JPH0323909A - Separately recovering method for refuse of composite material - Google Patents

Abstract

PURPOSE:To enable components of composite material to be separated and recovered easily in high purity and at a high collecting rate by crushing refuse of a composite material coarsely, next, stirring it by means of a high speed stirring machine so as to crush it into an average particle degree different from each material, followed by grading. CONSTITUTION:For instance, the trimming scraps of an automobile instalment panel pad (inner layer material: soft urethane foam, skin material: PVC) are crushed into the size of the order of 30mm in its outer dimension by means of a conventional uniaxial cutter mill, and coarsely crushed matters are collected which pass through a cutter screen of phi30. Next, the coarsely crushed matters are inputted into a high speed stirring machine, and when it is operated after closing of the lid 11, the treating matters in a mixing bath 1 are given upper directional rotating force by means of lower blades 6 and then flow therein, and receive forcible shearing forces by means of upper blades 5. The urethane is removed from the PVC by the shearing force in an extremely short period and crushed finely. The PVC remains as being a dimension of coarse crushing period. The treating matters taken out thereof are passed through a sieve of 8 mesh and thus the powder urethane of 1-2mm in its particle diameter and sheet piece-shaped PVC of the order of 30mm in its outer diameter are separated from each other.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention provides a method for separating and recovering one or more materials from composite waste (scrap, defective products, etc.) in which multiple materials are bonded together. Regarding.

<Prior Art> Recently, there has been a strong demand for the recycling of waste from the viewpoints of limited resources, rising prices of raw materials, and prevention of pollution. If waste is made of a single material, it is easy to recycle it. However, in the case of composite materials in which a plurality of materials are bonded together, it is often impossible to separate and recover the constituent materials in a profitable manner, and recycling is not carried out in most cases.

An example of such composite material waste is waste in which polyurethane and PVC (polyvinyl chloride) are laminated (hereinafter referred to as urethane-adhered PVc waste). A large amount of this is generated in factories manufacturing automobile interior parts, etc., and it is usually incinerated or disposed of in a landfill. However, when urethane-adhered PVc waste is incinerated, the chlorine contained in the PVc turns into hydrogen chloride, which corrodes the incinerator and its auxiliary equipment, shortening the life of the equipment and easily causing pollution problems.

Therefore, some attempts have been made to separate and recover urethane-adhered PVc waste. The method involves crushing urethane-adhered PVC waste with a cutter mill or the like to peel off the urethane from the PVC, and separating and recovering the PVC and urethane by classifying the crushed aggregate using a multi-stage classification device.

Problems to be Solved by the Invention> The above method for separating and recovering urethane-adhered PVC waste has the following problems: ■Crushing with a cutter mill macroscopically means peeling off urethane from PVC. However, microscopically, urethane is attached using a cutter.
The method is to cut the PVC into three types of pieces, and since the first two pieces are mainly produced in waste with a thin PVC layer, it is possible to avoid contamination of the recovered PVC with urethane, which is the main cause of deterioration of its physical properties. : ■Urethane and PV are crushed by cutter mill.
Since the C particles are crushed to approximately the same size, they cannot be classified using a sieve, and classification based on the difference in specific gravity is required. Since the wind force received depends on which direction each crushed piece faces, urethane and PVC cannot be adequately classified, and the wet classification method is very troublesome to operate.

As mentioned above, materials separated and recovered from composite materials made by bonding multiple different materials generally contain impurities and therefore have inferior physical properties compared to new materials. The problem with separation and recovery is that the yield is extremely low, making it difficult for companies to make a profit. These problems make it difficult to separate, collect, and recycle composite waste.

The present invention was made for the purpose of solving the above-mentioned problems, and the problem to be solved is to increase the constituent materials of waste composite materials made of multiple materials by simple means. It is an object of the present invention to provide a method for separating and recovering with high purity and high yield.

Means for Solving the Problems> The method for separating and recovering composite material waste of the present invention capable of solving the above problems coarsely crushes composite material waste in which a plurality of materials with different hardnesses are bonded together, and then crushes it. It is characterized by pulverizing each material to a different average particle size by stirring with a high-speed stirrer, and then classifying it.

In the method of the present invention, each material of the waste must have a different hardness, and the greater the difference in hardness, such as urethane-adhered P■C, the better the separation and recovery can be made. Because they are made of materials with different hardnesses,
The method of the invention can be applied to most wastes. Note that a composite material in which multiple materials are adhered refers to a material in which the materials are not mutually fused or uniformly dispersed, for example, a material in which each material is laminated or combined. The constituent materials of the composite material are thermoplastic resin,
Examples include thermosetting resins, soft and hard rubbers, and the like.

The method of the present invention, so to speak, consists of a first step in which the waste is coarsely pulverized, a second step in which the waste is pulverized with a high-speed stirrer, and a third step in which the pulverized material is classified. Each step will be explained below.

The coarse pulverization in the first step is carried out to improve workability in the second step, since the waste generated from factories and the like is elongated like trimming waste. Therefore, even though it is coarsely ground, it is better to make it as fine as possible, but the finer the grinding, the higher the grinding cost 1.0 and the benefit of recycling is lost.

On the other hand, the larger the grinding, the worse the workability in the next process. Therefore, in the first step of coarse pulverization, it is preferable to use a suitable crusher or cutter to coarsely crush the material into lumps having an outer size of approximately 20 mm to 50 mm.

