JP3198742U - Biodegradable composite resin pellet manufacturing equipment - Google Patents

Abstract

The present invention provides an apparatus for producing biodegradable composite resin pellets produced by an integrated molding machine from waste paper powder finely pulverized by a single pulverizer, a polylactic acid resin and a crosslinking agent. A manufacturing apparatus includes a single pulverizer, and the pulverizer includes a pulverization chamber, a plurality of fixed blades and a rotary blade that pulverize used paper put into the pulverization chamber into paper powder. A suction screen for dropping the paper powder from the crushing chamber, and the manufacturing apparatus also has a molding machine, and the finely pulverized paper powder is quantitatively introduced into the hopper 23 by the belt conveyor 20. The molding machine has a kneading chamber 26 for kneading the resin composition under heating, and an extrusion molding chamber 41 from which the resin composition kneaded in the kneading chamber 26 is discharged. The resin composition in 41 is pressure-extruded from the die hole 43 and integrally molded. [Selection] Figure 3

Description

Detailed description of the invention

In the present invention, when a composite material made of waste paper and polylactic acid is produced, the waste paper powder finely pulverized by a single pulverizer, polylactic acid resin and cross-linking agent are produced by an integrated molding machine consisting of a kneading chamber and an extrusion chamber. The present invention relates to an apparatus for producing biodegradable composite resin pellets.

In recent years, from the viewpoint of environmental protection of wastes due to the use of petroleum-based plastics and the reduction of carbon dioxide gas as a countermeasure against global warming, the use of plant-derived biodegradable resin and polylactic acid resin as well as waste paper with plant-derived cellulose fiber Composite materials are being developed.

Waste paper used as a raw material for composite materials must be pulverized to maintain a size and strength suitable for blending. Conventionally, waste paper can be crushed wet, or it can be crushed with a hammer mill into a cotton-like form using a simpler dry method. A device has been devised in which a composite material having a uniform composition can be obtained by finely pulverizing or finely pulverizing to 200 μm or less with a roll crusher or a cutter mill. However, it is not easy to pulverize a large amount of waste paper to provide a composite material while maintaining the strength of the fiber. Usually, as shown in JP-A-08-283475 and JP-A-11-099522, A coarsely pulverized paper powder that is coarsely pulverized to a size of 2 to 5 mm with a coarse pulverizer and then finely pulverized to 200 μm or less with a fine pulverizer is used for a composite material. After adding the additive to the resin and kneading and extruding to form a composite material, the molded composite material is pulverized again and kneaded and extruded to obtain the desired composite material. ing. Such a two-stage process has a problem that the number of processes increases, the cost increases, the heating history increases, material deterioration occurs, and product quality decreases.

Furthermore, the polylactic acid resin used as the raw material of the composite material is desired to be a powder having a particle size of 3 to 200 μm as shown in Patent Documents 3597645 and 4590378 in order to improve dispersion in the composite material. However, in addition to the problem of dust scattering, the polylactic acid resin has higher strength than general-purpose resins such as polyolefin, and it has been difficult to finely pulverize the pellets with a pulverizer and to provide the composite material.

Polylactic acid is produced by ring-opening polymerization of lactide, which is a purified cyclic dimer of fermented lactic acid, and dehydration polymerization in a solvent, but the asymmetric carbon of lactic acid constitutes D-form, L-form, There are various types such as DL mixtures, and high purity D-form or L-form polylactic acid exceeding the purity of 98%, which is high in crystallinity, is usually selected from the viewpoint of strength and heat resistance. However, the use of such high-purity polylactic acid for the production of composites with waste paper increases the material cost, raises the melting point, raises the working temperature during kneading, melting, and extrusion, and increases the waste paper. This causes problems such as deterioration of the material, clogging of the extrusion nozzle (die hole), and fusion of the extracted pellets.

Furthermore, in order to mix and knead, melt and extrude paper powder, polylactic acid resin and cross-linking agent, usually a composite material kneaded and melted with a pressure type or double arm type kneader (kneader) is used as a belt conveyor, etc. It is introduced into the inlet of a biaxial or biaxial tapered extruder (pelletizer) that is excellent in mixing and dispersing functions and can be expected to have a stable extrusion amount, and is pressurized and applied with a screw. The composite pellets are produced from the extrusion nozzle through a rotary cutter while warming. However, when fine paper powder and polylactic acid resin are put into the hopper of the kneader, dust is scattered, and materials with different bulk specific gravity are produced. Due to the introduction, the materials are separated in the hopper, which causes a problem in uniform supply and mixing, resulting in a problem that pellets having a homogeneous composition cannot be obtained.
Further, when the molten composite material is transferred from the kneader to the extruder, a temperature change occurs, causing a problem that the pellet discharged from the die hole of the extruder is defective or clogged.

