Title of Invention : Apparatus and method for separation of light plastic materials from waste materials j

Technical Field

[0001] The present invention relates to a method and apparatus for separating materials and more particularly to an apparatus and method for separating light plastic materials from conventional waste materials.

Background Art

[0002] In many recycling systems, at the start of the sorting process, plastic films are picked out of the recycling line by hand. In some modern recycling system, separation of plastic films from paper can be achieved with a combination of air- based and near-infrared (NIR) technologies, which is expensive and ineffective.

[0003] W02009079022 discloses a separation system comprising an air separator that primarily separates Municipal Solid Waste (MSW) containing relatively light recyclable MSW materials and further containing other heavier MSW materials and the air separator blowing the relatively light recyclable MSW materials up through a chamber and onto a first conveyer while the other heavier MSW materials drop down a chute onto a second conveyer.

Summary of Invention

[0004] The summary of disclosed invention is intended to provide an overview of the subject matter of the invention, and is not intended to identify essential elements or key elements of the subject matter, nor is it intended to be used to determine the scope of the claimed implementations. The proper scope of the present disclosure may be ascertained from the claims set forth below in view of the detailed description below

[0005] The light material separator apparatus, consists of several sections, comprising a light material separator from the waste processing line, a non plastic material disposal section , a shredding assembly, a light materials extraction section and a cleaning section.

[0006] The materials enters the sieving unit and then the waste materials are transferred to the waste processing line or separating conveyor (16) to be separated from the recycled items processing line. Unseparated wastes on the separating conveyor (16) are considered as input (or initial) materials of the method and apparatus disclosed in this document.

[0007] In this method, light plastic materials are separated from other materials. This separation is based on the weight (relative density) and the flexibility of the materials and is done by the process of air suction thorough which the light materials separate from other heavy materials and stick to the hooks.

[0008] In the second step, non-plastic materials are separated from collected materials that can be plastic or non-plastic. This separation is based on the flexibility and elasticity of the material and is done by the process of creating vibration to the carrier line of the separated materials which are connected to the hooks. Contaminants attached to lightly collected plastics are collected.

[0009] In the third step, the shredding process is performed to reduce the volume of the separated plastics in the form of large plastic films.

[0010] In the fourth step, with the blowing process and special design of the apparatus and hooks with sloping edges, light plastics stuck to the hooks, are easily removed and dropped down.

[0011] In the fifth step, since the materials attached to the hooks reduce the performance of the apparatus in attaching plastic materials to the hooks the hooks of the device are cleaned of contaminants and sticky materials.

Technical Problem

[0012] Plastic flexible films are used in many applications due to their lightness and flexibility. Currently, in developed countries, about 50% of plastics in domestic waste are plastic films. In some developed countries, there are some companies or associations which provide a collection service for plastic bottles and other rigid plastic containers. However, very few associations collect flexible plastic packaging such as plastic film, wrappers and bags.

[0013] Plastic film and plastic bags are among the main causes of pollution. Each of these items endangers the proportion of material the recycling sector can recover. [0014] Plastic bags are made from thin flexible sheets of plastic film. Typically the plastic films has good flexibility and less than 10mm thick .

[0015] When these thin plastic films enter a conventional materials recycling facility, they can seriously damage the efficient operation recycling system. The composition of films and their high tensile strength means that such materials can quickly become wrapped around moving or revolving machinery. For example when the screens in the recycling system become blocked by the plastic films, their capability of sorting materials is reduced. In extreme cases, the screens become severely blocked and need thorough cleaning, which causes plant downtime. Then it is important to remove such material as early as possible.

Brief Description of Drawings

[0016] The figures of the present document are intended to be illustrative, not limiting.

[0017] Fig.1 illustrates a perspective view of the main light material separator apparatus.

[0018] Fig.2 is a flowchart illustrating a method for separating low weight materials according to a preferred embodiment.

[0019] Fig.3 illustrates a side elevation view of main apparatus.

[0020] Fig.4 illustrates a schematic perspective view of the light material separator section.

[0021] Fig.5 illustrates a schematic perspective view of non-plastic materials disposal system and shredding assembly.

[0022] Fig.6 illustrates another view of non-plastic material disposal system and shredding assembly.

