JPS62164505A - Material separating device - Google Patents

Abstract

PURPOSE:To improve the quality of reproduced resin as well as the yield of reproduc tion by a method wherein the order of separating objects is determined upon separating proposes for removing paper, synthetic paper, adhesive agent or the like from plastic resin or from a bottle made of polyester especially. CONSTITUTION:The flakes of crushed plastic resin are sent into an air classification machine 1 from a chute 6 through a constant quantity supplying means 7 at first to separate mixed label pieces (paper). Subsequently, the flakes are sent into a mixing tank 2 to peel and separate the labels from adhesive agent which are bonded to the pieces of plastics. This mixing is effected while supplying water, having the weight of 10-35% of the weight of plastic material and the temperature of a normal tempera ture to 60 deg.C, from a water reserving tank 13, under the number of rotation of about 1,000-1,200rpm. According to this method, the softening and separation of the adhesive agent as well as the separation of the bonded labels is promoted by friction between plastics each other and the temperature increase (70-80 deg.C) of the water. Further, the material is sent into a washing tank 15 to dilute the whole of the water and the plastic, thereafter, unnecessary contents can be separated and discharged to the outside of a screw conveyor while passing them through the screw conveyor 17 equipped with a filter 18.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a technology for collecting and reusing used polyester bottles, and in particular, it relates to a technology for sorting and labeling recovered raw materials that have undergone a crushing process. The present invention relates to a technique for obtaining clean plastic resin flakes by removing labels (paper, synthetic paper) and adhesives from plastic resin flakes (slices or granules) to which adhesives and adhesives are attached.

(Technical Background) To date, the technology of collecting and reusing used polyester bottles has been impractical. It has been pointed out that when plastic waste is incinerated, the inside of the incinerator becomes high temperature, which reduces the durability of the incinerator.However, it is laborious and costly to separate the plastic from other waste. Since then, there has been no technological development to make recovery and reuse a profitable business. From the perspective of effective resource use or social demands to save on public investments such as large incinerators, measures should be taken not to treat plastic as industrial waste and to switch from disposable to reusable plastic products. is a contemporary issue that the plastics industry is required to solve.

Therefore, the inventors of the present invention focused on polyester bottles, whose consumption is rapidly increasing, and started developing technology for collecting and reusing them.

There are various types of polyester bottles, but
Examples of complex structures include an aluminum stopper, a polyethylene seal attached to the inside of the stopper so that the mouth of the bottle can fit tightly, a polyester that forms the entire bottle (neck and body), and a seal that fits into the bottom of the bottle. Examples include a hakama made of polyethylene that allows the bottle to stand on its own, a label (made of paper or synthetic paper) that is attached to the outer surface of the bottle, and an adhesive to which the label is attached. and,
In order to collect and reuse polyethylene and polyester from such bottles, it is necessary to collect as many bottles of the same type as possible and to streamline the process for collection and reuse.

The first step in the recovery work is to remove the metal stopper. Used (waste) bottles without metal stoppers are extremely easy to handle and can be easily disposed of afterwards. However, it is generally difficult to remove the metal stopper or to separate the metal stopper and the plastic (bottle body) by means other than manual means. Therefore, a technology that can separate plastic and metal when metal plugs are mixed in is essential. Waste bottles are transported by land or sea in trunks, ships, etc. Then, in order to increase the amount of transportation, it is crushed and densified before being transported.

Therefore, in order to collect it, it must first be crushed into flakes. Among the crushed flakes are fragments of metal stoppers such as aluminum, glue or adhesive for attaching labels to plastics, labels (paper or synthetic paper) attached to plastics, and foreign materials. Contains plastic etc.

Therefore, the first problem is to remove the label and the adhesive to which the label is attached from the crushed flakes.

In addition, for collection and reuse, fragments of aluminum plugs,
It is also necessary to separate and remove different types of plastics.

As already mentioned, a waste (used) bottle has a label affixed to a part of the container indicating when the bottle was used as a bottle. This label is used to clearly indicate the contents, brand, etc. of the container, and is often attached using an adhesive.

