The present subject matter relates to systems and methods for recycling wet waste material. In particular, the present subject matter relates to systems and related methods for taking wet waste material, such as wet wipe fabrics and wet plastic waste, and process the waste material through a recycling process line that comprises recycling process machinery designed for converting wet waste material, such as wet wipe fabrics into recycled plastic.
Wet wipe products have been available for use in a variety of products that can include baby wipes, hand wipes, make-up wipes, kitchen wipes, medical wipes, anti-bacterial or cleaning wipes, other wipes, or the like. A single manufacturer of wet wipe products can generate roughly three to five hundred tons of post-industrial waste per month. Currently, this waste is disposed of in landfills and incinerators. Post-consumer wet wipe waste is substantially larger in volume in comparison to post-industrial waste. Additionally, post-consumer wet wipe waste is significantly more challenging to recycle compared to post-industrial waste. Post-consumer waste has varying concerns regarding contamination levels and the collection of wipes. Due to this reason, a vast majority of post-consumer wet wipe waste ends up in landfills.
Generally, wet wipe products are normally made of nonwoven fabric. Roughly 90% of nonwoven fabrics being produced contain plastics or polymers, in particular, in the form of extruded polymer fibers that are bound in a manner that forms the nonwoven fabric. For example, these nonwoven fabrics can comprise spunbond nonwovens, spunlaced nonwovens, meltblown nonwovens, flashspun nonwovens, needlepunched nonwovens, other staple and/or continuous fiber nonwovens held together with different bonding materials, techniques, and methods, or the like. Approximately 10% and less are produced with biodegradable material techniques. Wet wipe fabrics can be made of polymer filaments bonded with natural fibers. For example, in some embodiments, the polymer content can range from 15% to 75%, containing polypropylene (PP) or polyethylene terephthalate (PET). Other polymers may also be used but on a less frequent basis. The fiber content can also contain natural fibers such as rayon, wood pulp, cotton, and other natural fibers, ranging from 15% to 75% depending on manufacturing design formulas.
Wet wipes are designed to absorb and preserve high levels of moisture (lotions) contents. Design load levels can range from 1% to 700% (by substrate weight) depending on the manufacturing design for their wet wipe product application. The moisture content in wet wipe fabric is considered as internal moisture content instead of surface moisture content.
Due to the high load levels of moisture content, wet wipes have been a challenge to recycle using traditional methods. The moisture in wet wipes in many instances can cause harm and can damage traditional recycling process. Further, traditional recycling methods and processes cannot effectively handle the moisture content of the wet wipes in a manner that can produce a reusable or processable product. Wet wipe fabrics can contain moisture or lotions that are beneficial for their initial intended use. For example, the ingredients of the lotion may contain antibacterial agents, perfume, Citric Acid, PEG-40 Hydrogenated Castor Oil, Sodium Citrate, Sorbitan Caprylate, Sodium Benzoate, Disodium EDTA, Bis-PEG/PPG-16/16, PEG/PPG-16/16, Dimethicone, Xanthan Gum, Pentadecalactone, Dipropylene Glycol, and Caprylic/Capric Triglyceride. Traditional recycling methods and processes, however, are not designed to effectively use, process, and/or remove these ingredients during the recycle process. Therefore, these wet wipes have been generally excluded from collection for traditional recycling methods and processes. For these reasons, there are currently not any recycling processes of post-industrial or post-consumer wet wipe waste.
As such, a need exists for providing recycling processes of post-industrial or post-consumer wet wipe waste that provide useful materials that can be reused in other applications.
The present subject matter relates to systems and methods for recycling wet waste material, such as wet wipe, or wet plastic comprising, products. In particular, the present subject matter relates to systems and related methods for taking wet waste material, such as wet wipe fabrics and/or wet plastic waste, and process the waste material through a recycling process line that comprises recycling process machinery designed for converting wet wipe fabric into recycled plastic.
While one or more objects of the presently disclosed subject matter having been stated hereinabove, and which is achieved in whole or in part by the presently disclosed subject matter, other objects will become evident as the description proceeds when taken in connection with the accompanying drawings as best described hereinbelow proceeds when taken in connection with the accompanying drawings as best described hereinbelow.
