JPH0631733A - Treating method for making plastic waste materials resources again and its apparatus - Google Patents

Abstract

PURPOSE:To carry out especially crushing, grinding and cleaning effectively in a treatment for making resources again of used waste materials of industrial plastic packaging materials. CONSTITUTION:Packaging waste materials are roughly crushed to an extent suitable for cleaning with a primary crusher 1, and cleaning by acid or alkali is carried out with a primary cleaning tank. Water washing is carried out with a secondary cleaning tank, and the product is further finely ground with a secondary grinding machine 4. The ground materials are transferred successively to a dehydrator 5, a dryer 6, and a volume-reducing solidifying shredder 7. By rotation of water wheels 8 provided to the cleaning tanks 2, 3, materials to be cleaned which float on a water surface are forced to sink into water and cleaning is carried out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method and apparatus for recycling used waste products of industrial plastic packaging materials.

[0002]

2. Description of the Related Art Conventionally, plastic waste products with little dirt have been subjected to processing such as crushing, washing, melting and molding,
Although various methods of manufacturing recycled plastic products are in use, used waste products of plastic packaging materials that contain industrial materials such as cement are recycled because the contents adhere to them and are extremely dirty. At present, it is considered difficult to dispose of and is disposed of as landfill as industrial waste. However, recently, it is not easy to secure a landfill site, and chemical substances contained in the deposits may contaminate groundwater. From the viewpoint of environmental conservation and resource utilization, recycling of this type of plastic waste is required. ing.

Examining the problems in processing the above-mentioned industrial plastic packaging waste products, since the waste products are mainly bag-like products, the crushed products enclose air and are bulky, and the apparent specific gravity is extremely small. Therefore, there is a problem that when cleaning this, it floats on the water surface and makes the treatment difficult. Also, since waste products often have hard materials attached,
There is also a risk of damaging the blade of the crusher. Therefore, the success or failure of the treatment depends on how to overcome these difficulties and to effectively remove the deposits containing chemical substances, hard substances and the like.

[0004]

In view of the above problems, it is an object of the present invention to devise the most effective method of crushing and washing in the recycling process of waste plastic packaging materials for industrial use. And

[0005]

Means adopted for solving the above problems will be described with reference to the drawings. The present invention is a polyethylene containing industrial materials such as cement,
Used waste of plastic packaging materials such as polypropylene shall be the object of recycling treatment. This plastic waste is roughly crushed by the primary crusher 1 to an extent suitable for washing. The crushed material is chemically washed with acid or alkali in the primary cleaning tank 2 and then washed with water in the secondary cleaning tank 3. The washed product is further finely crushed by the secondary crusher 4. The crushed material is dehydrated by the dehydrator 5 and dried by the dryer 6. The dried material is introduced into a volume reduction solidification crushing device 7, and volume reduction, solidification, and crushing are performed to obtain chips of recycled plastic raw material.

The primary cleaning tank 2 and the secondary cleaning tank 3 are provided with a plurality of water wheels 8 in the upper part of the tanks, and by the rotation of these water wheels, the objects to be washed floating on the water surface are pushed into the water. .

In the above, industrial materials include cement, lime, calcium carbonate, silica sand, other chemicals,
A wide variety of mineral products and agricultural products. The packaging material is mainly made of a bag, and also includes strings and sheets. Chemical cleaning refers to cleaning involving a chemical reaction such as neutralization. Volume reduction means reducing the volume, and shredding means chopping.

[0008]

Since the materials packaged by the industrial packaging material include acidic substances, alkaline substances, oily substances and the like, it is not easy to wash off these deposits by simply washing with water. Therefore, in the present invention, in the primary cleaning tank using an acid or an alkali, if the deposit is an alkaline substance, an acid wash is performed, and if the deposit is an acidic substance or an oily substance, an alkali wash is performed to neutralize the deposit. Washed off by chemical cleaning, etc., and then rinsed with water in the secondary cleaning tank,
It was decided to remove the acid or alkali.

The crushed material of the waste plastic packaging material treated in the present invention has an extremely small apparent specific gravity, and thus floats on the water surface of the cleaning tank and makes cleaning difficult. Therefore, in the present invention, a plurality of water wheels are provided in the upper part of the tank of the cleaning tank, and the crushed material floating on the water surface is pushed into the water by the rotation of the water wheel.
The cleaning was done without any problems.

Since the crushing of the waste packaging materials by the primary crusher is limited to the rough crushing of a degree suitable for cleaning, the overuse of the knives can be avoided, and the damage of the knives that can occur when hard materials adhere to the waste packaging materials The fear was significantly reduced. After the completion of washing, the primary crushed material was crushed into smaller pieces by a secondary crusher to an extent suitable for introduction into the volume reduction solidification crushing apparatus.

[0011]

[Examples] Waste packaging materials are thrown into the primary crusher 1 by the conveyor 11 and crushed to a size suitable for cleaning. The crushed material is put into the primary cleaning tank 2 and washed with acid or alkali. The washed product is picked up by the conveyor 12, put into the secondary washing tank 3, and washed with water. In the primary cleaning tank and the secondary cleaning tank, as shown in FIG. 2, a plurality of cleaning water turbines 8 are arranged in parallel on one side and a water circulation water turbine 9 is arranged on the other side, with a partition 10 in between, in the upper part of the tank. It is provided. These are four-bladed water wheels. The crushed material floating on the water surface is pushed into the water by the rotating water wheel 8 and moves while being washed by the rotation of the water wheel and the circulating water flow as indicated by the arrow. Two
The crushed material washed with water in the next cleaning tank 3 is scraped up by the conveyor 13 and charged into the secondary crusher 4 to further crush it.
The secondary crusher is provided with a conveyor 14 for feeding plastic waste products that do not require cleaning.