In order to reuse waste bottles, this label and the adhesive used to attach the label must be removed. By the way, since waste bottles are transported in a crushed state, they are first crushed into flakes using a crusher. Therefore, the label remains affixed and remains in the form of sections or particles. Ideally, only containers (plastic resin) with labels and aluminum stoppers removed would be collected, but if waste bottles with labels still attached are crushed and transported, the labels and adhesives can be removed after crushing. There must be. As a recovery method, if you separate only the plastic resin by removing the resin flakes and labels that have labels attached, the labels and adhesives will be removed from the resin surface (this will no longer be necessary.However, this recovery method will reduce the amount of resin that can be reused). The reason for this is that labels are usually affixed to 20 to 80% of the container surface, and a method that can only recycle half of the collected amount cannot be called an original recycling technology. .

Therefore, there is a need to develop a technique for peeling labels and adhesives from the surface of plastic resin flakes at the lowest possible cost. From this point of view, the present inventors have diligently developed efficient and practical collection devices and techniques for separating labels and adhesives, and have arrived at the present invention.

(Object of the Invention) An object of the present invention is to provide an apparatus for separating and removing paper, synthetic paper, adhesive, etc. from plastic resin.

(Structure of the Invention) The present invention provides label pieces (
an agitation tank equipped with an agitation means to peel off label pieces and adhesives attached to some surfaces of plastic resin flakes from the surface; and a cleaning tank to clean the plastic resin. This is a device for separating plastic resin (material) and foreign substances (label paper, adhesive).

The present invention is divided into a step of separating only the label from crushed resin flakes, and a step of peeling off the label piece and adhesive stuck to the flakes via adhesive, and these two steps are connected. This is a device that has Foreign objects (labels,
When separating the adhesive (adhesive) from the plastic resin, it is possible to improve the quality of the recycled resin and the recycling yield by ordering the separation purpose.

The present invention will be explained with reference to the drawings.

Plastic resin flakes as well as foreign objects should be removed from Shoes 1 and 6.
The paper label and the plastic resin (including the plastic resin to which the label is attached as flakes to the resin) are classified by the wind classifier 1. The plastic resin is transported to the stirring tank 2 after being classified. This transport means is arranged to transport raw material flakes by combining a pressure blower 3, a transport pipe 4, a cyclone 5, etc.

The wind classifier 1 is equipped with a chute 6, a quantitative supply means 7, a blower 8 equipped with an appropriate air volume adjustment mechanism, and is further provided with discharge holes 9 and 10 for discharging the classified raw material. There is also a stirrer (not shown) in the stirring tank, which is rotated at a constant speed by a drive motor 11 via a power transmission mechanism. A water injection hole 12 is attached to this stirring tank, and a water storage tank 13 is installed.
In addition, a discharge valve 14 is provided below and is connected to a cleaning tank 15. A water sprinkling chamber 16 is attached to this cleaning tank, and a screw conveyor 17 is connected below. The screw conveyor is equipped with a suitable aperture filter 18.

Next, to explain the operation of this material separation device, a pre-pulverized raw material is first put into a chute 6, and a predetermined amount is supplied to the wind classifier 1 by a quantitative feeder 7. The supplied flaky resin and label pieces are separated into heavy parts (plastic resin, etc.) and light parts (label pieces of paper, synthetic paper, etc.) by appropriate air speed (or air volume) by the blower 8. . On the other hand, the heavy components fall into the discharge hole 9 and are guided to the stirring tank by the pressure blower 3 and the transport pipe 4. On the other hand, light components are discharged from the device through the discharge hole 10 and can be disposed of as appropriate.

