JP2015058694A - Production device of polymer composite material and production method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for stably producing a polymer composite material uniformly dispersed with a filler at a high mixing ratio while suppressing the amount of a charging liquid medium.SOLUTION: A production device 20 of a polymer composite material comprises: a cylinder 23 where a hopper 21 to charge a raw material is disposed at an upstream side and a die part 22 from which a kneaded material is extruded is disposed at a downstream side; a screw 24 where heat is input while extruding the raw material from the upstream side toward the downstream side rotating shafts at the inside of the cylinder 23 and the kneaded material is produced; a vent part 25 to exhaust a gas component separated from the kneaded material from the cylinder 23; chambers 26 (26a, 26b and 26c) to store at least powder, a synthetic polymer and a liquid medium separately and to supply each predetermined quantity; and a mixing part 27 where the supplied powder, synthetic polymer and liquid medium are mixed and charged to the hopper 21 as the raw material.

Description

  The present invention relates to a technique for producing a polymer composite material filled with powder.

As shown in FIG. 1, in a coal-fired power plant 10, coal pulverized into powder is burned in a boiler 11, and its energy is converted into electricity by a turbine 12 and a generator 13.
Along with the combustion of the coal, a large amount of coal ash corresponding to about 10% of the coal is generated.
And this coal ash is classified into fly ash and clinker ash.

In the fly ash, molten coal ash particles float in a high-temperature combustion gas, are cooled at a low-temperature boiler outlet, become glassy spherical particles, and are collected by the electric dust collector 14. The combustion gas from which fly ash has been recovered is released from the chimney 15 into the atmosphere.
The fly ash is sorted and stored in the silo 16 according to the particle size.

On the other hand, in the clinker ash, the coal ash particles in the boiler 11 adhere to each other to form a porous mass and remain in the boiler 11.
This clinker ash falls and accumulates in a water tank (clinker hopper 17) provided in the lower part of the boiler 11. Then, it is crushed into sand by a pulverizer, dehydrated in the dewatering tank 18, and then stored in the storage tank 19 in the form of sand.

In recent years, the dependence on coal-fired power generation has improved in light of accidents at nuclear power plants.
Therefore, a new application of fly ash generated in coal-fired power generation is being studied.
Until now, fly ash has been used for landfill applications and concrete admixtures.
However, for landfill applications, the liquefaction phenomenon that occurred at the time of the earthquake occurred frequently in landfills due to fly ash, and its use tends to be avoided.
On the other hand, the demand for use as a concrete admixture has reached its peak, and it is not expected to expand in the future.

A plastic composite filler can be considered as an application where mass consumption of fly ash is expected, but it has not been put into practical use.
On the other hand, many attempts have been reported to utilize fine powders such as fly ash as fillers for plastic composites.

  Specifically, in order to efficiently knead plastic composites with an extruder, multiple types of raw materials with small bulk specific gravity are not put together from one place, but separately from multiple feed openings. A technique to be introduced is disclosed (for example, Patent Document 1).

  Further, a technique for kneading a synthetic resin and a filler together with a liquid medium (water) in order to uniformly form a dispersed phase of a filler obtained by pulverizing shells in a matrix phase of a synthetic resin is disclosed (for example, Patent Document 2).

  Further, when the synthetic resin, the filler and the liquid medium (water) are kneaded together, an on-off valve is provided to adjust the internal pressure of the extruder in order to further refine and homogenize the dispersed phase of the filler. A technique is disclosed (for example, Patent Document 3).

Japanese Patent No. 3650915 Japanese Patent No. 5097191 Japanese Patent No. 4660528

However, the technique disclosed in Patent Document 1 has a problem that the configuration of the extruder is complicated.
In addition, in the disclosed technologies of Patent Documents 2 and 3, it is possible to achieve a fine dispersion (homogenization) of the dispersed phase at the micro level. There was a problem of unevenness in level. Further, since the rotational resistance of the screw fluctuates, there is a problem that the operation of the extruder is not stable.
Further, in the disclosed techniques of Patent Documents 2 and 3, when increasing the blending ratio of the filler, it is necessary to introduce an excess liquid medium (water) in order to ensure the refinement (homogenization) of the dispersed phase. However, there is a problem that a large amount of heat of vaporization is taken away from the kneaded product when the liquid medium is discharged.

  The present invention has been made in view of such circumstances, and provides a technique for stably producing a polymer composite material in which a high-mixing-rate filler is uniformly dispersed while suppressing the amount of liquid medium to be introduced. The purpose is to do.

  In the apparatus for producing a polymer composite material according to the present invention, a hopper for introducing raw materials is provided on the upstream side, and a die part for extruding the kneaded material is provided on the downstream side. A screw that heats the raw material while extruding it downstream to make the kneaded product, a vent that discharges the gas component separated from the kneaded product from the cylinder, and at least powder, synthetic polymer, and liquid medium are separated. And a mixing unit that mixes the supplied powder, synthetic polymer, and liquid medium and feeds them into the hopper as the raw material.

