JP7683948B2 - Waste glass recycling method and recycling system - Google Patents

Description

The present invention relates to a method and system for recycling waste glass, such as waste laminated glass and waste building glass, into glass materials and plastic materials.

For example, laminated glass (with a film material as an intermediate layer) is widely used in vehicle windshields and security window glass in buildings. A typical example of this type of laminated glass is a vehicle windshield, which has a glass sheet facing the inside of the vehicle, a glass sheet facing the outside, and an intermediate layer (film material) interposed between the pair of glass sheets, and the intermediate layer is made of, for example, polyvinyl butyral (PVB).

In recent years, efforts to reuse resources have been promoted in order to keep the global environment clean, and attempts have been made to separate laminated glass to be discarded, laminated glass that has become defective during the manufacturing process, etc. (hereinafter also referred to as "waste glass") into a glass sheet portion (hereinafter also referred to as "glass material") and a film material portion (hereinafter also referred to as "film material") and reuse these (see, for example, Patent Document 1).

In conventional reprocessing methods, waste glass (waste laminated glass) is crushed and separated into glass material and glass-attached film material, and the separated glass-attached film material is further processed as follows to obtain plastic materials. That is, the glass-attached film material is immersed in an organic solvent to melt it, and the fine glass fragments adhering to the film material are separated. The organic solvent is then evaporated from the solution of the film material from which the glass fragments have been separated, and the crushed fragments of the film material are recovered.

Then, the crushed pieces of the recovered film material are mixed with an anti-adhesion material (such as calcium carbonate) and finely pulverized using a grinder (such as a high-speed rotary mill). The anti-adhesion material prevents the film material from sticking during this fine pulverization. After that, an elastic matrix material (such as a rubber/asphalt-based material) is dispersed and kneaded into the mixture of film material and anti-adhesion material using a kneading machine to form a vibration-damping material. In this way, the glass-attached film material is regenerated and reused as a vibration-damping material.

JP 2007-203594 A

However, in such conventional recycling methods, when recycling glass-attached film material, first the glass particles are removed using an organic solvent, then an anti-adhesion material is mixed into the film material, and the mixture is crushed into small particles using a crusher. Therefore, to recycle glass-attached film material, processing using an organic solvent, an anti-adhesion material, etc. is required, which increases the processing cost for recycling, complicates the recycling process, and further increases the time required for this recycling process.

The object of the present invention is to provide a method for recycling waste glass that can prevent sticking of glass-attached film material when it is crushed into small pieces.

Another object of the present invention is to provide a waste glass recycling system that can crush and pulverize waste glass and recycle it as glass and plastic materials.

The waste glass recycling method of the present invention is a method for recycling waste glass having a glass plate and a film material provided on a surface of the glass plate into a glass material and a plastic material,
The method includes a first crushing process for crushing the waste glass into large pieces, a second crushing process for crushing the waste glass after the first crushing process into small pieces, a sorting process for sorting the waste glass after the second crushing process into a glass material and a glass-attached film material, a cleaning and crushing process for cleaning and crushing the glass-attached film material after the sorting process, and a crushing process for crushing the glass-attached film material after the cleaning and crushing process into small pieces to produce a plastic material.

In this type of recycling method, a large number of glass particles remain on the surface of the glass-attached film material, and it is preferable to reduce the size of these glass particles to 100 μm or less. By configuring it in this way, the glass-attached film materials are prevented from sticking together and from adhering to the crusher.

If the size of the glass particles exceeds 100 μm, the recycled plastic material will contain a large amount of glass components, which is undesirable as it places restrictions on the recycling of the plastic material. It is even more preferable to keep the size of these glass particles to 70 μm or less.

In this recycling method, the second crushing process preferably includes an impact crusher process for crushing the waste glass into medium-sized pieces, and a hammer crusher process for crushing the waste glass after the impact crusher process into small pieces. By crushing the waste glass in two stages in this way in the second crushing process, the waste glass can be crushed into small pieces efficiently.

In this recycling method, pellets may be formed from the plastic material to be recycled, and pelletization can expand the range of uses for the reuse of the plastic material. In addition, when pelletizing, it is preferable to add 1% by weight or more of polypropylene to the plastic material and melt mix it, which can prevent the pellets from sticking together.