A full and enabling disclosure of the present subject matter including the best mode thereof to one of ordinary skill in the art is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
Repeat use of reference characters in the present specification and drawings is intended to represent the seam or analogous features or elements of the present subject matter.
Reference now will be made to the embodiments of the present subject matter, one or more examples of which are set forth below. Each example is provided by way of an explanation of the present subject matter, not as a limitation. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present subject matter without departing from the scope or spirit of the present subject matter. For instance, features illustrated or described as one embodiment can be used on another embodiment to yield still a further embodiment. It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present subject matter, which broader aspects are embodied in exemplary constructions.
Although the terms first, second, right, left, front, back, top, bottom, etc. may be used herein to describe various features, elements, components, regions, layers and/or sections, these features, elements, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one feature, element, component, region, layer, or section from another feature, element, component, region, layer, or section. Thus, a first feature, element, component, region, layer, or section discussed below could be termed a second feature, element, component, region, layer, or section without departing from the teachings of the disclosure herein.
Similarly, when a feature or element is being described in the present disclosure as “on” or “over” another feature or element, it is to be understood that the features or elements can either be directly contacting each other or have another feature or element between them, unless expressly stated to the contrary. Thus, these terms are simply describing the relative position of the features or elements to each other and do not necessarily mean “on top of” since the relative position above or below depends upon the orientation of the device to the viewer.
Embodiments of the subject matter of the disclosure are described herein with reference to schematic illustrations of embodiments that may be idealized. As such, variations from the shapes and/or positions of features, elements, or components within the illustrations as a result of, for example but not limited to, user preferences, manufacturing techniques and/or tolerances are expected. Shapes, sizes and/or positions of features, elements or components illustrated in the figures may also be magnified, minimized, exaggerated, shifted, or simplified to facilitate explanation of the subject matter disclosed herein. Thus, the features, elements or components illustrated in the figures are schematic in nature and their shapes and/or positions are not intended to illustrate the precise configuration of the subject matter and are not necessarily intended to limit the scope of the subject matter disclosed herein unless it specifically stated otherwise herein.
It is to be understood that the ranges and limits mentioned herein include all ranges located within the prescribed limits (i.e., subranges). For instance, a range from about 100 to about 200 also includes ranges from 110 to 150, 170 to 190, 153 to 162, and 145.3 to 149.6. Further, a limit of up to about 7 also includes a limit of up to about 5, up to 3, and up to about 4.5, as well as ranges within the limit, such as from about 1 to about 5, and from about 3.2 to about 6.5.
As used herein, the term “polymer” generally includes, but is not limited to, homopolymers; copolymers, such as, for example, block, graft, random and alternating copolymers; and terpolymers; and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” shall include all possible geometrical configurations of the material. These configurations include, but are not limited to isotactic, syndiotactic, and random symmetries.
The term “plastic” or “thermoplastic” is used herein to mean any material formed from a polymer which softens and flows when heated; such a polymer may be heated and softened a number of times without suffering any basic alteration in characteristics, provided heating is below the decomposition temperature of the polymer. Examples of thermoplastic polymers include, by way of illustration only, polyolefins, polyesters, polyamides, polyurethanes, acrylic ester polymers and copolymers, polyvinyl chloride, polyvinyl acetate, etc. and copolymers thereof.
As used herein, the term “wet waste material” includes wet wipe products, such as wet woven and non-woven fabrics with or without polymers, and wet plastic waste material, such as hydrapulper/hydro pulp waste, wet plastic films, wet shredded plastics, and wet waste comprising natural or synthetic rubber.
The present subject matter relates to systems, apparatuses, and methods for recycling wet waste materials, such as wet wipe fabrics. The waste wet wipes material can be sent through custom-designed recycling wet wipes machinery. The systems and apparatuses can convert waste wet wipes into pellet form. The recycled wet wipe (pellet form) can be suitable for many applications in the plastics industry.