  According to the present invention, there is provided a technique for stably producing a polymer composite material in which a filler with a high blending ratio is uniformly dispersed while suppressing the amount of liquid medium to be charged.

Schematic diagram of a coal-fired power plant. (A) The longitudinal cross-sectional view which shows 1st Embodiment of the manufacturing apparatus of the polymer composite material which concerns on this invention, (B) A horizontal sectional view. The longitudinal cross-sectional view which shows 2nd Embodiment of the manufacturing apparatus of the polymer composite material which concerns on this invention.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 2, the polymer composite material manufacturing apparatus 20 according to the first embodiment includes a cylinder in which a hopper 21 for introducing raw materials is provided on the upstream side and a die part 22 for extruding the kneaded material is provided on the downstream side. 23, a screw 24 that rotates inside the cylinder 23 and heats it while extruding the raw material from upstream to downstream to make a kneaded product, and a vent portion 25 that discharges the gas component separated from the kneaded product from the cylinder 23, A container 26 (26a, 26b, 26c) for separately containing at least a powder, a synthetic polymer and a liquid medium and supplying a predetermined amount, respectively, and a mixture of the supplied powder, synthetic polymer and liquid medium And a mixing unit 27 to be put into the hopper 21.

The container 26 (26a, 26b, 26c) contains powder, synthetic polymer, and liquid medium, respectively.
The fly ash employed as the powder in the present embodiment has a form having an average particle diameter of 10 to 30 μm in which spherical and irregular shapes are mixed.
As can be seen from the production process shown in FIG. 1, this fly ash is supplied in an absolutely dry state with a water content of almost zero.
The main components of fly ash are 70 to 80% of silica (SiO ₂ ) and alumina (Al ₂ O ₃ ), and other components are iron oxide (Fe ₂ O ₃ ), calcium oxide (CaO), Magnesium oxide (MgO), sodium oxide (Na ₂ O), potassium oxide (K ₂ O) and the like.

  A synthetic polymer forms a matrix phase of a polymer composite material, and can be any of a thermoplastic resin that melts by heating and a thermosetting resin that cures by heating. The one that is fluidized by raising the temperature is applied.

  Thermoplastic resins include low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene (PP), ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl acrylate copolymer Polyolefin resins such as coalesced (EEA) are suitable.

In addition, without limitation, polycarbonate resin (PC), polyethylene terephthalate resin (PET), acrylic / butylene / styrene (ABS), polyvinyl chloride (PVC), polystyrene (PS), polyamide (PA), etc. Any material can be used without particular limitation as long as it has the property of being heat-flowable by heating and can generally be extruded.
Furthermore, these thermoplastic resins may be used as a mixture of two or more.
Also, recycled products of these thermoplastic resins can be used.

As the liquid medium, water is preferably employed, but any liquid can be used as long as it vaporizes at the set temperature in the cylinder 23 and the atmospheric pressure level.
When the liquid medium is heated and kneaded together with the powder and the synthetic resin in a sealed state, the liquid medium has an effect of forming a fine dispersed phase of the powder in the fluid matrix phase of the synthetic resin.
That is, the liquid medium has the function of preventing the powder from aggregating in the fluid of the synthetic resin during the heat-kneading and making the composite uniform at the micro level.

The raw material accommodated in each of the containers 26 (26a, 26b, 26c) is 5 to 500 parts by weight of the synthetic polymer and 100% by weight of the liquid medium (100% by weight) with respect to 100 parts by weight of the powder (fly ash). It is supplied at a ratio of 1 to 1 part by weight.
Here, when the proportion of the synthetic polymer is lower than 5 parts by weight, the formation of the matrix phase of the synthetic polymer constituting the polymer composite material becomes insufficient.
And when the ratio of a synthetic polymer is higher than 500 weight part, the mixing | blending of powder becomes relatively small and the various characteristics as a polymer composite material will fall.

Moreover, when the ratio of a liquid medium is lower than 0.1 weight part, the surface of a fly ash particle cannot be wetted, and the inhibitory effect of the powder aggregation in a heating kneading process falls. Further, when the raw material is mixed in the mixing unit 27 or dropped onto the hopper 21, the fly ash powder rises and the working environment is deteriorated.
Moreover, when the ratio of a liquid medium is higher than 1 weight part, the required specification of the vent part 25 required in order to fully remove a liquid medium from a kneaded body will go up, and equipment cost will rise.

