JPH10151629A - Plastic waste material recycling molding method - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a method for molding a molded product without separating it even if it is a plastic waste material in which various plastic materials are mixed, and to reduce costs and promote recycling of the plastic waste material. SOLUTION: A plastic waste material in which a plurality of types of plastic materials are mixed is stirred by a mixing device 1 having blades 11a to 11f rotating at a high speed, and melted by frictional heat generated by the stirring to form a gel state. Is directly loaded into a molding machine 42 to form a desired molded product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic waste material recycling molding method for molding useful molded articles by recycling plastic-based waste materials.

[0002]

2. Description of the Related Art A large amount of plastic waste generated from used plastic packaging containers or scrap car bumpers, battery cases, and other plastic products is made of polyvinyl chloride, polyethylene, polypropylene, nylon, acrylonitrile, polystyrene, polyamide, and the like. Various thermoplastic or thermosetting plastic materials such as polyester, urethane, epoxy, phenol, etc., or a mixture of these copolymer resins are mixed with foreign materials such as metal pieces, wood pieces, glass pieces, and fiber waste. It will be mixed. Conventionally, such plastic waste materials have different melting temperatures for each material, so it has been difficult to supply recycled plastics to a well-known injection molding machine, for example. Therefore, it was considered impossible to recycle unless the materials were separated. However, since advanced separation technology is required for separation and its cost is high, most of such plastic waste materials are conventionally dumped into disposal sites as industrial waste. In addition, even if such plastic waste is incinerated, there is a problem that a toxic gas having a strong odor is generated and the air is polluted.

[0003]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a method for recycling and reusing a plastic waste material in which various plastic materials are mixed into a useful molded product without any need for separation. An object of the present invention is to solve the above-mentioned problems by reducing the cost required and promoting the recycling of plastic waste materials.

[0004]

For this purpose, a plastic waste material recycling molding method according to the present invention is characterized in that a plastic waste material in which a plurality of types of plastic materials are mixed is agitated by a mixing device having blades rotating at high speed, and the agitation is accompanied by the agitation. It is characterized in that it is melted by the generated frictional heat to be in a gel state, and this is directly loaded into a molding machine to form a molded article.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a process chart of this recycling molding method. The first step (a) is a step of pulverizing various plastic waste materials obtained from the waste into an appropriate size to form chips, granules or powder. Then, measurement (step b) is performed to adjust the components according to the physical properties required as a molded article. At that time, if necessary, a material other than plastic (for example, rubber, wood powder, paper, fiber, etc.) may be added for the purpose of reinforcing, improving elasticity, or increasing the amount. Furthermore, colorings, agents, new plastic materials, reinforcing agents and the like can be added.

[0006] The plastic waste material thus measured is put into a mixing apparatus 1 illustrated in FIG. This mixer 1 forms a horizontal cylindrical chamber 3 on a machine base 2,
A rotating shaft 5 horizontally supported by bearings 4 and 4 is guided to the center of the chamber 3, and one end of the rotating shaft 5 is connected to a motor 7 via a joint 6. The rotary shaft 5 is hollow, and a rotary joint 8 and a coupling 9 are provided at its shaft end. Cooling water is supplied through the rotary joint 8 to a water supply pipe 10 provided at the center of the rotary shaft 5.
The cooling water is reciprocated in the rotating shaft 5 and discharged from the coupling 9.

As shown in FIGS. 2 to 4, a total of six blades 11a to 1
If is protruded. The blades 11a at both ends
And 11f are inclined at an angle of about 15 degrees so that the leading edge thereof makes sliding contact with the inner surfaces of both end walls 12 and 12 of the chamber 3 with almost no clearance when rotated in the direction indicated by the arrow. It is fixed to the outer peripheral surface. The four intermediate blades 11b, 11c, 11d, and 11e are staggered to the outer peripheral surface of the rotating shaft 5, and the leading edge of each of the outer blades is oriented such that the leading edge during rotation faces both ends of the chamber 3. Each is turned at an angle of about 15 degrees.

Reference numeral 12 denotes a material supply opening formed in one end wall of the chamber 3, reference numeral 13 denotes a spiral material supply screw formed on the outer periphery of the rotating shaft 5, and reference numeral 14 surrounds the supply screw 13. The material supply box 15 is a hopper provided above the supply box, and the hopper is provided with a lid 16 that can be hermetically closed. Reference numerals 17 and 17 denote balance wheels fixed to the rotating shaft 5.