Effect of device

The purpose of the present invention is to produce waste paper having a uniform blending composition and a particle size with less dust scattering when producing a composite material comprising waste paper and polylactic acid in a single step by a single crusher. Crushing to increase production efficiency and reduce costs, put into an integrated molding machine consisting of a kneading chamber and an extrusion chamber, melt at a low temperature to obtain a homogeneous blending composition, and less dust scattering. By mixing with polylactic acid in the form of inexpensive pellets and adding a crosslinking agent to knead, melt, and extrude, there is no clogging of the die holes or fusion of the extracted pellets, and it is inexpensive and homogeneous biodegradability It is providing the manufacturing apparatus of a composite resin pellet.

As the best mode for carrying out the present invention, a plurality of used papers put into a crushing chamber are pulverized at 150 to 800 rpm by a single crusher having a plurality of fixed blades and rotating blades, and a suction screen is used. 40 to 60 parts by weight of paper powder having a diameter of 2 to 4 mm obtained through the process, 40 to 60 parts by weight of L-form polylactic acid resin having a melting point of 140 to 160 ° C. and a D-lactic acid content of 2 to 5% by weight, and a crosslinking agent 1 to 4 parts by weight are quantitatively charged into a kneading chamber of a molding machine having a kneading chamber and an extrusion chamber, and a composite resin composition kneaded under heating at 180 to 190 ° C. has a die hole with a diameter of 2 to 5 mm from the extrusion molding chamber. An apparatus for producing biodegradable composite resin pellets that are integrally molded by pressure extrusion is provided.

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a front view of a used paper crusher of a biodegradable composite resin pellet manufacturing apparatus showing a configuration example of the present invention. A used sheet of 0.2 to 1.0 m ² and a thickness of 0.1 to 5 mm is continuously dropped into the pulverizing chamber 4 by 2 to 10 sheets from the input port 3 of the input stage 2 of the pulverizer 1. The paper powder crushed by the roller drive motor 6 on the gantry 5 is collected in the storage box 11 from the suction cylinder 8 installed in the lower part of the shooter chamber 7 through the blower 9 and the cyclone 10, and the lightened paper powder is belted. It is put into the hopper of the kneader with a transfer device such as a conveyor.

  FIG. 2 is a cross-sectional view of a crushing chamber of a used paper crusher showing a configuration example of the present invention. Used paper is fed from a hopper 12 above the crushing chamber 4, and a plurality of rotary blades 15 fixed to a motor cylinder 14 connected to a roller drive motor 6 in the crusher main body 13 and a plurality of fixed blades fixed to the crusher main body 13. The paper powder crushed and crushed by the fixed blade 16 passes through the suction screen 17 and falls into the repair chamber 18. A blade 19 is installed in the rotor portion of the rotary blade 15. In FIG. 2, an example of a rotary blade having three blades and two fixed blades is shown, but a plurality of blades can be installed respectively. The paper dust dropped in the repair chamber 18 is discharged from the suction cylinder 8 by the blower 9 and transferred to the storage box 11. The suction screen 17 made of stainless steel mesh is provided with punch holes with a diameter of 2 to 4 mm, and can produce paper powder with a diameter of 2 to 4 mm with less dust scattering in a single pulverization step.

FIG. 3 is a side view of an integral molding machine having a kneading chamber and an extrusion chamber of a biodegradable composite resin pellet manufacturing apparatus showing a configuration example of the present invention.
In FIG. 3, the measured paper powder having a diameter of 2 to 4 mm finely pulverized by the pulverizer of the present invention is blended by the belt conveyor 20 from the paper powder inlet 21 to the hopper 23 of the kneader 22 at a blending ratio of 40 to 60 weight. It is quantitatively added so that it becomes a part. Similarly, the L-type polylactic acid resin having a melting point of 140 to 160 ° C. and a D-lactic acid content of 2 to 5% by weight of the present invention. Quantitatively charged from the feeder 25 to the hopper 23 such that the blending ratio is 40 to 60 parts by weight and 1 to 4 parts by weight, respectively. The kneading chamber 26 of the kneader 22 is kneaded by rotating the rotors 29 and 30 having blades by driving motors 27 and 28 at 160 to 200 ° C. for 5 to 10 minutes and 20 to 50 rpm. The drive unit for kneading and discharging the kneaded material and transferring it to the extrusion chamber includes a motor 31, a transmission 32, a speed reducer 33, and the like. It is preferable to provide a temperature control mechanism with a heat medium and cooling water inside the rotor. The kneading chamber 26 is pressurized by a pressure cylinder 34 and a pressure lid 35 at a pressure of ² to 7 kg / cm ² . At the end of kneading, the bottom plate 36 installed at the bottom of the kneading chamber 26 is slid and opened by an open / close motor 37 to discharge the kneaded material and drop it onto a discharge screw 38 for secondary kneading. A rotating disk 39 connected to the outlet side of the discharge screw 38 is provided. A large number of holes with a diameter of 4 to 8 mm are laid in the rotating disk 39 and are in contact with the fixed disk 40 through bearings. A large number of holes having a diameter of 4 to 8 mm are laid in the rotating disk 39 and the fixed disk 40, and the kneaded material that has passed is introduced into the extrusion chamber 41. The kneaded material introduced into the extrusion chamber 41 is provided with a temperature control mechanism using a heat medium and cooling water on the outer periphery of the extrusion screw 42 by an extrusion screw 42 whose pitch is smaller than the discharge screw, while keeping the temperature at 170 to 190 ° C. It is extruded through an extrusion die 43 in which a 4 mm diameter hole is laid. The kneaded product extruded from the extrusion die 43 efficiently produces biodegradable composite resin pellets having a diameter of 2 to 4 mm and a length of 2 to 4 mm by a screw cutter 45 connected to the extrusion screw 42 via the lid 44. It is accommodated in the pellet storage box 46, packaged in a shipping container after weighing, and shipped.

