantity thereof. Can be set to an optimum quantity according to the conditions such as the size of the c) and the amount of molding the particles of the thermoplastic resin. In other words, what is necessary is just to have a structure in which a cartridge heater is arrange | positioned at the circumferential direction side of the resin flow path 14.

And although the temperature measuring body 19 is set to four, it is not limited to this, For example, two temperature measuring bodies 19 may be located in an up-down position.

In addition, the shape, size, and other configurations of the extruder 2, the carter 3, the chamber 4, the die holder 11, the die body 10, and the like can be arbitrarily set without particular limitation. For example, in this embodiment, although the extruder is employ | adopted as a resin supply apparatus, a starting mixer, a gear pump, etc. can be used besides this.

Industrial availability

According to the present invention, there is provided a granulation die, an assembling apparatus, and a method for producing expandable thermoplastic resin particles which can prevent clogging of a nozzle in a granulation die by a hot cut method and efficiently produce particles having a uniform particle size. Can provide.

1: Die for assembly 2: Extruder (resin feeder) 3: Carter 4: Chamber
6: Foaming agent-containing resin 10: Die body 11: Die holder 13: Resin discharge surface
14, 14A: resin flow paths 14a, 14b: slope (straight line) 15: nozzle 16: heat insulating material
17: cartridge heater 18: short heater 19: thermometer
L: Heater depth (position of the cartridge heater on the resin discharge surface) T: Assembly device

Claims (14)

A resin discharge surface provided in contact with the cooling medium;
A plurality of resin flow paths communicating with the resin supply device,
A nozzle communicating with the resin flow path and opening to the resin discharge surface;
A plurality of cartridge heaters provided in the vicinity of the resin discharge surface
And,
The resin flow path is arranged on the circumference of one virtual circle on the resin discharge surface,
The cartridge heater 17 is arranged on both sides of the circumferential direction on the circumference of the resin flow passages 14 and 14A, and is assembled in a state in which the longitudinal direction is traversed in the circumference toward the circumference of the circumference. Dragon dice. The method of claim 1,
8 or more cartridge heaters are provided,
Assembly dies with a central angle of 45 ° or less. The method of claim 1,
The cartridge heater is a die for assembling provided at a position of 10 to 50 mm from the resin discharge surface. The method of claim 1,
The cross-sectional shape of the said resin flow path has a straight part in the outer side,
The assembly die of which the said linear part is arrange | positioned substantially parallel to the longitudinal direction of the said cartridge heater. The method of claim 1,
The die for assembly in which the said nozzle flow path is provided with the some nozzle along the said cross-sectional shape. The method of claim 1,
A temperature sensor is provided at least on the upstream side and the downstream side in the water flow direction of the cooling medium,
And an assembly die configured to individually turn off the cartridge heater on the basis of the measured temperature of the temperature sensor. The die for granulation according to any one of claims 1 to 6,
A resin supply device in which the assembly die is installed at the tip;
And a chamber for cutting the resin discharged from the nozzle of the assembling die and having a chamber for bringing the cooling medium into contact with the resin discharge surface of the assembling die. A step of melting and kneading the thermoplastic resin by supplying the thermoplastic resin to the resin supply apparatus provided with the assembling die according to any one of claims 1 to 6;
Forming a blowing agent-containing resin by injecting a blowing agent into the thermoplastic resin while moving the thermoplastic resin toward the assembling die;
A step of cutting the blowing agent-containing resin discharged from the nozzle of the granulation die in a cooling medium by a carter to obtain expandable thermoplastic resin particles
Method for producing a foamable thermoplastic resin particles having a. 9. The method of claim 8,
A method for producing expandable thermoplastic resin particles in which on-off control of each cartridge heater is performed at least by measuring die temperatures on the upstream side and the downstream side in the water flow direction of the cooling medium so that the respective measured values are the same. A step of supplying a thermoplastic resin to the resin supply apparatus provided with the assembling die of any one of Claims 1-6, and melt-kneading,
Injecting a blowing agent into the thermoplastic resin while forming the blowing agent-containing resin while moving the thermoplastic resin toward the assembling die;
Cutting the blowing agent-containing resin discharged from the nozzle of the assembling die in a cooling medium by a carter to obtain expandable thermoplastic resin particles;
A method for producing a thermoplastic resin foamed particle having a step of pre-expanding the foamable thermoplastic resin particles to obtain thermoplastic resin foamed particles. A step of supplying a thermoplastic resin to the resin supply apparatus provided with the assembling die of any one of Claims 1-6, and melt-kneading,
Injecting a blowing agent into the thermoplastic resin while forming the blowing agent-containing resin while moving the thermoplastic resin toward the assembling die;
Cutting the blowing agent-containing resin discharged from the nozzle of the assembling die in a cooling medium by a carter to obtain expandable thermoplastic resin particles;
Heating and foaming the foamable thermoplastic resin particles to obtain thermoplastic resin foamed particles;
Obtaining a thermoplastic resin foamed molded product by foam molding the thermoplastic resin foam particles in the mold
Method for producing a thermoplastic resin foamed molded article having a. The expandable thermoplastic resin particle obtained by the manufacturing method of the expandable thermoplastic resin particle of Claim 8. The thermoplastic resin foamed particle obtained by pre-expanding the foamable thermoplastic resin particle of Claim 12. A thermoplastic resin foamed molded article obtained by foaming the thermoplastic resin foamed particles according to claim 13 in a mold.

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