The mixing unit 27 uniformly mixes the powder, the synthetic polymer, and the liquid medium at a predetermined mixing ratio, and then puts the raw material into the hopper 21.
Thereby, the mixing | blending nonuniformity of the raw material thrown into the hopper 21 is eliminated, and the uniformity in the macro level of the polymer composite material manufactured continuously is ensured.
In addition, since the mixing unevenness of the raw material charged into the hopper 21 is eliminated, the powder mixing ratio can be improved, and the load of the vent portion 25 is reduced because there is no need to excessively add the liquid medium. be able to.
Further, by eliminating the uneven mixing of the raw materials put into the hopper 21, the torque fluctuation of the drive unit 29 necessary for rotating the screw 24 at a constant speed can be suppressed, and the production of the polymer composite material Can be ensured.

The cylinder 23 vaporizes a feed zone A provided with a hopper 21 for charging raw materials (powder, synthetic polymer and liquid medium), a heating kneading zone B for the charged raw materials, and a liquid medium contained in the kneaded product. The liquid medium discharge zone C is discharged from the vent portion 25, and the metering zone D is adjusted so that the melted kneaded material is pushed out from the die portion 22 at a constant pressure and a constant amount.
The cylinder 23 is provided with a heater 28 on the outer periphery of the portion excluding the feed zone A. Each zone of the cylinder 23 is controlled to an appropriate temperature by the heater 28.
The kneaded material in a molten state is discharged from the die portion 22 provided on the most downstream side, passes through a cooling bath (not shown), and solidifies, and then is cut into rice granular pellets by a pelletizer (not shown). .

The screw 24 is formed with a spiral flight around its axis, and is rotated by a drive unit 29 provided at the end thereof. Accordingly, the raw material and the kneaded material are pushed from the upstream side of the cylinder 23 toward the downstream side under pressure from the flight.
As for this screw 24, it is desirable that the deep groove ratio represented by the ratio of the outer diameter and the valley diameter is 1.5 or more.
Thus, by setting the deep groove ratio of the screw 24, a large free volume is formed in the cylinder 23, and the throughput can be stabilized even with a raw material having a small bulk density.

  In addition, although the manufacturing apparatus 20 of the polymer composite material in the embodiment illustrates a biaxial type in which the spiral direction of the flight is the same and rotates in the same direction, even if the spiral direction of the flight is reverse rotation, It may be uniaxial or multiaxial. Further, the present invention can also be applied to a conical type extruder in which the screw outer diameter becomes narrower toward the tip.

  In the cylinder 23, the feed zone A is a non-heated zone in which the heater 28 is not provided, so that the liquid medium vaporizes out of the charged raw materials (powder, synthetic polymer and liquid medium) and dissipates from the hopper 21. Is prevented.

In the heat-kneading zone B, the raw material is heated and kneaded by the action of the screw 24 and the heater 28 that rotate on the shaft, and the synthetic resin contained in the raw material is melted.
The powder contained in the raw material is re-aggregated by the action of the high-temperature and high-pressure liquid medium in the closed system, and is finely and uniformly dispersed in the matrix of the melt.

Next, when the kneaded product is passed through the liquid medium discharge zone C, the system is switched from the closed system to the open system, and the internal pressure is reduced to the atmospheric pressure level, so that the contained liquid medium is vaporized.
And the gas component isolate | separated from the kneaded material in the vent part 25 is discharged | emitted.
The vent 25 is configured so that the opening formed in the cylinder 23 is covered with a mesh plate (not shown) so that the kneaded body does not jump out of the vent 25.
On the other hand, the vaporized gas of the liquid medium is selectively discharged outside through the mesh plate.

A plurality of vent portions 25 provided with throttle valves (not shown) are arranged in the longitudinal direction of the cylinder 23 and their internal pressures are set so as to gradually approach the atmospheric pressure from the upstream to the downstream. Rapid vaporization of the medium may be prevented.
Moreover, the discharge of the liquid medium may be promoted by providing a pressure reducing pump (not shown) in the vent portion 25 and setting the internal pressure of the cylinder 23 to be lower than the atmospheric pressure.

The polymer composite material finally outputted from the die part 22 and formed into pellets is remelted and formed into various final products after distribution in the market.
The final product suitable for molding with the fly ash filled polymer composite material shown in the embodiment includes a resin plate for civil engineering such as a plywood for concrete formwork (compane), and a fly ash made of synthetic polymer as polypropylene. Examples thereof include a plastic corrugated cardboard compounded in 30 to 70 parts by weight, a sheet, a film, or a bag in which a synthetic polymer is low density polyethylene and / or linear low density polyethylene and fly ash is compounded in 20 to 60 parts by weight.