[0023] Fig.7 illustrates a schematic perspective view of the light materials extraction section.

[0024] Fig.8 illustrate a schematic view of the cleaning section along the light materials extraction section.

Description of Embodiments [0025] The light plastic materials in the present documents refers to any light material made of thin, flexible plastic film or plastic textile and in any forms and types including but not limited to the plastic bags, poly bags, nylon bags, nylon webs or thin plastic films.

[0026] As shown in Fig.1 , the light material separator apparatus (10), consists of several sections, comprising the light material separator from the waste processing line (20), the non-plastic material disposal section (30), and shredding assembly(40), the light materials extraction section (50) and the cleaning section (60).

[0027] The apparatus(10) has a material transfer system(12) such as a conveyor that carries light waste material, such as paper and light plastic film materials(l) separated from the separating conveyor(16) along the apparatus(10). Conveyor(12) can be in the form of perforated chains, but is not limited to these models. The chassis(11) or body of the apparatus consists of metal bars and used for holding the components of different parts of the main apparatus (10).

[0028] In certain places of the chassis(11), the rotating shafts (19) of material transfer system is installed. The said rotary shafts(19) are connected to the chassis (11) of the apparatus by an assembly of bolts and nuts(63). The driving force required to move the conveyor is provided by a power generation and transmission system(13), including the engine and electric gearbox (13), and then driving force is transmitted to the shafts(19) through chains and sprockets(17). Like any other rotating system, this system also has a number of bearings, bushings, etc. to perform smooth rotational movement.

[0029] As shown in Fig.2 the method of processing of the wastes is such that the waste materials are dumped from the waste collection area by a loader and a slot conveyor into the shredder unit. In the next step, the materials enters the sieving unit and then the waste materials are transferred to the waste processing line or separating conveyor (16) to be separated from the recycled items processing line. Unseparated wastes on the separating conveyor (16) are considered as input (or initial) materials of the method and apparatus disclosed in this document. [0030] In this method, light plastic materials are separated from other materials. The said separation is based on the weight and the flexibility of the material and is done by the process of suction and blowing the air and separation of light materials from other heavy material in the conveyor or processing line.

[0031] In the second step, non-plastic materials are separated from lightly collected materials that can be plastic or non-plastic. This separation is based on the flexibility of the material and is done by creating and transferring vibration to the conveyor or carrier line of the separated materials which are connected to the hooks. By this way contaminants attached to lightly collected plastic materials are removed too.

[0032] In the third step, the shredding process is performed to reduce the volume of the separated plastic materials which are in the form of large plastic films .In the shredding process also the tied bags are wrapped.

[0033] In the fourth step, with the blowing process and special design of the apparatus in which the conveyor is almost vertical and tip edge of the hooks is downward, the light plastics sucked to the hooks, are easily removed from the apparatus.

[0034] In the fifth step, science the materials attached to the hooks reduce the performance of the apparatus, the hooks of the device are cleaned of contaminants and stuck materials.

[0035] As mentioned above, the method and the apparatus disclosed in this document is used for separating light plastic materials (1) from other waste or other materials (2) on the separating conveyor (16). On the said separating conveyor (16), some wastes remains from conventional recycling materials such as foods, papers, woods, etc.

[0036] In the separator section(20) of apparatus(10), an air suction fan (21) with a known pressure is used to separate light waste materials(l) . The fan (21) in the separator section(20) runs by engine(22) and the air is sucked through the inlet valve (23) and the air conduction pipes (24). The fan (21) can be chosen from the centrifuge models but is not limited to these models.

[0037] During the suction process by the fan (21), light waste materials (1) such as papers, light plastic materials, tissues, and other low density materials are detached from the separating conveyor (16) and, light waste materials (1) approach the separator conveyor (12) by air pressure. The hooks(14) penetrate into the light waste materials (1) due to the their sharp edges, in other words, the light waste materials(l) are stuck to the main conveyor (12) by the conveyor hooks (14) and with movement of the main conveyor (12) of the apparatus (10), light materials (1) are also moved along the main conveyor(12) in a certain direction.

[0038] Non-plastic materials disposal system (30)

[0039] By moving the conveyor (12), light materials move upwards along with the conveyor at a certain angle(for example 20 degrees) and then exit from the gate or opening(23) of the fan (21 ).