The systems, apparatuses, and methods disclosure herein can provide a way to recycle wet wipes and wet plastic waste, and convert them to wet wipe plastic composite (WWPC). There exists a potential for using WWPC to substitute wood plastic composite (WPC). Wood plastic composites (WPC) materials are widely used in the plastics industry, including extrusion profile applications decking lumber, decking rails, fencing, door & window components. WPCs are also used in plastics injection molding and other forms of molding applications. Products made of WPC are durable and require low maintenance. The lifespan of products made of WPC is two to three times longer compared to products made from natural wood. WPC materials require roughly 50:50 mixtures of thermoplastic polymers and wood particles (wood flour or wood fiber). Wood flour or wood fiber must be dry before the raw material can be used in the WPC manufacturing process. Common plastics used in WPC are polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), and polyethylene (PE, LDPE, and HDPE). Recycled polymers are also often used in the WPC process. The fibers used in WPC have particle sizes ranging from 177 microns to 2000 microns. The selection of fiber specifications depends on product quality requirements. The process of compounding wood fiber with plastic requires a twin-screw extruder and an aggressive screw mixer design configuration. The WPC manufacturing process requires additives such as waxes, coupling agents, pigments, and others. These additives help the process of mixing, bonding/adhesion, and product surface appearance. Adding wood fiber to the polymer improves the flexural modulus properties while reducing the percentage of polymers that help in reducing cost.
The process of compounding WWPC is more straightforward compared to the WPC process. Wet wipe fabrics contain natural fibers with a uniform distribution particle size that are generally smaller than wood flour and wood fiber. Wet wipes are made of fibers and polymers that are already bonded in fabric form, and the input fibers have a smaller particle size. The WWPC process can be achieved using a single screw extruder. The twin-screw extruder may also be used in the WWPC process but is unnecessary. The moisture in wet wipes does not entirely harm the recycling process. Wet wipe fabrics contain good moisture or lotions (the ingredients of the lotion may contain antibacterial agents, perfume, Citric Acid, PEG-40 Hydrogenated Castor Oil, Sodium Citrate, Sorbitan Caprylate, Sodium Benzoate, Disodium EDTA, Bis-PEG/PPG-16/16, PEG/PPG-16/16, Dimethicone, Xanthan Gum, Pentadecalactone, Dipropylene Glycol, and Caprylic/Capric Triglyceride). Many of these ingredients can help the WWPC manufacturing process to improve throughput, material-dispersion/mixing, bonding, and product surface appearance. The operation costs of manufacturing WWPC can be significantly less compared to the WPC manufacturing process. The WWPC manufacturing process uses recycled wet wipe fabrics containing fiber and plastic compared to the WPC manufacturing process, which requires the input of various raw materials.
There are a number of benefits of WWPC as compared to WPC. For example, WWPC can have low manufacturing costs due to the source of raw materials. The process of compounding WWPC can also be more straightforward because of the wet wipe fabrics' consistent layers of fiber and polymer and their small size fiber particles. WWPC can have a higher water-resistance in comparison to WPC. The lower water-resistance of WPC can lead to higher moisture absorption, which, in turn, can lead to a higher susceptibility to mold and decay. WWPC can be made of recycled material (fiber and polymer), which is more sustainable and environmentally friendly.
The systems, apparatuses, and methods disclosure herein can remove moisture content in wet wipe waste in a controlled manner that allows for wet wipe recycling.
The recycled input raw material (wet wipes) can generally be received in bale form from a post-industrial provider. Wet wipes contained in the same bale can have different levels of moisture content. It is estimated that the top portion of the bale can contain a moisture content of 20-100% by substrate weight. The middle portion of the bale may contain a moisture content of 100-200% by substrate weight, and the bottom can contain a moisture content of 200%-500% or more by substrate weight. Tests have been performed to remove moisture content in wet wipe fabrics using machinery such as film densifier machines, tumbler dryers, pellet mills or press mills. The film densifier machine, which is also known as a plastic agglomerate machine, and other similar machines like the cutter compactor can be used to cut up or chop film into smaller particles. For example, such machines use a high-speed rotating blade or knife to chop film particles into small pieces. At the same time, the rotating blade/knife can generate heat through friction from the high rotation speed. The heat friction helps the film dry (if the film contains moisture) and can shrink the film in size simultaneously. Due to the high moisture content in the wet wipes, these machines did not effectively process the wet wipes alone. The high moisture content of the wet wipes prevented the heat friction from building up to a high enough temperature to dry or shrink wet wipe fabric.