The waste glass recycling system of the present invention is a waste glass recycling system that recycles waste glass having a glass plate and a film material provided on a surface of the glass plate into a glass material and a plastic material,
The waste glass recycling system includes a first crusher that crushes the waste glass into large pieces, a second crusher that crushes the waste glass crushed by the first crusher into smaller pieces, a sorting machine that separates the waste glass crushed by the second crusher into glass material and glass-attached film material, a cleaning and crushing machine that cleans and crushes the glass-attached film material sorted by the sorting machine, and a crusher that further crushes the glass-attached film material cleaned and crushed by the cleaning and crushing machine into smaller pieces to produce plastic material.

In such a waste glass recycling system, it is preferable that the size of the majority of glass particles remaining on the surface of the glass-attached film material selected by the sorting machine is 100 μm or less.

According to the waste glass recycling method (and recycling system) of the present invention, the waste glass is roughly crushed in the first crushing process (first crusher), then crushed into small pieces in the second crushing process (second crusher), and thus crushed into smaller pieces step by step, so that it can be sorted into glass material and glass-attached film material in the subsequent sorting process (sorter). Then, this glass-attached film material can be crushed while being washed in the cleaning and crushing process (cleaning and crushing machine), and further crushed into smaller pieces in the crushing process, so that it can be made into fine glass-attached film material. The glass material generated in the second crushing process (second crusher), sorting process (sorting machine), and cleaning and crushing process (cleaning and crushing machine) can be reused as glass material, and the fine glass-attached film material after the crushing process (crusher) can be reused as plastic material, so that the waste glass (e.g., waste laminated glass) can be recycled into glass material and plastic material.

FIG. 2 is a process diagram showing a processing flow of an example of a method for recycling waste glass according to the present invention. FIG. 2 is an explanatory diagram illustrating the flow of waste glass processed in the recycling method of FIG. 1, and the glass material and glass-attached film material produced by the processing.

Hereinafter, an embodiment of the waste glass recycling method (and recycling system for carrying out this recycling method) according to the present invention will be described with reference to the attached drawings. In this embodiment, the recycling of laminated glass used in vehicle windshields will be described as waste glass having a film material. However, the present invention is not limited to such windshields, and can be applied to the recycling of waste glass such as laminated glass used in architectural glass such as window glass in buildings (a glass material is provided on both sides of the film material and is referred to as "laminated glass"), laminated glass used for various purposes such as glass with a film used in rear windows of vehicles and solar panels (a glass material is provided on one side of the film material and is referred to as "glass with a film"), and laminated glass and glass with a film to be discarded are collectively referred to as "waste glass".

In Figures 1 and 2, to recycle waste glass having a film material (e.g., a vehicle windshield, etc.), a first crushing step S1 is carried out to crush the waste glass into large pieces, then a second crushing step S2 is carried out to crush the waste glass into small pieces, and then a sorting step S3 is carried out to sort the crushed waste glass into glass material and glass-attached film material.

In the first crushing step S1, a biaxial crusher 2 is used to roughly crush the waste glass (windshield). This biaxial crusher 2 (specific structure omitted) may be a well-known commercially available one, for example one equipped with a biaxial cutter structure, and the waste glass is roughly crushed in the first stage by passing it between the cutter structure.

In the second crushing process S2, a second crusher 4 is used to crush the waste glass crushed in the first crushing process S1 into smaller pieces in the second stage. In this embodiment, an impact crusher 6 (impact crusher process) and a hammer crusher 8 (hammer crusher process) are used as the second crusher 4, and the waste glass is crushed into smaller pieces in two stages.

The impact crusher 6 (specific structure omitted) may be a commercially available one that is well known in itself, and may, for example, be equipped with a rotor that rotates in a predetermined direction, a striking plate attached to the rotor, and a collision plate disposed opposite the rotor. Waste glass is fed to the striking plate, and the fed waste glass is collided with the collision plate using the rotation of the rotor, thereby crushing the waste glass into medium-sized pieces.

The hammer crusher 8 (specific structure omitted) may be a well-known, commercially available product, and may, for example, be one equipped with a rotor that rotates in a predetermined direction, a hammer attached to the rotor, and a fixed plate that prevents the waste glass from moving. The rotation of the rotor is used to impact the waste glass with the hammer, thereby crushing it into smaller pieces.