[0040] The light plastic materials(1 ) as plastic bags or plastic films due to their flexibility and elasticity attach to the hooks (14) and most other light waste materials(3) such as paper wastes, tissue wastes and other similar materials which cannot be attached to the hooks(14) drop in this section and then return back to the separating conveyor(16).

[0041] In the non- plastic materials disposal section (30), a conveyor vibration device is used to separate the light plastic materials from other light waste as well as the dirt attached to the plastic wastes (1) .The vibration device consists of a vibrating engine(31) attached to the conveyor (12). The vibrating engine (31) is mounted on a chassis (32) (in one embodiment of this invention, the chassis (32) is a plate on which the vibrating engine is installed) and the said vibrating engine(31) causes vibration in the conveyor section. The said vibration is transmitted to the main conveyor (12) by a connection piece (33), in one embodiment of this invention the connection piece is a drum.

Other wastes attached to the light plastic materials (1 ) are dumped on the main conveyor(12) due to the transmission of vibrational motion to the conveyor(12) and successively to the light plastic materials attached to the conveyor(12). Moving upwards and eliminating force of air blowing makes non-plastic materials to be dropped down.

[0042] It is conceivable that not every one of the light plastic materials in the line attache to the hooks or even some of them become detached when the conveyor vibrates. However, this method and apparatus can easily remove a large number of light plastic materials in the separation line.

[0043] Shredding assembly (40)

[0044] As mentioned before, light plastic materials gets stuck in the hooks (14) and separates from the inlet separating conveyor (16). Among these light plastic materials, if there are some items such as the long piece of plastic films or large plastic sheets or tied bags, the said large plastic pieces are shredded and striped by the shredder section (40). The bags are emptied and cleaned in the process of lifting and vibrating the main conveyor (12) in the non-plastic materials disposal system (30) and/or shredding section(40). The bag shredder assembley(40) consist of a conveyor(41) which a number of cutting blades or knife(42) are fixed on the surface of the conveyor(41).

[0045] Extraction of light plastic materials (50)

[0046] After the initial separation of the light plastic materials from the separating conveyor (16), the light plastic materials are directed to the bag shredding section and the vibration section subsequently, materials that are placed on the horizontal part of conveyor are directed to the output section.

[0047] For better extraction of the separated light plastic materials, the device is designed in such a way that the light plastic materials fall on the vertical part of the conveyor due to their weight. In this part, the tip of the hooks (14) is downward and therefore does not prevent the light plastic materials from falling down. The air blowing system has also been used to increase the performance of the device and ensure the release of light plastic materials in this section. In this way, the fan (21 ) sucks air from one valve (23) and blow with the other valve(51), which works as a the blow valve, the air is blown at a certain speed in the external space of the device,

[0048] In this apparatus, both suction and blowing capabilities of the fan (21) have been used simultaneously. The removed light plastic materials are dumped onto the output conveyor (18) and exit for other recycling operations.

[0049] Cleaning section (60): [0050] The light plastic materials are separated or detached from the main conveyor at the output section, then the conveyor (12) is cleaned from any other sticky wastes. In the cleaning section (60), a roller brush (61) is used to clean the main conveyor(12) and the hooks(14). The said brush (61) is mounted on a rotating shaft and rotates with it.

[0051] In the apparatus (10) an electrical control panel is used, which supplies the required electricity for different sections of the apparatus(10) and also indicates the failure of any part of apparatus.

[0052] Other embodiments, extensions, and modifications of the ideas presented above are comprehended and within the reach of one skilled in the art upon reviewing the present disclosure. Accordingly, the scope of the present invention in its various aspects should not be limited by the figures and embodiments presented above. The individual aspects of the present invention, and the entirety of the invention should be regarded so as to allow for modifications and future developments within the scope of the present disclosure.

Advantageous Effects of Invention

[0053] Recycling flexibles and films will cause lower environmental effects, including reducing climate change, enabling recycling targets to be met and a more circular economy for plastics packaging.

Collecting all plastic materials including flexible films will make the recycling of plastics packaging much simpler and appropriate for the consumers and recycling industry.!