FIELD OF INVENTION

[0001] The present disclosure, in general, relates to the field of recycling plastic waste. More particularly, the disclosure relates to a plastic recycling machine and a method of recycling plastic.

BACKGROUND OF THE INVENTION

[0002] Recycling of plastic material is desirable both from an economical and from an environmental point of view and various industrial scale solutions are available for the same. Challenges remain in processing unsorted plastic material such as multi layer plastic and mixed plastics waste that includes different types of plastics as well as other substances such as paper or aluminium in the form of layers especially at a small scale. Hospitals, for example, generate large amounts of unsorted plastic waste. It is not practical or safe to sort such solid waste material and often such solid waste material is incinerated.

[0003] Solid waste material is typically collected and brought to plastic recycling plants or sorting centers. At such places where waste material from multiple sources gets received, it is often not practical to recover certain fraction of thin plastic waste into useful plastic material that can be considered as up- cycled materials or value-added materials.

SUMMARY OF THE INVENTION

[0004] In an aspect of the disclosure, a plastic recycling machine is disclosed. The plastic recycling machine comprises a housing that defines a housing inlet and a housing outlet. The housing inlet may be configured for receiving unsorted solid waste plastic material into the housing. The plastic recycling machine also comprises a crusher positioned within the housing and proximate the housing inlet. The crusher may be configured to process the unsorted solid waste plastic material and convert the unsorted solid waste plastic material into a crushed raw material within a predetermined size range. Further, the plastic recycling machine compnses an extrusion system positioned within the housing that defines an extrusion system outlet. The extrusion system may be configured to process the crushed raw material and convert the crushed raw material into a compounded material. Further, the extrusion system may also be configured to provide a metered flow of the compounded material at the extrusion system outlet. In addition, the plastic recycling machine comprises a pelletizer positioned within the housing. The pelletizer may be configured to process the compounded material from the extrusion system outlet and convert the compounded material into a pelletized plastic material. The housing outlet may be configured for exiting the pelletized plastic material from the housing.

[0005] In another aspect of the disclosure, a method for recycling plastic is disclosed. The method comprises a step of receiving an unsorted solid waste plastic material in a housing through a housing inlet. The method also comprises a step of processing and converting the unsorted solid waste plastic material into a crushed raw material within a predetermined size range in a crusher within the housing. Further, the method comprises a step of processing and converting the crushed raw material into a compounded material in an extrusion system positioned within the housing. Furthermore, the method comprises a step of providing a metered flow of the compounded material at an extrusion system outlet of the extrusion system. In addition, the method comprises a step of processing and converting the compounded material into a pelletized plastic material in a pelletizer positioned within the housing. In addition, the method comprises a step of exiting the pelletized plastic material from a housing outlet of the housing.

BRIEF DESCRIPTION OF DRAWINGS

[0006] The accompanying drawings, similar reference numerals, may refer to identical or functionally similar elements. These reference numerals are used in the detailed description to illustrate various embodiments and to explain various aspects and advantages of the present disclosure. [0007] FIG. 1 is an exemplary illustration of a plastic recycling machine in accordance with an embodiment of the present disclosure;

[0008] FIG. 2 is an exemplary illustration of different components of the plastic recycling machine of FIG. 1, in accordance with the embodiment of the present disclosure;

[0009] FIG. 3 is an exemplary illustration of a crusher in the plastic recycling machine of FIG. 1, in accordance with the embodiment of the present disclosure;

[0010] FIG. 4 is an exemplary illustration of an extrusion system in the plastic recycling machine of FIG. 1, in accordance with the embodiment of the present disclosure;

[0011] FIG. 5 is a top sectional view of the extrusion system of FIG. 4, in accordance with the embodiment of the present disclosure;

[0012] FIG. 6 is an exemplary illustration of a pelletizer in the plastic recycling machine of FIG. 1, in accordance with the embodiment of the present disclosure; and

[0013] FIG. 7 is a flow chart of a method for recycling plastic, in accordance with the embodiment of the present disclosure.

[0014] Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present disclosure.