In the sorting process S3, a sorting machine 10 is used to sort the glass material (e.g., windshield glass) crushed as described above from the glass-attached film material (e.g., windshield interlayer) (a large number of glass particles remain on the surface of the film material). When the first crushing process S1 and the second crushing process S2 (impact pressure process and hammer crusher process) are performed, the waste laminated glass (waste windshield) as waste glass becomes crushed glass material and crushed glass-attached film material, and in the sorting process S3, the glass material and glass-attached film material resulting from the crushing are sorted using the sorting machine 10.

The sorting machine may be a commercially available one that is well known in itself, and may, for example, be equipped with a cylindrical frame that is supported at an angle so as to be freely rotatable, and a mesh screen arranged around the cylindrical frame. The glass material falls downward through the mesh screen, and the glass-attached film material is sent to the downstream side of the cylindrical frame and discharged from the discharge section. By using such a sorting machine 10, the glass material and the glass-attached film material can be separated.

The selected glass material is reused as glass material, and the desired glass recycling process S4 is carried out using this glass material. Through this glass recycling process S4, for example, glass fiber, security gravel, soil improvement material, etc. can be produced.

The glass material crushed by the twin-shaft crusher 2, the glass material crushed by the impact crusher 6, and the glass material crushed by the hammer crusher 8 are reused as glass material together with the glass material selected by the sorter 10.

The glass-attached film material selected by the sorting machine 10 is further recycled and reused as plastic material as follows. The glass-attached film material is first subjected to a cleaning and crushing process S5. In the cleaning and crushing process S5, a cleaning and crushing machine 12 is used to crush the glass-attached film material while cleaning it. This cleaning and crushing machine 12 (specific structure is omitted) may be a well-known commercially available machine, for example, one equipped with a cutting structure that cuts with a fixed blade and a rotating blade. The glass-attached film material is crushed by the cutting structure while being cleaned, and the glass-attached film material is crushed into small pieces. In the cleaning and crushing process S5, the film material is crushed while being cleaned, which prevents small dust particles from scattering around, and keeps the working environment clean.

The cleaning and crushing machine 12 may be equipped with a drying function. When using a cleaning and crushing machine with a drying function, the glass-attached film material after cleaning and crushing can be dried to remove moisture, thereby improving the efficiency of the cleaning and crushing work.

In the cleaning and crushing step S5 (cleaning and crushing operation using the cleaning and crushing machine 12), crushing is performed while cleaning, so there is a risk that the film materials will stick together and become difficult to crush. However, if a large number of glass particles remain on the surface of the film material (the entire surface), the film materials will not stick together, and it will be possible to crush the glass-attached film material as desired using the cleaning and crushing machine 12.

If a large amount of glass remains in this film material, the glass component contained in the plastic material will be high, making it difficult to reuse this plastic material. For this reason, it is preferable that the size of the numerous glass particles remaining on the surface of the glass-attached film material is, for example, 100 μm or less; if they exceed 100 μm, the final plastic material will contain a large amount of glass components. It is more preferable that the size of the numerous glass particles remaining in this glass-attached film material is, for example, 70 μm or less; by reducing the size of the glass particles in this way, the glass component contained in the plastic material can be reduced.

After the cleaning and crushing step S5, a crushing step S6 is carried out to further crush the glass-attached film material after cleaning and crushing. In the crushing step S6, a crusher 14 is used to crush the glass-attached film material into smaller pieces. This crusher 14 (specific structure is omitted) may be a well-known commercially available one, for example, one equipped with a crushing structure having a fixed blade and a rotary blade that rotates in a predetermined direction, and the glass-attached film material can be crushed and further crushed into smaller pieces by this crushing structure. In this embodiment, the glass-attached film material is finally crushed to a size of, for example, about 0.5 to 10 mm.

The glass material produced in the cleaning and crushing process S5 (cleaning and crushing machine 12) and the glass material produced in the crushing process S6 (crusher 14) are reused as glass material together with the glass material sorted by the sorting machine 10, as shown in FIG. 2.

The glass-attached film material thus crushed is reused as a plastic material, and the desired plastic recycling process S7 is carried out using this plastic material. Through this plastic recycling process S7, the recycled plastic material can be used to manufacture, for example, plastic floor boards, car stops, rebar floors, etc., and can also be used as a bulking agent for resins, such as polypropylene (PP), polyethylene (PE), polyamide (PA), and ABS resins.