The crushed material from the secondary crusher is transferred to the dehydrator 5 by the air flow of the blower 15 and dehydrated. The dewatering device 5 is composed of a cyclone 5a that drops the feed while rotating it with an air flow, a screw conveyor 5b, and a main body 5c that incorporates a vertical screw. A dryer 6 is provided so as to be connected to the dehydrator. This drying device is composed of several cyclones 6a connected in series via a blower 6b. A heater can be provided on the cyclone 6a.
The arrow above each cyclone indicates the release of air, and the arrow below it indicates the inflow of air. The crushed material dried by this drying device is transferred by an air flow, passed through the cyclone 16, and fed into a hopper 17 equipped with a stirring device 17a. The crushed material stored in the hopper is introduced into the volume-reducing solidification crushing device 7 by a fixed amount by a constant-volume feeder 18 which is a conveyor.

The volume reduction solidification shredding device 7 comprises a crush melt feeder 7a, a solidification portion 7b, and a shredder 7c. The crush melt feeder compresses the crushed material with two internal screws and melts the crushed material with the frictional heat and the heat from the auxiliary heater. A bulky crushed material with an extremely small apparent specific gravity is reduced in volume by melting, solidified by water cooling in the solidification section, and shredded into amorphous chips by a shredder. The chips are sent to the bagging and weighing device 19 and packed in a bag. 20 is a dust collector. The packed chips are sent to the processing plant as recycled plastic raw materials and reused as various plastic products.

In FIG. 1, the thick solid line indicates the transfer line of the object to be treated, the thick two-dot chain line indicates the concentrated waste liquid line, the thick one-dot chain line indicates the dilute waste liquid line, and the thin one-dot chain line indicates the water supply line.
The concentrated waste liquid is sent to the waste liquid pit 21. The supernatant of this pit is reused. The diluted waste liquid is sent to the wastewater treatment device 23. The treated water is sent to the reused water pit 22 and reused. Water is supplied to the cleaning tanks 2 and 3 and the solidifying portion 7b as shown in the figure.

[0015]

INDUSTRIAL APPLICABILITY According to the present invention, the object to be treated is a used waste product of an industrial plastic packaging material, most of which has chemical substances and hard substances attached thereto, and the waste product mainly consisting of a bag-like product is crushed. In consideration of the fact that the apparent specific gravity of a product is small and that it floats on the surface of the water, it was developed with particular in mind for crushing and washing.

The present invention employs a two-stage crushing method in which the primary crushing before cleaning is roughly crushed to an extent suitable for cleaning and the secondary crushing after cleaning is finely crushed. As described above, the risk of damaging the blade of the primary crusher was significantly reduced.

By washing with an acid or alkali in the primary washing tank, the alkaline or acidic substances adhering to the waste packaging materials are neutralized and washed off at the same time, so that the washing efficiency is good. The kimono can be removed quickly and surely.

By providing a plurality of water wheels in the upper part of the cleaning tank, the object to be washed which has an extremely small apparent specific gravity and floats on the water surface is sunk into the water by the rotation of the water wheel to facilitate the difficult cleaning. I was able to do it.

On the basis of the above effects, the present invention places used waste products of industrial plastic packaging materials, which have been conventionally disposed of, in a recycling process including volume reduction, solidification and shredding, and various It was able to be revived as a raw material for recycled plastic processed products.

[Brief description of drawings]

FIG. 1 is a flow sheet of processing steps.

FIG. 2 is a schematic plan view of a cleaning tank.

[Explanation of symbols]

1 ... Primary crusher, 2 ... Primary washing tank, 3 ... Secondary washing tank, 4 ... Secondary crusher, 5 ... Dehydrating device, 6 ... Drying device, 7 ... Volume reduction solidification shredding device, 8, 9 ... watermill.

Claims (4)

[Claims] 1. A used waste product of a plastic packaging material such as polyethylene or polypropylene containing industrial materials such as cement is subjected to treatments such as crushing, washing, dehydration, drying, volume reduction, solidification and crushing. Thus, in the treatment method of changing the waste product into chips of recycled plastic raw material, the waste product is roughly crushed to an extent suitable for washing, the crushed product is chemically washed with an acid or an alkali, then washed with water, and further crushed finely. A method for recycling plastic waste products, wherein the crushed material is sequentially transferred to the subsequent steps such as dehydration. 2. In the chemical cleaning and the water cleaning, the plurality of water wheels provided in the upper part of the tank inside the cleaning tank are rotated so that the object to be washed floating on the water surface is pushed into the water. A method for recycling the waste plastic products described. 3. A crusher and a washing machine, which are provided to treat used waste products of plastic packaging materials such as polyethylene and polypropylene containing industrial materials such as cement and to convert the waste products into chips of recycled plastic raw materials. In a series of processing equipment consisting of a tank, dehydration equipment, drying equipment, volume reduction solidification shredding equipment, etc., a primary shredder that roughly crushes the waste products to a degree suitable for washing, and chemical washing of the crushed material with acid or alkali A primary cleaning tank for cleaning, a secondary cleaning tank for subsequent water washing, and a secondary crusher for further crushing are provided, and the crushed material is sequentially transferred to the subsequent dehydrator or the like. Recycling equipment for plastic waste products. 4. A plurality of water wheels are provided in the upper parts of the primary cleaning tank and the secondary cleaning tank, and the objects to be washed floating on the water surface are sunk into the water by the rotation of the water wheels. The recycling apparatus for recycling plastic waste according to claim 3.