DETAILED DESCRIPTION

[0015] Referring to FIG. 1, an exemplary illustration of a plastic recycling machine 100, herein referred to as “recycler 100” is disclosed. The recycler 100 may comprise a housing 102 that defines a housing inlet 104 and a housing outlet 106. The housing 102 may include a frame 108, racks 110 - 114 mounted on and/or supported by the frame 108, and enclosure walls 116 that may be detachably attached to the frame 108. The frame 108 may include vertical support elements that may be in an upright position with respect to a ground surface. The vertical support elements of the frame 108 may be interconnected via the racks 110 - 114 that may be placed horizontally and/or parallelly with respect to the ground surface. In an embodiment, the racks 110 - 114 may be detachably attached to the frame 108. The enclosure walls 116 may be mounted on and/or supported by the racks 110 - 114 so as to form respective enclosures inside the recycler 100. The enclosure walls 116 may be attached to the frame 108 via a slidable arrangement, press-fit connection, hinged connection, or any other known techniques in the art. The enclosure walls 116 may facilitate access to different components of the recycler 100 arranged inside the housing 102. Further, the enclosure walls 116 may be configured to be opened or detached from the frame 108 during repair, maintenance and/or monitoring of the recycler 100. In an embodiment, the housing 102 may be mounted on mobility or transport means 118, for example, wheels or rollers, that may be detachably attached to the housing 102. The transport means 118 may enable the recycler 100 to be moved and/or manoeuvred to different locations and in different directions.

[0016] The housing inlet 104 may be configured for receiving an unsorted solid waste plastic material or “plastic waste” in the housing 102 of the recycler 100. Examples of the plastic waste include, but not limited to, plastic bags, personal protective equipment, miscellaneous plastic packaging materials, and may include stray paper and other generic waste material that is typically discarded in an unsorted and unsegregated manner. In an embodiment, the housing inlet 104 may include an inlet cover 120 that may be detachably attached to the housing 102. The inlet cover 120 may be configured to be opened to facilitate receiving of the plastic waste in the recycler 100 during operation of the recycler 100. The inlet cover 120 may also be configured to be closed for instances when the recycler 100 is in operation or not in operation.

[0017] The housing outlet 106 may be configured for collection and/or removal of pelletized plastic material or pellets generated from the plastic waste by the recycler 100. In an embodiment, the housing outlet 106 may also include an outlet cover 122 that may be detachably attached to the housing 102. The outlet cover 122 may be configured to be opened to facilitate the collection and/or removal of the pelletized plastic material from the housing 102, during and/or after the operation of the recycler 100. Further, the outlet cover 122 may also be configured to be closed for instances when the recycler 100 is operational and/or non-operational.

[0018] The recycler 100 may also include a power unit (not shown) positioned inside the housing 102 to supply power to the different components positioned inside the housing 102 of the recycler 100. The power unit may be coupled to a power chord 124 extending outside the housing 102. The power chord 124 may be adapted to connect the power unit of the recycler 100 to a power source (not shown), such as an electricity supply point/s witch. In an exemplary embodiment, the power chord 124 may be connected to a power source of 100 - 240 V and/or a power rating ranging from 100W to 1500W for operating the recycler 100. In an embodiment, the power chord 124 may be connected to a power source adapted to supply current for household use, for example, the power chord 124 may be connected to a 15A power source, thereby eliminating a need for an industrial power connection for operation of the recycler 100. In an embodiment, the recycler 100 may also include more than one power chord similar to the power chord 124 that may extend outside the housing 124. The additional power chords may be configured to supply power separately to the different components of the recycler 100.

[0019] In an embodiment, the recycler 100 may also include a sensor system (not shown) positioned proximate the housing inlet 104. The sensor system may be configured to detect a presence of the plastic waste at the housing inlet 104. The sensor system may further be configured to automatically start operations of the recycler 100 on detecting the plastic waste at the housing inlet 104. The sensing system may include one or more sensors (not shown) and a controller (not shown) electrically coupled to the power source or to an alternate power source, such as batteries. In an embodiment, the one or more sensors may detect the plastic waste at the housing inlet 104 and direct the controller to automatically begin the operation of the recycler 100. Examples of the one or more sensors include proximity sensors, piezoelectric sensors and other known sensors in the art. Further, the sensor system may be configured to cease the operations on the recycler 100 on determining an absence of the plastic waste at the housing inlet 104. The sensor system may determine the absence of the plastic material when the sensors fail to detect the plastic waste at the housing inlet 104 for a predetermined time. In an embodiment, the predetermined time may correspond to an operation cycle of the recycler 100. In an exemplary embodiment, the predetermined time may vary within a range of 5-30 minutes.