(Second Embodiment)
Next, a second embodiment of the present invention will be described based on FIG.
3, parts having the same configuration or function as those in FIG. 2 are denoted by the same reference numerals, and redundant description is omitted.
In the polymer composite material manufacturing apparatus 20 according to the second embodiment, the zone C of the cylinder provided with the vent portion 25 has a gap 33 formed in the groove portion of the screw 24 rather than the zones B and D before and after the zone C. Is set larger.
As a result, in the liquid medium discharge zone C, the pressure received by the kneaded body from the cylinder 23 and the screw 24 is reduced, the vaporization of the liquid medium is promoted, and the phenomenon that the kneaded body rises from the vent portion 25 can be suppressed.

Furthermore, in the polymer composite material manufacturing apparatus 20 according to the second embodiment, reverse feed shapes 31 and 32 for extruding the kneaded material in the reverse direction are formed at both ends of the screw 24 in the zone C in which the vent portion 25 is provided. Has been.
Due to the reverse feed shape 31 on the upstream side, the kneaded body to which the back pressure is applied in the heating and kneading zone B is suddenly reduced when it reaches the liquid medium discharge zone C, and the vaporization of the liquid medium is promoted.
Further, due to the reverse feed shape 32 on the downstream side, the residence time of the kneaded body in the liquid medium discharge zone C is extended, and the discharge of the liquid medium is promoted.

  According to the apparatus for producing a polymer composite material of at least one embodiment described above, the amount of the liquid medium to be charged is obtained by mixing the powder, the synthetic polymer, and the liquid medium and then supplying the mixed liquid to the hopper of the extruder. It is possible to stably produce a polymer composite material in which a filler with a high blending ratio is uniformly dispersed while suppressing the above.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 10 ... Coal thermal power plant, 20 ... Production apparatus of polymer composite material, 21 ... Hopper, 22 ... Die part, 23 ... Cylinder, 24 ... Screw, 25 ... Vent part, 26 (26a, 26b, 26c) ... Container, 27: Mixing section, 28: Heater, 29: Drive section, 31, 32 ... Reverse feed shape, 33 ... Gap, A ... Feed zone, B ... Heat kneading zone, C ... Liquid medium discharge zone, D ... Metalling zone.

In the apparatus for producing a polymer composite material according to the present invention, a hopper for introducing raw materials is provided on the upstream side, and a die part for extruding the kneaded material is provided on the downstream side. A screw that heats the raw material while extruding it downstream and turns it into the kneaded product, a vent that discharges the gas component separated from the kneaded product from the cylinder, and at least fly ash , synthetic polymer, and liquid medium are separated. Container for supplying the synthetic polymer in an amount of 5 to 500 parts by weight and the liquid medium in an amount of 0.1 to 1 part by weight, and the supplied fly ash and the synthetic polymer. And a mixing unit that mixes the liquid medium and puts it as the raw material into the hopper.

Claims (8)

A cylinder in which a hopper for charging the raw material is provided on the upstream side and a die part on which the kneaded material is extruded is provided on the downstream side;
A screw that rotates inside the cylinder and heats it while extruding the raw material from upstream to downstream to make the kneaded product;
A vent part for discharging the gas component separated from the kneaded material from the cylinder;
A container for separately containing at least powder, a synthetic polymer and a liquid medium and supplying a predetermined amount, respectively;
An apparatus for producing a polymer composite material, comprising: a mixing unit that mixes the supplied powder, a synthetic polymer, and a liquid medium, and inputs the mixture into the hopper as the raw material.   2. The apparatus for producing a polymer composite material according to claim 1, wherein the powder is fly ash.   The polymer according to claim 2, wherein the raw material is a mixture of 5 to 500 parts by weight of a synthetic polymer and 0.1 to 1 part by weight of a liquid medium with respect to 100 parts by weight of the powder. Composite material production equipment.   The zone of the cylinder in which the vent portion is provided has a larger gap formed in the groove portion of the screw than the zones before and after the zone. An apparatus for producing a polymer composite material according to claim 1.   5. The apparatus for producing a polymer composite material according to claim 4, wherein a reverse feed shape is formed at both ends of the screw in the zone provided with the vent portion to push the kneaded material in the reverse direction. .   6. The polymer composite material manufacturing apparatus according to claim 1, wherein a zone of the cylinder in which the hopper is provided is a non-heating zone. 7.   The said screw has a deep groove ratio of 1.5 or more, The manufacturing apparatus of the polymeric composite material of any one of Claims 1-6 characterized by the above-mentioned. A step of axially rotating the screw inside a cylinder in which a hopper for introducing the raw material is provided on the upstream side and a die portion from which the kneaded material is extruded is provided on the downstream side;
Supplying at least a predetermined amount from a container separately containing at least a powder, a synthetic polymer, and a liquid medium to the mixing unit;
Mixing the powder, the synthetic polymer and the liquid medium supplied to the mixing unit and charging the raw material into the hopper;
Discharging the gas component separated from the kneaded material that is heat-input while extruding the raw material from the upstream to the downstream of the cylinder;
And a step of taking out the kneaded material after discharging the gas component from the die part.

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