  FIG. 4 is a side view showing an example of a connected integrated molding machine in which a kneader and an extruder of a biodegradable composite resin pellet manufacturing apparatus showing another configuration example of the present invention are connected by a screw conveyor. In FIG. 4, the mechanism of the kneading machine 25 is the same as that in FIG. 3, and each part is denoted by the same reference numeral. The kneaded material discharged from the discharge screw 38 is fed into the hopper 50 of the extruder 49 by a screw conveyor 48 in the kneaded material storage box 47. The screw conveyor 48 is driven by a screw motor 51, and the outer periphery of the screw cylinder is kept warm by heating means 52 such as a belt heater or a ribbon heater. In the feeder unit 53 of the extruder 49, the kneaded material is extruded by a screw type extruder by driving the extrusion motor 54. As the screw type extruder, a single screw or a twin screw is known. FIG. 4 shows an example of a biaxial taper screw 55 that is particularly excellent in mixing efficiency. The kneaded material is well pushed into the extrusion chamber 41 and is biodegraded according to the present invention in the same manner as the method described in FIG. Can be produced efficiently.

  As described above, as shown in FIG. 3 and FIG. 4, by using the integrated molding machine having the kneading chamber and the extrusion chamber of the present invention, mixing, kneading, melting, and extrusion can be integrally formed. A homogeneous biodegradable composite resin pellet can be produced while avoiding troubles such as heat history, die clogging, and fusion of extruded pellets.

FIG. 1 is a front view of a used paper crusher of a biodegradable composite resin pellet manufacturing apparatus showing a configuration example of the present invention. FIG. 2 is a cross-sectional view of a crushing chamber of a used paper crusher showing a configuration example of the present invention. FIG. 3 is a side view of an integral molding machine having a kneading chamber and an extrusion chamber of a biodegradable composite resin pellet manufacturing apparatus showing a configuration example of the present invention. FIG. 4 is a side view showing an example of a connected integrated molding machine in which a kneader and an extruder of a biodegradable composite resin pellet manufacturing apparatus showing another configuration example of the present invention are connected by a screw conveyor.

1: Crusher 2: Input stage 3: Input port 4: Crushing chamber 5: Mounting base 6: Drive motor 7: Shooter chamber 8: Suction cylinder 9: Blower 10: Cyclone 11: Storage box 12: Hopper 13: Crusher main body 14 : Motor cylinder 15: Rotary blade 16: Fixed blade 17: Screen 18: Collection chamber 19: Traction weight 20: Belt conveyor 21: Powder feeder 22: Kneader 23: Hopper 24: Polylactic acid feeder 25: Cross-linking agent Feeder 26: Kneading chamber 27, 28: Drive motor 29, 30: Rotor 31: Motor 32: Transmission 33: Reduction gear 34: Pressure cylinder 35: Pressure lid 36: Bottom plate 37: Opening / closing motor 38: Discharge screw 39 : Rotating disc 40: Fixed disc 41: Extrusion chamber 42: Extruding screw 43: Extrusion die 44: Lid 45: Screw -Cutter 46: Pellet storage box 47: Kneaded material storage box 48: Screw conveyor 49: Extruder 50: Hopper 51: Screw motor 52: Heating means 53: Feeder section 54: Extrusion motor 55: Biaxial taper screw

Claims (1)

A plurality of waste papers put into the crushing chamber are finely pulverized at 150 to 800 rpm by a single crusher having a plurality of fixed blades and rotating blades, and obtained from 2 to 4 mm diameter paper powder 40 to 40 mm. 60 to 60 parts by weight, 40 to 60 parts by weight of L-form polylactic acid resin containing 2 to 5% by weight of D-form lactic acid having a particle size of 1 to 3 mm and a melting point of 140 to 160 ° C. and crosslinking agents 1 to 4 Weight parts are quantitatively charged into a kneading chamber of a molding machine having a kneading chamber and an extrusion chamber, and a composite resin composition kneaded under heating at 170 to 190 ° C. is pressed from a die hole having a diameter of 2 to 5 mm from the extrusion molding chamber. Equipment for producing homogeneous biodegradable composite resin pellets by extrusion and integral molding

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