The second step is, so to speak, a step of crushing the waste using a high-speed agitator. In conventional pulverization using a cutter mill, each material of a composite material is pulverized to the same degree, whereas in the present invention, each material has a different average particle size, that is, each material has a particle size distribution that is separated from each other. Shatter it like this.

Conventionally, a stirrer was used to uniformly mix two or more types of materials, but in the present invention, it is used to separate two or more types of materials, so it has a completely opposite effect to the conventional one. It will make you work. Moreover, as an effect, the above-mentioned selective pulverization becomes possible.

Conditions such as the rotational speed of the high-speed stirrer, the shape of the rotary blades, the stirring time, and the temperature may be selected so that each material of the composite waste to be treated is pulverized to a different particle size.

In the third step, the pulverized aggregate obtained in the second step is appropriately classified, and it is convenient to use a sieve sorter using the particle size difference. is sufficient. If there is a considerable difference in specific gravity between the materials, they can be separated using the specific gravity as usual.

When a high-speed agitator is used to agitate composite waste consisting of materials of different hardness bonded together, the waste receives shearing force from the agitation blades rotating at high speed. Since the corresponding stress differs for materials of different hardness, either only one material is pulverized or each material is pulverized so that it has a separate particle size distribution. By dividing the crushed aggregate into several classes with uniform particle sizes, isolated materials of each material can be obtained.

<Example> Trimming waste generated in the manufacturing process of an automobile instrument panel pad (inner layer material: soft urethane foam, outer layer material: PVC) (frame shape of approximately 140 x 50 cm, width of surrounding flesh part 10 to 15 cm, same thickness) 10 to 15 mm) was obtained and coarsely ground to an outer size of about 30 mm. This pulverization was carried out using an ordinary single-shaft cutter mill, and the coarsely pulverized material that had passed through a φ30 cutter screen was collected and subjected to high-speed agitation treatment as follows.

The high-speed stirrer used here is a Mitsui Henschel mixer FM150J manufactured by Mitsui Miike Kakoki ■, and has a structure as shown in the figure. The mixing tank 1 has a capacity of 150° C. and is equipped with a jacket 2 that allows temperature adjustment. Discharge valve 3
Opening and closing is performed by an air cylinder 4. The upper blade 5 and the lower blade 6 are rotated by a three-phase induction motor 7. 8 in the figure represents each V-pulley around which bells 1 to 1 are stretched.

Open the lid l1 to which the air vent 9 and deflector io are attached, put in the coarsely ground urethane-adhered PVC waste, close the lid l1, and then operate the high-speed agitator.
The material to be treated in the mixing tank 1 is given an upward rotational force by the lower blade 6 and flows, and is subjected to a strong shearing force by the upper blade 5. This shearing force converts urethane into P in an extremely short time.
It is exfoliated from Vc and pulverized. PVC remains approximately at the same size as when it was coarsely ground.

In this treatment, the high-speed stirrer was heated at 7000 rpm at room temperature and normal pressure.
pm for 5 minutes. The processed material taken out is then
Powdered urethane with a particle size of 1 to 2 mm and sheet piece PVC with an outer dimension of about 30 mm were separated using a mesh sieve. The PVC thus recovered had a theoretical recovery rate of about 95%.

The PVC separated and recovered as described above is processed into 1 roll using a 2-roll machine.
Test specimens were prepared by kneading for 5 minutes and examined for specific gravity, hardness, tensile strength, elongation, and tear strength. The specific gravity was measured by JIS-K-7112 test method 6.2 submersion method, and the hardness was measured by JIS-K-6031 test method: Spring hardness (20° C.) method. Moreover, tensile strength, elongation, and tear strength were all measured based on the JIS-K6301 test method.

The test results obtained are shown in the table below. As a control test, the results of tests conducted on PVC separated and recovered by conventional methods, new PVC, and untreated waste are also shown.

This result shows that the PVc separated and recovered by the method of the present invention has physical properties more suitable for recycling than the conventional method.

The PVc collected as described above can be used alone as PVc Sea! ~
It can be used as a vibration-proof sheet 1, etc. by adding calcium carbonate, etc. In addition, since the recovered urethane is pulverized, it can be widely used as a high value-added product. Its uses include sun visor base materials, cushion materials, etc.

9 { 0 In this example, waste with a two-layer structure was used, but it is now known that waste with three or more layers can be separated and recovered in the same way as in this example, or by repeating high-speed stirring and sieving. This will be easily understood from the explanation given above.

<Effects of the Invention> The method for separating and recovering composite material waste of the present invention has the following effects.

First, the rotating blades of the high-speed stirrer apply shearing force to the composite waste, allowing almost complete separation of each material, further improving the recovery rate and contributing to resource conservation.

The nearly complete separation also increases the purity of the recovered material. This means that it is possible to obtain materials that are even closer to new materials in terms of physical properties, and the range of reuse can be expanded.

Furthermore, since each material can be recovered as pulverized products with different particle sizes, the classification method is easy, and even a sieve can be used for sufficient classification. Therefore, it is possible to reduce the cost of separation and recovery.

[Brief explanation of the drawing]

The figure is a schematic diagram showing a high-speed stirrer used in one embodiment of the method of the present invention.

Claims (1)

[Claims] It is characterized by coarsely pulverizing composite waste made up of multiple materials of different hardness bonded together, and then stirring it with a high-speed stirrer to crush each material to a different average particle size, and then classifying it. Separation and recovery method for composite waste.