Tumbler dryers are dryers in which material flows through a large, rotating, horizontal screen drum. During this process, heated air is circulated through the drum of the dryer to dry the material. Again, due to the high moisture content in the wet wipes, these dryers did not effectively process the wet wipes alone. The heated air was not sufficient to evaporate moisture contents to achieve satisfactory dryness of material. Other concerns during the testing of these dryers included dust particles from wet wipe fabrics contaminating the air heating system.
Pellet mills or press mills use rotating rollers on the die surface. The rollers mill and compress the material through the die holes. The heat created by friction from the rollers rotating at high rotation speeds against the material softens and compacts the material. Once again, due to the high moisture content in the wet wipes, these pellet mills or press mills did not effectively process the wet wipes alone. During the tests, the moisture content prevented the heat friction from building up and caused the die holes to freeze and the rollers to seize.
Referring to
The DDC Extruder system 100 can comprise a motor 500, pulley/belts 501 and a gear box 502 used to control rotation of the specially designed extruder screw 504 as shown in
The rotation of dewatering, degassing and compression screw section 504A of the extruder screw 504 within the inner chamber 505A can facilitate the removal of liquid from the wet waste material being processed, the compression of the wet waste material, and the melting and degassing of the wet waste material as the heaters 506 heat the main barrel 505. A die 513 can be positioned at the end of the main barrel 505. The die 513 can comprise one or more flow channels 513A and configured to restrict a flow of material being processed in the main barrel 505. The die 513 with the small flow channels 513A can create backpressure and heat friction to help melt the wet waste material being processed into the molten polymer. Molten polymer material that exits through the die 513 can enter a predischarge flow channel 511A which is configured for receiving the molten polymer exiting the die. The predischarge flow channel 511A is heated to aid further with the heating and degassing the molten polymer. A discharge barrel 515 can be connected to the predischarge flow channel 511A. The discharge barrel 515 can comprise an inner chamber 515A in which the discharge screw section 504B of the extruder screw 504 resides for receiving the molten polymer and a discharge port 515B for discharging the molten polymer. A hood 515C with a vacuum line (not shown) attached to it can cover a portion of the discharge port 515B to remove additional gas and vapors as the molten polymer 011 exits the discharge port 515B.
To facilitate the turning of the wet waste material to a molten polymer, gas, vapors, and/or material residue should be removed from the extruder system 100 to increase the speed and opportunity for the wet waste material to remove the wetness and the polymers therein to melt. For this reason, one or more degassing ports 507A are provided on the main barrel 505 to remove gas or vapor released by a molten polymer generated from a waste material being processed within the main barrel 505. These one or more degassing ports 507A can be considered solid stage degassing ports. Additionally, one or more degassing ports 508A can provided that engage the predischarge flow channel 511A to remove gas or vapor released by a molten polymer that has entered the predischarge flow channel 511A from the die 513. These one or more degassing ports 508A can be considered molten stage degassing ports. Additionally, in some embodiments, to facilitate the turning of the wet waste material into a molten polymer, polymer resin can be added to the extruder system 100. In some embodiments, extra polymer can be added as described below, for example, if the wet waste material, such as certain wet wipe products have a lower polymer content.
Referring to
Each of the one or more solid stage degassing ports 507A can have a corresponding solid stage vent stuffer 507 that can be configured to prevent backflow of material out of the degassing port 507A.
At a third stage S3 as shown in
Each of the one or more molten stage degassing ports 508A can have a corresponding molten stage vent stuffer 508 that can be configured to prevent backflow of material out of the degassing port 508A. As shown in
The solid stage vent stuffer 507 and the molten stage vent stuffer 508 can be similar in construction. Each vent stuffer 507, 508 can comprise a motor, a support frame, a shaft coupling, a barrel, a screw, gas/vapor entry port, and gas/vapor exit port with the motor being linked to the screw via shaft coupling as explained further below. The screw of the respective vent stuffer 507, 508 can rotate in a direction within the barrel to prevent material from entering the respective vent stuffer gas/vapor entry port, while gas or vapors are permitted to flow out of the gas/vapor exit port.