A water passage 18 is formed in the peripheral wall of the chamber 3, and a water supply pipe 19 and a drain pipe 20 communicating with the water passage 18 are provided. Three walls can be cooled. Reference numeral 26 denotes an optical thermometer, 21 denotes a measuring head of the optical thermometer provided on a part of the peripheral wall of the chamber 3, and the measuring head 21 and the optical thermometer 26 are connected via a connection cable. Have been. Reference numeral 22 denotes a water passage provided around the periphery of the measuring head 21 to prevent cooling water from flowing through a water supply pipe 23 and a drain pipe 24 in order to prevent the measurement head 21 from being overheated. Reference numeral 25 denotes a digital panel meter for displaying the temperature measured by the optical thermometer 26. In this way, by passing the cooling water through the measuring head 21 to prevent overheating, it is possible to prevent the resin from sticking to the light receiving surface and to ensure the accuracy of the measuring temperature.

A gel discharge door 27 is provided on the bottom wall of the chamber 3. The door 27 is rotatably supported by a shaft 28, and a gear 29 provided on the shaft 28
When the rack 30 is moved forward and backward by the operation of the cylinder 32, the shaft 28 rotates and the door 27 can be opened and closed. Reference numeral 31 denotes a tray for receiving the gel, which is disposed immediately below the door 27.

A gas vent pipe 33 is connected to one side wall of the chamber 3, and the pipe 33 is provided in a vacuum exhaust gas device 34. Reference numeral 40 denotes a control panel. The control panel 40 is connected to an inverter for controlling the rotation speed of the motor 7 and includes an ammeter for measuring the load current of the motor 7 and a timer. And the door 27 can be opened and closed.

In the mixing apparatus 1 configured as described above, cooling water is circulated in the rotating shaft 5 and the wall of the chamber 3, respectively, and the blades 11 a to 11 a through the rotating shaft 5 are driven by the motor 7.
11f is rotated at high speed. For example, the blades 11a to 11f are rotated at a high speed so that the tip speed of the blades 11a to 11f can be increased to about 20 to 50 m / s. And a chip of a certain size in advance,
The plastic waste material pulverized into granules or the like is put into the hopper 15, and the plastic waste material is supplied into the chamber 3 from the material supply port 12 by the guide of the supply screw 13.
This is stirred from the blades 11a to 11f.

FIG. 6 shows an optical thermometer 26 when plastic waste material having a composition of 50% of polypropylene and 50% of acrylonitrile / ethylene propylene rubber / styrene copolymer resin is filled in the chamber 3 and stirred as described above. The measured temperature change of the plastic waste material in the chamber 3 (indicated by the symbol A) and the change of the load current of the motor 7 (indicated by the symbol B) at that time are shown in a chart with the horizontal axis as the time axis. It is a thing. In this way, the plastic waste material in the chamber 3 generates frictional heat as it is agitated, and the temperature gradually rises due to the frictional heat. When the plastic waste material is in a gel state having an appropriate softness as indicated by a point a in FIG. Melts. Further, the load current of the motor 7 reaches a peak at a point b in the figure, and within a few seconds thereafter, the temperature of the plastic waste material becomes an appropriate gel state. By detecting the time when the load current of the motor 7 reaches a peak in this manner, the chamber 3
It is possible to detect that the plastic waste material inside has just started to melt. That is, when the melting of the plastic waste material starts, the stirring resistance increases most, and the load current also reaches a peak at the same time. For this reason, the control panel 40 detects that the load current has peaked out, activates the timer, and activates the cylinder 32 a few seconds later (the setting time of the timer differs slightly depending on the amount and composition of the injected plastic waste material). If the door 27 is opened and the plastic waste in the chamber 3 is discharged, the plastic waste can always be discharged when it is melted into a gel having a moderate softness. For this reason, by taking such a discharge timing, it is possible to adjust the viscosity so as to always have the optimum softness for the convenience of molding in the next molding step.