Water injection hole 12 is supplied to the raw material fed into the next stirring tank from the water storage tank.
10% to 35% of the weight of raw materials at room temperature to 60°
C water is added. Thereafter, the drive motor is rotated to rotate the stirrer provided in the tank at a high speed of about 1000 to 120 rpm. With this high-speed agitation, the plastic resin flakes are violently agitated and the resins come into contact with each other.
Collision generates heat. The overall temperature rises due to frictional heat, and the water temperature reaches about 80-85°C. Due to mutual contact and collision of the resin flakes, the label attached to the surface is peeled off or further cut into pieces. If the label is paper, it will be decomposed into fibers by forced stirring. When the temperature further rises to about 70 to 80°C, the adhesive softens and begins to peel off from the resin surface. When using room temperature water, the water temperature will reach 80 to 85 degrees Celsius in about 10 to 15 minutes, but if you forcefully stir it at this temperature, the adhesive will completely peel off, so the water temperature will reach 85 degrees Celsius.
(If the temperature exceeds 85°C, water tends to rapidly evaporate from the Ia bath, and there is a concern that local heating may cause deterioration of the resin.) At this point, the discharge valve 14 is opened while the operation continues, and the plastic resin flakes are transferred to the cleaning tank 15. The discharged flakes have a viscous liquid attached to them due to peeled paper or fiber-like paper, but they are cleaned by spraying or sprinkling warm water or room temperature water from Water Spray Quality 16 in the cleaning tank. The viscous liquid is then diluted and removed by water. The plastic resin flakes whose surfaces have been cleaned are conveyed by a screw conveyor 17.

A filter 18 with an appropriate mesh size is installed on the bottom surface of the screw conveyor 17 to allow label fragments and fibrous paper to pass through, so that these are separated and discharged together with water, and only the resin is transferred to the screw conveyor 17. It will be extracted by.

Polyester resins are generally produced by polycondensation reactions, and it is well known that if they are exposed to high temperatures with water added to them, they will undergo hydrolysis, resulting in severe deterioration of quality. However, according to the present invention, By achieving an adhesive peeling temperature of approximately 80 to 85°C that does not reach a temperature that would cause quality deterioration, it becomes possible to safely and reliably separate and remove dissimilar materials, that is, labels and adhesives. .

Additionally, if the amount of water injected during mixing is small, it will rapidly evaporate due to an exothermic reaction, making it difficult to control the temperature between 80°C and 85°C, resulting in the above-mentioned hydrolysis, resulting in a low-quality resin. .

Furthermore, if the steps of separating the label sections and the adhesive are performed in the reverse order of the above explanation, it will be difficult to break the labels into small pieces in a short time, resulting in poor separation efficiency. The remaining label and resin will adhere to each other due to moisture, making it impossible to classify them using a wind classifier.

(Effects of the Invention) As described above, label pieces can be completely removed by first separating by air classification, then mixing at 80°C to 85°C with water addition of 10 to 35 wt%, and performing water cooling washing. This makes it possible to improve the quality of recycled polyester resin and dramatically increase the recycling yield.

[Brief explanation of drawings]

The drawings are schematic illustrations of embodiments of the invention. In the figure, 1 is a wind classifier, 2 is an agitation tank, 6 is a chute, 7 is a quantitative feeder, 8 is a blower, 11 is a drive motor, 15 is a washing tank, and 17 is a screw container.

Claims (2)

[Claims] (1) A device for separating plastic resin that has been crushed into pieces or granules from label pieces attached to the resin via an adhesive or label pieces that have peeled off from the resin, including a wind classifier. , a stirring tank and a cleaning tank.The wind classifier has the function of removing label pieces that have peeled off from plastic resin by wind classification, and the stirring tank can remove label pieces that are attached to plastic resin via adhesive. The cleaning tank has a function of peeling off the adhesive and the label piece from the plastic resin surface by forced stirring in the presence of a small amount of water, and the cleaning tank removes the peeled adhesive and the label piece from the plastic resin surface in the presence of a large amount of water. A material separation device capable of separating and removing label pieces and adhesive from a plastic resin, which has a function of removing and cleaning the resin surface. (2) A stirring tank contains 10 parts by weight to 35 parts by weight of water for 100 parts by weight of the plastic resin and the plastic resin to which the label piece is attached, and the stirring means provided in the stirring tank is rotated at 1000 to 1200 revolutions per minute. The water temperature is raised to 80°C to 85°C by rotating the plastic resin and generating friction between them.
The material separation device according to claim 1, which is capable of achieving the following.