At a fourth stage S4, which is in the discharging barrel 515, the material is conveyed and discharged by the discharging screw section 504B of the extruder screw 504, i.e., the discharge screw 512, from the DDC extruder system 100. the discharging barrel 515 can be heated by heaters 506 to facilitate further processing of the molten polymer as it is conveyed by the discharge screw 512.
The extruder screw 504 will be described as two connected screws 521 and 512 below. The main extruder screw 521 and the discharge screw 512 of the extruder screw 504 illustrated in
Referring to
Referring to
The DDC extruder system 100 can comprise a degassing system, which can include a vacuum pump. Referring to
The present disclosure can also provide a plastic foaming process that can create a cellular structure within molten plastic. The standard methods used in the plastic foaming process are to use direct-injected gas and chemical foaming agents. The direct-injected gas process uses gases such as nitrogen, carbon dioxide, pentane, or butane. The gas is injected directly into the extruder process under high pressure to mix with the polymers. The combination of gas and polymer creates a cellular structure or foaming polymer. The chemical foaming agent process can add a small percentage of special compound foaming agents (solid form) to the polymer melt. The foaming agent decomposes during the extrusion process and releases an expanding gas to create the foaming polymer. Plastic foaming has different properties. Thus, it is used in different application areas.
As disclosed herein, wet wipe fabrics (non-woven fabric) can comprise consistent layers of fiber and polymer, such as a thermoplastic polymer. The fiber can absorb and preserve internal moisture content. The DDC extruder system and related process as disclosed herein can utilize these fabric properties to permit the production of a hard-shell lightweight plastic (HSLP) pellet using H2O gas as a nucleating agent. This technique can also be used in other processes, such as the profile extrusion process.
The second belt conveyor 006 conveys wet wipe waste pieces WP2 to the third shredder 007 where the third shredder 007 can shred and breakdown the wet wipe waste pieces WP2 from the second shredder 005 into wet wipe waste pieces WP3 of even smaller size. For example, in some embodiments, the wet wipe waste pieces WP3 can have a nominal size of roughly about 1 inch×0.5 inches×0.5 inches. Thus, generally speaking, the wet wipe waste pieces WP3 is a size 008 conducive for being fed to a DDC extruder system 010 as described above. The shredders can be single shaft, dual shaft, triple shaft, or quad shaft.
The wet wipe waste pieces WP3 can then be discharged from third shredder 007 onto a third belt conveyor 009 which can then convey the wet wipe waste pieces WP3 to the DDC extruder system 010. The DDC extruder system 010 can then process the wet wipe waste pieces WP3 by compressing to dewater and/or remove liquids, mixed citric acid 728, vent stuffers 507 and 508 degasses and compacting the wet wipe waste material to a molten polymer. The transfer blower 516 conveys materials and gases that may pass through the vent stuffer 507 to the cyclone system 517. The cyclone system 517 separates solid materials to discharge port 519, the transfer blower 518 boosts air velocity to transport gases/vapors through exhaust port 520. The DDC extruder system 010 can discharge the molten polymer 011 into a compound extruder system 012 for further processing. While the molten polymer 011 is discharging, any remaining gas in the molten polymer is allowed to escape into the atmosphere before entering the compound extruder system 012. At this point in the processing system 104, feeders 016, 017, and 018 can feed additives, colors, and booster resin into the compound extruder system 012 as needed or desired for the end recycled product based on a formula requirement.