The blades 11a and 11f prevent the molten plastic waste material from adhering to the inner surfaces of both end walls. Further, the blades 11b to 11e guide the plastic waste material toward the center in the chamber 3 by its inclination, so that the plastic waste material melted in the chamber 3 can be formed into a cake-like mass without being dispersed. And chamber 3
The wall is cooled by cooling water, and the rotating shaft 5 and the blade 11a
Since 11f is cooled by the cooling water circulating in the rotating shaft 5, the temperature difference from the molten plastic waste material can be sufficiently maintained and the sticking thereof can be prevented. Therefore, the door 27
Is opened, the plastic waste in the gel state is easily discharged onto the tray 31 by centrifugal force. (Steps c and d).

While the plastic waste material thus discharged is in a molten state, it is loaded into a molding machine (not shown) such as a pressure molding machine or an extrusion molding machine, and is formed into a plate, rod, granule, chip, box, or the like. Into a desired shape such as a shape. (Step e). FIG. 7 shows an example of a pressure molding machine 42 including a lower mold 40 and an upper mold 41 for that purpose. The plastic waste material 50 melted in a gel state is loaded into the lower mold 40, and the upper mold 41 is lowered and pressed to form the plastic waste material 50 into a plate shape.

The plastic waste material melted by the frictional heat of stirring is immediately loaded into the next molding machine without reheating, so that various plastic materials in the waste material can be completely integrated without being separated. A molded article can be molded as For this reason, it is possible to mold a molded article having excellent physical properties such as strength and elasticity despite various plastic materials being mixed. Incidentally, in the plastic waste material having the above composition, the flexural modulus is 1700 kg · f / cm ² or more, the bending strength is 300 kg · f / cm ² or more, and the tensile strength is 150 kg · f.
/ cm ² or higher characteristics were obtained. For this reason, the use of the molded article is extremely wide without using new materials and discoloration. The plastic waste material that can be recycled here is not limited to the above composition, and various kinds of waste plastic products such as automobile bumpers, automobile interior parts, plastic bottles, styrofoam containers, chemical containers, and battery cases can be mixed and used.

If the gas in the chamber 3 is sucked by the vacuum exhaust device 34 through the pipe 33, the harmful gas generated when the plastic waste such as vinyl chloride is melted can be discharged to the outside. A good working environment can be maintained. Further, by closing the lid 16 of the hopper 15 in an airtight manner and reducing the pressure in the chamber 3, the mixing ratio of air, gas and the like into the molten resin due to the stirring can be reduced as much as possible. More desirable to improve.

As described above, the plastic waste material melted by the frictional heat of the stirring is immediately loaded into the next molding machine without reheating, so that various plastic materials in the waste material can be completely integrated without being separated. A molded article can be molded as For this reason, even though various plastic materials such as thermoplasticity and thermosetting are mixed, it is possible to mold a material having excellent physical properties such as strength and elasticity, and the use of the molded product is wide. .

[0019]

As described above, according to the recycle molding method of the present invention, a useful molded article can be molded by melting plastic waste materials into an appropriate gel state by frictional heat generated by stirring and integrating different types of plastic materials. For this reason, plastic waste can be recycled at low cost without requiring separation, resources can be effectively used, and the problem of treating plastic waste is extremely effective.

[Brief description of the drawings]

FIG. 1 is a process diagram of a plastic waste material recycling molding method according to the present invention.

FIG. 2 is a longitudinal sectional view of a mixer for performing the plastic waste material recycling molding method according to the present invention.

FIG. 3 is an enlarged view of a blade of the mixer of FIG. 2;

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a sectional view taken along line AA of FIG. 3;

FIG. 6 is a diagram showing a change in temperature and a change in load current of a motor accompanying agitation of plastic waste.

FIG. 7 is a longitudinal sectional view of a molding machine for performing the plastic waste material recycling molding method of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mixing device 3 Chamber 5 Rotating shaft 11a-11f Blade 12 Material supply port 42 Molding machine

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI B29C 45/00 B09B 3/00 301W // B29K 105: 26

Claims (1)

[Claims] 1. A plastic waste material in which a plurality of types of plastic materials are mixed is stirred by a mixing device equipped with high-speed rotating blades, and melted by frictional heat generated by the stirring to form a gel state, which is molded as it is. A plastic waste material recycling molding method characterized in that a molded product is molded by being loaded into a machine.