[0020] Referring to FIG. 2, an exemplary illustration of the different components positioned within the housing 102 of the recycler 100 of FIG. 1 is disclosed. The recycler 100 may include a crusher 202, an extrusion system 204, and a pelletizer 206 positioned within the housing 102. In an embodiment, the crusher 202, the extrusion system 204, and the pelletizer 206 may be mounted on the racks 110 - 114, respectively, of the housing 102. The crusher 202 may be positioned proximate the housing inlet 104 of the housing 102. In an embodiment, the crusher 202 may be positioned above the extrusion system 204. In another embodiment, the extrusion system 204 may be positioned above the pelletizer 206. It may be apparent that alternate embodiments of arrangement of the the crusher 202, the extrusion system 204, and the pelletizer 206 within the housing 102 may be contemplated.

[0021] The recycler 100 may further include a control panel (not shown) for controlling one or more operations of the recycler 100 and/or the crusher 202, the extrusion system 204, and the pelletizer 206. In an embodiment, the control panel may be mounted on the housing 102 of the recycler 100, and may be adapted to be operated from outside when the recycler is in operation. The one or more operations, which may be controlled by the control panel include, but not limited to, rate of operation of the recycler 100, cutting speed of blades of the crusher 202, feed rate of the extrusion system 204, cutting rate of the pelletizer 206, heating and cooling rates of heating and cooling means of the recycler 100, etc. [0022] Refemng to FIG. 3, an exemplary illustration of the crusher 202 of FIG. 2 is disclosed. The crusher 202 may be configured to receive the plastic waste via the housing inlet 104 (see FIG. 1). In an embodiment, the plastic waste may be fed into the crusher 202 in plastic bags B. The plastic bags B may include mixed plastic waste including, but not limited to miscellaneous plastic packaging material or objects, stray paper and personal protection equipment kits. The crusher 202 may be configured to crush the plastic waste in the plastic bags B and convert the plastic waste to a crushed raw material within a predetermined size range of typically 4 to 8 mm overall size.

[0023] The crusher 202 may include a conveying unit 208 and one or more cutting blades (not shown) in communication with the conveying unit 208. The cutting blades maybe placed inside a blade housing 210. The conveying unit 208 may include conveyor belts that may direct the plastic waste in the plastic bags B received via the housing inlet 104 towards the cutting blades. In an embodiment, the conveying unit 208 may be configured to be supported and/or mounted on the rack 110 via an opening in the rack 110. The cutting blades may be configured to crush the plastic waste received via the conveying unit 208 and convert the plastic waste to the crushed raw material. In an embodiment, the cutting blades may be made of stainless steel, high strength alloy, or any suitable material configured for cutting and/or disintegrating the plastic waste. The cutting blades may also be configured to eject certain metallic scrap or metallic objects detected in the plastic waste, especially large size metallic objects. In an embodiment, the crusher 202 may also include a segregation container 212 placed adjacent to the blade housing 210 in order to collect the metallic scrap or objects ejected by the cutting blades. The segregation container 212 may be detachably attached to the rack 110 and may be configured to be mounted on the rack 110 via an opening (not shown) in the plank 110. In an alternate embodiment, the rack 110 may include the segregation container 212 to collect metallic scrap or objects. In an exemplary embodiment, the crusher 202 may be operated at a power rating of 1500 W. [0024] Refemng to FIG. 4, an exemplary illustration of the extrusion system 204 of FIG. 2 is disclosed. In an embodiment, the extrusion system 204 may be placed below the crusher 202 in the housing 102 (see FIG. 1) and may be mounted and/or supported on the rack 112. The extrusion system 204 may be configured to receive the crushed raw material from the crusher 202, via a hopper 222, and convert the crushed raw material into a compounded material. The extrusion system 204 may define an extrusion system outlet 214 and may be configured to provide a metered flow of the compounded material at the extrusion system outlet 214.

[0025] The extrusion system 204 may comprise an intake zone 216, a melt zone 218 downstream from the intake zone 216, and a metering zone 220 positioned downstream from the melt zone 218 and proximate the extrusion system outlet 214. The intake zone 216 may be configured to receive the crushed material from the crusher 202 via the hopper 222. The intake zone 216 may include one or more conveying elements and may be configured to direct the crushed raw material to the melt zone 218.