The compound extruder system 012 can finish the processes in two stages. In the first zone of the compound extruder system 012, the compound extruder system 012 can continuously mix the molten polymer which includes fibers and polymer simultaneously with the additives, colors, and booster resin. In the second stage of the compound extruder system 012, the compound extruder system 012 can degas and pump the polymer through a screen changer 019. A degassing system 015, which, for example can be a vacuum pump system in some embodiments, can draw the vapors/gas during the processing of both the DDC extruder system 010 via a line 014 and the compound extruder system 012 via a line 013. The compound extruder system 012 can comprise single-screw, twin-screw, and ring type extruders use in the wet wipe recycling process. By using a two-stage extruders layout concept that includes the DDC extruder system 010 and the compounding extruder 012 for the wet wipe recycling process, the molten polymer is processed in a manner that is conducive for recycled materials with high moisture content. Using both the DDC extruder system 010 and the compounding extruder 012 can allow the molten polymer to discharge into the atmosphere and permit remaining gas to escape from the molten polymer. Such a two-stage process line can also allow additives, colors, and booster resin to be fed into the molten polymer at the compound extruder system 012 once the wet wipe waste material has been already processed into a molten polymer state. In some embodiments, the principles of operation of the DDC extruder can be combined with the principles of operation of the compounding extruder into a single stage for the wet wipe recycling process to allow the wet wipe recycling apparatus to have reduced space and components as well and lower power consumption and maintenance costs.
The screen changer 019 can filter the molten polymer 011 to remove contamination particles from the polymer 011. The screen changer 019 can comprise slide plate, single bolts, dual bolts, rotary, belt, or a filter drum screen changer. The polymer 011 can then be discharged to a pelletizer system 020 that can include the pelletizer cutting chamber 024 cuts the molten polymer 011 into small pieces. The pelletizers can include, but are not limited to, underwater pelletizer, strand cut pelletizer, watering pelletizer, hot air, or hot face pelletizer, or the like. Process water from the water pump 021 flows through the heat exchanger 022 to condition the water temperature of the process water and is then pumped through the process water line 023 to collect the cut pellets at the cutting chamber 024. The process water solidifies the molten polymer 011 into a solid form (pellets form) during the cutting process. A slurry of processed water and pellets can then be pump through the line 025 from the cutting chamber 024 through the agglomerate catcher 026 to the centrifugal dryer 027. The agglomerate catcher 026 can prevent and remove any large particle size lumps from entering the centrifugal dryer 027 to prevent damage within the centrifugal dryer 027. The centrifugal dryer 027 can separate the pellets from the process water, and the process water can be discharged from a centrifugal dryer 027 to a water tank 028 so that the process water can be reused. A blower 029 can create a counter current airflow, allowing longer pellet resident time in the centrifugal dryer 027. Simultaneously, the blower 029 can pull off surface moisture from the pellets, and the pellets 030 can be then discharged from the centrifugal dryer 027.
Referring the
Referring the
Referring to
Thus, as described above, extruder systems, recycling systems, apparatuses, and related methods for recycling wet wipe waste material are disclosed herein. As described herein, post-industrial wet wipe and post-consumer wet wipe waste 10, which can be provided in bales to a recycler or in some other bulk can be recycled into wet wipe plastic composites (WWPC) in the form of pellets 12 in some embodiments shown in
The extruder systems, recycling systems, apparatuses, and related methods for recycling wet wipe waste material described herein can be used to create hard-shell lightweight plastic (HSLP) pellet from wet wipe and other non-woven fabrics which can use the consistent layers of fiber and polymer in the fabric and the internal moisture contents in the fabric. For example, the internal moisture contents of fabric (H2O gas) can be used as a nucleating agent. The HSLP pellets can be used to form or create aggregate in concrete, bean bags, packaging, filtration application, or the like. The technique of using internal moisture contents of fabric, particularly, H2O gas, as a nucleating agent can be applied to the extrusion profile process to create a lightweighter profile. Similarly, the recycling systems and processes disclosed herein can utilize the consistent layers of fiber and polymer in the wet wipe fabrics in forming the lightweight extrusion profile parts.