This glass-attached film material as a plastic material can be used as a raw material for pellets, in which case a pellet processing step S8 is carried out. In this pellet processing step S8, a pellet manufacturing machine 16 is used to manufacture chip-shaped pellets from the glass-attached film material. This pellet manufacturing machine 16 (specific structure omitted) may be a well-known commercially available machine, for example one equipped with a melting section that melts the glass-attached film material as a plastic material, an extrusion section that extrudes the molten plastic material, and a cutting section that cuts the extruded plastic material. By using such a pellet manufacturing machine 16, chip-shaped pellets can be manufactured from the plastic material.

When forming such pellets, it is desirable to add at least 1% by weight, and preferably at least 3% by weight, of polypropylene when melting the plastic material using the pelletizer 16. By adding polypropylene in this manner, it is possible to prevent the pellets from sticking together after molding.

The produced pellets are reused in the form of pellets, and the desired pellet recycling process S9 is carried out using these pellets. This pellet recycling process S9 can be used to produce, for example, plastic spacers, sheet materials, etc., and can also be used as a bulking agent for resins, such as polypropylene (PP), polyethylene (PE), polyamide (PA), ABS resin, etc.

In the waste glass recycling method (recycling system) described above, waste glass (such as waste laminated glass) is crushed into glass material and glass-attached film material in the first crushing step S1 and the second crushing step S2, and the crushed material is sorted by a sorting machine into glass material and glass-attached film material suitable for reuse. This glass-attached film material can then be processed into plastic material suitable for reuse in the cleaning and crushing step S5 and the pulverizing step S6.

The above describes one embodiment of the waste glass recycling method (recycling system) according to the present invention, but the present invention is not limited to such an embodiment, and various changes and modifications are possible without departing from the scope of the present invention.

2. First crusher (two-shaft crusher)
4 Second crusher 6 Impact crusher 8 Hammer crusher 10 Sorting machine 12 Washing and crushing machine 14 Crusher 16 Pellet manufacturing machine

Claims (8)

A method for recycling waste glass, which includes recycling a waste glass having a glass plate and a film material provided on a surface of the glass plate into a glass material and a plastic material, comprising:
A method for recycling waste glass, comprising: a first crushing process for crushing the waste glass into large pieces; a second crushing process for crushing the waste glass after the first crushing process into small pieces; a sorting process for sorting the waste glass after the second crushing process into glass material and glass-attached film material; a cleaning and crushing process for crushing the glass-attached film material after the sorting process while cleaning it; and a crushing process for crushing the glass-attached film material after the cleaning and crushing process into small pieces to make a plastic material. The method for recycling waste glass according to claim 1, characterized in that a large number of glass particles remain on the surface of the glass-attached film material after the sorting process, and the size of the large number of glass particles is 100 μm or less. The method for recycling waste glass according to claim 2, characterized in that the size of the numerous glass particles is 70 μm or less. The method for recycling waste glass according to claim 1, characterized in that the second crushing process includes an impact crusher process for crushing the waste glass after the first crushing process into medium-sized pieces, and a hammer crusher process for crushing the waste glass after the impact crusher process into small pieces. The method for recycling waste glass according to claim 1, characterized in that after the crushing process, a pellet forming process is carried out to form pellets from the plastic material. The method for recycling waste glass according to claim 5, characterized in that in the pellet forming process, 1% by weight or more of polypropylene is added to the plastic material, which is then melted and mixed to form the pellets. A waste glass recycling system for recycling waste glass having a glass plate and a film material provided on a surface of the glass plate into a glass material and a plastic material,
a second crusher that crushes the waste glass crushed by the first crusher into smaller pieces; a sorting machine that separates the waste glass crushed by the second crusher into glass material and glass-attached film material; a cleaning and crushing machine that cleans and crushes the glass-attached film material sorted by the sorting machine; and a crusher that crushes the glass-attached film material cleaned and crushed by the cleaning and crushing machine into small pieces to make plastic material. The waste glass recycling system according to claim 7, characterized in that a large number of glass particles remain on the surface of the glass-attached film material sorted by the sorting machine, and the size of the large number of glass particles is 100 μm or less.

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