[0026] The melt zone 218 may be configured to melt and/or mix the crushed raw material received from the intake zone 216 and form the compounded material. In an embodiment, the melt zone 218 may consist of one or more elongated mixing elements. The elongated mixing elements may include fractional lobe elements and/or melt formation elements. Further, the extrusion system 204 may also include heating elements (not shown) configured to heat and melt the crushed raw material in the melt zone 218. In an exemplary embodiment, the crushed raw material may be heated to a temperature ranging from 180 °C - 240 °C. The melt zone 218 may further be configured to direct and convey the compounded material to the metering zone 220.

[0027] The metering zone 220 is configured to provide the metered flow of the compounded material at the extrusion system outlet 214. The metered flow at the extrusion system outlet may be at a pressure range of upto 150 bar of the compounded matenal. The metenng zone is further configured to ensure a certain residence time of the compounded material within the extrusion system. In an embodiment, the residence time within the extrusion system is 1 to 3 minutes.

[0028] Referring to FIG. 5, a top sectional view of the extrusion system 204 of FIG. 4 is disclosed. In an embodiment, the extrusion system 204 may include a screw configuration of a co -rotating twin screw extruder 224 in the intake zone 216 and the melt zone 218. Further, the extrusion system 204 may also include a screw configuration of a single screw extruder 230 in the metering zone 220. In an exemplary embodiment as shown, the intake zone 216 and the melt zone 218 may include two intermeshing screw shafts 226, 228. The screw shaft 228 may be elongated such that the screw shaft 228 extends into the metering zone 220. In another embodiment, the intake zone 216 and the melt zone 218 may include the two intermeshing screw shafts 226, 228 forming a co-rotating twin screw processor that may be coupled with a single screw processor in the metering zone 220. In an exemplary embodiment, a diameter of the extrusion system 204 may vary within the range of 20 mm to 30 mm, the diameter may be preferably 25 mm.

[0029] In accordance with the disclosure, the increased residence time of the compounded material provides better control on the flow of the compounded material at the extrusion system outlet 214 for making stable pelletized plastic material. Also, the increased residence time of the compounded material facilitates better elimination of viruses, bacteria or other harmful contaminants from the plastic waste, especially from the medical plastic waste.

[0030] Referring to FIGS. 4 - 5, the extrusion system 204 may also include a drive means 232 including a motor 234 and transmission means 236 to drive the co-rotating twin screw extruder 224 in the intake zone 216 and the melt zone 218 as well as the single screw extruder 230 in the metering zone 220. Further, the extrusion system 204 may include support means 238 to support and/or mount the extrusion system 204 on the rack 112. In an exemplary embodiment, the extrusion system 204 may be operated at a power rating of 1500 W.

[0031] Referring to FIG. 6, an exemplary illustration of the pelletizer 206 of FIG. 2 is disclosed. In an embodiment, the pelletizer 206 may be placed below the extrusion system 204 within the housing 102. The pelletizer 206 may also be mounted on and/or supported by the rack 114 by means of supporting elements 252. The pelletizer 206 may be configured to receive the compounded material from the extrusion system outlet 214 and convert the compounded material into the pelletized plastic material or pellets.

[0032] The pelletizer 206 may include an inlet pipe 240, a roller 242 in communication with the inlet pipe 240 and a cutter 244 placed below the roller 242. The pelletizer 206 may also include a conveying belt 248 downstream of the cutter 244 that may in turn be connected to the pelletizer outlet 250. In an embodiment, the pelletizer outlet 250 may be positioned proximate the housing outlet 106 of the housing 102.

[0033] The inlet pipe 240 may be configured to convey the compounded material from the extrusion system outlet 214 to the roller 242 of the pelletizer 206. The roller 242 may be made of high strength alloy and adapted to rotate at speeds in the range of 30 to 3000 RPM (revolutions per minute) to homogenize the compounded material. The cutter 244 may then cut the homogenized compounded material to form the pelletized plastic material. In an embodiment, the predefined speed of the roller 242 may be controlled in order to obtain different sizes of the pelletized plastic material. In an embodiment, the pelletizer 206 may be operated at a power rating of 120 W. In an exemplary embodiment, a diameter of the cuter may be 70 mm.

[0034] The conveying belt 248 positioned downstream of the cutter 244, may be configured to receive the pelletized plastic material through a guide orifice 246, and may direct the pelletized plastic material towards the pelletizer outlet 250. In an embodiment, the conveying belt 248 may be inclined. Further, the pelletizer outlet 250 may discharge the pelletized plastic material into a pellet collection box 256 positioned proximate the housing outlet 106. The pellet collection box 256 may be slidably fitted into the housing 102 such that the pelletized plastic material can be exited from the housing 102 by sliding the pellet collection box 256 out of the housing 102 through the housing outlet 106. In an embodiment, the pellet collection box 256 may include a collection bag to hold the pelletized plastic material received from the pelletizer outlet 250.