The extruder systems, recycling systems, apparatuses, and related methods for recycling wet wipe waste material described herein can be used to create recycled plastic pellets and lumber from hydrapulper/hydro pulp plastics waste material as shown in
Thus, as disclosed above, the present disclosure also provides a recycling process for recycling wet waste material. The recycling process can comprise breaking down wet waste material being processed with one or more shredders and processing the broken-down wet waste material into a molten polymer using a dewatering, degassing, and compacting extruder. The recycling process can also comprise dewatering, degassing, and compacting the broken-down wet waste material and the molten polymer being processed in the dewatering, degassing, and compacting extruder and removing gas and waste material residue from the dewatering, degassing, and compacting extruder and capturing large residue particles.
The present disclosure also provides a recycling system for recycling wet wipe waste material. The recycling system can comprise a dewatering, degassing, and compacting extruder for receiving the broken-down wet wipe waste material. The dewatering, degassing, and compacting extruder can be configured to dewater, degas, and compact the wet wipe waste material received from the shredder to a molten polymer. The recycling system can also comprise a solid stage degassing port on the dewatering, degassing, and compacting extruder to remove gas or vapor released by molten polymer generated from the waste material being processed in the dewatering, degassing, and compacting extruder. In some embodiments, the recycling system can comprise one or more shredders for breaking down wet wipe waste material being processed for feeding the dewatering, degassing, and compacting extruder.
For example, as described above, the present disclosure provides for an extruder system for recycling wet waste products. The extruder system can comprise a main barrel comprising an inner chamber having a compressing and dewatering section and a heating, degassing, and compacting section following the compressing and dewatering section. An extruder screw can be provided. The extruder screw can comprise a dewatering, degassing and compression screw section and a discharge screw section. The dewatering, degassing and compression screw section of the extruder screw being configured to rotate within the inner chamber of the main barrel. The extruder system can also comprise a solid-stage degassing port positioned on the main barrel and engaging the inner chamber of the main barrel to remove gas or vapor released by molten polymer generated from the waste material being processed within the main barrel. Additionally, the extruder system can comprise a die positioned at the end of the main barrel and a predischarge flow channel for receiving the molten polymer exiting the die. The die can comprise one or more flow channels and can be configured to restrict a flow of material being processed in the main barrel to create backpressure and heat friction to help melt the waste material being processed into the molten polymer. The predischarge flow channel can be configured for heating and degassing the molten polymer. Further, the extruder system can comprise a discharge barrel connected to the predischarge flow channel. The discharge barrel can comprise an inner chamber in which the discharge screw section of the extruder screw can reside for receiving the molten polymer and a discharge port for discharging the molten polymer.
In some embodiments, the extruder system can comprise a molten-stage degassing port engaging the predischarge flow channel to remove the gas or vapor released by the molten polymer generated from the waste material being processed within the predischarge flow channel. In some embodiments, the extruder system can comprise a solid stage vent stuffer connected to the solid stage degassing port. The solid stage vent stuffer can have a vapor exhaust line extending therefrom and can be configured to prevent waste material being processed from entering the vapor exhaust line. In some embodiments, the extruder system can comprise a transfer blower connected to the vapor exhaust line of the solid stage vent stuffer. The transfer blower configured to provide air through the vapor exhaust line to convey vapors and material particles through the vapor exhaust line should any material particles pass through the solid stage vent stuffer. In some such embodiments, the extruder system can comprise a cyclone system connected to the vapor exhaust line. The cyclone system configured to separate the material particles from the vapors provided to the cyclone system by the vapor exhaust line. In some embodiments, the extruder system can comprise a molten stage vent stuffer connected to the molten stage degassing port. The molten stage vent stuffer can be connected to a vacuum line and can be configured to prevent the molten polymer within the predischarge flow channel entering the vacuum line and allow only gas or vapors to enter the vacuum line.
These and other modifications and variations to the present subject matter may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present subject matter, which is more particularly set forth herein above and any appending claims. In addition, it should be understood the aspects of the various embodiments may be interchanged either in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only and is not intended to limit the present subject matter.
The present application and presently disclosed subject matter claims the benefit of U.S. Provisional Patent Application Ser. No. 63/280,973, filed Nov. 18, 2021, the disclosure of which is incorporated herein by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/US2022/050471 | 11/18/2022 | WO |
Number | Date | Country | |
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63280973 | Nov 2021 | US |