[0035] The recycler 100 may further include a cooling system 254 enclosed within the housing 102 to cool and reduce a temperature of the compounded material and/or a temperature of the pelletized plastic material converted from the compounded material. In an embodiment, the cooling system 254 may include a water jacket (not shown) mounted around the inlet pipe 240 of the pelletizer 206 for cooling the compounded material conveyed inside the inlet pipe 240. In another embodiment, the cooling system 254 may include a cooling jacket surrounding the pellet collection box 256 for cooling the pelletized plastic material received from the pelletizer outlet 250, prior to a removal of the pelletized plastic material from the housing outlet 106.

[0036] In yet another embodiment, the cooling system 254 may also include a cooling jacket 258 surrounding the conveying belt 248 to cool the pelletized plastic material being conveyed to the pelletizer outlet 250. The water jacket and/or the cooling jacket 258 may include one or more pipes (not shown) positioned around the conveying belt 248 that may continuously circulate a coolant or a refrigerant in order to cool down and reduce the temperature of the compounded material and/or the pelletized plastic material being conveyed. Examples of the coolants include, but are not limited to, water, air or other such coolants having a desired heat absorption coefficient and cooling effects.

[0037] The recycler 100 and the different components of the recycler 100 may be of different dimensions and may be fabricated based on space constraints at different locations where the recycler 100 is to be installed and/or employed. In an exemplary embodiment, the housing 102 of the recycler 100 may have length ranging from 0.50 meters to 2.0 meters, width ranging from 0.40 meters to 0.80 meters, and height ranging from 0.50 meters to 2.0 meters.

Industrial Applicability

[0038] Referring to FIG. 7, a method 700 of recycling plastic using the recycler 100 of FIG. 1 is disclosed. The method 700 may include a step 702 of receiving the plastic waste in the housing 102 through the housing inlet 104. The method 700 also includes a step 704 of processing and converting the plastic waste into a crushed raw material within a predetermined size range in the crusher 202 within the housing 102.

[0039] Further, the method 700 also includes a step 706 of processing and converting the crushed raw material into a compounded material in the extrusion system 204 positioned within the housing 102. Furthermore, the method 700 includes a step 708 of providing a metered flow of the compounded material at the extrusion system outlet 214 of the extrusion system 204. In addition, the method 700 includes a step 710 of processing and converting the compounded material into a pelletized plastic material in the pelletizer 206 positioned within the housing 102. In addition, the method 700 also includes a step 712 of exiting the pelletized plastic material from the housing outlet 106 of the housing 102.

[0040] It will be apparent to those skilled in the art that the recycler 100 and the method of recycling plastic waste as taught by the present disclosure allows recycling of plastics from unsorted, unsegregated, and unwashed solid waste plastic material. The recycler 100 as taught thereby eliminates the steps of sorting and washing/c leaning the waste plastic before carrying out the recycling process. Hence, an overall time of the recycling process is reduced and an efficiency of the recycling process is increased.

[0041] Further, the recycler 100 as taught may be suitable for compounding/ processing of different kinds of plastics. In addition, the recycler 100 as taught facilitates compounding of the plastic waste and production of the pellets. [0042] Further, a compact size of the recycler 100 as taught is achieved as a result of the positioning and arrangement of the different components, such as the crusher 202, the extrusion system 204, and the pelletizer 206, in accordance with the embodiments of the present disclosure. The compact size of the recycler 100 as taught offers portability and thereby, enables the recycler 100 to be moved or manoeuvred with ease and be deployed at different locations or plastic collection sites such as hospitals, hotels, companies, and industries.

[0043] Thus, the recycler 100 as taught is economical, environment-friendly, and improves productivity.

[0044] The system disclosed is suitable for use directly in small scale establishments such as hospitals and residential complexes and eliminates the need to transport material to recycling plants. The system further converts waste plastic material to useful plastic pellets that can then be used as a suitable raw material for moulding plastic products.

[0045] The system further runs on a conventional power source and does not need industrial grade power connections making it suitable for domestic use and allowing for its portability.

[0046] It will also be apparent to those skilled in the art that various modifications and variations can be made to the method and/or recycler 100 of the present disclosure without departing from the scope of the disclosure. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the method and/or system disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalent.